Sprecies profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Mid-Atlantic): Bluefish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pottern, G.B.; Huish, M.T.; Kerby, J.H.

1989-02-01

Species profiles are literature summaries of the taxonomy, morphology, distribution, life history, and environmental requirements of coastal fishes and invertebrates within a specified range. They are written to assist in environmental impact assessment and decision making by coastal planners and developers. Bluefish are the most important recreational fish in the United States, especially in the mid-Atlantic region. The commercial catch is smaller but has increased during recent years. One population spawns offshore during spring from northern Florida to North Carolina, and these young migrate into mid-Atlantic coastal waters to spend their summer and fall. A second population spawns offshore duringmore » summer from North Carolina to Massachusetts, but most of these young remain offshore for the remainder of the season. In late fall, young and adults of both populations migrate south until the following spring. Bluefish are migratory, opportunistic, pelagic predators throughout life, and their seasonal abundance may have profound community structuring effects. Schools of juvenile bluefish may be important forage for many pelagic predators, including adults of their own species. Photoperiod apparently triggers long-range migration, and temperature serves as a proximal cue to short-range migration. Bluefish are sensitive to bacterial infection in polluted water and have little tolerance for low oxygen conditions. 55 refs., 6 figs., 3 tabs.« less

Migration of Tundra Swans (Cygnus columbianus) Wintering in Japan Using Satellite Tracking: Identification of the Eastern Palearctic Flyway.

PubMed

Chen, Wenbo; Doko, Tomoko; Fujita, Go; Hijikata, Naoya; Tokita, Ken-Ichi; Uchida, Kiyoshi; Konishi, Kan; Hiraoka, Emiko; Higuchi, Hiroyoshi

2016-02-01

Migration through the Eastern Palearctic (EP) flyway by tundra swans (Cygnus columbianus) has not been thoroughly documented. We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1) to show the migration pattern of the EP flyway of tundra swans; 2) to compare this pattern with the migration pattern of whooper swans; and 3) to identify stopover sites that are important for these swans' conservation. Tundra swans were captured at Kutcharo Lake, Hokkaido, in 2009-2012 and satellite-tracked. A new method called the "MATCHED (Migratory Analytical Time Change Easy Detection) method" was developed. Based on median, the spring migration began on 18 April and ended on 27 May. Autumn migration began on 9 September and ended on 2 November. The median duration of the spring and autumn migrations were 48 and 50 days, respectively. The mean duration at one stopover site was 5.5 days and 6.8 days for the spring and autumn migrations, respectively. The number of stopover sites was 3.0 and 2.5 for the spring and autumn migrations, respectively. The mean travel distances for the spring and autumn migrations were 6471 and 6331 km, respectively. Seven migration routes passing Sakhalin, the Amur River, and/or Kamchatka were identified. There were 15, 32, and eight wintering, stopover, and breeding sites, respectively. The migration routes and staging areas of tundra swans partially overlap with those of whooper swans, whose migration patterns have been previously documented. The migration patterns of these two swan species that winter in Japan confirm the importance of the Amur River, Udyl' Lake, Shchastya Bay, Aniva Bay, zaliv Chayvo Lake, zal Piltun Lake, zaliv Baykal Lake, Kolyma River, Buyunda River, Sen-kyuyel' Lake, and northern coastal areas of the Sea of Okhotsk.

Challenging a 15-year-old claim: The North Atlantic Oscillation index as a predictor of spring migration phenology of birds.

PubMed

Haest, Birgen; Hüppop, Ommo; Bairlein, Franz

2018-04-01

Many migrant bird species that breed in the Northern Hemisphere show advancement in spring arrival dates. The North Atlantic Oscillation (NAO) index is one of the climatic variables that have been most often investigated and shown to be correlated with these changes in spring arrival. Although the NAO is often claimed to be a good predictor or even to have a marked effect on interannual changes in spring migration phenology of Northern Hemisphere breeding birds, the results on relations between spring migration phenology and NAO show a large variety, ranging from no, over weak, to a strong association. Several factors, such as geographic location, migration phase, and the NAO index time window, have been suggested to partly explain these observed differences in association. A combination of a literature meta-analysis, and a meta-analysis and sliding time window analysis of a dataset of 23 short- and long-distance migrants from the constant-effort trapping garden at Helgoland, Germany, however, paints a completely different picture. We found a statistically significant overall effect size of the NAO on spring migration phenology (coefficient = -0.14, SE = 0.054), but this on average only explains 0%-6% of the variance in spring migration phenology across all species. As such, the value and biological meaning of the NAO as a general predictor or explanatory variable for climate change effects on migration phenology of birds, seems highly questionable. We found little to no definite support for previously suggested factors, such as geographic location, migration phenology phase, or the NAO time window, to explain the heterogeneity in correlation differences. We, however, did find compelling evidence that the lack of accounting for trends in both time series has led to strongly inflated (spurious) correlations in many studies (coefficient = -0.13, SE = 0.019). © 2017 John Wiley & Sons Ltd.

Southward autumn migration of waterfowl facilitates cross-continental transmission of the highly pathogenic avian influenza H5N1 virus

NASA Astrophysics Data System (ADS)

Xu, Yanjie; Gong, Peng; Wielstra, Ben; Si, Yali

2016-08-01

The highly pathogenic avian influenza subtype H5N1 (HPAI H5N1) is a worldwide zoonotic infectious disease, threatening humans, poultry and wild birds. The role of wild birds in the spread of HPAI H5N1 has previously been investigated by comparing disease spread patterns with bird migration routes. However, the different roles that the southward autumn and northward spring migration might play in virus transmission have hardly been explored. Using direction analysis, we analyze HPAI H5N1 transmission directions and angular concentration of currently circulating viral clades, and compare these with waterfowl seasonal migration directions along major waterfowl flyways. Out of 22 HPAI H5N1 transmission directions, 18 had both a southward direction and a relatively high concentration. Differences between disease transmission and waterfowl migration directions were significantly smaller for autumn than for spring migration. The four northward transmission directions were found along Asian flyways, where the initial epicenter of the virus was located. We suggest waterfowl first picked up the virus from East Asia, then brought it to the north via spring migration, and then spread it to other parts of world mainly by autumn migration. We emphasize waterfowl autumn migration plays a relatively important role in HPAI H5N1 transmission compared to spring migration.

Lipid reserves of Lesser Scaup (Aythya affinis) migrating across a large landscape are consistent with the "Spring Condition" hypothesis

USGS Publications Warehouse

Anteau, M.J.; Afton, A.D.

2009-01-01

The “spring condition” hypothesis (SCH) states that nutrition during spring migration affects survival, reproductive success, and, ultimately, population size of migratory birds. The North American population of Lesser Scaup (Aythya affinis) has experienced a marked decline, apparently because of poor recruitment. An important prediction of the SCH is that female Lesser Scaup have low lipid reserves during spring migration. We previously reported that lipid reserves and body mass of females collected on migratory stopover areas in northwestern Minnesota in springs 2000–2001 were lower than those on the same areas in the 1980s and markedly lower than those collected at Pool 19 of the Mississippi River in 2000–2001, an important preceding stopover area. However, it was unclear whether these findings represented a site-specific result or a landscape-scale phenomenon. Accordingly, we examined lipid and body mass of 641 female Lesser Scaup migrating across seven eco-physiographic regions of Iowa, Minnesota, and North Dakota during springs 2003–2005. We found that lipids and body mass of females throughout the Upper Midwest were similar to or less than the low values documented in northwestern Minnesota in springs 2000–2001 and markedly lower than those of females at Pool 19 in springs 2000–2001. Accordingly, our results are consistent with a prediction of the SCH, because lipid and body mass of females are low throughout this large landscape, lower than at an important preceding stopover area, and lower than all historical values. Finally, our results suggest the potential for cross-seasonal influences of nutrition on recruitment and that a stronger management focus on spring migration habitats may be necessary for conservation and recovery of declining migratory birds, especially Lesser Scaup.

Migration of the Willow Flycatcher along the Middle Rio Grande

Treesearch

Wang Yong; Deborah M. Finch

1997-01-01

We studied timing, abundance, subspecies composition, fat stores, stopover length, and habitat use of Willow Flycatchers (Empidonax traillii) during spring and fall stopover along the Middle Rio Grande, New Mexico. Spring migration started in mid-May and lasted about a month. Fall migration started in early-August and also lasted about a month. The most abundant...

Bioacoustic monitoring of nocturnal songbird migration in a southern great lakes ecosystem

NASA Astrophysics Data System (ADS)

Sanders, Claire Elizabeth

Many species of birds produce short vocalizations during nocturnal migration. My thesis uses bioacoustic monitoring of these night flight calls to study bird migration through a southern Great Lakes ecosystem. I deployed recording devices around western Lake Erie during spring and fall migrations. Analysis of thousands of hours of recordings revealed that night flight calls accurately predicted both the magnitude of migration, as well as the timing of migrant passage, as assessed by banding. The first arrival dates for 48 species of migratory birds were significantly earlier on Pelee Island than on mainland Ontario in the spring. More flight calls were detected over Pelee Island than over mainland comparison sites. These results suggest that many birds cross Lake Erie in spring and fall, and that islands are important for migratory birds. This research provides insight into the use of acoustics for monitoring birds in active migration.

Seasonal effects of wind conditions on migration patterns of soaring American white pelican.

PubMed

Gutierrez Illan, Javier; Wang, Guiming; Cunningham, Fred L; King, D Tommy

2017-01-01

Energy and time expenditures are determinants of bird migration strategies. Soaring birds have developed migration strategies to minimize these costs, optimizing the use of all the available resources to facilitate their displacement. We analysed the effects of different wind factors (tailwind, turbulence, vertical updrafts) on the migratory flying strategies adopted by 24 satellite-tracked American white pelicans (Pelecanus erythrorhynchos) throughout spring and autumn in North America. We hypothesize that different wind conditions encountered along migration routes between spring and autumn induce pelicans to adopt different flying strategies and use of these wind resources. Using quantile regression and fine-scale atmospheric data, we found that the pelicans optimized the use of available wind resources, flying faster and more direct routes in spring than in autumn. They actively selected tailwinds in both spring and autumn displacements but relied on available updrafts predominantly in their spring migration, when they needed to arrive at the breeding regions. These effects varied depending on the flying speed of the pelicans. We found significant directional correlations between the pelican migration flights and wind direction. In light of our results, we suggest plasticity of migratory flight strategies by pelicans is likely to enhance their ability to cope with the effects of ongoing climate change and the alteration of wind regimes. Here, we also demonstrate the usefulness and applicability of quantile regression techniques to investigate complex ecological processes such as variable effects of atmospheric conditions on soaring migration.

Seasonal effects of wind conditions on migration patterns of soaring American white pelican

PubMed Central

Wang, Guiming; Cunningham, Fred L.; King, D. Tommy

2017-01-01

Energy and time expenditures are determinants of bird migration strategies. Soaring birds have developed migration strategies to minimize these costs, optimizing the use of all the available resources to facilitate their displacement. We analysed the effects of different wind factors (tailwind, turbulence, vertical updrafts) on the migratory flying strategies adopted by 24 satellite-tracked American white pelicans (Pelecanus erythrorhynchos) throughout spring and autumn in North America. We hypothesize that different wind conditions encountered along migration routes between spring and autumn induce pelicans to adopt different flying strategies and use of these wind resources. Using quantile regression and fine-scale atmospheric data, we found that the pelicans optimized the use of available wind resources, flying faster and more direct routes in spring than in autumn. They actively selected tailwinds in both spring and autumn displacements but relied on available updrafts predominantly in their spring migration, when they needed to arrive at the breeding regions. These effects varied depending on the flying speed of the pelicans. We found significant directional correlations between the pelican migration flights and wind direction. In light of our results, we suggest plasticity of migratory flight strategies by pelicans is likely to enhance their ability to cope with the effects of ongoing climate change and the alteration of wind regimes. Here, we also demonstrate the usefulness and applicability of quantile regression techniques to investigate complex ecological processes such as variable effects of atmospheric conditions on soaring migration. PMID:29065188

Negotiating an ecological barrier: crossing the Sahara in relation to winds by common swifts

PubMed Central

2016-01-01

The Sahara Desert is one of the largest land-based barriers on the Earth, crossed twice each year by billions of birds on migration. Here we investigate how common swifts migrating between breeding sites in Sweden and wintering areas in sub-Saharan Africa perform the desert crossing with respect to route choice, winds, timing and speed of migration by analysing 72 geolocator tracks recording migration. The swifts cross western Sahara on a broad front in autumn, while in spring they seem to use three alternative routes across the Sahara, a western, a central and an eastern route across the Arabian Peninsula, with most birds using the western route. The swifts show slower migration and travel speeds, and make longer detours with more stops in autumn compared with spring. In spring, the stopover period in West Africa coincided with mostly favourable winds, but birds remained in the area, suggesting fuelling. The western route provided more tailwind assistance compared with the central route for our tracked swifts in spring, but not in autumn. The ultimate explanation for the evolution of a preferred western route is presumably a combination of matching rich foraging conditions (swarming insects) and favourable winds enabling fast spring migration. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. PMID:27528783

Agricultural practices and residual corn during spring crane and waterfowl migration in Nebraska

USGS Publications Warehouse

Sherfy, M.H.; Anteau, M.J.; Bishop, A.A.

2011-01-01

Nebraska's Central Platte River Valley (CPRV) is a major spring-staging area for migratory birds. Over 6 million ducks, geese, and sandhill cranes (Grus canadensis) stage there en route to tundra, boreal forest, and prairie breeding habitats, storing nutrients for migration and reproduction by consuming primarily corn remaining in fields after harvest (hereafter residual corn). In springs 2005-2007, we measured residual corn density in randomly selected harvested cornfields during early (n=188) and late migration (n=143) periods. We estimated the mean density of residual corn for the CPRV and examined the influence of agricultural practices (post-harvest field management) and migration period on residual corn density. During the early migration period, residual corn density was greater in idle harvested fields than any other treatments of fields (42%, 48%, 53%, and 92% more than grazed, grazed and mulched, mulched, and tilled fields, respectively). Depletion of residual corn from early to late migration did not differ among post-harvest treatments but was greatest during the year when overall corn density was lowest (2006). Geometric mean early-migration residual corn density for the CPRV in 2005-2007 (42.4 kg/ha; 95% CI=35.2-51.5 kg/ha) was markedly lower than previously published estimates, indicating that there has been a decrease in abundance of residual corn available to waterfowl during spring staging. Increases in harvest efficiency have been implicated as a cause for decreasing corn densities since the 1970s. However, our data show that post-harvest management of cornfields also can substantially influence the density of residual corn remaining in fields during spring migration. Thus, managers may be able to influence abundance of high-energy foods for spring-staging migratory birds in the CPRV through programs that influence post-harvest management of cornfields. ?? 2011 The Wildlife Society.

Influence of summer biogeography on wood warbler stopover abundance

Treesearch

Jeffrey F. Kelly; Rob Smith; Deborah M. Finch; Frank R. Moore; Wang Yong

1999-01-01

We evaluated the effect of summer biogeography of migrant wood warblers (Parulidae) on their stopover abundance. To characterize abundance patterns, we used mist-net capture data from spring and fall migration in the Middle Rio Grande Valley, New Mexico, spring migration on the Gulf Coast of Louisiana, and fall migration on the Gulf Coast of Alabama. To describe the...

Multiple spring migration strategies in a population of Pacific Common Eiders

USGS Publications Warehouse

Petersen, M.R.

2009-01-01

Spring migration strategies vary within and among species. Examination of this variability extends our understanding of life histories and has implications for conservation. I used satellite transmitters to determine migration strategies and evaluate factors influencing the timing of spring migration of Pacific Common Eiders (Somateria mollissima v-nigrum) that nest along the western Beaufort Sea coast. Adult females were marked at nesting colonies in the summers of 2000, 2001, and 2003, and were followed throughout spring migration the following year. Each year approximately equal proportions of eiders used three distinct migration strategies varying in duration, staging locations (waters near the Chukotka Peninsula, Russia, and the Chukchi and Beaufort seas, Alaska), and arrival dates at the nesting areas. It is unlikely that differences in the timing of movements to stopover sites in the Chukchi and Beaufort seas were a result of responses to changes in weather, particularly wind direction. Ice distribution and melt/movement patterns vary substantially among staging areas and thus may affect risk of starvation and reproductive potential. Long-term (decadal) changes in climate may favor birds using one strategy during "warmer" and another during "colder" years. ?? 2009 by The Cooper Ornithological Society. All rights reserved.

Environmental factors influence lesser scaup migration chronology and population monitoring

USGS Publications Warehouse

Finger, Taylor A.; Afton, Alan D.; Schummer, Michael L.; Petrie, Scott A.; Badzinski, Shannon S.; Johnson, Michael A.; Szymanski, Michael L.; Jacobs, Kevin J.; Olsen, Glenn H.; Mitchell, Mark

2016-01-01

Identifying environmental metrics specific to lesser scaup (Aythya affinis; scaup) spring migration chronology may help inform development of conservation, management and population monitoring. Our objective was to determine how environmental conditions influence spring migration of lesser scaup to assess the effectiveness of the Waterfowl Breeding Population and Habitat Survey in accurately estimating scaup populations. We first compared peak timing of mallard (Anas platyrhynchos) and scaup migration from weekly ground surveys in North Dakota, USA because the Waterfowl Breeding Population and Habitat Survey is designed to capture annual mallard migration. As predicted, we detected that peak timing of scaup and mallard migrations differed in 25 of 36 years investigated (1980–2010). We marked scaup with satellite transmitters (n = 78; 7,403 locations) at Long Point, Lake Erie, Ontario, Canada; Pool 19 of the Mississippi River, Iowa and Illinois, USA; and Presque Isle Bay, Lake Erie, Pennsylvania, USA. We tested the assumption that our marked scaup were representative of the continental population using the traditional survey area by comparing timing of migration of marked birds and scaup counted in the North Dakota Game and Fish Department survey. We detected a strong positive correlation between marked scaup and the survey data, which indicated that marked scaup were representative of the population. We subsequently used our validated sample of marked scaup to investigate the effects of annual variation in temperature, precipitation, and ice cover on spring migration chronology in the traditional and eastern survey areas of the Waterfowl Breeding Population and Habitat Survey, 2005–2010. We evaluated competing environmental models to explain variation in timing and rate of scaup migration at large-scale and local levels. Spring migration of scaup occurred earlier and faster during springs with warmer temperatures and greater precipitation, variables known to influence energy budgets and wetland availability. Our results suggest that surveys designed to index abundance of breeding mallards is imprecise for estimating scaup abundance, and inaccurate at estimating breeding population size by survey stratum.

An experimental field evaluation of winter carryover effects in semi-anadromous brown trout (Salmo trutta).

PubMed

Midwood, Jonathan D; Larsen, Martin H; Boel, Mikkel; Aarestrup, Kim; Cooke, Steven J

2015-11-01

For semi-anadromous brown trout, the decision whether or not to smoltify and migrate to the sea is believed to be made at the end of the preceding summer in response to both local environmental conditions and individual physiological status. Stressors experienced during the fall may therefore influence their propensity to migrate as well as carry over into the winter resulting in mortality when fish face challenging environmental conditions. To evaluate this possibility, we artificially elevated cortisol levels in juvenile trout (via intracoelomic injection of cortisol in the fall) and used passive integrated transponder tags to compare their overwinter and spring survival, growth, and migration success relative to a control group. Results suggest that overwinter mortality is high for individuals in this population regardless of treatment. However, survival rates were 2.5 times lower for cortisol-treated fish and they experienced significantly greater loss in mass. In addition, less than half as many cortisol-treated individuals made it downstream to a stationary antenna over the winter and also during the spring migration compared to the control treatment. These results suggest that a fall stressor can reduce overwinter survival of juvenile brown trout, negatively impact growth of individuals that survive, and ultimately result in a reduction in the number of migratory trout. Carryover effects such as those documented here reveal the cryptic manner in which natural and anthropogenic stressors can influence fish populations. J. Exp. Zool. 323A: 645-654, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Temporal shifts and temperature sensitivity of avian spring migratory phenology: a phylogenetic meta-analysis.

PubMed

Usui, Takuji; Butchart, Stuart H M; Phillimore, Albert B

2017-03-01

There are wide reports of advances in the timing of spring migration of birds over time and in relation to rising temperatures, though phenological responses vary substantially within and among species. An understanding of the ecological, life-history and geographic variables that predict this intra- and interspecific variation can guide our projections of how populations and species are likely to respond to future climate change. Here, we conduct phylogenetic meta-analyses addressing slope estimates of the timing of avian spring migration regressed on (i) year and (ii) temperature, representing a total of 413 species across five continents. We take into account slope estimation error and examine phylogenetic, ecological and geographic predictors of intra- and interspecific variation. We confirm earlier findings that on average birds have significantly advanced their spring migration time by 2·1 days per decade and 1·2 days °C -1 . We find that over time and in response to warmer spring conditions, short-distance migrants have advanced spring migratory phenology by more than long-distance migrants. We also find that larger bodied species show greater advance over time compared to smaller bodied species. Our results did not reveal any evidence that interspecific variation in migration response is predictable on the basis of species' habitat or diet. We detected a substantial phylogenetic signal in migration time in response to both year and temperature, suggesting that some of the shifts in migratory phenological response to climate are predictable on the basis of phylogeny. However, we estimate high levels of species and spatial variance relative to phylogenetic variance, which is consistent with plasticity in response to climate evolving fairly rapidly and being more influenced by adaptation to current local climate than by common descent. On average, avian spring migration times have advanced over time and as spring has become warmer. While we are able to identify predictors that explain some of the true among-species variation in response, substantial intra- and interspecific variation in migratory response remains to be explained. © 2016 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Investigations into the Early Life History of Naturally Produced Spring Chinook Salmon and Summer Steelhead in the Grande Ronde River Subbasin, Annual Report 2008 : Project Period 1 February 2008 to 31 January 2009.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yanke, Jeffrey A.; Alfonse, Brian M.; Bratcher, Kyle W.

2009-07-31

This study was designed to document and describe the status and life history strategies of spring Chinook salmon and summer steelhead in the Grande Ronde River Subbasin. We determined migration timing, abundance, and life-stage survival rates for juvenile spring Chinook salmon Oncorhynchus tshawytscha and summer steelhead O. mykiss in four streams during migratory year 2008 from 1 July 2007 through 30 June 2008. As observed in previous years of this study, spring Chinook salmon and steelhead exhibited fall and spring movements out of natal rearing areas, but did not begin their smolt migration through the Snake and lower Columbia Rivermore » hydrosystem until spring. In this report we provide estimates of migrant abundance and migration timing for each study stream, and their survival and timing to Lower Granite Dam. We also document aquatic habitat conditions using water temperature and stream flow in four study streams in the subbasin.« less

Investigations into the Early Life History of Naturally Produced Spring Chinook Salmon in the Grande Ronde Riiver Basin : Fish Research Project Oregon : Annual Progress Report 1 September 1995 to 1 August 1996.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jonasson, Brian C.; Carmichael, Richard W.; Keefe, MaryLouise

1997-09-01

Historically, the Grande Ronde River produced an abundance of salmonids including stocks of spring, summer and fall chinook salmon, sockeye salmon, coho salmon, and summer steelhead. During the past century, numerous factors have caused the reduction of salmon stocks such that only sustainable stocks of spring chinook salmon and summer steelhead remain. The sizes of spring chinook salmon populations in the Grande Ronde River basin also have been declining steadily and are substantially depressed from estimates of historic levels. In addition to a decline in population abundance, a reduction of spring chinook salmon spawning distribution is evident in the Grandemore » Ronde River basin. Numerous factors are thought to contribute to the decline of spring chinook salmon in the Snake River and its tributaries. These factors include passage problems and increased mortality of juvenile and adult migrants at mainstem Columbia and Snake river dams, overharvest, and habitat degradation associated with timber, agricultural, and land development practices. This study was designed to describe aspects of the life history strategies exhibited by spring chinook salmon in the Grande Ronde River basin. During the past year the focus was on rearing and migration patterns of juveniles in the upper Grande Ronde River and Catherine Creek. The study design included three objectives: (1) document the annual in-basin migration patterns for spring chinook salmon juveniles in the upper Grande Ronde River and Catherine Creek, including the abundance of migrants, migration timing and duration; (2) estimate and compare smolt survival indices to mainstem Columbia and Snake river dams for fall and spring migrating spring chinook salmon; and (3) determine summer and winter habitat utilization and preference of juvenile spring chinook salmon in the upper Grande Ronde River and Catherine Creek.« less

First evidence that paired Roseate Terns may travel together during spring migration

USGS Publications Warehouse

Spendelow, Jeffrey A.; Lugo, Gabriel

2017-01-01

A mated pair of colorbanded Roseate Terns from the Northwest Atlantic Ocean breeding population was photographed on 12 May 2010 while staging near Mayaguez, Puerto Rico. This represents the first evidence that mated pairs of this species may travel together during their northward spring migration

Migration patterns and movements of sandhill cranes wintering in central and southwestern Louisiana

USGS Publications Warehouse

King, Sammy L.; Pierce, Aaron R.; Hersey, Kent R.; Winstead, Nicholas; Hartup, Barry K.

2010-01-01

In this study we trapped wintering sandhill cranes (Grus canadensis) in Louisiana and fitted them with satellite transmitters to determine their migration routes. Four of the 6 sandhill cranes with validated locations and a terminus point used the Central Flyway for spring migration; 2 of these 4 (the only 2 for which we have data) also used the Central Flyway for fall migration. Two of the 6 birds used the Mississippi Flyway for spring migration. The results of this study suggest that reintroduced whooping cranes (G. americana) that intermix and migrate with sandhill cranes that winter in Louisiana may enter the Central Flyway. In addition, the Mississippi Flyway is a viable option to use as a migration route for whooping cranes if they are reintroduced in Louisiana.

Migration behavior and dispersal of adult spring Chinook salmon released into Lake Scanewa on the upper Cowlitz River during 2005

USGS Publications Warehouse

Perry, R.W.; Kock, Tobias J.; Kritter , M.A; Rondorf, Dennis W.

2007-01-01

During 2005, we conducted a radio-telemetry study to answer a number of basic questions about the migration behavior of adult Spring Chinook salmon (Oncorhynchus tshawytscha) released into the upper Cowlitz River watershed. We also conducted a pilot study of adult Coho salmon (Oncorhynchus kisutch) using radio-tags recovered from adult spring Chinook salmon. This data is included as an Appendix. Our study was designed to evaluate the dispersal of adult spring Chinook salmon to determine the proportion of the run 1) spawning in the Cispus River, 2) spawning in the Cowlitz River, 3) passing downstream through Cowlitz Falls Dam into Riffe Lake, and 4) remaining in Lake Scanewa. We also examined spatial patterns of movement in the study area and temporal patterns of fish movements. Last, we examined differences in migration behavior between hatchery and wild fish and male and female fish.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berggren, Thomas J.; Franzoni, Henry; Basham, Larry R.

The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer Chinook (hereafter, Chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of Chinook marked in two different regions (which differ in the number of dams Chinook have to migrate through) provides insight into the effectsmore » of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River Chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well as comparison between the different collector projects from which smolts are transported. CSS also compares survival rates for wild Snake River spring and summer Chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species. Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. The parameter D is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to Lower Granite Dam. When D = 1, there is no difference in survival rate after hydrosystem passage. When D < 1, then transported smolts die at a greater rate after release below Bonneville Dam than smolts that have migrated in-river to below Bonneville Dam Major objectives of the CSS include: (1) development of a long-term index of transport SAR to in-river SAR for Snake River hatchery and wild spring and summer Chinook smolts measured at Lower Granite Dam; (2) develop a long-term index of survival rates from release of smolts at Snake River hatcheries to return of adults to the hatcheries; (3) compute and compare the overall SARs for selected upriver and downriver spring and summer Chinook hatchery and wild stocks; and (4) begin a time series of SARs for use in hypothesis testing and in the regional long-term monitoring and evaluation program. Primary CSS focus in this report is for wild and hatchery spring/summer Chinook that outmigrated in 1997 to 2002 and their respective adult returns through 2004.« less

Investigations into the Early Life-history of Naturally Produced Spring Chinook Salmon and Summer Steelhead in the Grande Ronde River Basin, Annual Report 2001.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reischauer, Alyssa; Monzyk, Frederick; Van Dyke, Erick

2003-06-01

We determined migration timing and abundance of juvenile spring chinook salmon Oncorhynchus tshawytscha and juvenile steelhead/rainbow trout Oncorhynchus mykiss using rotary screw traps on four streams in the Grande Ronde River basin during the 2001 migratory year (MY 2001) from 1 July 2000 through 30 June 2001. Based on migration timing and abundance, two distinct life-history strategies of juvenile spring chinook and O. mykiss could be distinguished. An 'early' migrant group left upper rearing areas from 1 July 2000 through 29 January 2001 with a peak in the fall. A 'late' migrant group descended from upper rearing areas from 30more » January 2001 through 30 June 2001 with a peak in the spring. The migrant population of juvenile spring chinook salmon in the upper Grande Ronde River in MY 2001 was very low in comparison to previous migratory years. We estimated 51 juvenile spring chinook migrated out of upper rearing areas with approximately 12% of the migrant population leaving as early migrants to overwinter downstream. In the same migratory year, we estimated 16,067 O. mykiss migrants left upper rearing areas with approximately 4% of these fish descending the upper Grande Ronde River as early migrants. At the Catherine Creek trap, we estimated 21,937 juvenile spring chinook migrants in MY 2001. Of these migrants, 87% left upper rearing areas early to overwinter downstream. We also estimated 20,586 O. mykiss migrants in Catherine Creek with 44% leaving upper rearing areas early to overwinter downstream. At the Lostine River trap, we estimated 13,610 juvenile spring chinook migrated out of upper rearing areas with approximately 77% migrating early. We estimated 16,690 O. mykiss migrated out of the Lostine River with approximately 46% descending the river as early migrants. At the Minam River trap, we estimated 28,209 juvenile spring chinook migrated out of the river with 36% migrating early. During the same period, we estimated 28,113 O. mykiss with approximately 14% of these fish leaving as early migrants. Juvenile spring chinook salmon PIT-tagged at trap sites in the fall and in upper rearing areas during winter were used to compare migration timing and survival to Lower Granite Dam of the early and late migrant groups. Juvenile spring chinook tagged on the upper Grande Ronde River were detected at Lower Granite Dam from 4 May to 20 May 2001, with a median passage date of 17 May. Too few fish were collected and tagged to conduct detection rate and survival comparisons between migrant groups. PIT-tagged salmon from Catherine Creek trap were detected at Lower Granite Dam from 27 April to 13 July 2001. Early migrants were detected significantly earlier (median = 10 May) than late migrants (median = 1 June). Also, early migrants from Catherine Creek were detected at a significantly higher rate than fish tagged in upper rearing areas in the winter, suggesting better survival for fish that migrated out of upper rearing areas in the fall. Juvenile spring chinook salmon from the Lostine River were detected at Lower Granite Dam from 2 April through 4 July 2001. Early migrants were detected significantly earlier (median = 27 April) than late migrants (median = 14 May). However, there was no difference in detection rates between early and late migrants. Survival probabilities showed similar patterns as dam detection rates. Juvenile spring chinook salmon from the Minam River were detected at Lower Granite Dam from 8 April through 18 August 2001. Early migrants were detected significantly earlier (median = 28 April) than late migrants (median = 14 May). Late migrants from the Minam River were tagged at the trap in the spring. Spring chinook salmon parr PIT-tagged in summer 2000 on Catherine Creek and the Imnaha, Lostine, and Minam rivers were detected at Lower Granite Dam over an 87 d period from 8 April to 3 July 2001. The migratory period of individual populations ranged from 51 d (Imnaha River) to 67 d (Catherine Creek) in length. Median dates of migration ranged from 30 April (Imnaha River) to 17 May (Catherine Creek). Detection rates differed between populations with Catherine Creek spring chinook salmon detected at the lowest rate (8.2%). Imnaha, Lostine, and Minam detection rates were not significantly different from each other. A similar pattern was seen for survival probabilities. Using mark-and-recapture and scale-aging techniques, we determined the population size and age-structure of spring chinook salmon parr in Catherine Creek and the Lostine River during the summer of 2001. In Catherine Creek, we estimated that 986 mature age-1 parr (precocious males) and 15,032 immature age-0 parr were present during August 2001. We estimated there were 7.5 mature male parr for every anadromous female spawner in Catherine Creek in 2001. We estimated 33,086 immature, age-0 parr inhabited the Lostine River in August 2001.« less

Breeding and moulting locations and migration patterns of the Atlantic population of Steller's eiders Polysticta stelleri as determined from satellite telemetry

USGS Publications Warehouse

Petersen, M.R.; Bustnes, J.O.; Systad, G.H.

2006-01-01

This study was designed to determine the spring, summer, autumn, and early winter distribution, migration routes, and timing of migration of the Atlantic population of Steller's eiders Polysticta stelleri. Satellite transmitters were implanted in 20 eiders captured in April 2001 at Vads??, Norway, and their locations were determined from 5 May 2001 to 6 February 2002. Regions where birds concentrated from spring until returning to wintering areas included coastal waters from western Finnmark, Norway, to the eastern Taymyr Peninsula, Russia. Novaya Zemlya, Russia, particularly the Mollera Bay region, was used extensively during spring staging, moult, and autumn staging; regions of the Kola, Kanin, and Gydanskiy peninsulas, Russia, were used extensively during spring and moult migrations. Steller's eiders migrated across the Barents and Kara seas and along the Kara Sea and Kola Peninsula coastal waters to nesting, moulting, and wintering areas. The majority of marked eiders (9 of 15) were flightless in near-shore waters along the west side of Novaya Zemlya. Eiders were also flightless in northern Norway and along the Kanin and at Kola Peninsula coasts. We compare and contrast natural history characteristics of the Atlantic and Pacific populations and discuss evolutionary and ecological factors influencing their distribution. © Journal of Avian Biology.

Characteristics of Fishes with the Potential to Cause Acoustic Clutter off Oregon and Washington during the Summer of 2012

DTIC Science & Technology

2014-05-10

14. Barboza, T., "West Coast sardine crash could radiate throughout ecosystem," Los Angeles Times, January 5, 2014. 15. Enticknap, B., Letter to the...AND SURVEYS Much of the Pacific sardine and Pacific hake stocks undertake annual north-south migrations . They migrate in late spring from off...California to the Pacific Northwest to feed during the summer. In the fall they migrate back to California to spawn during the winter and spring. The

Spring resource phenology and timing of songbird migration across the Gulf of Mexico

USGS Publications Warehouse

Paxton, Eben H.; Cohen, Emily B.; Németh, Zoltan; Zenzal, Theodore J.; Paxton, Kristina L.; Diehl, Robert H.; Moore, Frank R.

2015-01-01

Migratory songbirds are advancing their arrival to breeding areas in response to climatic warming at temperate latitudes. Less is understood about the impacts of climate changes outside the breeding period. Every spring, millions of migrating songbirds that overwinter in the Caribbean and Central and South America stop to rest and refuel in the first available habitats after crossing the Gulf of Mexico. We used capture data from a long-term banding station (20 years: 1993 to 2012) located on the northern coast of the Gulf to assess the passage timing of 17 species making northward migrations into eastern North America. We further assessed spring resource phenology as measured by normalized difference vegetation index (NDVI) on nonbreeding ranges and en route. We tested the hypotheses that spring passage timing has advanced during the past two decades and that annual variability in passage timing into eastern North America is related to spring resource phenology on stationary nonbreeding ranges and during passage south of the Gulf. Further, we assessed whether annual variability in resource phenology south of the Gulf was a good indicator of the conditions that migrants encountered upon first landfall in eastern North America. We found no trend in migration timing for species that migrate from South America and annual variability in their passage timing was unrelated to environmental conditions in nonbreeding ranges or en route. Species that migrate from Central America and the Caribbean delayed arrival by 2 to 3 days over the 20-year period and arrived later during years when conditions were dryer in nonbreeding ranges and passage areas south of the Gulf. Further, year to year variability in spring resource phenology in nonbreeding ranges and passage areas south of the Gulf were not good indicators of resource phenology upon arrival in eastern North America. Therefore, despite the fact that many migrant species have been arriving increasingly earlier to breeding grounds, the passage timing of 17 species into eastern North America has either not changed or is slightly later, due to drying spring conditions in Central America and the Caribbean. Our results suggest that Nearctic–Neotropical migratory birds adjust the rate of migration primarily within eastern North America and, in light of warmer temperatures in the temperate zone and earlier arrival timing to breeding ranges, species that overwinter in Central America and the Caribbean may be increasing the speed of migration within eastern North America.

Organochlorine pesticides in plasma of migrating peregrine falcons at Padre Island, Texas, Spring 1978-80 vs. Spring 1984

USGS Publications Warehouse

Henny, C.J.; Riddle, K.E.; Hulse, C.S.

1985-01-01

A spring concentration of migrating Peregrine Falcons (Falco peregrinus) was first discovered at Padre Island, Texas, in April 1978. The birds were first captured and blood-sampled for monitoring residue burdens and trends in the late 1970' s. Only 29 Peregrines were sampled in 1978 and 1979, but 111 were sampled in 1980. The initial investigation showed that DDE in the plasma of spring migrants returning from Latin America for the first time declined significantly during the study (through 1980). In the spring of 1984, 48 Peregrines were captured at Padre Island with blood samples again collected. This report will compare plasma residue data from the earlier study with residues obtained in 1984.

Spatiotemporal associations between Pacific herring spawn and surf scoter spring migration: evaluating a "silver wave" hypothesis

USGS Publications Warehouse

Lok, E.K.; Esler, Daniel N.; Takekawa, John Y.; De La Cruz, S.W.; Boyd, W.S.; Nysewander, D.R.; Evenson, J.R.; Ward, D.H.

2012-01-01

Surf scoters Melanitta perspicillata are sea ducks that aggregate at spawning events of Pacific herring Clupea pallasi and forage on the eggs, which are deposited in abundance during spring at discrete sites. We evaluated whether migrating scoters followed a ‘silver wave’ of resource availability, analogous to the ‘green wave’ of high-quality foraging conditions that herbivorous waterfowl follow during spring migration. We confirmed that herring spawning activity began later in the year at higher latitudes, creating a northward-progressing wave of short-term localized food availability. Using satellite telemetry and aerial surveys, we documented the chronology of scoter spring migration and the use of stopover locations in relation to herring spawn timing and locations. We found that the migration chronology paralleled the northward progression of herring spawning events. Although there was considerable variability in the timing of both scoter migration and the initiation of herring spawning, the processes were related beyond a coincidental northward progression. During migration, 60% of the tracked scoters visited at least 1 spawn site, and those that used spawn sites were located on spawn sites for approximately one-third of their migration locations. Surf scoters showed close spatiotemporal associations with herring spawning events, confirming that the presence of herring spawn was a factor determining habitat use for many individuals. Surf scoters showed close spatiotemporal associations with herring spawning events, confirming that the presence of herring spawn was a factor determining habitat use for many individuals, a conclusion that is consistent with previous studies which used physiologically based metrics to evaluate the importance of herring spawn.

Connectivity of wood thrush breeding, wintering, and migration sites based on range-wide tracking.

PubMed

Stanley, Calandra Q; McKinnon, Emily A; Fraser, Kevin C; Macpherson, Maggie P; Casbourn, Garth; Friesen, Lyle; Marra, Peter P; Studds, Colin; Ryder, T Brandt; Diggs, Nora E; Stutchbury, Bridget J M

2015-02-01

Many migratory animals are experiencing rapid population declines, but migration data with the geographic scope and resolution to quantify the complex network of movements between breeding and nonbreeding regions are often lacking. Determining the most frequently used migration routes and nonbreeding regions for a species is critical for understanding population dynamics and making effective conservation decisions. We tracked the migration of individual Wood Thrushes (Hylocichla mustelina) (n = 102) from across their range with light-level geolocators and, for the first time, quantified migration routes and wintering regions for distinct breeding populations. We identified regional and species-level migratory connectivity networks for this declining songbird by combining our tracking results with range-wide breeding abundance estimates and forest cover data. More than 50% of the species occupied the eastern wintering range (Honduras to Costa Rica), a region that includes only one-third of all wintering habitat and that is undergoing intensive deforestation. We estimated that half of all Wood Thrushes in North America migrate south through Florida in fall, whereas in spring approximately 73% funnel northward through a narrow span along the central U.S. Gulf Coast (88-93°W). Identifying migratory networks is a critical step for conservation of songbirds and we demonstrated with Wood Thrushes how it can highlight conservation hotspots for regional populations and species as a whole. © 2014 Society for Conservation Biology.

Timing and location of mortality of fledgling, subadult, and adult California Gulls

USGS Publications Warehouse

Pugesek, B.H.; Diem, K.L.

2008-01-01

We investigated patterns of mortality during post-breeding migrations of California Gulls (Larus californicus) nesting near Laramie, Wyoming, USA. We used 151 recoveries and 647 sightings of banded and patagially-marked gulls to compare ratios of mortalities to observations of live birds (1) during four time periods (early and late fall migration, winter, and spring migration), (2) at two locations (Pacific coast and inland), and (3) among three age-classes of gulls (fledglings, 1- and 2-year-olds, and breeding-age adults). Mortality rates were higher in inland areas (35%) than in coastal areas (15%) and were dependent on season within inland areas, but not in coastal areas. Mortality in inland areas during early fall (21%) was comparable with that in coastal areas (13%) but was higher during late fall (68 vs. 13%) and spring migration (46 vs. 17%). Both fledgling (71%) and adult (64%) gulls experienced high mortality rates during late fall migration, possibly because some gulls were too weak to make their way to the Pacific coast and became trapped by poor weather conditions. Adult gulls also experienced high mortality inland during spring migration; few subadults made the costly migration to and from the breeding area. Some adults also skipped breeding and remained in coastal areas during the breeding season.

Migration of radio-marked whooping cranes from the Aransas-wood buffalo population: Patterns of habitat use, behavior, and survival. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howe, M.A.

1989-01-01

Use of migration stopovers by radio-marked whooping cranes (Grus americana) between Aransas National Wildlife Refuge, Texas, and central Saskatchewan was studied in fall 1981-83 and spring 1983-84 as part of a cooperative program with the Canadian Wildlife Service. Twenty-seven cranes were monitored for one or several seasons, including nine radio-marked birds and others that associated with them. Whooping cranes showed variations in their use of migration habitats, feeding primarily in a variety of croplands and roosting primarily in palustrine wetlands. More than 40% of the roosting wetlands were smaller than 0.5 ha. Although heavily vegetated wetlands were generally not used,more » family groups appeared to select more heavily vegetated wetlands than nonfamilies. Juveniles allocated 25% more time to foraging than did parents. Parents increased their foraging rate and showed less alert behavior in spring migration. Dissociation of parents and young occurred late in spring migration and after arrival on the breeding grounds.« less

Facilitators and constraints at each stage of the migration decision process.

PubMed

Kley, Stefanie

2017-10-01

Behavioural models of migration emphasize the importance of migration decision-making for the explanation of subsequent behaviour. But empirical migration research regularly finds considerable gaps between those who intend to migrate and those who actually realize their intention. This paper applies the Theory of Planned Behaviour, enriched by the Rubicon model, to test specific hypotheses about distinct effects of facilitators and constraints on specific stages of migration decision-making and behaviour. The data come from a tailor-made panel survey based on random samples of people drawn from two German cities in 2006-07. The results show that in conventional models the effects of facilitators and constraints on migration decision-making are likely to be underestimated. Splitting the process of migration decision-making into a pre-decisional and a pre-actional phase helps to avoid bias in the estimated effects of facilitators and constraints on both migration decision-making and migration behaviour.

Wolf predation risk associated with white-tailed deer movements

USGS Publications Warehouse

Nelson, M.E.; Mech, L.D.

1991-01-01

The survival of 159 yearling and adult deer (Odocoileus virginianus) was monitored by telemetry during 282 spring and 219 fall individual migrations to winter deeryards in northeastern Minnesota. A disproportionate number of deer were killed by wolves (Canis lupus) during fall migration relative to the short time they spent migrating, but not during spring migration. Predation was also significantly greater for male and female yearlings and adult females outside deeryards during winter. Survival of 79 yearlings dispersing from natal ranges was high (1.00). It appears that changing climatic conditions combined with unfamiliar terrain and undetermined factors predispose migratory deer to wolf predation during fall. These findings support an earlier hypothesis that winter yarding is an antipredator strategy.

Stopover ecology of landbirds migrating along the middle Rio Grande in spring and fall

Treesearch

Wang Yong; Deborah M. Finch

2002-01-01

This research represents the first comprehensive summary of our study of stopover ecology of migratory landbirds in riparian habitats along the middle Rio Grande of central New Mexico. We report results from mist-netting operations conducted during spring and fall migration in 1994, 1995, and 1996. A total of 23,800 individuals of 146 species were captured during the...

Landbird species composition and relative abundance during migration along the Rio Grande

Treesearch

Wang Yong; Deborah M. Finch

1996-01-01

In this paper, we report species composition and relative abundances of stopover migrants during spring and fall migration along the middle Rio Grande in 1994. We recorded 157 landbird species using mist-netting and survey methods at two sites on the Rio Grande, the Bosque del Apache and the Rio Grande Nature Center. A total of 6,509 birds was captured during spring...

Satellite tracking of the migration of Whooper Swans Cygnus cygnus wintering in Japan

USGS Publications Warehouse

Shimada, Tetsuo; Yamaguchi, Noriyuki M.; Hijikata, N.; Hiraoka, Emiko N.; Hupp, Jerry W.; Flint, Paul L.; Tokita, Ken-ichi; Fujita, Go; Uchida, Kiyoshi; Sato, F.; Kurechi, Masayuki; Pearce, John M.; Ramey, Andy M.; Higuchi, Hiroyoshi

2014-01-01

We satellite-tracked Whooper Swans Cygnus cygnus wintering in northern Japan to document their migration routes and timing, and to identify breeding areas. From 47 swans that we marked at Lake Izunuma-Uchinuma, Miyagi Prefecture, northeast Honshu, and at Lake Kussharo, east Hokkaido, we observed 57 spring and 33 autumn migrations from 2009-2012. In spring, swans migrated north along Sakhalin Island from eastern Hokkaido using stopovers in Sakhalin, at the mouth of the Amur River and in northern coastal areas of the Sea of Okhotsk. They ultimately reached molting/breedmg areas along the Indigirka River and the lower Kolyma River in northern Russia. In autumn, the swans basically reversed the spring migration routes. We identified northern Honshu, eastern Hokkaido, coastal areas in Sakhalin, the lower Amur River and northern coastal areas of the Sea of Okhotsk as the most frequent stopover sites, and the middle reaches of the Indigirka and the lower Kolyma River as presumed breeding sites. Our results are helpful in understanding the distribution of the breeding and stopover sites of Whooper Swans wintering in Japan and in identifying their major migration habitats. Our findings contribute to understanding the potential transmission process of avian influenza viruses potentially carried by swans, and provide information necessary to conserve Whooper Swans in East Asia.

The limits of modifying migration speed to adjust to climate change

NASA Astrophysics Data System (ADS)

Schmaljohann, Heiko; Both, Christiaan

2017-08-01

Predicting the range of variation over which organisms can adjust to environmental change is a major challenge in ecology. This is exemplified in migratory birds which experience changes in different habitats throughout the annual cycle. Earlier studies showed European population trends declining strongest in migrant species with least adjustment in spring arrival time. Thus, the increasing mismatches with other trophic levels in seasonal breeding areas probably contribute to their large-scale decline. Here we quantify the potential range of adjusting spring arrival dates through modifying migration speeds by reviewing 49 tracking studies. Among-individual variation in migration speed was mainly determined by the relatively short stop-over duration. Assuming this population response reflects individual phenotypic plasticity, we calculated the potential for phenotypic plasticity to speed-up migration by reducing stop-over duration. Even a 50% reduction would lead to a mere two-day advance in arrival, considering adjustments on the final 2,000 km of the spring journey. Hence, in contrast to previous studies, flexibility in the major determinant of migration duration seems insufficient to adjust to ongoing climate change, and is unlikely to explain some of the observed arrival advancements in long-distance migrants.

February precipitation in the wintering grounds of the lesser whitethroat, Sylvia curruca: is it a cue for migration onset?

PubMed

Aloni, Irith; Markman, Shai; Ziv, Yaron

2017-02-01

Numerous studies report shifts in bird migration phenology, presumably owing to global warming. However, most studies focus on migration patterns in the Northern Hemisphere. In this study, we investigated associations between weather conditions in African wintering grounds of the lesser whitethroat, Sylvia curruca, and spring arrival time in Eilat, Israel. Using multivariate regression models, we analysed a 30-year dataset in order to examine correlations between median springtime arrival and 46 climate variables of the wintering quarters. The model obtained exhibited a highly statistical fit, involving mean precipitation in February and March with negative effects and number of wet days during November-February. February precipitation levels were also the major factor associated with the interquartile range of arrival time. Interestingly and contrary to published results, annual or seasonal precipitation showed no correlation with spring arrival time, nor did temperature. Moreover, winter in this region falls into dry season with negligible rainfall quantities. Hence, it is unlikely that precipitation effect on habitat productivity is a driving force of migration, as suggested by other studies. Instead, we propose that precipitation in February acts as a cue for the birds, indicating the approach of spring and migration time.

The influence of weather on Golden Eagle migration in northwestern Montana

USGS Publications Warehouse

Yates, R.E.; McClelland, B.R.; Mcclelland, P.T.; Key, C.H.; Bennetts, R.E.

2001-01-01

We analyzed the influence of 17 weather factors on migrating Golden Eagles (Aquila chrysaetos) near the Continental Divide in Glacier National Park, Montana, U.S.A. Local weather measurements were recorded at automated stations on the flanks of two peaks within the migration path. During a total of 506 hr of observation, the yearly number of Golden Eagles in autumn counts (1994-96) averaged 1973; spring counts (1995 and 1996) averaged 605 eagles. Mean passage rates (eagles/hr) were 16.5 in autumn and 8.2 in spring. Maximum rates were 137 in autumn and 67 in spring. Using generalized linear modeling, we tested for the effects of weather factors on the number of eagles counted. In the autumn model, the number of eagles increased with increasing air temperature, rising barometric pressure, decreasing relative humidity, and interactions among those factors. In the spring model, the number of eagles increased with increasing wind speed, barometric pressure, and the interaction between these factors. Our data suggest that a complex interaction among weather factors influenced the number of eagles passing on a given day. We hypothesize that in complex landscapes with high topographic relief, such as Glacier National Park, numerous weather factors produce different daily combinations to which migrating eagles respond opportunistically. ?? 2001 The Raptor Research Foundation, Inc.

Scaup migration patterns in North Dakota relative to temperatures and water conditions

USGS Publications Warehouse

Austin, J.E.; Granfors, D.A.; Johnson, M.A.; Kohn, S.C.

2002-01-01

Greater (Aythya marila) and lesser scaup (A. affinis) have protracted spring migrations. Migrants may still be present on southern breeding areas when the annual Waterfowl Breeding Population and Habitat Surveys (WBPHS) are being conducted. Understanding factors affecting the chronology and rate of spring migration is important for the interpretation of data from annual population surveys. We describe the general temporal pattern of scaup numbers in south-central North Dakota in spring, examine the relationships between scaup numbers and measures of local water conditions and spring temperatures, and assess timing of the WBPHS relative to numbers of scaup occurring in the study area in late May. Scaup were counted weekly on a 95-km, 400-m-wide transect from late March through May, 1957-1999. Average numbers of scaup per count were positively associated with numbers of seasonal, semipermanent, and total ponds. Average minimum daily ambient temperatures showed a trend of increasing temperatures over the 43 years, and dates of peak scaup counts became progressively earlier. Weeks of early migration usually had higher temperatures than weeks of delayed migration. The relationship between temperature and timing of migration was strongest during the second and third weeks of April, which is A# 1 week before numbers peak (median date = 19 Apr). Trends in sex and pair ratios were not consistent among years. Counts in late May-early June indicated considerable annual variability in the magnitude of late migrants. Scaup numbers during this period seemed to stabilize in only 5 of the 19 years when 2 or more surveys were conducted after the WBPHS. These findings corroborate concerns regarding the accuracy of the WBPHS for representing breeding populations of scaup and the possibility of double-counting scaup in some years.

International importance of the eastern Chukchi Sea as a staging area for migrating king eiders

USGS Publications Warehouse

Oppel, S.; Dickson, D.L.; Powell, A.N.

2009-01-01

The evaluation of habitats used by arctic birds on migration is crucial for their conservation. We explored the importance of the eastern Chukchi Sea (ECS) as a staging area for king eiders (Somateria spectabilis) migrating between breeding areas in Siberia and western North America and wintering areas in the Bering Sea. We tracked 190 king eiders with satellite transmitters between 1997 and 2007. In late summer, 74% of satellite-tracked king eiders migrating south staged in the ECS for 13 ?? 13 (SD) days between late June and early November. During spring migration, king eiders staged in the ECS between mid-April and early June for 21 ?? 10 days. All instrumented birds migrating to breeding grounds in western North America (n = 62), and 6 of 11 males migrating to breeding grounds in Siberia, used this area for at least 1 week during spring migration. The importance of this staging area renders it possible that industrial development could adversely affect king eider populations in both Siberia and North America. ?? 2009 US Government.

Estimating shorebird populations during spring stopover in rice fields of the Louisiana and Texas Gulf Coastal Plain

USGS Publications Warehouse

Norling, Wayne; Jeske, Clinton W.; Thigpen, Tyler F.; Chadwick, Paul C.

2012-01-01

Migrating shorebird populations using approximately 2% of Louisiana and Texas Gulf Coastal rice fields were surveyed during spring migration (March–May of 1997 and 1998) using biweekly stratified random surveys conducted at 50 roadside survey points and approximately 30,000 shorebirds were observed. Shorebird counts were extrapolated and almost 1.4 million birds in 1997 and over 1.6 million birds of 31 species in 1998 were estimated to use rice field habitat for stopover sites in Louisiana and Texas. Greater than 50% of the estimated North American populations were estimated to use rice field habitats for five species, including a species of concern, Buff-breasted Sandpiper (Tryngites subruficollis) at 187%. Because of predictability of suitable rice field habitat acreage, timing of field preparation and water availability, coastal rice prairies are identified as critical spring migration stopover sites.

Tracking from the tropics reveals behaviour of juvenile songbirds on their first spring migration.

PubMed

McKinnon, Emily A; Fraser, Kevin C; Stanley, Calandra Q; Stutchbury, Bridget J M

2014-01-01

Juvenile songbirds on spring migration travel from tropical wintering sites to temperate breeding destinations thousands of kilometres away with no prior experience to guide them. We provide a first glimpse at the migration timing, routes, and stopover behaviour of juvenile wood thrushes (Hylocichla mustelina) on their inaugural spring migration by using miniaturized archival geolocators to track them from Central America to the U.S. and Canada. We found significant differences between the timing of juvenile migration and that of more experienced adults: juveniles not only departed later from tropical wintering sites relative to adults, they also became progressively later as they moved northward. The increasing delay was driven by more frequent short stops by juveniles along their migration route, particularly in the U.S. as they got closer to breeding sites. Surprisingly, juveniles were just as likely as adults to cross the Gulf of Mexico, an open-water crossing of 800-1000 km, and migration route at the Gulf was not significantly different for juveniles relative to adults. To determine if the later departure of juveniles was related to poor body condition in winter relative to adults, we examined percent lean body mass, fat scores, and pectoral muscle scores of juvenile versus adult birds at a wintering site in Belize. We found no age-related differences in body condition. Later migration timing of juveniles relative to adults could be an adaptive strategy (as opposed to condition-dependent) to avoid the high costs of fast migration and competition for breeding territories with experienced and larger adults. We did find significant differences in wing size between adults and juveniles, which could contribute to lower flight efficiency of juveniles and thus slower overall migration speed. We provide the first step toward understanding the "black box" of juvenile songbird migration by documenting their migration timing and en route performance.

Tracking from the Tropics Reveals Behaviour of Juvenile Songbirds on Their First Spring Migration

PubMed Central

McKinnon, Emily A.; Fraser, Kevin C.; Stanley, Calandra Q.; Stutchbury, Bridget J. M.

2014-01-01

Juvenile songbirds on spring migration travel from tropical wintering sites to temperate breeding destinations thousands of kilometres away with no prior experience to guide them. We provide a first glimpse at the migration timing, routes, and stopover behaviour of juvenile wood thrushes (Hylocichla mustelina) on their inaugural spring migration by using miniaturized archival geolocators to track them from Central America to the U.S. and Canada. We found significant differences between the timing of juvenile migration and that of more experienced adults: juveniles not only departed later from tropical wintering sites relative to adults, they also became progressively later as they moved northward. The increasing delay was driven by more frequent short stops by juveniles along their migration route, particularly in the U.S. as they got closer to breeding sites. Surprisingly, juveniles were just as likely as adults to cross the Gulf of Mexico, an open-water crossing of 800–1000 km, and migration route at the Gulf was not significantly different for juveniles relative to adults. To determine if the later departure of juveniles was related to poor body condition in winter relative to adults, we examined percent lean body mass, fat scores, and pectoral muscle scores of juvenile versus adult birds at a wintering site in Belize. We found no age-related differences in body condition. Later migration timing of juveniles relative to adults could be an adaptive strategy (as opposed to condition-dependent) to avoid the high costs of fast migration and competition for breeding territories with experienced and larger adults. We did find significant differences in wing size between adults and juveniles, which could contribute to lower flight efficiency of juveniles and thus slower overall migration speed. We provide the first step toward understanding the “black box” of juvenile songbird migration by documenting their migration timing and en route performance. PMID:25141193

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouwes, Nick; Petrosky, Charlie; Schaller, Howard

The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer chinook (hereafter, chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of chinook marked in two different regions (which differ in the number of dams chinook have to migrate through) provides insight into the effectsmore » of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well comparison between the different collector projects from which smolts are transported. CSS also compares these survival rates for wild Snake River spring and summer chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species.Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts. experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. ''D'', or differential delayed mortality, is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to Lower Granite Dam. A ''D'' equal to one indicates that there is no difference in survival rate after hydrosystem passage, while a ''D'' less than one indicates that transported smolts die at a greater rate after release, than smolts that have migrated through the hydrosystem. While the relative survival rates of transported and in-river migrants are important, the SARs must be also be sufficient to allow the salmon to persist and recover (Mundy et al. 1994). Decreased SARs could result from delayed hydrosystem mortality for either transported or in-river migrants, or both. Major objectives of CSS include: (1) development of a long-term index of transport SAR to in-river SAR for Snake River hatchery spring and summer chinook smolts measured at Lower Granite Dam; (2) develop a long-term index of survival rates from release of smolts at Snake River hatcheries to return of adults to the hatcheries; (3) compute and compare the overall SARs for selected upriver and downriver spring and summer chinook hatcheries; (4) begin a time series of SARs for use in hypothesis testing and in the regional long-term monitoring and evaluation program; (5) evaluate growth patterns of transported and in-river migrating smolts, and of upriver and downriver stocks. Primary CSS focus in this report for the 1997-1999 migration years included hatchery chinook tasks for objectives 1, 4 and 5.« less

Integrated wetland management for waterfowl and shorebirds at Mattamuskeet National Wildlife Refuge, North Carolina

USGS Publications Warehouse

Tavernia, Brian G.; Stanton, John D.; Lyons, James E.

2017-11-22

Mattamuskeet National Wildlife Refuge (MNWR) offers a mix of open water, marsh, forest, and cropland habitats on 20,307 hectares in coastal North Carolina. In 1934, Federal legislation (Executive Order 6924) established MNWR to benefit wintering waterfowl and other migratory bird species. On an annual basis, the refuge staff decide how to manage 14 impoundments to benefit not only waterfowl during the nonbreeding season, but also shorebirds during fall and spring migration. In making these decisions, the challenge is to select a portfolio, or collection, of management actions for the impoundments that optimizes use by the three groups of birds while respecting budget constraints. In this study, a decision support tool was developed for these annual management decisions.Within the decision framework, there are three different management objectives: shorebird-use days during fall and spring migrations, and waterfowl-use days during the nonbreeding season. Sixteen potential management actions were identified for impoundments; each action represents a combination of hydroperiod and vegetation manipulation. Example hydroperiods include semi-permanent and seasonal drawdowns, and vegetation manipulations include mechanical-chemical treatment, burning, disking, and no action. Expert elicitation was used to build a Bayesian Belief Network (BBN) model that predicts shorebird- and waterfowl-use days for each potential management action. The BBN was parameterized for a representative impoundment, MI-9, and predictions were re-scaled for this impoundment to predict outcomes at other impoundments on the basis of size. Parameter estimates in the BBN model can be updated using observations from ongoing monitoring that is part of the Integrated Waterbird Management and Monitoring (IWMM) program.The optimal portfolio of management actions depends on the importance, that is, weights, assigned to the three objectives, as well as the budget. Five scenarios with a variety of objective weights and budgets were developed. Given the large number of possible portfolios (1614), a heuristic genetic algorithm was used to identify a management action portfolio that maximized use-day objectives while respecting budget constraints. The genetic algorithm identified a portfolio of management actions for each of the five scenarios, enabling refuge staff to explore the sensitivity of their management decisions to objective weights and budget constraints.The decision framework developed here provides a transparent, defensible, and testable foundation for decision making at MNWR. The BBN model explicitly structures and parameterizes a mental model previously used by an expert to assign management actions to the impoundments. With ongoing IWMM monitoring, predictions from the model can be tested, and model parameters updated, to reflect empirical observations. This framework is intended to be a living document that can be updated to reflect changes in the decision context (for example, new objectives or constraints, or new models to compete with the current BBN model). Rather than a mandate to refuge staff, this framework is intended to be a decision support tool; tool outputs can become part of the deliberations of refuge staff when making difficult management decisions for multiple objectives.

Investigations into the Early History of Naturally Produced Spring Chinook Salmon in the Grand Ronde Basin : Fish Research Project Oregon : Annual Progress Report Project Period September 1, 1996 to August 31, 1997.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johasson, Brian C.; Tranquilli, J. Vincent; Keefe, MaryLouise

1998-10-28

We have documented two general life history strategies utilized by juvenile spring chinook salmon in the Grande Ronde River basin: (1) juveniles migrate downstream out of summer rearing areas in the fall, overwinter in river valley habitats, and begin their seaward migration in the spring, and (2) juveniles remain in summer rearing areas through the winter and begin seaward migration in the spring. In migration year 96-97, the patterns evident from migrant trap data were similar for the three Grande Ronde River populations studied, with 42% of the Lostine River migrants and 76% of the Catherine Creek migrants leaving uppermore » rearing areas in the fall. Contrary to past years, the majority (98%) of upper Grande Ronde River migrants moved out in the fall. Total trap catch for the upper Grande Ronde River was exceedingly low (29 salmon), indicating that patterns seen this year may be equivocal. As in previous years, approximately 99% of chinook salmon juveniles moved past our trap at the lower end of the Grande Ronde River valley in the spring, reiterating that juvenile chinook salmon overwinter within the Grande Ronde valley section of the river. PIT-tagged fish were recaptured at Grande Ronde River traps and mainstem dams. Recapture data showed that fish that overwintered in valley habitats left as smolts and arrived at Lower Granite Dam earlier than fish that overwintered in upstream rearing areas. Fish from Catherine Creek that overwintered in valley habitats were recaptured at the dams at a higher rate than fish that overwintered upstream. In this first year of data for the Lostine River, fish tagged during the fall migration were detected at a similar rate to fish that overwintered upstream. Abundance estimates for migration year 96-97 were 70 for the upper Grande Ronde River, 4,316 for the Catherine Creek, and 4,323 for the Lostine River populations. Although present in most habitats, juvenile spring chinook salmon were found in the greatest abundance in pool habitats, particularly alcove and backwater pools. These results were consistent for both summer and winter surveys.« less

Flower power: tree flowering phenology as a settlement cue for migrating birds.

PubMed

McGrath, Laura J; van Riper, Charles; Fontaine, Joseph J

2009-01-01

1. Neotropical migrant birds show a clear preference for stopover habitats with ample food supplies; yet, the proximate cues underlying these decisions remain unclear. 2. For insectivorous migrants, cues associated with vegetative phenology (e.g. flowering, leaf flush, and leaf loss) may reliably predict the availability of herbivorous arthropods. Here we examined whether migrants use the phenology of five tree species to choose stopover locations, and whether phenology accurately predicts food availability. 3. Using a combination of experimental and observational evidence, we show migrant populations closely track tree phenology, particularly the flowering phenology of honey mesquite (Prosopis glandulosa), and preferentially forage in trees with more flowers. Furthermore, the flowering phenology of honey mesquite reliably predicts overall arthropod abundance as well as the arthropods preferred by migrants for food. 4. Together, these results suggest that honey mesquite flowering phenology is an important cue used by migrants to assess food availability quickly and reliably, while in transit during spring migration.

Flower power: Tree flowering phenology as a settlement cue for migrating birds

USGS Publications Warehouse

McGrath, L.J.; van Riper, Charles; Fontaine, J.J.

2009-01-01

1. Neotropical migrant birds show a clear preference for stopover habitats with ample food supplies; yet, the proximate cues underlying these decisions remain unclear. 2. For insectivorous migrants, cues associated with vegetative phenology (e.g. flowering, leaf flush, and leaf loss) may reliably predict the availability of herbivorous arthropods. Here we examined whether migrants use the phenology of five tree species to choose stopover locations, and whether phenology accurately predicts food availability. 3. Using a combination of experimental and observational evidence, we show migrant populations closely track tree phenology, particularly the flowering phenology of honey mesquite (Prosopis glandulosa), and preferentially forage in trees with more flowers. Furthermore, the flowering phenology of honey mesquite reliably predicts overall arthropod abundance as well as the arthropods preferred by migrants for food. 4. Together, these results suggest that honey mesquite flowering phenology is an important cue used by migrants to assess food availability quickly and reliably, while in transit during spring migration. ?? 2008 The Authors.

Harbingers of Spring

ERIC Educational Resources Information Center

Serrao, John

1976-01-01

Emphasizing the spring migration of frogs, toads, and salamanders to their watery breeding sites, this article presents information on numerous amphibians and suggests both indoor and outdoor educational activities appropriate for elementary and/or early secondary instruction. (JC)

Spring migration of mallards from Arkansas as determined by satellite telemetry

USGS Publications Warehouse

Krementz, David G.; Asante, Kwasi; Naylor, L.M.

2011-01-01

We used satellite telemetry to document spring migration phenology, routes, stopover regions, and nesting sites of mallards Anas platyrhynchos marked in Arkansas during the winters of 2004-2007. Of the 143 marked mallards that migrated from Arkansas, they did so, on average, by mid-March. Mallards flew over the Missouri Ozarks and 42% made an initial stopover in Missouri, where they used areas that had larger rivers (Mississippi River, Missouri River) embedded in an agricultural landscape. From this stopover region they either migrated directly to the Prairie Pothole Region (PPR) or they migrated north to Minnesota where they either moved next to the PPR or to the north and east of the PPR. For those mallards (83%) that stopped for >1 d before entering the PPR, the average length at each stop was 12 d (SE = 0.90 d, range = 2-54 d). Mallards made more stopovers, made shorter migration movements, and took longer to move to the PPR in wetter than drier years. Mallards arrived in the PPR earlier in 2006 x- = 30 March, SE = 2.18 d) than in 2005 x- = 7 April, SE = 2.30 d). Females nested across nine Bird Conservation Regions. Nesting occurred most frequently in South Dakota (n = 9). The average date when females nested was 19 April (SE = 2.44 d, range = 12 March-26 May). Because many mallards headed for the large river corridors in Missouri for their first stopover, this region is an important spring migration stopover of continental importance to mallards and might be considered a focal area for conservation.

Use of multiple modes of flight subsidy by a soaring terrestrial bird, the golden eagle Aquila chrysaetos, when on migration

PubMed Central

Katzner, Todd E.; Turk, Philip J.; Duerr, Adam E.; Miller, Tricia A.; Lanzone, Michael J.; Cooper, Jeff L.; Brandes, David; Tremblay, Junior A.; Lemaître, Jérôme

2015-01-01

Large birds regularly use updrafts to subsidize flight. Although most research on soaring bird flight has focused on use of thermal updrafts, there is evidence suggesting that many species are likely to use multiple modes of subsidy. We tested the degree to which a large soaring species uses multiple modes of subsidy to provide insights into the decision-making that underlies flight behaviour. We statistically classified more than 22 000 global positioning satellite–global system for mobile communications telemetry points collected at 30-s intervals to identify the type of subsidized flight used by 32 migrating golden eagles during spring in eastern North America. Eagles used subsidized flight on 87% of their journey. They spent 41.9% ± 1.5 (, range: 18–56%) of their subsidized northbound migration using thermal soaring, 45.2% ± 2.1 (12–65%) of time gliding between thermals, and 12.9% ± 2.2 (1–55%) of time using orographic updrafts. Golden eagles responded to the variable local-scale meteorological events they encountered by switching flight behaviour to take advantage of multiple modes of subsidy. Orographic soaring occurred more frequently in morning and evening, earlier in the migration season, and when crosswinds and tail winds were greatest. Switching between flight modes allowed migration for relatively longer periods each day and frequent switching behaviour has implications for a better understanding of avian flight behaviour and of the evolution of use of subsidy in flight. PMID:26538556

The role of the US Great Plains low-level jet in nocturnal migrant behavior

NASA Astrophysics Data System (ADS)

Wainwright, Charlotte E.; Stepanian, Phillip M.; Horton, Kyle G.

2016-10-01

The movements of aerial animals are under the constant influence of atmospheric flows spanning a range of spatiotemporal scales. The Great Plains nocturnal low-level jet is a large-scale atmospheric phenomenon that provides frequent strong southerly winds through a shallow layer of the airspace. The jet can provide substantial tailwind assistance to spring migrants moving northward, while hindering southward migration during autumn. This atmospheric feature has been suspected to play a prominent role in defining migratory routes, but the flight strategies used with respect to these winds are yet to be examined. Using collocated vertically pointing radar and lidar, we investigate the altitudinal selection behavior of migrants over Oklahoma during two spring and two autumn migration seasons. In general, migrants choose to fly within the jet in spring, often concentrating in the favorable wind speed maximum. Autumn migrants typically fly below the jet, although some will rapidly climb to reach altitudes above the inhibiting winds. The intensity of migration was relatively constant throughout the spring due to the predominantly favorable southerly jet winds. Conversely, autumn migrants were more apt to delay departure to wait for the relatively infrequent northerly winds.

Wind assistance: A requirement for migration of shorebirds?

USGS Publications Warehouse

Butler, Robert W.; Williams, Tony D.; Warnock, Nils; Bishop, Mary Anne

1997-01-01

We investigated the importance of wind-assisted flight for northward (spring) migration by Western Sandpipers (Calidris mauri) along the Pacific Coast of North America. Using current models of energy costs of flight and recent data on the phenology of migration, we estimated the energy (fat) requirements for migration in calm winds and with wind-assisted flight for different rates of fat deposition: (1) a variable rate, assuming that birds deposit the minimum amount of fat required to reach the next stopover site; (2) a constant maximum rate of 1.0 g/day; and (3) a lower constant rate of 0.4 g/day. We tested these models by comparing conservative estimates of predicted body mass along the migration route with empirical data on body mass of Western Sandpipers at different stopover sites and upon arrival at the breeding grounds. In calm conditions, birds would have to deposit unrealistically high amounts of fat (up to 330% of observed values) to maintain body mass above absolute lean mass values. Fat-deposition rates of 1.0 g/day and 0.4 g/day, in calm conditions, resulted in a steady decline in body mass along the migration route, with predicted body masses on arrival in Alaska of only 60% (13.6 g) and 26% (5.9 g) of average lean mass (22.7 g). Conversely, birds migrating with wind assistance would be able to complete migration with fat-deposition rates as low as 0.4 g/day, similar to values reported for this size bird from field studies. Our results extend the conclusion of the importance of winds for large, long-distance migrants to a small, short-distance migrant. We suggest that the migratory decisions of birds are more strongly influenced by the frequency and duration of winds aloft, i.e. by events during the flight phase, than by events during the stopover phase of migration, such as fat-deposition rate, that have been the focus of much recent migration theory.

Longer wings for faster springs - wing length relates to spring phenology in a long-distance migrant across its range.

PubMed

Hahn, Steffen; Korner-Nievergelt, Fränzi; Emmenegger, Tamara; Amrhein, Valentin; Csörgő, Tibor; Gursoy, Arzu; Ilieva, Mihaela; Kverek, Pavel; Pérez-Tris, Javier; Pirrello, Simone; Zehtindjiev, Pavel; Salewski, Volker

2016-01-01

In migratory birds, morphological adaptations for efficient migratory flight often oppose morphological adaptations for efficient behavior during resident periods. This includes adaptations in wing shape for either flying long distances or foraging in the vegetation and in climate-driven variation of body size. In addition, the timing of migratory flights and particularly the timely arrival at local breeding sites is crucial because fitness prospects depend on site-specific phenology. Thus, adaptations for efficient long-distance flights might be also related to conditions at destination areas. For an obligatory long-distance migrant, the common nightingale, we verified that wing length as the aerodynamically important trait, but not structural body size increased from the western to the eastern parts of the species range. In contrast with expectation from aerodynamic theory, however, wing length did not increase with increasing migration distances. Instead, wing length was associated with the phenology at breeding destinations, namely the speed of local spring green-up. We argue that longer wings are beneficial for adjusting migration speed to local conditions for birds breeding in habitats with fast spring green-up and thus short optimal arrival periods. We suggest that the speed of spring green-up at breeding sites is a fundamental variable determining the timing of migration that fine tune phenotypes in migrants across their range.

Relationships of cadmium, mercury, and selenium with nutrient reserves of female lesser scaup (Aythya affinis) during winter and spring migration

USGS Publications Warehouse

Anteau, M.J.; Afton, A.D.; Custer, Christine M.; Custer, T.W.

2007-01-01

Trace elements may have important effects on body condition of ducks during spring migration, because individuals are experiencing energetically costly events (e.g., migration, nutrient reserve accumulation, pair formation, feather molt, and ovarian follicle development). We examined relationships among hepatic cadmium, mercury, and selenium concentrations (microg/g dry wt) and nutrient reserves (lipid, protein, and mineral) of female lesser scaup (Aythya affinis) during winter and spring migration at four locations within the Mississippi Flyway (LA, IL, and MN, USA, and MB, Canada). Selenium concentrations (range, 3.73-52.29 microg/g dry wt) were positively correlated with lipid reserves (F1,73 = 22.69, p < 0.001, type III partial r2 = 0.24), whereas cadmium was negatively correlated with lipid reserves (F1,73 = 6.92, p = 0.010, type III partial r2 = 0.09). The observed relationship between cadmium and lipid reserves may be cause for concern, because lipid reserves of females declined by 55 g (47%), on average, within the range of observed cadmium concentrations (0.23-7.24 microg/g dry wt), despite the relatively low cadmium concentrations detected. Mean cadmium concentrations were higher in Minnesota (1.23 microg/g dry wt) and Manitoba (1.11 microg/g dry wt) than in Louisiana (0.80 microg/g dry wt) and Illinois (0.69 microg/g dry wt). However, mean cadmium concentrations predict lipid reserves of females to be only 11 g lower, on average, in Minnesota than in Illinois. Previous research documented that lipid reserves were 100 g lower in Minnesota than in Illinois; consequently, cadmium is unlikely to be the sole cause for decreases in lipid reserves of females during late-spring migration.

Use of the Beaufort Sea by king eiders breeding on the North Slope of Alaska

USGS Publications Warehouse

Phillips, Laura M.; Powell, A.N.; Taylor, E.J.; Rexstad, E.A.

2007-01-01

We estimated areas used by king eiders (Somateria spectabilis) in the Alaskan Beaufort Sea, how distributions of used areas varied, and characteristics that explained variation in the number of days spent at sea, to provide regulatory agencies with baseline data needed to minimize impacts of potential offshore oil development. We implanted sixty king eiders with satellite transmitters at nesting areas on the North Slope of Alaska, USA, in 2002-2004. More than 80% of marked eiders spent >2 weeks staging offshore prior to beginning a postbreeding molt migration. During postbreeding staging and migration, male king eiders had much broader distributions in the Alaskan Beaufort Sea than female eiders, which were concentrated in Harrison and Smith Bays. Distribution did not vary by sex during spring migration in the year after marking. Shorter residence times of eiders and deeper water at locations used during spring migration suggest the Alaskan Beaufort Sea might not be as critical a staging area for king eiders during prebreeding as it is postbreeding. Residence time in the Beaufort Sea varied by sex, with female king eiders spending more days at sea than males in spring and during postbreeding. We conclude the Alaskan Beaufort Sea is an important staging area for king eiders during postbreeding, and eider distribution should be considered by managers when mitigating for future offshore development. We recommend future studies examine the importance of spring staging areas outside the Alaskan Beaufort Sea.

Amphibian terrestrial habitat selection and movement patterns vary with annual life-history period

USGS Publications Warehouse

Groff, Luke A.; Calhoun, Aram J.K.; Loftin, Cynthia S.

2017-01-01

Identification of essential habitat is a fundamental component of amphibian conservation; however, species with complex life histories frequently move among habitats. To better understand dynamic habitat use, we evaluated Wood Frog (Lithobates sylvaticus (LeConte, 1825)) habitat selection and movement patterns during the spring migration and foraging periods and described the spatiotemporal variability of habitats used during all annual life-history periods. We radio-tracked 71 frogs in Maine during 2011–2013 and evaluated spring migration, foraging activity center (FAC), and within-FAC habitat selection. Telemetered frogs spent the greatest percentage of each field season in hibernacula (≥54.4%), followed by FACs (≥25.5%), migration habitat (≥16.9%), and breeding sites (≥4.5%). FACs ranged 49 – 1 335 m2 (568.0 ± 493.4 m2) and annual home ranges spanned 1 413 – 32 165 m2 (11 780.6 ± 12 506.1 m2). During spring migration, Wood Frogs exhibited different movement patterns (e.g., turn angles), selected different habitat features, and selected habitat features less consistently than while occupying FACs, indicating that the migration and foraging periods are ecologically distinct. Habitat-use studies that do not discriminate among annual life-history periods may obscure true ecological relationships and fail to identify essential habitat necessary for sustaining amphibian populations.

Preliminary Optimization for Spring-Run Chinook Salmon Environmental Flows in Lassen Foothill Watersheds

NASA Astrophysics Data System (ADS)

Ta, J.; Kelsey, R.; Howard, J.; Hall, M.; Lund, J. R.; Viers, J. H.

2014-12-01

Stream flow controls physical and ecological processes in rivers that support freshwater ecosystems and biodiversity vital for services that humans depend on. This master variable has been impaired by human activities like dam operations, water diversions, and flood control infrastructure. Furthermore, increasing water scarcity due to rising water demands and droughts has further stressed these systems, calling for the need to find better ways to identify and allocate environmental flows. In this study, a linear optimization model was developed for environmental flows in river systems that have minimal or no regulation from dam operations, but still exhibit altered flow regimes due to surface water diversions and groundwater abstraction. Flow regime requirements for California Central Valley spring-run Chinook salmon (Oncorhynchus tshawytscha) life history were used as a test case to examine how alterations to the timing and magnitude of water diversions meet environmental flow objectives while minimizing impact to local water supply. The model was then applied to Mill Creek, a tributary of the Sacramento River, in northern California, and its altered flow regime that currently impacts adult spring-run Chinook spawning and migration. The resulting optimized water diversion schedule can be used to inform water management decisions that aim to maximize benefit for the environment while meeting local water demands.

Anticipated Job Benefits, Career Aspiration, and Generalized Self-efficacy as Predictors for Migration Decision-Making

PubMed Central

Hoppe, Annekatrin; Fujishiro, Kaori

2015-01-01

This study aims to identify person-level factors, rather than economic situations, that influence migration decision-making and actual migration. Building on the theory of planned behavior, this study investigated potential migrants’ expectations and attitudes toward migration and career (i.e., anticipated job benefits of migration, career aspiration) as well as beliefs (i.e., generalized self-efficacy) as predictors of migration decision-making conceptualized in three phases: the pre-decisional, pre-actional, and actional phases. This was examined with cross-sectional pre-migration questionnaire data from 1163 potential migrants from Spain to Germany. We also examined whether the migration decision-making phases predicted actual migration with a subsample (n=249) which provided follow-up data within twelve months. For the cross-sectional sample, multinomial logistic regressions revealed that anticipated job benefits and career aspiration are predictive for all migration phases. Self-efficacy predicts the preactional (e.g., gathering information) and actional phases (e.g., making practical arrangements). Finally, for those with low self-efficacy, anticipated job benefits play a stronger role for taking action. For the longitudinal subsample, a logistic regression revealed that being in the preactional and actional phases at baseline is predictive of actual migration within twelve months. This study expands previous research on migration intentions and behaviors by focusing on expectations, values, and beliefs as person-level predictors for migration decision-making. With a longitudinal sample, it shows that international migration is a process that involves multiple phases. PMID:26379343

Assessment of bird populations in a high quality savanna/woodland: a banding approach

USGS Publications Warehouse

Wilmore, Sandra L.; Glowacki, Gary A.; Grundel, Ralph

2005-01-01

During the course of this six year study, the fall migration capture rate declined significantly, suggesting that reduced productivity may have occurred in bird populations. There was a positive response during the spring migration to earlier spring wildfires, indicated by high capture rates in 2000 and 2002 that corresponded with fires affecting most of the bird banding net locations. For several common species found at the Miller Woods site, the ratio of juveniles to adults was compared to ratios at other banding stations in the north central U.S. Breeding site fidelity was documented for 20 species, all common breeders. Variation in capture rates among net locations demonstrated the role of the shrub layer within the savanna habitat mosaic during migration stopover.

Interactions between a Candidate Gene for Migration (ADCYAP1), Morphology and Sex Predict Spring Arrival in Blackcap Populations.

PubMed

Mettler, Raeann; Segelbacher, Gernot; Schaefer, H Martin

2015-01-01

Avian research has begun to reveal associations between candidate genes and migratory behaviors of captive birds, yet few studies utilize genotypic, morphometric, and phenological data from wild individuals. Previous studies have identified an association between ADCYAP1 polymorphism and autumn migratory behavior (restlessness, or zugunruhe), but little is known about the relationship between ADCYAP1 and spring migratory behavior. The timing of spring migration and arrival to the breeding ground are phenological traits which could be particularly favorable for establishing territories and acquiring mates, thus important to fitness and reproductive success. Here, we investigated how individual genotypic ADCYAP1 variation and phenotypic variation (wing length and shape) of blackcaps (Sylvia atricapilla) affect spring arrival date across nine natural populations in Europe. We hypothesized that longer alleles should be associated with earlier spring arrival dates and expected the effect on arrival date to be stronger for males as they arrive earlier. However, we found that longer wings were associated with earlier spring arrival to the breeding grounds for females, but not for males. Another female-specific effect indicated an interaction between ADCYAP1 allele size and wing pointedness on the response of spring arrival: greater allele size had a positive effect on spring arrival date for females with rounder wings, while a negative effect was apparent for females with more pointed wings. Also, female heterozygotes with pointed wing tips arrived significantly earlier than both homozygotes with pointed wings and heterozygotes with round wings. Stable isotope ratios (δ2H) of a subset of blackcaps captured in Freiburg in 2011 allowed us also to assign individuals to their main overwintering areas in northwest (NW) and southwest (SW) Europe. NW males arrived significantly earlier to the Freiburg breeding site than both SW males and females in 2011. NW females had more pointed wing tips compared to SW females, but no difference in ADCYAP1 allele size was found between the different migration routes.

Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam Turbines, Early Spring 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Fenton; Royer, Ida M.

2012-02-01

This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam turbines during early spring 2011. The study was conducted by Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE) to investigate whether adult steelhead are passing through turbines during early spring before annual sluiceway operations typically begin. The sluiceway surface flow outlet is the optimal non-turbine route for adult steelhead, although operating the sluiceway reduces hydropower production. This is a follow-up study to similar studies of adult steelheadmore » passage at the sluiceway and turbines we conducted in the fall/winter 2008, early spring 2009, fall/winter 2009, and early spring 2010. The goal of the 2011 study was to characterize adult steelhead passage rates at the turbines while the sluiceway was closed so fisheries managers would have additional information to use in decision-making relative to sluiceway operations. Sluiceway operations were not scheduled to begin until April 10, 2011. However, based on a management decision in late February, sluiceway operations commenced on March 1, 2011. Therefore, this study provided estimates of fish passage rates through the turbines, and not the sluiceway, while the sluiceway was open. The study period was March 1 through April 10, 2011 (41 days total). The study objective was to estimate the number and distribution of adult steelhead and kelt-sized targets passing into turbine units. We obtained fish passage data using fixed-location hydroacoustics with transducers deployed at all 22 main turbine units at The Dalles Dam. Adult steelhead passage through the turbines occurred on 9 days during the study (March 9, 12, 30, and 31 and April 2, 3, 5, 7, and 9). We estimated a total of 215 {+-} 98 (95% confidence interval) adult steelhead targets passed through the turbines between March 1 and April 10, 2011. Horizontal distribution data indicated Main Unit 18 passed the majority of fish. Fish passage occurred throughout the day. We conclude that adult steelhead passed through turbines during early spring 2011 at The Dalles Dam.« less

Individual versus Household Migration Decision Rules: Gender and Marital Status Differences in Intentions to Migrate in South Africa.

PubMed

Gubhaju, Bina; De Jong, Gordon F

2009-03-01

This research tests the thesis that the neoclassical micro-economic and the new household economic theoretical assumptions on migration decision-making rules are segmented by gender, marital status, and time frame of intention to migrate. Comparative tests of both theories within the same study design are relatively rare. Utilizing data from the Causes of Migration in South Africa national migration survey, we analyze how individually held "own-future" versus alternative "household well-being" migration decision rules effect the intentions to migrate of male and female adults in South Africa. Results from the gender and marital status specific logistic regressions models show consistent support for the different gender-marital status decision rule thesis. Specifically, the "maximizing one's own future" neoclassical microeconomic theory proposition is more applicable for never married men and women, the "maximizing household income" proposition for married men with short-term migration intentions, and the "reduce household risk" proposition for longer time horizon migration intentions of married men and women. Results provide new evidence on the way household strategies and individual goals jointly affect intentions to move or stay.

Do Arctic breeding geese track or overtake a green wave during spring migration?

PubMed

Si, Yali; Xin, Qinchuan; de Boer, Willem F; Gong, Peng; Ydenberg, Ronald C; Prins, Herbert H T

2015-03-04

Geese breeding in the Arctic have to do so in a short time-window while having sufficient body reserves. Hence, arrival time and body condition upon arrival largely influence breeding success. The green wave hypothesis posits that geese track a successively delayed spring flush of plant development on the way to their breeding sites. The green wave has been interpreted as representing either the onset of spring or the peak in nutrient biomass. However, geese tend to adopt a partial capital breeding strategy and might overtake the green wave to accomplish a timely arrival on the breeding site. To test the green wave hypothesis, we link the satellite-derived onset of spring and peak in nutrient biomass with the stopover schedule of individual Barnacle Geese. We find that geese track neither the onset of spring nor the peak in nutrient biomass. Rather, they arrive at the southernmost stopover site around the peak in nutrient biomass, and gradually overtake the green wave to match their arrival at the breeding site with the local onset of spring, thereby ensuring gosling benefit from the peak in nutrient biomass. Our approach for estimating plant development stages is critical in testing the migration strategies of migratory herbivores.

Yakima River Radio-Telemetry Study: Spring Chinook Salmon, 1991-1992 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hockersmith, Eric

1994-09-01

As part of the presupplementation planning, baseline data on the productivity of spring chinook salmon (Oncorhynchus tshawytscha) in the Yakima River have been collected. However, for adult salmonids, data on habitat use, delays in passage at irrigation diversions, migration rates, and substock separation had not been previously collected. In 1991, the National Marine Fisheries Service began a 2-year radio-telemetry study of adult spring chinook salmon in the Yakima River Basin. Specific objectives addressed in this study were: to determine spawning populations` run timing, passage patterns at irrigation diversion dams, and morphometric characteristics to determine where and when substocks become separated;more » to evaluate fish passage at Yakima River Basin diversion dams including Prosser, Sunnyside, Wapato, Roza, Town Diversion, Easton, Cowiche, and Wapatox Dams; to determine spring chinook salmon migration rates between Yakima River Basin dams, prespawning behavior, temporal distribution, and habitat utilization; to identify spawning distribution and timing of spring chinook salmon; to determine the amount and cause of prespawning mortality of spring chinook salmon; and to evaluate adult fish-handling procedures for the right-bank, adult-trapping facility at Prosser Dam.« less

Timing of seasonal migration in mule deer: effects of climate, plant phenology, and life-history characteristics

USGS Publications Warehouse

Monteith, Kevin L.; Bleich, Vernon C.; Stephenson, Thomas R.; Pierce, Beck M.; Conner, Mary M.; Klaver, Robert W.; Bowyer, R. Terry

2011-01-01

Phenological events of plants and animals are sensitive to climatic processes. Migration is a life-history event exhibited by most large herbivores living in seasonal environments, and is thought to occur in response to dynamics of forage and weather. Decisions regarding when to migrate, however, may be affected by differences in life-history characteristics of individuals. Long-term and intensive study of a population of mule deer (Odocoileus hemionus) in the Sierra Nevada, California, USA, allowed us to document patterns of migration during 11 years that encompassed a wide array of environmental conditions. We used two new techniques to properly account for interval-censored data and disentangle effects of broad-scale climate, local weather patterns, and plant phenology on seasonal patterns of migration, while incorporating effects of individual life-history characteristics. Timing of autumn migration varied substantially among individual deer, but was associated with the severity of winter weather, and in particular, snow depth and cold temperatures. Migratory responses to winter weather, however, were affected by age, nutritional condition, and summer residency of individual females. Old females and those in good nutritional condition risked encountering severe weather by delaying autumn migration, and were thus risk-prone with respect to the potential loss of foraging opportunities in deep snow compared with young females and those in poor nutritional condition. Females that summered on the west side of the crest of the Sierra Nevada delayed autumn migration relative to east-side females, which supports the influence of the local environment on timing of migration. In contrast, timing of spring migration was unrelated to individual life-history characteristics, was nearly twice as synchronous as autumn migration, differed among years, was related to the southern oscillation index, and was influenced by absolute snow depth and advancing phenology of plants. Plasticity in timing of migration in response to climatic conditions and plant phenology may be an adaptive behavioral strategy, which should reduce the detrimental effects of trophic mismatches between resources and other life-history events of large herbivores. Failure to consider effects of nutrition and other life-history traits may cloud interpretation of phenological patterns of mammals and conceal relationships associated with climate change.

Mule deer and pronghorn migration in western Wyoming

USGS Publications Warehouse

Sawyer, H.; Lindzey, F.; McWhirter, D.

2005-01-01

Migratory mule deer (Odocoileus hemionus) and pronghorn (Antilocapra americana) populations rely on seasonal ranges to meet their annual nutritional and energetic requirements. Because seasonal ranges often occur great distances apart and across a mix of vegetation types and land ownership, maintaining migration corridors to and from these ranges can be difficult, especially if managers do not have detailed information on mule deer and pronghorn seasonal movements. We captured, radiomarked, and monitored mule deer (n = 171) and pronghorn (n = 34) in western Wyoming to document seasonal distribution patterns and migration routes. Mule deer and pronghorn migrated 20-158 km and 116-258 km, respectively, between seasonal ranges. These distances represented the longest recorded migrations for either species. We identified a number of bottlenecks along the migration routes of mule deer and pronghorn, but the most critical appeared to be the 1.6-km-wide Trapper's Point bottleneck, which was used by both mule deer and pronghorn during their spring and autumn migrations. Housing developments and roadways apparently have reduced the effective width of this bottleneck to <0.8 km. We estimate 2,500-3,500 mule deer and 1,500-2,000 pronghorn move through the bottleneck twice a year during spring and autumn migrations. Identification and protection of migration corridors and bottlenecks will be necessary to maintain mule deer and pronghorn populations throughout their range.

Where in the air? Aerial habitat use of nocturnally migrating birds.

PubMed

Horton, Kyle G; Van Doren, Benjamin M; Stepanian, Phillip M; Farnsworth, Andrew; Kelly, Jeffrey F

2016-11-01

The lower atmosphere (i.e. aerosphere) is critical habitat for migrant birds. This habitat is vast and little is known about the spatio-temporal patterns of distribution and abundance of migrants in it. Increased human encroachment into the aerosphere makes understanding where and when migratory birds use this airspace a key to reducing human-wildlife conflicts. We use weather surveillance radar to describe large-scale height distributions of nocturnally migrating birds and interpret these distributions as aggregate habitat selection behaviours of individual birds. As such, we detail wind cues that influence selection of flight heights. Using six radars in the eastern USA during the spring (2013-2015) and autumn (2013 and 2014), we found migrants tended to adjust their heights according to favourable wind profit. We found that migrants' flight altitudes correlated most closely with the altitude of maximum wind profit; however, absolute differences in flight heights and height of maximum wind profit were large. Migrants tended to fly slightly higher at inland sites compared with coastal sites during spring, but not during autumn. Migration activity was greater at coastal sites during autumn, but not during spring. This characterization of bird migration represents a critical advance in our understanding of migrant distributions in flight and a new window into habitat selection behaviours. © 2016 The Author(s).

Where in the air? Aerial habitat use of nocturnally migrating birds

PubMed Central

Van Doren, Benjamin M.; Stepanian, Phillip M.; Farnsworth, Andrew; Kelly, Jeffrey F.

2016-01-01

The lower atmosphere (i.e. aerosphere) is critical habitat for migrant birds. This habitat is vast and little is known about the spatio-temporal patterns of distribution and abundance of migrants in it. Increased human encroachment into the aerosphere makes understanding where and when migratory birds use this airspace a key to reducing human–wildlife conflicts. We use weather surveillance radar to describe large-scale height distributions of nocturnally migrating birds and interpret these distributions as aggregate habitat selection behaviours of individual birds. As such, we detail wind cues that influence selection of flight heights. Using six radars in the eastern USA during the spring (2013–2015) and autumn (2013 and 2014), we found migrants tended to adjust their heights according to favourable wind profit. We found that migrants' flight altitudes correlated most closely with the altitude of maximum wind profit; however, absolute differences in flight heights and height of maximum wind profit were large. Migrants tended to fly slightly higher at inland sites compared with coastal sites during spring, but not during autumn. Migration activity was greater at coastal sites during autumn, but not during spring. This characterization of bird migration represents a critical advance in our understanding of migrant distributions in flight and a new window into habitat selection behaviours. PMID:27881761

Growth and survival of sea lampreys from metamorphosis to spawning in Lake Huron

USGS Publications Warehouse

Swink, William D.; Johnson, Nicholas S.

2014-01-01

Larval Sea Lampreys Petromyzon marinus live burrowed in stream bottoms and then metamorphose into their parasitic stage. Among larvae that metamorphose in a given year (i.e., parasitic cohort), autumn out-migrants (October–December) to the Laurentian Great Lakes can feed on fish for up to 6 months longer than spring outmigrants (March–May), which overwinter in streams without feeding. We evaluated whether the season of outmigration affected growth or survival of newlymetamorphosed Sea Lampreys in LakeHuron. Newlymetamorphosed individuals (n=2,718) from three parasitic cohorts were netted during their out-migration from BlackMallard Creek, Michigan, to LakeHuron during autumn 1997 through spring 2000; each out-migrant was injected with a sequentially numbered coded wire tag and was released back into the creek. After up to 18 months of feeding in the Great Lakes, 224 (8.2%) Sea Lampreys were recaptured (in 1999–2001) as upstream-migrating adults in tributaries to Lakes Huron and Michigan. Recovery rates of autumn and spring out-migrants as adults were 9.4% and 7.8%, respectively, and these rates did not significantly differ. Overwinter feeding (i.e., as parasites) by autumn out-migrants did not produce adult mean sizes greater than those of spring out-migrants. Because we detected no growth or survival differences between autumn and spring out-migrants, the capture of newly metamorphosed Sea Lampreys at any point during their out-migration should provide equal reductions in damage to Great Lakes fisheries. The absence of a difference in growth or survival between autumn and spring out-migrants is an aspect of Sea Lamprey life history that yields resiliency to this invasive parasite and complicates efforts for its control in the Great Lakes.

Changes in nutrient dynamics of midcontinent greater white-fronted geese during spring migration

USGS Publications Warehouse

Pearse, Aaron T.; Alisauskas, Ray T.; Krapu, Gary L.; Cox, Robert R.

2011-01-01

Waterfowl and other migratory birds commonly store nutrients at traditional staging areas during spring for later use during migration and reproduction. We investigated nutrient-storage dynamics in the midcontinent population of greater white-fronted geese (Anser albifrons; hereafter white-fronted geese) at spring staging sites in the Rainwater Basin of Nebraska during February-April and in southern Saskatchewan during April-May, 1998 and 1999. In Nebraska, lipid content of white-fronted geese did not increase, and protein content changed little over time for most age and sex categories. In Saskatchewan, lipids increased 11.4 g/day (SE = 1.7) and protein content increased 1.6 g/day (SE = 0.6) in the sample of adult geese collected over a 3-week period. A study conducted during 1979-1980 in the Rainwater Basin reported that white-fronted geese gained 8.8-17.7 g of lipids per day during spring, differing greatly from our results 2 decades later. In addition, lipid levels were less in the 1990s compared to spring 1980 for adult geese nearing departure from staging sites in Saskatchewan. This shift in where geese acquired nutrient stores from Nebraska to more northern staging sites coincided with a decrease in availability of waste corn in Nebraska, their primary food source while staging at that stopover site, and an increase in cultivation of high-energy pulse crops in Saskatchewan. White-fronted geese exhibited flexibility in nutrient dynamics during spring migration, likely in response to landscape-level variation in food availability caused by changes in agricultural trends and practices. Maintaining a wide distribution of wetlands in the Great Plains may allow springstaging waterfowl to disperse across the region and facilitate access to high-energy foods over a larger cropland base.

Diet of some spring migrant landbirds on the Caribbean coast of Costa Rica

Treesearch

Jared D. Wolfe

2009-01-01

Spring dietary patterns of migrants in tropical latitudes are largely unknown. Here I present diet data derived from an analysis of fecal samples for six migrant landbird species during spring migration along the Caribbean coast of Costa Rica. High levels of insectivory were detected for all six species captured. The nature of the data presented is discussed in light...

Spring migration and summer destinations of northern pintails from the coast of southern California

USGS Publications Warehouse

Miller, Michael R.; Takekawa, John Y.; Battaglia, Daniel S.; Golightly, Richard T.; Perry, William M.

2010-01-01

To examine pathways, timing, and destinations during migration in spring, we attached satellite-monitored transmitters (platform transmitting terminals) to 10 northern pintails (Anas acuta) during February 2001, at Point Mugu, Ventura County, California. This is a wintering area on the southern coast of California. We obtained locations from five adult males and three adult females every 3rd day through August. Average date of departure from the wintering area was 15 March (SE  =  3 days). We documented extended stopovers of ≥30 days for several northern pintails that could have accommodated nesting attempts (San Joaquin Valley, southwestern Montana, southern Alberta, north-central Nevada) or post-nesting molt (eastern Oregon, south-central Saskatchewan, northern Alaska, central Alberta). Wintering northern pintails from the southern coast of California used a wide range of routes, nesting areas, and schedules during migration in spring, which was consistent with the larger, wintering population in the Central Valley of California. Therefore, conservation of habitat that is targeted at stopover, nesting, and molting areas will benefit survival and management of both wintering populations.

Timing of spring surveys for midcontinent sandhill cranes

USGS Publications Warehouse

Pearse, Aaron T.; Krapu, Gary L.; Brandt, David A.; Sargeant, Glen A.

2015-01-01

The U.S. Fish and Wildlife Service has used spring aerial surveys to estimate numbers of migrating sandhill cranes (Grus canadensis) staging in the Platte River Valley of Nebraska, USA. Resulting estimates index the abundance of the midcontinent sandhill crane population and inform harvest management decisions. However, annual changes in the index have exceeded biologically plausible changes in population size (>50% of surveys between 1982 and 2013 indicate >±20% change), raising questions about nuisance variation due to factors such as migration chronology. We used locations of cranes marked with very-high-frequency transmitters to estimate migration chronology (i.e., proportions of cranes present within the Platte River Valley). We also used roadside surveys to determine the percentage of cranes staging at the Platte River Valley but outside of the survey area when surveys occur. During March 2001–2007, an average of 86% (71–94%; SD = 7%) of marked cranes were present along the Platte River during scheduled survey dates, and 0–11% of cranes that were present along the Platte River were not within the survey boundaries. Timing of the annual survey generally corresponded with presence of the greatest proportion of marked cranes and with least inter-annual variation; consequently, accuracy of estimates could not have been improved by surveying on different dates. Conducting the survey earlier would miss birds not yet arriving at the staging site; whereas, a later date would occur at a time when a larger portion of birds may have already departed the staging site and when a greater proportion of birds occurred outside of the surveyed area. Index values used to monitor midcontinent sandhill crane abundance vary annually, in part, due to annual variation in migration chronology and to spatial distribution of cranes in the Platte River Valley; therefore, managers should interpret survey results cautiously, with awareness of a continuing need to identify and understand components of variation. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Quantitative and qualitative approaches to identifying migration chronology in a continental migrant

USGS Publications Warehouse

Beatty, William S.; Kesler, Dylan C.; Webb, Elisabeth B.; Raedeke, Andrew H.; Naylor, Luke W.; Humburg, Dale D.

2013-01-01

The degree to which extrinsic factors influence migration chronology in North American waterfowl has not been quantified, particularly for dabbling ducks. Previous studies have examined waterfowl migration using various methods, however, quantitative approaches to define avian migration chronology over broad spatio-temporal scales are limited, and the implications for using different approaches have not been assessed. We used movement data from 19 female adult mallards (Anas platyrhynchos) equipped with solar-powered global positioning system satellite transmitters to evaluate two individual level approaches for quantifying migration chronology. The first approach defined migration based on individual movements among geopolitical boundaries (state, provincial, international), whereas the second method modeled net displacement as a function of time using nonlinear models. Differences in migration chronologies identified by each of the approaches were examined with analysis of variance. The geopolitical method identified mean autumn migration midpoints at 15 November 2010 and 13 November 2011, whereas the net displacement method identified midpoints at 15 November 2010 and 14 November 2011. The mean midpoints for spring migration were 3 April 2011 and 20 March 2012 using the geopolitical method and 31 March 2011 and 22 March 2012 using the net displacement method. The duration, initiation date, midpoint, and termination date for both autumn and spring migration did not differ between the two individual level approaches. Although we did not detect differences in migration parameters between the different approaches, the net displacement metric offers broad potential to address questions in movement ecology for migrating species. Ultimately, an objective definition of migration chronology will allow researchers to obtain a comprehensive understanding of the extrinsic factors that drive migration at the individual and population levels. As a result, targeted conservation plans can be developed to support planning for habitat management and evaluation of long-term climate effects.

Quantitative and qualitative approaches to identifying migration chronology in a continental migrant.

PubMed

Beatty, William S; Kesler, Dylan C; Webb, Elisabeth B; Raedeke, Andrew H; Naylor, Luke W; Humburg, Dale D

2013-01-01

The degree to which extrinsic factors influence migration chronology in North American waterfowl has not been quantified, particularly for dabbling ducks. Previous studies have examined waterfowl migration using various methods, however, quantitative approaches to define avian migration chronology over broad spatio-temporal scales are limited, and the implications for using different approaches have not been assessed. We used movement data from 19 female adult mallards (Anas platyrhynchos) equipped with solar-powered global positioning system satellite transmitters to evaluate two individual level approaches for quantifying migration chronology. The first approach defined migration based on individual movements among geopolitical boundaries (state, provincial, international), whereas the second method modeled net displacement as a function of time using nonlinear models. Differences in migration chronologies identified by each of the approaches were examined with analysis of variance. The geopolitical method identified mean autumn migration midpoints at 15 November 2010 and 13 November 2011, whereas the net displacement method identified midpoints at 15 November 2010 and 14 November 2011. The mean midpoints for spring migration were 3 April 2011 and 20 March 2012 using the geopolitical method and 31 March 2011 and 22 March 2012 using the net displacement method. The duration, initiation date, midpoint, and termination date for both autumn and spring migration did not differ between the two individual level approaches. Although we did not detect differences in migration parameters between the different approaches, the net displacement metric offers broad potential to address questions in movement ecology for migrating species. Ultimately, an objective definition of migration chronology will allow researchers to obtain a comprehensive understanding of the extrinsic factors that drive migration at the individual and population levels. As a result, targeted conservation plans can be developed to support planning for habitat management and evaluation of long-term climate effects.

Individual versus Household Migration Decision Rules: Gender and Marital Status Differences in Intentions to Migrate in South Africa

PubMed Central

Gubhaju, Bina; De Jong, Gordon F.

2009-01-01

This research tests the thesis that the neoclassical micro-economic and the new household economic theoretical assumptions on migration decision-making rules are segmented by gender, marital status, and time frame of intention to migrate. Comparative tests of both theories within the same study design are relatively rare. Utilizing data from the Causes of Migration in South Africa national migration survey, we analyze how individually held “own-future” versus alternative “household well-being” migration decision rules effect the intentions to migrate of male and female adults in South Africa. Results from the gender and marital status specific logistic regressions models show consistent support for the different gender-marital status decision rule thesis. Specifically, the “maximizing one’s own future” neoclassical microeconomic theory proposition is more applicable for never married men and women, the “maximizing household income” proposition for married men with short-term migration intentions, and the “reduce household risk” proposition for longer time horizon migration intentions of married men and women. Results provide new evidence on the way household strategies and individual goals jointly affect intentions to move or stay. PMID:20161187

High-resolution GPS tracking reveals sex differences in migratory behaviour and stopover habitat use in the Lesser Black-backed Gull Larus fuscus.

PubMed

Baert, Jan M; Stienen, Eric W M; Heylen, Brigitte C; Kavelaars, Marwa M; Buijs, Roland-Jan; Shamoun-Baranes, Judy; Lens, Luc; Müller, Wendt

2018-03-29

Sex-, size- or age-dependent variation in migration strategies in birds is generally expected to reflect differences in competitive abilities. Theoretical and empirical studies thereby focus on differences in wintering areas, by which individuals may benefit from avoiding food competition during winter or ensuring an early return and access to prime nesting sites in spring. Here, we use GPS tracking to assess sex- and size-related variation in the spatial behaviour of adult Lesser Black-backed Gulls (Larus fuscus) throughout their annual cycle. We did not find sex- or size-dependent differences in wintering area or the timing of spring migration. Instead, sexual differences occurred prior to, and during, autumn migration, when females strongly focussed on agricultural areas. Females exhibited a more protracted autumn migration strategy, hence spent more time on stopover sites and arrived 15 days later at their wintering areas, than males. This shift in habitat use and protracted autumn migration coincided with the timing of moult, which overlaps with chick rearing and migration. Our results suggest that this overlap between energy-demanding activities may lead females to perform a more prolonged autumn migration, which results in spatiotemporal differences in foraging habitat use between the sexes.

Forecasting spring from afar? Timing of migration and predictability of phenology along different migration routes of an avian herbivore.

PubMed

Kölzsch, Andrea; Bauer, Silke; de Boer, Rob; Griffin, Larry; Cabot, David; Exo, Klaus-Michael; van der Jeugd, Henk P; Nolet, Bart A

2015-01-01

Herbivorous birds are hypothesized to migrate in spring along a seasonal gradient of plant profitability towards their breeding grounds (green wave hypothesis). For Arctic breeding species in particular, following highly profitable food is important, so that they can replenish resources along the way and arrive in optimal body condition to start breeding early. We compared the timing of migratory movements of Arctic breeding geese on different flyways to examine whether flyways differed in the predictability of spring conditions at stopovers and whether this was reflected in the degree to which birds were following the green wave. Barnacle geese (Branta leucopsis) were tracked with solar GPS/ARGOS PTTs from their wintering grounds to breeding sites in Greenland (N = 7), Svalbard (N = 21) and the Barents Sea (N = 12). The numerous stopover sites of all birds were combined into a set of 16 general stopover regions. The predictability of climatic conditions along the flyways was calculated as the correlation and slope between onsets of spring at consecutive stopovers. These values differed between sites, mainly because of the presence or absence of ecological barriers. Goose arrival at stopovers was more closely tied to the local onset of spring when predictability was higher and when geese attempted breeding that year. All birds arrived at early stopovers after the onset of spring and arrived at the breeding grounds before the onset of spring, thus overtaking the green wave. This is in accordance with patterns expected for capital breeders: first, they must come into condition; at intermediate stopovers, arrival with the food quality peak is important to stay in condition, and at the breeding grounds, early arrival is favoured so that hatching of young can coincide with the peak of food quality. Our results suggest that a chain of correlations between climatic conditions at subsequent stopovers enables geese to closely track the green wave. However, the birds' precision of migratory timing seems uninfluenced by ecological barriers, indicating partly fixed migration schedules. These might become non-optimal due to climate warming and preclude accurate timing of long-distance migrants in the future. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Observations of emperor geese feeding at Nelson Lagoon, Alaska

USGS Publications Warehouse

Petersen, Margaret R.

1983-01-01

Estuaries along the north side of the Alaska Peninsula provide essential habitat for most of the American population of Emperor Goose (Chen canagica) during migration (Petersen and Gill 1982). Most of the population passes through Nelson Lagoon in spring and fall, with over 40,000 birds recorded there (Gill et al 1981). Little is known about the feeding activity of Emperor Geese while they are in estuaries, and the importance of estuaries as staging areas during spring and fall migration is poorly understood. Here I report observations on the feeding activity of emperor Geese at one estuary (Nelson Lagoon).

Tracking climate impacts on the migratory monarch butterfly

USGS Publications Warehouse

Zipkin, Elise F.; Ries, Leslie; Reeves, Rick; Regetz, James; Oberhauser, Karen S.

2012-01-01

Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad-scale climate metric can explain summer breeding phenology or the substantial year-to-year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state-wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to understand how monarchs will be affected by future climate conditions will be challenging.

Count trends for migratory Bald Eagles reveal differences between two populations at a spring site along the Lake Ontario shoreline

PubMed Central

2016-01-01

The recovery of Bald Eagles (Haliaeetus leucophalus), after DDT and other organochlorine insecticides were banned in the United States, can be regarded as one of the most iconic success stories resulting from the Endangered Species Act. Interest remains high in the recovery and growth of the Bald Eagle population. Common to evaluating growth and recovery rates are counts at nesting sites and analyses of individuals fledged per season. But this is merely one snapshot that ignores survival rates as eagles grow to maturity. By analyzing indices from migration counts, we get a different snapshot better reflecting the survival of young birds. Different populations of Bald Eagles breed at different sites at different times of the year. Typical migration count analyses do not separate the populations. A separation of two distinct populations can be achieved at spring count sites by taking advantage of the tendency for northern summer breeding birds to migrate north in spring earlier than southern winter breeding birds who disperse north later in spring. In this paper I analyze migratory indices at a spring site along Lake Ontario. The analysis shows that eagles considered to be primarily of the northern summer breeding population showed an estimated growth rate of 5.3 ± 0.85% (SE) per year with 49% of eagles tallied in adult plumage, whereas the migrants considered to be primarily of the southern breeding population had an estimated growth rate of 14.0 ± 1.79% with only 22% in adult plumage. Together these results argue that the populations of southern breeding Bald Eagles are growing at a substantially higher rate than northern breeding eagles. These findings suggest that aggregate population indices for a species at migration counting sites can sometimes obscure important differences among separate populations at any given site and that separating counts by time period can be a useful way to check for differences among sub-populations. PMID:27231647

Uncovering patterns of spring migration in the monarch butterfly using stable isotopes and demographic models

NASA Astrophysics Data System (ADS)

Norris, R.; Miller, N.; Wassenaar, L.; Hobson, K.

2010-12-01

Each spring, millions of monarch butterflies (Danaus plexippus) migrate up to 3000 km from central Mexico to re-colonize eastern North America. However, despite centuries of research, the patterns of re-colonization are not well understood. We combined stable-hydrogen (δD) and -carbon (δ13C) isotope measurements with demographic models to test (1) whether individuals sampled in the northern part of the breeding range in the Great Lakes originate directly from Mexico or are second generation individuals born in the southern US and (2) to estimate whether populations on the eastern seaboard migrate longitudinally over the Appalachians or originate directly from the Gulf Coast. In the Great Lakes, we found that the majority of individuals were second-generation monarchs born in the Gulf Coast and Central regions of the US. However, 25% individuals originated directly from Mexico and we estimated that these individuals produced the majority of offspring born in the Great Lakes region during June. On the eastern seaboard, we found the majority of monarchs (88%) originated in the mid-west and Great Lakes regions, providing the first direct evidence that second generation monarchs born in June complete a (trans-) longitudinal migration across the Appalachian mountains. The remaining individuals (12%) originated from parents that migrated directly from the Gulf coast during early spring. Our results demonstrate how stable isotopes, when combined with ecological data, can provide insights into patterns of connectivity in migratory insects that have been impossible to test using conventional techniques. The migration patterns presented here have important implications for predicting future changes in population size and for developing effective conservation plans for this species.

Difficult decisions: Migration from Small Island Developing States under climate change

NASA Astrophysics Data System (ADS)

Kelman, Ilan

2015-04-01

The impacts of climate change on Small Island Developing States (SIDS) are leading to discussions regarding decision-making about the potential need to migrate. Despite the situation being well-documented, with many SIDS aiming to raise the topic to prominence and to take action for themselves, limited support and interest has been forthcoming from external sources. This paper presents, analyzes, and critiques a decision-making flowchart to support actions for SIDS dealing with climate change-linked migration. The flowchart contributes to identifying the pertinent topics to consider and the potential support needed to implement decision-making. The flowchart has significant limitations and there are topics which it cannot resolve. On-the-ground considerations include who decides, finances, implements, monitors, and enforces each decision. Additionally, views within communities differ, hence mechanisms are needed for dealing with differences, while issues to address include moral and legal blame for any climate change-linked migration, the ultimate goal of the decision-making process, the wider role of migration in SIDS communities and the right to judge decision-making and decisions. The conclusions summarize the paper, emphasizing the importance of considering contexts beyond climate change and multiple SIDS voices.

Gender, Power, and Emigration From Mexico.

PubMed

Nobles, Jenna; McKelvey, Christopher

2015-10-01

The prevailing model of migration in developing countries conceives of a risk-diversifying household in which members act as a single entity when making migration decisions. Ethnographic studies challenge this model by documenting gender hierarchy in family decisions and arguing that, in many contexts, men and women have differing views on the value of migration. We assess these perspectives using longitudinal survey data from Mexico. We show that Mexican households are heterogeneous in terms of women's decision-making authority and control over resources, and this variation predicts the subsequent emigration of their male partners to the United States. We then use data from a policy experiment to demonstrate that an exogenous increase in a woman's control over household resources decreases the probability that her spouse migrates. Our findings support the presence of important gender differences in how migration is valued. They also suggest that women's role in these decisions is inadvertently underrepresented in studies of migrant families. Staying is also a migration decision, and it is more likely in homes in which women have greater authority. From a policy perspective, the results suggest that Mexican migration is influenced not only by increases in household resources but also by which members of the household control them.

Gender, Power, and Emigration From Mexico

PubMed Central

Nobles, Jenna; McKelvey, Christopher

2015-01-01

The prevailing model of migration in developing countries conceives of a risk-diversifying household in which members act as a single entity when making migration decisions. Ethnographic studies challenge this model by documenting gender hierarchy in family decisions and arguing that, in many contexts, men and women have differing views on the value of migration. We assess these perspectives using longitudinal survey data from Mexico. We show that Mexican households are heterogeneous in terms of women's decision-making authority and control over resources, and this variation predicts the subsequent emigration of their male partners to the United States. We then use data from a policy experiment to demonstrate that an exogenous increase in a woman's control over household resources decreases the probability that her spouse migrates. Our findings support the presence of important gender differences in how migration is valued. They also suggest that women's role in these decisions is inadvertently underrepresented in studies of migrant families. Staying is also a migration decision, and it is more likely in homes in which women have greater authority. From a policy perspective, the results suggest that Mexican migration is influenced not only by increases in household resources but also by which members of the household control them. PMID:26100982

Coastal Forests of the Gulf of Mexico: A Description and Some Thoughts on Their Conservation

Treesearch

W. C. Barrow; L. A. Johnson Randall; M. S. Woodrey; J. Cox; E. Ruelas I.; C. M. Riley; R. B. Hamilton; C. Eberly

2005-01-01

Millions of Nearctic-Neotropical landbirds move through the coastal forests of the Gulf of Mexico each spring and autumn as they migrate across and around the gulf. Migration routes in the gulf region are not static—they shift year to year and season to season according to prevailing wind patterns. Given the dynamic nature of migration routes, coastal forests...

Landbird migration along the Middle Rio Grande: Summary of banding data from spring and fall 1994

Treesearch

Wang Yong; Deborah M. Finch; Steve W. Cox

1995-01-01

Northbound and southbound movement along major waterways is characteristic of migratory birds nesting in North America. It is likely that river corridors are more important to migrating birds in arid parts of North America than in humid, more heavily vegetated areas (Wauer 1977). Although quantitative analyses of landbird migration along the Rio Grande corridor are not...

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008

DOE Office of Scientific and Technical Information (OSTI.GOV)

Achord, Stephen; Sandford, Benjamin P.; Hockersmith, Eric E.

2009-07-09

This report provides results from an ongoing project to monitor the migration behavior and survival of wild juvenile spring/summer Chinook salmon in the Snake River Basin. Data reported is from detections of PIT tagged fish during late summer 2007 through mid-2008. Fish were tagged in summer 2007 by the National Marine Fisheries Service (NMFS) in Idaho and by the Oregon Department of Fish and Wildlife (ODFW) in Oregon. Our analyses include migration behavior and estimated survival of fish at instream PIT-tag monitors and arrival timing and estimated survival to Lower Granite Dam. Principal results from tagging and interrogation during 2007-2008more » are: (1) In July and August 2007, we PIT tagged and released 7,390 wild Chinook salmon parr in 12 Idaho streams or sample areas. (2) Overall observed mortality from collection, handling, tagging, and after a 24-hour holding period was 1.4%. (3) Of the 2,524 Chinook salmon parr PIT tagged and released in Valley Creek in summer 2007, 218 (8.6%) were detected at two instream PIT-tag monitoring systems in lower Valley Creek from late summer 2007 to the following spring 2008. Of these, 71.6% were detected in late summer/fall, 11.9% in winter, and 16.5% in spring. Estimated parr-to-smolt survival to Lower Granite Dam was 15.5% for the late summer/fall group, 48.0% for the winter group, and 58.5% for the spring group. Based on detections at downstream dams, the overall efficiency of VC1 (upper) or VC2 (lower) Valley Creek monitors for detecting these fish was 21.1%. Using this VC1 or VC2 efficiency, an estimated 40.8% of all summer-tagged parr survived to move out of Valley Creek, and their estimated survival from that point to Lower Granite Dam was 26.5%. Overall estimated parr-to-smolt survival for all summer-tagged parr from this stream at the dam was 12.1%. Development and improvement of instream PIT-tag monitoring systems continued throughout 2007 and 2008. (4) Testing of PIT-tag antennas in lower Big Creek during 2007-2008 showed these antennas (and anchoring method) are not adequate to withstand high spring flows in this drainage. Future plans involve removing these antennas before high spring flows. (5) At Little Goose Dam in 2008, length and/or weight were taken on 505 recaptured fish from 12 Idaho stream populations. Fish had grown an average of 40.1 mm in length and 10.6 g in weight over an average of 288 d. Their mean condition factor declined from 1.25 at release (parr) to 1.05 at recapture (smolt). (6) Mean release lengths for detected fish were significantly larger than for fish not detected the following spring and summer (P < 0.0001). (7) Fish that migrated through Lower Granite Dam in April and May were significantly larger at release than fish that migrated after May (P < 0.0001) (only 12 fish migrated after May). (8) In 2008, peak detections at Lower Granite Dam of parr tagged during summer 2007 (from the 12 stream populations in Idaho and 4 streams in Oregon) occurred during moderate flows of 87.5 kcfs on 7 May and high flows of 197.3 kcfs on 20 May. The 10th, 50th, and 90th percentile passage occurred on 30 April, 11 May, and 23 May, respectively. (9) In 2007-2008, estimated parr-to-smolt survival to Lower Granite Dam for Idaho and Oregon streams (combined) averaged 19.4% (range 6.2-38.4% depending on stream of origin). In Idaho streams the estimated parr-to-smolt survival averaged 21.0%. This survival was the second highest since 1993 for Idaho streams. Relative parr densities were lower in 2007 (2.4 parr/100 m2) than in all previous years since 2000. In 2008, we observed low-to-moderate flows prior to mid-May and relatively cold weather conditions throughout the spring migration season. These conditions moved half of the fish through Lower Granite Dam prior to mid-May; then high flows moved 50 to 90% of the fish through the dam in only 12 days. Clearly, complex interrelationships of several factors drive the annual migrational timing of the stocks.« less

Adaptive genetic markers discriminate migratory runs of Chinook salmon (Oncorhynchus tshawytscha) amid continued gene flow

PubMed Central

O'Malley, Kathleen G; Jacobson, Dave P; Kurth, Ryon; Dill, Allen J; Banks, Michael A

2013-01-01

Neutral genetic markers are routinely used to define distinct units within species that warrant discrete management. Human-induced changes to gene flow however may reduce the power of such an approach. We tested the efficiency of adaptive versus neutral genetic markers in differentiating temporally divergent migratory runs of Chinook salmon (Oncorhynchus tshawytscha) amid high gene flow owing to artificial propagation and habitat alteration. We compared seven putative migration timing genes to ten microsatellite loci in delineating three migratory groups of Chinook in the Feather River, CA: offspring of fall-run hatchery broodstock that returned as adults to freshwater in fall (fall run), spring-run offspring that returned in spring (spring run), and fall-run offspring that returned in spring (FRS). We found evidence for significant differentiation between the fall and federally listed threatened spring groups based on divergence at three circadian clock genes (OtsClock1b, OmyFbxw11, and Omy1009UW), but not neutral markers. We thus demonstrate the importance of genetic marker choice in resolving complex life history types. These findings directly impact conservation management strategies and add to previous evidence from Pacific and Atlantic salmon indicating that circadian clock genes influence migration timing. PMID:24478800

Movements of walruses radio-tagged in Bristol Bay, Alaska

USGS Publications Warehouse

Jay, C.V.; Hills, Susan

2005-01-01

Satellite radio-location data from 57 adult male Pacific walruses (Odobenus rosmarus divergens) were used to estimate haul-out fidelity, broadly describe seasonal foraging distributions, and determine the approximate timing of autumn migration from Bristol Bay, Alaska. Data were collected intermittently during 1987-91 and 1995-2000, primarily during the period from May to October. Transmitter longevity ranged from less than 1 day to 560 days (median 75 d). The four tagging sites were the only haul-outs that were commonly used in the bay from spring through autumn. Mean fidelity, defined as the chance that an animal will return to an area where it previously hauled out, was 0.56 (SE = 0.09). However, small sample sizes precluded comparisons of fidelity among years and among haul-outs by season. No tagged animals migrated out of the bay between spring and early autumn. Combined monthly locations suggest that foraging occurred primarily in the southern and eastern areas of the bay in spring and gradually shifted towards northwestern areas in late autumn and winter. Ninety-eight percent of the in-water locations were in waters under 60 m deep, which account for 76% of the study area. Some animals migrated out of the bay in late autumn and winter; others remained within the bay throughout the year. Those making long-range migrations departed the bay during November and December. ?? The Arctic Institute of North America.

Diel feeding behavior and ingestion rate in the copepod Calanus finmarchicus in the southern Gulf of Maine during late spring

NASA Astrophysics Data System (ADS)

Durbin, Edward G.; Campbell, Robert G.; Gilman, Sharon L.; Durbin, Ann G.

In situ feeding was measured on late stage Calanus finmarchicus in the southern Gulf of Maine during late spring 1988 and 1989. The region is a spring feeding ground for the planktivorous right whale, Eubalaena glacialis. Measurements in 1988 were made during the declining spring bloom, when phytoplankton showed considerable spatial variability. 1989 observations were made after summer stratification had become established, when phytoplankton biomass was low and dominated by the <7 μm size fraction. In situ ingestion rates of C. finmarchicus reflected these differences in food, and ranged from 30.2% body C day -1 at a spring bloom station to 0.6% body C day -1 after stratification. These values compare with a maximum ingestion rate of 44.3% body C day -1 measured in a shipboard grazing experiment using cultured algae as food, and indicate that C. finmarchicus became food limited in the southern Gulf of Maine after stratification. Calanus finmarchicus diet feeding behavior and diet vertical migration patterns changed during the seasonal progression from spring bloom to summer stratification. Diet feeding rhythms and vertical migration were absent during the bloom, but developed as the bloom declined. During the post-bloom stratified conditions, diet feeding rhythms continued but vertical migration ceased. Most of the C. finmarchicus population remained near the surface, while a small population of nonmigratory individuals resided at depth and appeared to be feeding upon sedimented spring bloom diatoms. At the spring bloom station C. finmarchicus ingested only a small proportion of the phytoplankton standing stock in the > 7 μm size fraction (2.9% day -1), reflecting the high biomass of phytoplankton and the stage composition of the C. finmarchicus population, dominated by early copepodite stages with low biomass. In contrast, at the post-bloom stations in 1989, the dense surface aggregations of C. finmarchicus populations were dominated by late copepodite stages whose total biomass was comparable to that of the phytoplankton, and C. finmarchicus consumed a significantly larger fraction of the > 7 μm phytoplankton standing crop (up to 62.5% day -1.

Beach recovery capabilities after El Niño 2015–2016 at Ensenada Beach, Northern Baja California

NASA Astrophysics Data System (ADS)

Ruiz de Alegría-Arzaburu, Amaia; Vidal-Ruiz, Jesús Adrián

2018-06-01

This study investigates the recovery capabilities of a single-barred beach in the Pacific Mexican coast before and after the 2015-2016 El Niño winter. Concurrent hydrodynamic and morphological data collected over a 3-year period (August 2014-2017) were analysed to determine the subaerial-subtidal volumetric exchange and cross-shore subtidal sandbar migrations, in relation to the incident wave forcing. The beach presented a seasonal seaward and landward sandbar migration cycle. The sandbar migrated offshore during the energetic waves between November and February, and onshore during the milder wave period in spring, until welding to the subaerial beach around May. The transfer of sediment towards the subaerial section continued over the summer, reaching a complete recovery by September/October. Prior to El Niño, the subaerial beach successfully recovered by the end of summer 2015 through the landward sandbar migration process. The 2015-2016 energetic winter waves caused a subaerial volume loss of 140 m3 m-1 (from October 2015 to March 2016), more than twice the amount eroded in the other winters, and the sandbar moved further offshore and to deeper depths (3-4 m) than the winter before. In addition, the energetic 2015-2016 winter waves lasted for 2 months longer than in other years, making the 2016 spring shorter. Consequently, during the onshore migration, the sandbar was unable of reaching shallow depths, and a large portion of sand remained in the subtidal beach. The subaerial beach recovered 60 and 65% of the loss in the 2016 and 2017 summers, respectively. It is concluded that the landward migration process of the sandbar during the spring is critical to ensure a full subaerial beach recovery over the mild wave period in summer. The recovery capabilities of the subaerial beach will depend on the cross-shore distance and depth where the sandbar is located, and on the duration of mild wave conditions required for the sandbar to migrate onshore.

Beach recovery capabilities after El Niño 2015-2016 at Ensenada Beach, Northern Baja California

NASA Astrophysics Data System (ADS)

Ruiz de Alegría-Arzaburu, Amaia; Vidal-Ruiz, Jesús Adrián

2018-05-01

This study investigates the recovery capabilities of a single-barred beach in the Pacific Mexican coast before and after the 2015-2016 El Niño winter. Concurrent hydrodynamic and morphological data collected over a 3-year period (August 2014-2017) were analysed to determine the subaerial-subtidal volumetric exchange and cross-shore subtidal sandbar migrations, in relation to the incident wave forcing. The beach presented a seasonal seaward and landward sandbar migration cycle. The sandbar migrated offshore during the energetic waves between November and February, and onshore during the milder wave period in spring, until welding to the subaerial beach around May. The transfer of sediment towards the subaerial section continued over the summer, reaching a complete recovery by September/October. Prior to El Niño, the subaerial beach successfully recovered by the end of summer 2015 through the landward sandbar migration process. The 2015-2016 energetic winter waves caused a subaerial volume loss of 140 m3 m-1 (from October 2015 to March 2016), more than twice the amount eroded in the other winters, and the sandbar moved further offshore and to deeper depths (3-4 m) than the winter before. In addition, the energetic 2015-2016 winter waves lasted for 2 months longer than in other years, making the 2016 spring shorter. Consequently, during the onshore migration, the sandbar was unable of reaching shallow depths, and a large portion of sand remained in the subtidal beach. The subaerial beach recovered 60 and 65% of the loss in the 2016 and 2017 summers, respectively. It is concluded that the landward migration process of the sandbar during the spring is critical to ensure a full subaerial beach recovery over the mild wave period in summer. The recovery capabilities of the subaerial beach will depend on the cross-shore distance and depth where the sandbar is located, and on the duration of mild wave conditions required for the sandbar to migrate onshore.

Waterfowl migration on Klamath Basin National Wildlife Refuges 1953-2001

USGS Publications Warehouse

Gilmer, David S.; Yee, Julie L.; Mauser, David M.; Hainline, James M.

2004-01-01

The Klamath Basin National Wildlife Refuge (NWR) complex, located in northeastern California and southern Oregon, is situated on a major Pacific Flyway migration corridor connecting waterfowl breeding grounds in the north with major wintering grounds in California and Mexico. The complex comprises five waterfowl refuges including Lower Klamath NWR, Tule Lake NWR, Upper Klamath NWR, Klamath Marsh NWR, and Clear Lake NWR, and one bald eagle refuge, Bear Valley NWR. Lower Klamath and Tule Lake NWRs are the largest refuges in the complex; historically, they supported some of the greatest autumn and spring concentrations of migrating waterfowl in North America. Starting in 1953, standardized waterfowl surveys from small aircraft have been conducted in autumn through spring. This report summarizes waterfowl migration activity (i.e., abundance, species composition, distribution on refuges, and chronology) over four time periods—the long-term (1953-2001), early (1953-76), recent (1977-2001), and the most recent (1998-2001)—to describe changing patterns of migration on Klamath Basin refuges from autumn 1953 to spring 2001.Over the long term, waterfowl abundance (birds per day) on the refuge complex averaged about 1.0 million in autumn and about 360,000 in spring. A record peak count of 5.8 million waterfowl was recorded September 24-25, 1958. Average abundance of autumn staging waterfowl for the refuge complex, after reaching record levels in the 1950s and early 1960s, began a decline that lasted until the 1980s. A gradual recovery occurred during the 1990s, but autumn abundance has not recovered to pre-1970 levels. In contrast to autumn, average spring abundance was generally lower in the early decades but has gradually increased through the 1990s, particularly on Lower Klamath NWR.Dabbling ducks represented an average of 68% of all waterfowl in autumn and 55% in spring for the long term. Northern pintail (Anas acuta) was dominant, representing 62% of all dabblers in autumn and 51% in spring. A significant decline in pintail abundance starting in the late 1950s altered waterfowl composition on Klamath Basin refuges. As pintail declined, other species such as mallard (Anas platyrhynchos) and green-winged teal (Anas crecca) increased in abundance. Although Arctic nesting geese, including white-fronted (Anser albifrons), cackling Canada (Branta canadensis minima), white geese (lesser snow [Chen caerulescens caerulescens], and Ross’s [Chen rossii]) have become less prominent in recent decades, they reached an historically high abundance during autumn in the 1960s and 1970s, particularly on Tule Lake NWR.Tule Lake NWR supported the highest average autumn waterfowl populations until surpassed by Lower Klamath NWR around 1980. During the recent period (1977-2001), Lower Klamath NWR accounted for 60% of all waterfowl using the refuge complex in autumn and 61% in spring. Habitat diversity and wetland productivity contributed to its greater waterfowl abundance. Tule Lake NWR supported the most geese over the long term, 79% in autumn and 66% in spring; however, total waterfowl abundance on this refuge in autumn has been in decline, likely because of reduced diversity and productivity of sumps in the refuge. Upper Klamath, Klamath Marsh, and Clear Lake NWRs accounted for less than 8% of total waterfowl use in autumn and spring but provided diverse habitats for migrants.Waterfowl use-days on Klamath Basin refuges typically peaked in mid-autumn, decreased as migrants passed through the basin, and then reached a lesser peak during spring passage. Waterfowl abundance reached a pronounced peak in autumn during the early period (1953-76), but spring peak buildup was much less pronounced. For the recent period the autumn peak was more subdued.Waterfowl abundance, species composition, and distribution on Klamath Basin refuges have fluctuated over the decades and have been influenced by events such as productivity on breeding grounds and habitat conditions on wintering grounds that cause shifts in migration patterns. A major challenge for the future appears to be the availability of adequate water for wetland management on Klamath Basin refuges.

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. An appeal from an adverse decision by the... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. An appeal from an adverse decision by the... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. An appeal from an adverse decision by the... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

Migration Decision-Making among Mexican Youth: Individual, Family, and Community Influences

PubMed Central

Tucker, Christine M.; Torres-Pereda, Pilar; Minnis, Alexandra M.; Bautista-Arredondo, Sergio A.

2013-01-01

We explored migration decisions using in-depth, semi-structured interviews with male and female youth ages 14 to 24 (n=47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were non-migrants with relatives in the U.S. Migrant and non-migrant youth expressed different preferences, especially in terms of education and their ability to wait for financial gain. Reasons for migration were mostly similar across the two communities; however, the perceived risk of the migration journey was higher in the low density migration community while perceived opportunities in Mexico were higher in the high density migration community. Reasons for return were related to youths’ initial social and economic motivations for migration. A greater understanding of factors influencing migration decisions may provide insight into the vulnerability of immigrant youth along the journey, their adaptation process in the U.S., and their reintegration in Mexico. PMID:23626401

Migration Decision-Making among Mexican Youth: Individual, Family, and Community Influences.

PubMed

Tucker, Christine M; Torres-Pereda, Pilar; Minnis, Alexandra M; Bautista-Arredondo, Sergio A

2013-05-07

We explored migration decisions using in-depth, semi-structured interviews with male and female youth ages 14 to 24 (n=47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were non-migrants with relatives in the U.S. Migrant and non-migrant youth expressed different preferences, especially in terms of education and their ability to wait for financial gain. Reasons for migration were mostly similar across the two communities; however, the perceived risk of the migration journey was higher in the low density migration community while perceived opportunities in Mexico were higher in the high density migration community. Reasons for return were related to youths' initial social and economic motivations for migration. A greater understanding of factors influencing migration decisions may provide insight into the vulnerability of immigrant youth along the journey, their adaptation process in the U.S., and their reintegration in Mexico.

Spring migration routes and chronology of surf scoters (Melanitta perspicillata): a synthesis of Pacific coast studies

USGS Publications Warehouse

de la Cruz, S.E.W.; Takekawa, John Y.; Wilson, M.T.; Nysewander, D.R.; Evenson, J.R.; Esler, Daniel N.; Boyd, W.S.; Ward, D.H.

2009-01-01

Understanding interconnectivity among wintering, stopover, and breeding areas of migratory birds is pivotal to discerning how events occurring in each might have a cross-seasonal effect on another. Such information can guide the location and timing of conservation efforts. Thus, we examined spring migration routes, chronology, and stopover use of 85 surf scoters (Melanitta perspicillata (L., 1758)) marked with satellite transmitters at four Pacific Flyway wintering sites: San Quintin Bay, Baja California; San Francisco Bay, California; Puget Sound, Washington; and Strait of Georgia, British Columbia. Eighty-three percent of marked scoters followed two main routes to the breeding area: a Southern Inland route involving staging in Puget Sound and Strait of Georgia and protracted inland migration, or a Northern Coastal route characterized by short movements along the Pacific coast of British Columbia and southeast Alaska with inland migration initiating from Lynn Canal and surrounding areas. Route choice was related to nesting site latitude in the Canadian Northern Boreal Forest. Data from birds tracked over 2 years indicated strong migration route fidelity, but altered chronology and stopover locations between years. Departure date varied by wintering site, but arrival and apparent settling dates were synchronous, suggesting individuals adjusted migration timing to meet an optimized reproductive schedule.

Comparing Habitat Suitability and Connectivity Modeling Methods for Conserving Pronghorn Migrations

PubMed Central

Poor, Erin E.; Loucks, Colby; Jakes, Andrew; Urban, Dean L.

2012-01-01

Terrestrial long-distance migrations are declining globally: in North America, nearly 75% have been lost. Yet there has been limited research comparing habitat suitability and connectivity models to identify migration corridors across increasingly fragmented landscapes. Here we use pronghorn (Antilocapra americana) migrations in prairie habitat to compare two types of models that identify habitat suitability: maximum entropy (Maxent) and expert-based (Analytic Hierarchy Process). We used distance to wells, distance to water, NDVI, land cover, distance to roads, terrain shape and fence presence to parameterize the models. We then used the output of these models as cost surfaces to compare two common connectivity models, least-cost modeling (LCM) and circuit theory. Using pronghorn movement data from spring and fall migrations, we identified potential migration corridors by combining each habitat suitability model with each connectivity model. The best performing model combination was Maxent with LCM corridors across both seasons. Maxent out-performed expert-based habitat suitability models for both spring and fall migrations. However, expert-based corridors can perform relatively well and are a cost-effective alternative if species location data are unavailable. Corridors created using LCM out-performed circuit theory, as measured by the number of pronghorn GPS locations present within the corridors. We suggest the use of a tiered approach using different corridor widths for prioritizing conservation and mitigation actions, such as fence removal or conservation easements. PMID:23166656

Comparing habitat suitability and connectivity modeling methods for conserving pronghorn migrations.

PubMed

Poor, Erin E; Loucks, Colby; Jakes, Andrew; Urban, Dean L

2012-01-01

Terrestrial long-distance migrations are declining globally: in North America, nearly 75% have been lost. Yet there has been limited research comparing habitat suitability and connectivity models to identify migration corridors across increasingly fragmented landscapes. Here we use pronghorn (Antilocapra americana) migrations in prairie habitat to compare two types of models that identify habitat suitability: maximum entropy (Maxent) and expert-based (Analytic Hierarchy Process). We used distance to wells, distance to water, NDVI, land cover, distance to roads, terrain shape and fence presence to parameterize the models. We then used the output of these models as cost surfaces to compare two common connectivity models, least-cost modeling (LCM) and circuit theory. Using pronghorn movement data from spring and fall migrations, we identified potential migration corridors by combining each habitat suitability model with each connectivity model. The best performing model combination was Maxent with LCM corridors across both seasons. Maxent out-performed expert-based habitat suitability models for both spring and fall migrations. However, expert-based corridors can perform relatively well and are a cost-effective alternative if species location data are unavailable. Corridors created using LCM out-performed circuit theory, as measured by the number of pronghorn GPS locations present within the corridors. We suggest the use of a tiered approach using different corridor widths for prioritizing conservation and mitigation actions, such as fence removal or conservation easements.

Upstream migration of Pacific lampreys in the John Day River, Oregon: Behavior, timing, and habitat use

USGS Publications Warehouse

Robinson, T. Craig; Bayer, J.M.

2005-01-01

Adult Pacific lamprey migration and habitat preferences for over-winter holding and spawning, and larval rearing in tributaries to the Columbia River are not well understood. The John Day River is one such tributary where larval and adult stages of this species have been documented, and its free-flowing character provided the opportunity to study migration of Pacific lampreys unimpeded by passage constraints. Forty-two adult Pacific lampreys were captured in the John Day River near its mouth during their upstream migration. Pacific lampreys were surgically implanted with radio transmitters and released onsite, and tracked by fixed-site, aerial, and terrestrial telemetry methods for nearly one year. Adults moved upstream exclusively at night, with a mean rate of 11.1 ?? 6.3 km/day. They halted upstream migration by September, and held a single position for approximately six months in the lateral margins of riffles and glides, using boulders for cover. More than half of Pacific lampreys resumed migration in March before ending movement in early May. Pacific lampreys that resumed migration in spring completed a median of 87% of their upstream migration before over-winter holding. Upon completing migration. Pacific lampreys briefly held position before beginning downstream movement at the end of May. Though not directly observed, halting migration and movement downstream were likely the result of spawning and death. Gains in adult Pacific lamprey passage through the Columbia River hydrosystem and tributaries may be made by improvements that would expedite migration during spring and summer and increase the quantity and variety of cover and refuge opportunities. ?? 2005 by the Northwest Scientific Association. All rights reserved.

A comprehensive review of observational and site evaluation data of migrant whooping cranes in the United States, 1943-1999

USGS Publications Warehouse

Austin, Jane E.; Richert, Amy L.

2001-01-01

This report is a comprehensive analysis of existing observational data (1943–99) and site evaluation data (1977–99) for locations used by whooping cranes (Grus americana) during migration through the United States portion of the Wood Buffalo–Aransas flyway. The apparent migration path, as outlined by the distribution of whooping crane observations, is very similar to that delineated in earlier reports, following a relatively straight line north-northwest from Aransas National Wildlife Refuge (NWR) to central North Dakota then curving northwest along the Missouri Coteau to the North Dakota–Saskatchewan border. The distribution of spring and fall observations were relatively similar, except for the higher frequency of fall observations on Quivira NWR and Cheyenne Bottoms State Wildlife Area in Kansas, Salt Plains NWR in Oklahoma, and in Texas. Timing of spring and fall migrations also appears similar to that described earlier and shows no changes over the 57-year period of data collection. Regardless of season, most sightings included 1–3 whooping cranes, but groups with as many as 14 and 19 cranes have been sighted in spring and fall, respectively.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berggren Thomas J.; Franzoni, Henry; Basham, Larry R.

The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer chinook (hereafter, chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of chinook marked in two different regions (which differ in the number of dams chinook have to migrate through) provides insight into the effectsmore » of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well comparison between the different collector projects from which smolts are transported. CSS also compares these survival rates for wild Snake River spring and summer chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species. Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. The parameter D is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to Lower Granite Dam. When D = 1, there is no difference in survival rate after hydrosystem passage. When D < 1, then transported smolts die at a greater rate after release below Bonneville Dam than smolts that have migrated in-river to below Bonneville Dam. While the relative survival rates of transported and in-river migrants are important, the SARs must be also be sufficient to allow the salmon to persist and recover (Mundy et al. 1994). Decreased SARs could result from delayed hydrosystem mortality for either transported or in-river migrants, or both. Major objectives of the CSS include: (1) development of a long-term index of transport SAR to in-river SAR for Snake River hatchery and wild spring and summer chinook smolts measured at Lower Granite Dam; (2) develop a long-term index of survival rates from release of smolts at Snake River hatcheries to return of adults to the hatcheries; (3) compute and compare the overall SARs for selected upriver and downriver spring and summer chinook hatchery and wild stocks; and (4) begin a time series of SARs for use in hypothesis testing and in the regional long-term monitoring and evaluation program. Primary CSS focus in this report is for wild and hatchery spring/summer chinook that outmigrated in 1997 to 2000 and returned in 2003. Another goal of CSS was to help resolve uncertainty concerning marking, handling and bypass effects associated with control fish used in National Marine Fisheries Service's (NMFS) transportation research and evaluation. Significant concern had been raised that the designated control groups, which were collected, marked and released at dams, did not experience the same conditions as the in-river migrants which were not collected and bypassed under existing management, and that the estimated ratios of SARs of transported fish to SARs of control fish may be biased (Mundy et al. 1994). Instead of marking at the dams, as traditionally done for NMFS transportation evaluations, CSS began marking sufficient numbers of fish at the hatcheries and defining in-river groups from the detection histories at the dams (e.g., total arrivals, never detected, detected one or more times).« less

Detours in long-distance migration across the Qinghai-Tibetan Plateau: individual consistency and habitat associations.

PubMed

Liu, Dongping; Zhang, Guogang; Jiang, Hongxing; Lu, Jun

2018-01-01

Migratory birds often follow detours when confronted with ecological barriers, and understanding the extent and the underlying drivers of such detours can provide important insights into the associated cost to the annual energy budget and the migration strategies. The Qinghai-Tibetan Plateau is the most daunting geographical barrier for migratory birds because the partial pressure of oxygen is dramatically reduced and flight costs greatly increase. We analyzed the repeated migration detours and habitat associations of four Pallas's Gulls Larus ichthyaetus across the Qinghai-Tibetan Plateau over 22 migration seasons. Gulls exhibited notable detours, with the maximum distance being more than double that of the expected shortest route, that extended rather than reduced the passage across the plateau. The extent of longitudinal detours significantly increased with latitude, and detours were longer in autumn than in spring. Compared with the expected shortest routes, proximity to water bodies increased along autumn migration routes, but detour-habitat associations were weak along spring migration routes. Thus, habitat availability was likely one, but not the only, factor shaping the extent of detours, and migration routes were determined by different mechanisms between seasons. Significant between-individual variation but high individual consistency in migration timing and routes were revealed in both seasons, indicating a stronger influence of endogenous schedules than local environmental conditions. Gulls may benefit from repeated use of familiar routes and stopover sites, which may be particularly significant in the challenging environment of the Qinghai-Tibetan Plateau.

Evaluation of Fish Movements, Migration Patterns, and Population Abundance with Streamwidth PIT Tag Interrogation Systems, Final Report 2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zydlewski, Gayle; Winter, Christiane; McClanahan, Dee

2003-02-01

Two remote Streamwidth PIT tag Interrogation systems (SPIs) were operated continuously for over one year to test the feasibility of these systems for generating movement, migration, survival and smolt production estimates for salmonids. A total of 1,588 juvenile (< 100 mm FL) naturally produced salmonids (7 coho salmon, 482 cutthroat trout, and 1,099 steelhead) were PIT tagged above the upstream-most SPI (9 sites approximately 1 linear km each) in Fall 2001. Age at tagging for wild caught cutthroat and steelhead was 1 year. SPIs were operating before any PIT tagged fish were released in the creek. Over 390,000 detections weremore » recorded from October 2001 to 31 July 2002. Efficiencies were site dependent, but overall detection efficiency for the creek was 97% with 95% confidence intervals of 91-100%. PIT tag detection efficiency ranged from 55-100% depending on the SPI and varied throughout the year with average efficiencies of 73% and 89%. SPI efficiency of PIT tag detection was not completely dependent on electronics noise levels or environmental conditions. Fish from all tagging locations were detected at the SPIs. Steelhead and cutthroat trout were primarily detected moving in the Spring (April-June) coincident with the anticipated smolt migration. Steelhead were also detected moving past SPIs at lower numbers in the Fall and Winter. Travel time between SPIs (downstream movement) was highly dependent on time of year. Travel time in the Spring was significantly faster (34.4 {+-} 7.0 hours) for all species than during any other time of year (763.1 {+-} 267.0 hours). Steelhead and cutthroat migrating in the Spring were the same age as those that did not migrate in the Spring. Peak of steelhead migration recorded at the two SPIs was 5/11 and 5/12 and the peak in the screw trap was recorded on 5/17. Steelhead smolt production estimates using SPIs (3,802 with 95% confidence intervals of 3,440 - 4,245) was similar to those using more standard screw trap methods (approximately 5,400). All species used the faster moving/deeper section of the creek at both SPIs. A backpack PIT tag detector was also developed and used as another remote 'recapture' for additional accuracy in estimating population survival and recapture probability. This unit was used at an approximate efficiency of 24% to survey the creek after the Spring migration. Twenty-five individual fish were re-located. All PIT tag data were used to calculate survival and recapture probabilities using the Cormack-Jolly-Seber population model. Survival for steelhead was high and recapture probability depended greatly on season. Probability of recapture was highest in Spring (29.5%) and relatively low in all other seasons (< 7% in Fall, Winter, and Summer). Wild steelhead PIT tagged in the field and returned to the laboratory had a tag retention rate of 97.6%. A laboratory study was designed to determine the effects of 3-sized PIT tags (12 mm, 20 mm, and 23 mm) on survival and growth of individuals. Survival from surgical implantation of 23 mm PIT tags was > 98% for fish (coho salmon and steelhead). Retention of 23 mm PIT tags was 100% for coho salmon and 89% for steelhead. For both coho and steelhead, growth rates during the first month were affected by tagging, but by the end of 2 months growth effects equalized for all tag sizes. Life history characteristics quantified with SPI techniques are comparable to standard techniques. For example, peaks of Spring migration for steelhead and cutthroat were amazingly similar to those reported from the screw trap. These techniques will enable application of less laborious methods which are more accurate at estimating life history parameters.« less

Evaluation of Fish Movements, Migration Patterns and Populations Abundance with Streamwidth PIT Tag Interrogation Systems, Final Report 2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zydlewski, Gayle B.; Casey, Sean

2003-02-01

Two remote Streamwidth PIT tag Interrogation systems (SPIs) were operated continuously for over one year to test the feasibility of these systems for generating movement, migration, survival and smolt production estimates for salmonids. A total of 1,588 juvenile (< 100 mm FL) naturally produced salmonids (7 coho salmon, 482 cutthroat trout, and 1,099 steelhead) were PIT tagged above the upstream-most SPI (9 sites approximately 1 linear km each) in Fall 2001. Age at tagging for wild caught cutthroat and steelhead was 1 year. SPIs were operating before any PIT tagged fish were released in the creek. Over 390,000 detections weremore » recorded from October 2001 to 31 July 2002. Efficiencies were site dependent, but overall detection efficiency for the creek was 97% with 95% confidence intervals of 91-100%. PIT tag detection efficiency ranged from 55-100% depending on the SPI and varied throughout the year with average efficiencies of 73% and 89%. SPI efficiency of PIT tag detection was not completely dependent on electronics noise levels or environmental conditions. Fish from all tagging locations were detected at the SPIs. Steelhead and cutthroat trout were primarily detected moving in the Spring (April-June) coincident with the anticipated smolt migration. Steelhead were also detected moving past SPIs at lower numbers in the Fall and Winter. Travel time between SPIs (downstream movement) was highly dependent on time of year. Travel time in the Spring was significantly faster (34.4 {+-} 7.0 hours) for all species than during any other time of year (763.1 {+-} 267.0 hours). Steelhead and cutthroat migrating in the Spring were the same age as those that did not migrate in the Spring. Peak of steelhead migration recorded at the two SPIs was 5/11 and 5/12 and the peak in the screw trap was recorded on 5/17. Steelhead smolt production estimates using SPIs (3,802 with 95% confidence intervals of 3,440-4,245) was similar to those using more standard screw trap methods (approximately 5,400). All species used the faster moving/deeper section of the creek at both SPIs. A backpack PIT tag detector was also developed and used as another remote ''recapture'' for additional accuracy in estimating population survival and recapture probability. This unit was used at an approximate efficiency of 24% to survey the creek after the Spring migration. Twenty-five individual fish were re-located. All PIT tag data were used to calculate survival and recapture probabilities using the Cormack-Jolly-Seber population model. Survival for steelhead was high and recapture probability depended greatly on season. Probability of recapture was highest in Spring (29.5%) and relatively low in all other seasons (< 7% in Fall, Winter, and Summer). Wild steelhead PIT tagged in the field and returned to the laboratory had a tag retention rate of 97.6%. A laboratory study was designed to determine the effects of 3-sized PIT tags (12 mm, 20 mm, and 23 mm) on survival and growth of individuals. Survival from surgical implantation of 23 mm PIT tags was > 98% for fish (coho salmon and steelhead). Retention of 23 mm PIT tags was 100% for coho salmon and 89% for steelhead. For both coho and steelhead, growth rates during the first month were affected by tagging, but by the end of 2 months growth effects equalized for all tag sizes. Life history characteristics quantified with SPI techniques are comparable to standard techniques. For example, peaks of Spring migration for steelhead and cutthroat were amazingly similar to those reported from the screw trap. These techniques will enable application of less laborious methods which are more accurate at estimating life history parameters.« less

Evidence that dorsally mounted satellite transmitters affect migration chronology of Northern Pintails

USGS Publications Warehouse

Hupp, Jerry W.; Kharitonov, Sergei; Yamaguchi, Noriyuki M.; Ozaki, K.; Flint, Paul L.; Pearce, John M.; Tokita, Ken-ichi; Shimada, Tetsuo; Higuchi, Hiroyoshi

2015-01-01

We compared migration movements and chronology between Northern Pintails (Anas acuta) marked with dorsally mounted satellite transmitters and pintails marked only with tarsus rings. During weekly intervals of spring and autumn migration between their wintering area in Japan and nesting areas in Russia, the mean distance that ringed pintails had migrated was up to 1000 km farther than the mean distance radiomarked pintails migrated. Radiomarked pintails were detected at spring migration sites on average 9.9 days (90 % CI 8.0, 11.8) later than ringed pintails that were recovered within 50 km. Although ringed and radiomarked pintails departed from Japan on similar dates, the disparity in detection of radiomarked versus ringed pintails at shared sites increased 7.7 days (90 % CI 5.2, 10.2) for each 1000 km increase in distance from Japan. Thus, pintails marked with satellite transmitters arrived at nesting areas that were 2500 km from Japan on average 19 days later than ringed birds. Radiomarked pintails were detected at autumn migration stopovers on average 13.1 days (90 % CI 9.8, 16.4) later than ringed birds that were recovered within 50 km. We hypothesize that dorsal attachment of 12–20 g satellite transmitters to Northern Pintails increased the energetic cost of flight, which resulted in more rapid depletion of energetic reserves and shortened the distance pintails could fly without refueling. Radiomarked pintails may have used more stopovers or spent longer periods at stopovers. causing their migration schedule to diverge from ringed pintails. We urge further evaluation of the effects of dorsally mounted transmitters on migration chronology of waterfowl.

Candidate genes have sex-specific effects on timing of spring migration and moult speed in a long-distance migratory bird.

PubMed

Bazzi, Gaia; Podofillini, Stefano; Gatti, Emanuele; Gianfranceschi, Luca; Cecere, Jacopo G; Spina, Fernando; Saino, Nicola; Rubolini, Diego

2017-10-01

The timing of major life-history events, such as migration and moult, is set by endogenous circadian and circannual clocks, that have been well characterized at the molecular level. Conversely, the genetic sources of variation in phenology and in other behavioral traits have been sparsely addressed. It has been proposed that inter-individual variability in the timing of seasonal events may arise from allelic polymorphism at phenological candidate genes involved in the signaling cascade of the endogenous clocks. In this study of a long-distance migratory passerine bird, the willow warbler Phylloscopus trochilus , we investigated whether allelic variation at 5 polymorphic loci of 4 candidate genes ( Adcyap1 , Clock , Creb1 , and Npas2 ), predicted 2 major components of the annual schedule, namely timing of spring migration across the central Mediterranean sea and moult speed, the latter gauged from ptilochronological analyses of tail feathers moulted in the African winter quarters. We identified a novel Clock gene locus ( Clock region 3) showing polyQ polymorphism, which was however not significantly associated with any phenotypic trait. Npas2 allele size predicted male (but not female) spring migration date, with males bearing longer alleles migrating significantly earlier than those bearing shorter alleles. Creb1 allele size significantly predicted male (but not female) moult speed, longer alleles being associated with faster moult. All other genotype-phenotype associations were statistically non-significant. These findings provide new evidence for a role of candidate genes in modulating the phenology of different circannual activities in long-distance migratory birds, and for the occurrence of sex-specific candidate gene effects.

Seasonal and diel movements of white sturgeon in the lower columbia river

USGS Publications Warehouse

Parsley, M.J.; Popoff, N.D.; Van Der Leeuw, B. K.; Wright, C.D.

2008-01-01

Continuous monitoring of the movements and depths used by white sturgeon Acipenser transmontanus with acoustic telemetry technologies in the lower Columbia River provided information on diel and seasonal migrations, local movements, and site fidelity. White sturgeon moved to shallower water at night and showed greater activity, inferred from rates of movement, than during daytime. The extent of local movement within a season was variable among fish; some fish readily moved among habitats while the movements of others were more constrained. White sturgeon were absent from the study area (river kilometers 45-52) during winter and returned from upstream during the spring, confirming an upstream seasonal migration in the fall and downstream migration in spring. The return of individual fish and reoccupation of areas previously inhabited showed that some white sturgeon exhibit site fidelity. This work shows that studies seeking to characterize habitat for white sturgeon need to be cognizant of diel migrations and site fidelity. We urge caution in the use of limited fish location data to describe habitats if diel activities and fine-scale movements are not known.

Stock-specific migration timing of adult spring-summer Chinook salmon in the Columbia River basin

USGS Publications Warehouse

Keefer, M.L.; Peery, C.A.; Jepson, M.A.; Tolotti, K.R.; Bjornn, T.C.; Stuehrenberg, L.C.

2004-01-01

An understanding of the migration timing patterns of Pacific salmon Oncorhynchus spp. and steelhead O. mykiss is important for managing complex mixed-stock fisheries and preserving genetic and life history diversity. We examined adult return timing for 3,317 radio-tagged fish from 38 stocks of Columbia River basin spring-summer Chinook salmon O. tshawytscha over 5 years. Stock composition varied widely within and between years depending on the strength of influential populations. Most individual stocks migrated at similar times each year relative to overall runs, supporting the hypotheses that run timing is predictable, is at least partially due to genetic adaptation, and can be used to differentiate between some conspecific populations. Arrival timing of both aggregated radio-tagged stocks and annual runs was strongly correlated with river discharge; stocks arrived earlier at Bonneville Dam and at upstream dams in years with low discharge. Migration timing analyses identified many between-stock and between-year differences in anadromous salmonid return behavior and should and managers interested in protection and recovery of evolutionary significant populations.

Ticks (Ixodidae) on migrating birds in Egypt, spring and fall 1962*

PubMed Central

Hoogstraal, Harry; Traylor, Melvin A.; Gaber, Sobhy; Malakatis, George; Guindy, Ezzat; Helmy, Ibrahim

1964-01-01

Over a number of years studies have been carried out in Egypt on the transport by migrating birds of ticks that may transmit pathogens of man and animals. In continuation of these investigations 11 036 birds migrating southwards through Egypt were examined for ticks during the fall of 1962. The 881 infested birds (comprising 24 species and sub-species represented by 10 612 individuals) yielded 1442 ticks. Tick-host relationships were similar to those of previous years except that in 1962 the prevalence of infestation was almost invariably much higher than the averages for 1959-61. Five species of birds were added to the previous list of 40 infested forms. Previously unrecorded tick species taken during 1962 were Ixodes redikorzevi (a species from Asia very occasionally found in rodent burrows in Egypt), the rare Haemaphysalis inermis, and Hyalomma a. anatolicum, H. anatolicum excavatum and H. dromedarii, which may have been carried from Asia or have attached themselves to the birds at the time of netting. During the spring of 1962, altogether 1774 birds migrating northwards through Egypt were also examined. The 56 tick-infested birds (comprising 13 species represented by 867 individuals) yielded 186 ticks. As in previous years, Hyalomma marginatum rufipes was the chief species (89.25%) parasitizing spring migrants. A single specimen of Amblyomma variegatum was taken on Anthus cervinus and 19 specimens of Ixodes?sp. nov. were collected from Sylvia c. communis and Motacilla a. alba. PMID:14163959

How will predicted land-use change affect waterfowl spring stopover ecology? Inferences from an individual-based model

USGS Publications Warehouse

Beatty, William; Kesler, Dylan C.; Webb, Elisabeth B.; Naylor, Luke W.; Raedeke, Andrew H.; Humburg, Dale D.; Coluccy, John M.; Soulliere, Gregory J.

2017-01-01

Habitat loss, habitat fragmentation, overexploitation and climate change pose familiar and new challenges to conserving natural populations throughout the world. One approach conservation planners may use to evaluate the effects of these challenges on wildlife populations is scenario planning.We developed an individual-based model to evaluate the effects of future land use and land cover changes on spring-migrating dabbling ducks in North America. We assessed the effects of three Intergovernmental Panel on Climate Change emission scenarios (A1B, A2 and B1) on dabbling duck stopover duration, movement distances and mortality. We specifically focused on migration stopover duration because previous research has demonstrated that individuals arriving earlier on the nesting grounds exhibit increased reproductive fitness.Compared to present conditions, all three scenarios increased stopover duration and movement distances of agent ducks.Although all three scenarios presented migrating ducks with increased amounts of wetland habitat, scenarios also contained substantially less cropland, which decreased overall carrying capacity of the study area.Synthesis and applications. Land-use change may increase waterfowl spring migration stopover duration in the midcontinent region of North America due to reduced landscape energetic carrying capacity. Climate change will alter spatial patterns of crop distributions with corn and rice production areas shifting to different regions. Thus, conservation planners will have to address population-level energetic implications of shifting agricultural food resources and increased uncertainty in yearly precipitation patterns within the next 50 years.

Integrated Status and Effectiveness Monitoring Program; Expansion of Existing Smolt Trapping Program in Nason Creek, 2005 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prevatte, Scott A.

2006-03-01

In the fall of 2004, as one part of a Basin-Wide Monitoring Program developed by the Upper Columbia Regional Technical Team and Upper Columbia Salmon Recovery Board, the Yakama Nation Fisheries Resource Management program began monitoring downstream migration of ESA listed Upper Columbia River spring chinook salmon and Upper Columbia River steelhead in Nason Creek, a tributary to the Wenatchee River. This report summarizes juvenile spring chinook salmon and steelhead trout migration data collected in Nason Creek during 2005 and also incorporates data from 2004. We used species enumeration at the trap and efficiency trials to describe emigration timing andmore » to estimate population size. Data collection was divided into spring/early summer and fall periods with a break during the summer months occurring due to low stream flow. Trapping began on March 1st and was suspended on July 29th when stream flow dropped below the minimum (30 cfs) required to rotate the trap cone. The fall period began on September 28th with increased stream flow and ended on November 23rd when snow and ice began to accumulate on the trap. During the spring and early summer we collected 311 yearling (2003 brood) spring chinook salmon, 86 wild steelhead smolts and 453 steelhead parr. Spring chinook (2004 brood) outgrew the fry stage of fork length < 60 mm during June and July, 224 were collected at the trap. Mark-recapture trap efficiency trials were performed over a range of stream discharge stages whenever ample numbers of fish were being collected. A total of 247 spring chinook yearlings, 54 steelhead smolts, and 178 steelhead parr were used during efficiency trials. A statically significant relationship between stream discharge and trap efficiency has not been identified in Nason Creek, therefore a pooled trap efficiency was used to estimate the population size of both spring chinook (14.98%) and steelhead smolts (12.96%). We estimate that 2,076 ({+-} 119 95%CI) yearling spring chinook and 688 ({+-} 140 95%CI) steelhead smolts emigrated past the trap during the spring/early summer sample period along with 10,721 ({+-} 1,220 95%CI) steelhead parr. During the fall we collected 924 subyearling (2004 brood) spring chinook salmon and 1,008 steelhead parr of various size and age classes. A total of 732 spring chinook subyearlings and 602 steelhead parr were used during 13 mark-recapture trap efficiency trials. A pooled trap efficiency of 24.59% was used to calculate the emigration of spring chinook and 17.11% was used for steelhead parr during the period from September 28th through November 23rd. We estimate that 3758 ({+-} 92 95%CI) subyearling spring chinook and 5,666 ({+-} 414 95%CI) steelhead parr migrated downstream past the trap along with 516 ({+-} 42 95%CI) larger steelhead pre-smolts during the 2005 fall sample period.« less

Migrant decision-making in a frontier landscape

NASA Astrophysics Data System (ADS)

Salerno, Jonathan

2016-04-01

Across the tropics, rural farmers and livestock keepers use mobility as an adaptive livelihood strategy. Continued migration to and within frontier areas is widely viewed as a driver of environmental decline and biodiversity loss. Recent scholarship advances our understanding of migration decision-making in the context of changing climate and environments, and in doing so it highlights the variation in migration responses to primarily economic and environmental factors. Building on these insights, this letter investigates past and future migration decisions in a frontier landscape of Tanzania, East Africa. Combining field observations and household data within a multilevel modeling framework, the letter analyzes the explicit importance of social factors relative to economic and environmental factors in driving decisions to migrate or remain. Results indeed suggest that local community ties and non-local social networks drive both immobility and anticipated migration, respectively. In addition, positive interactions with local protected natural resource areas promote longer-term residence. Findings shed new light on how frontier areas transition to human dominated landscapes. This highlights critical links between migration behavior and the conservation of biodiversity and management of natural resources, as well as how migrants evolve to become integrated into communities.

Fat dynamics of arctic-nesting sandpipers during spring in mid-continental North America

USGS Publications Warehouse

Krapu, G.L.; Eldridge, J.L.; Gratto-Trevor, C. L.; Buhl, D.A.

2006-01-01

We measured fresh body mass, total body fat, and fat-free dry mass (FFDM) of three species of Arctic-nesting calidrid sandpipers (Baird's Sandpiper [Calidris bairdii], hereafter “BASA”; Semipalmated Sandpiper [C. pusilla], hereafter “SESA”; and White-rumped Sandpiper [C. fuscicollis], hereafter “WRSA”) during spring stopovers in the Prairie Pothole Region (PPR) of North Dakota, and evaluated the contribution of stored fat to (1) energy requirements for migration to their Arctic-breeding grounds and (2) nutrient needs for reproduction. All spring migrant WRSA (n = 124) and BASA (n = 111), and all but 2 of 99 SESA we collected were ≥2 years old. Male and female BASA migrated through North Dakota concurrently, male SESA averaged earlier than females, and WRSA males preceded females. Fat indices (ratio of fat to FFDM) of male and female SESA and WRSA averaged approximately twice those of male and female BASA. Total body fat of male and female BASA increased with date in spring 1980, but not in 1981; slopes were similar for both sexes each year. Male and female SESA arrived lean in 1980 and 1981, and total body fat increased with date in both years, with similar slopes for all combinations of sex and year. Male and female WRSA arrived lean in 1980–1981 and 1981, respectively, and total body fat increased with date, whereas females arrived with fat reserves already acquired in 1980. Interspecific and sex differences in migration schedules probably contributed to variation in fat storage patterns by affecting maintenance energy costs and food availability. Estimated flight ranges of BASA suggest that few could have met their energy needs for migration to the breeding grounds exclusively from fat stored by the time of departure from North Dakota. Estimated flight ranges of SESA and WRSA, along with fresh body masses of both species when live-trapped on or near their breeding grounds in northern Canada, suggest that major parts of both populations stored adequate fat by departure from temperate mid-continental North America to meet their energy requirements for migration and part of their nutrient needs for reproduction.

When push comes to shove: sites of vulnerability, personal transformation, and trafficked women's migration decisions.

PubMed

Yea, Sallie

2005-01-01

Discussions of the push and pull factors behind trafficked women's decisions to migrate abroad for tenuous work opportunities in the "entertainment" sector tend to variously privilege poverty, familial obligations, and, more recently, personal opportunism. This reinforces more general observations about motivations for "Third World" women who migrate to more developed regions globally. Although these factors are indeed important, the author's research has revealed the relevance of other explanations for migration decisions, including the prevalence of domestic violence, family dissolution, and escape from personal circumstances, which are themselves products of low self-esteem and sense of self-worth.

Wind effects on the migration routes of trans-Saharan soaring raptors: geographical, seasonal, and interspecific variation

PubMed Central

Vidal-Mateo, Javier; Mellone, Ugo; López-López, Pascual; La Puente, Javier De; García-Ripollés, Clara; Bermejo, Ana; Urios, Vicente

2016-01-01

Abstract Wind is among the most important environmental factors shaping birds’ migration patterns. Birds must deal with the displacement caused by crosswinds and their behavior can vary according to different factors such as flight mode, migratory season, experience, and distance to goal areas. Here we analyze the relationship between wind and migratory movements of three raptor species which migrate by soaring–gliding flight: Egyptian vulture Neophron percnopterus, booted eagle Aquila pennata, and short-toed snake eagle Circaetus gallicus. We analyzed daily migratory segments (i.e., the path joining consecutive roosting locations) using data recorded by GPS satellite telemetry. Daily movements of Egyptian vultures and booted eagles were significantly affected by tailwinds during both autumn and spring migrations. In contrast, daily movements of short-toed eagles were only significantly affected by tailwinds during autumn migration. The effect of crosswinds was significant in all cases. Interestingly, Egyptian vultures and booted eagles showed latitudinal differences in their behavior: both species compensated more frequently at the onset of autumn migration and, at the end of the season when reaching their wintering areas, the proportion of drift segments was higher. In contrast, there was a higher drift at the onset of spring migration and a higher compensation at the end. Our results highlight the effect of wind patterns on the migratory routes of soaring raptors, with different outcomes in relation to species, season, and latitude, ultimately shaping the loop migration patterns that current tracking techniques are showing to be widespread in many long distance migrants. PMID:29491895

Exploring the migration decisions of health workers and trainees from Africa: a meta-ethnographic synthesis.

PubMed

Blacklock, C; Ward, A M; Heneghan, C; Thompson, M

2014-01-01

The migration of healthcare workers from Africa depletes countries already suffering from substantial staffing shortages and considerable disease burdens. The recruitment of such individuals by high income countries has been condemned by the World Health Organisation. However, understanding the reasons why healthcare workers migrate is essential, in order to attempt to alter migration decisions. We aimed to systematically analyse factors influencing healthcare workers' decisions to migrate from Africa. We systematically searched CINAHL (1980-Nov 2010), Embase (1980-Nov 2010), Global Health (1973-Nov 2010) and Medline (1950-Nov 2010) for qualitative studies of healthcare workers from Africa which specifically explored views about migration. Two reviewers identified articles, extracted data and assessed quality of included studies. Meta-ethnography was used to synthesise new lines of understanding and meaning from the data. The search identified 1203 articles from which we included six studies of healthcare workers trained in seven African countries, namely doctors or medical students (two studies), nurses (three), and pharmacy students (one study). Using meta-ethnographic synthesis we produced six lines of argument relating to the migration decisions of healthcare workers: 1) Struggle to realise unmet material expectations of self, family and society, 2) Strain and emotion, interpersonal discord, and insecurity in workplace, 3) Fear from threats to personal or family safety, in and out of workplace, 4) Absence of adequate professional support and development, 5) Desire for professional prestige and respect, 6) Conviction that hopes and goals for the future will be fulfilled overseas. We conclude that a complex interaction of factors contribute to the migration decisions of healthcare workers from Africa. Some of the factors identified are more amenable to change than others, and addressing these may significantly affect migration decisions of African healthcare workers in the future. Copyright © 2013 Elsevier Ltd. All rights reserved.

Superfund Record of Decision (EPA Region 7): Cherokee County (Baxter Springs and Treece Subsites), Operable Unit 3/4, Cherokee County, KS, August 20, 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-11-01

This decision document presents the selected remedial action for the mining and milling wastes at the Baxter Springs and Treece subsites, which are part of the Cherokee County Superfund Site in Cherokee County, Kansas.

The contribution of ecosystem services to place utility as a determinant of migration decision-making

NASA Astrophysics Data System (ADS)

Adams, Helen; Adger, W. Neil

2013-03-01

Environment migration research has sought to provide an account of how environmental risks and resources affect migration and mobility. Part of that effort has focused on the role of the environment in providing secure livelihoods through provisioning ecosystem services. However, many of the models of environment migration linkages fail to acknowledge the importance of social and psychological factors in the decision to migrate. Here, we seek to provide a more comprehensive model of migration decision-making under environmental change by investigating the attachment people form to place, and the role of the environment in creating that attachment. We hypothesize that environmental factors enter the migration decision-making process through their contribution to place utility, defined as a function of both affective and instrumental bonds to location, and that ecosystem services, the aspects of ecosystems that create wellbeing, contribute to both components of place utility. We test these ideas in four rural highland settlements in Peru sampled along an altitudinal gradient. We find that non-economic ecosystem services are important in creating place attachment and that ecological place attachment exists independently of use of provisioning ecosystem services. Individuals’ attitudes to ecosystem services vary with the type of ecosystem services available at a location and the degree of rurality. While social and economic factors are the dominant drivers of migration in these locations, a loss of non-provisioning ecosystem services leads to a decrease in place utility and commitment to place, determining factors in the decision to migrate. The findings suggest that policy interventions encouraging migration as an adaptation to environmental change will have limited success if they only focus on provisioning services. A much wider set of individuals will experience a decrease in place utility, and migration will be unable to alleviate that decrease since the factors that create it are specific to place.

Spring-migration ecology of Northern Pintails in south-central Nebraska

USGS Publications Warehouse

Pearse, A.T.; Krapu, G.L.; Cox, R.R.; Davis, B.E.

2011-01-01

Spring-migration ecology of staging Northern Pintails, Anas acuta, was investigated in south-central Nebraska, USA. Habitat associations, local movements, settling patterns, arrival dates, residency times and survival were estimated from 71 radiomarked pintails during spring 2001, 2003 and 2004, and diet determined from 130 females collected during spring 1998 and 1999. Seventy-two percent of pintail diurnal locations were in palustrine wetlands, 7% in riverine wetlands, 3% in lacustrine wetlands, 6% in municipal sewage lagoons and irrigation reuse pits and 10.5% in croplands. Emergent wetlands with hemi-marsh conditions were used diurnally more often than wetlands with either open or closed vegetation structures. Evening foraging flights averaged 4.3 km (SE = 0.6) and 72% were to cornfields. In accord with these findings, 87% of 93 pintails collected during spring 1998 and 1999 returning to evening roosts consumed corn, which represented 84% dry mass of all foods. Pintails collected on non-cropped wetlands ingested invertebrates and seeds from wetland plants more frequently than birds returning to roost. Radiomarked pintails arrived in Nebraska on 7 March 2003 and 18 February 2004; average arrival date was six days earlier during 2004 compared to 2003. Residency time for individuals varied greatly (1-40 days) yet yearly means were similar and averaged 9.5 days within the region. No mortality was detected for 71 birds monitored over 829 exposure days. Conservation planners linking population dynamics and habitat conditions at spring-staging areas need to focus on pintail body condition during spring and its connection with reproductive success and survival during the breeding season.

Spring-migration ecology of Northern Pintails in south-central Nebraska

USGS Publications Warehouse

Pearse, Aaron T.; Krapu, Gary L.; Cox, Robert R.; Davis, Bruce E.

2011-01-01

Spring-migration ecology of staging Northern Pintails, Anas acuta, was investigated in south-central Nebraska, USA. Habitat associations, local movements, settling patterns, arrival dates, residency times and survival were estimated from 71 radiomarked pintails during spring 2001, 2003 and 2004, and diet determined from 130 females collected during spring 1998 and 1999. Seventy-two percent of pintail diurnal locations were in palustrine wetlands, 7% in riverine wetlands, 3% in lacustrine wetlands, 6% in municipal sewage lagoons and irrigation reuse pits and 10.5% in croplands. Emergent wetlands with hemi-marsh conditions were used diurnally more often than wetlands with either open or closed vegetation structures. Evening foraging flights averaged 4.3 km (SE = 0.6) and 72% were to cornfields. In accord with these findings, 87% of 93 pintails collected during spring 1998 and 1999 returning to evening roosts consumed corn, which represented 84% dry mass of all foods. Pintails collected on non-cropped wetlands ingested invertebrates and seeds from wetland plants more frequently than birds returning to roost. Radiomarked pintails arrived in Nebraska on 7 March 2003 and 18 February 2004; average arrival date was six days earlier during 2004 compared to 2003. Residency time for individuals varied greatly (1–40 days) yet yearly means were similar and averaged 9.5 days within the region. No mortality was detected for 71 birds monitored over 829 exposure days. Conservation planners linking population dynamics and habitat conditions at spring-staging areas need to focus on pintail body condition during spring and its connection with reproductive success and survival during the breeding season.

Nonbreeding isolation and population-specific migration patterns among three populations of Golden-winged Warblers

USGS Publications Warehouse

Kramer, Gunnar R.; Streby, Henry M.; Peterson, Sean M.; Lehman, Justin A.; Buehler, David A.; Wood, Petra B.; McNeil, Darin J.; Larkin, Jeffrey L.; Andersen, David E.

2017-01-01

Golden-winged Warblers (Vermivora chrysoptera) are Nearctic–Neotropical migrants experiencing varied regional population trends not fully explained by breeding-grounds factors such as nest success. A lack of detailed information on the nonbreeding distributions, migration routes, or timing of migration among populations hampers our ability to identify population processes outside the breeding period. We used geolocators to track annual movements of 21 Golden-winged Warblers from 3 North American breeding locations experiencing varying population trends to investigate the potential for nonbreeding site factors to influence breeding populations. We used the template-fit method to estimate locations of individual warblers throughout the year. Geolocator-marked warblers exhibited significant isolation among populations during migration and the nonbreeding period. During the nonbreeding period, Golden-winged Warblers from Minnesota, USA (n = 12) occurred in Central America from southern Mexico to central Nicaragua; warblers from Tennessee, USA (n = 7) occurred along the border of northern Colombia and Venezuela; and warblers from Pennsylvania, USA (n = 2) occurred in north-central Venezuela. Warblers travelled at slower rates over more days in fall migration than spring migration. Fall migration routes at the Gulf of Mexico were population-specific, whereas spring routes were more varied and overlapped among populations. Golden-winged Warblers from Pennsylvania migrated 4,000 and 5,000 km yr−1 farther than Tennessee and Minnesota warblers, respectively, and spent almost twice as long migrating in the fall compared to Minnesota warblers. Our results reveal nearly complete temporal and geographic isolation among 3 populations of Golden-winged Warblers throughout the annual cycle, resulting in opportunities for population- and site-specific factors to differentially influence populations outside the breeding period. Our findings highlight the need for monitoring multiple populations of migratory species to understand and better inform conservation strategies.

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008 Report of Research.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Achord, Stephen; Sandford, Benjamin P.; Hockersmith, Eric E.

2009-05-26

This report provides results from an ongoing project to monitor the migration behavior and survival of wild juvenile spring/summer Chinook salmon in the Snake River Basin. Data reported is from detections of PIT tagged fish during late summer 2007 through mid-2008. Fish were tagged in summer 2007 by the National Marine Fisheries Service (NMFS) in Idaho and by the Oregon Department of Fish and Wildlife (ODFW) in Oregon. Our analyses include migration behavior and estimated survival of fish at instream PIT-tag monitors and arrival timing and estimated survival to Lower Granite Dam. Principal results from tagging and interrogation during 2007-2008more » are listed below: (1) In July and August 2007, we PIT tagged and released 7,390 wild Chinook salmon parr in 12 Idaho streams or sample areas. (2) Overall observed mortality from collection, handling, tagging, and after a 24-hour holding period was 1.4%. (3) Of the 2,524 Chinook salmon parr PIT tagged and released in Valley Creek in summer 2007, 218 (8.6%) were detected at two instream PIT-tag monitoring systems in lower Valley Creek from late summer 2007 to the following spring 2008. Of these, 71.6% were detected in late summer/fall, 11.9% in winter, and 16.5% in spring. Estimated parr-to-smolt survival to Lower Granite Dam was 15.5% for the late summer/fall group, 48.0% for the winter group, and 58.5% for the spring group. Based on detections at downstream dams, the overall efficiency of VC1 (upper) or VC2 (lower) Valley Creek monitors for detecting these fish was 21.1%. Using this VC1 or VC2 efficiency, an estimated 40.8% of all summer-tagged parr survived to move out of Valley Creek, and their estimated survival from that point to Lower Granite Dam was 26.5%. Overall estimated parr-to-smolt survival for all summer-tagged parr from this stream at the dam was 12.1%. Development and improvement of instream PIT-tag monitoring systems continued throughout 2007 and 2008. (4) Testing of PIT-tag antennas in lower Big Creek during 2007-2008 showed these antennas (and anchoring method) are not adequate to withstand high spring flows in this drainage. Future plans involve removing these antennas before high spring flows. (5) At Little Goose Dam in 2008, length and/or weight were taken on 505 recaptured fish from 12 Idaho stream populations. Fish had grown an average of 40.1 mm in length and 10.6 g in weight over an average of 288 d. Their mean condition factor declined from 1.25 at release (parr) to 1.05 at recapture (smolt). (6) Mean release lengths for detected fish were significantly larger than for fish not detected the following spring and summer (P < 0.0001). (7) Fish that migrated through Lower Granite Dam in April and May were significantly larger at release than fish that migrated after May (P < 0.0001) (only 12 fish migrated after May). (8) In 2008, peak detections at Lower Granite Dam of parr tagged during summer 2007 (from the 12 stream populations in Idaho and 4 streams in Oregon) occurred during moderate flows of 87.5 kcfs on 7 May and high flows of 197.3 kcfs on 20 May. The 10th, 50th, and 90th percentile passage occurred on 30 April, 11 May, and 23 May, respectively. (9) In 2007-2008, estimated parr-to-smolt survival to Lower Granite Dam for Idaho and Oregon streams (combined) averaged 19.4% (range 6.2-38.4% depending on stream of origin). In Idaho streams the estimated parr-to-smolt survival averaged 21.0%. This survival was the second highest since 1993 for Idaho streams. Relative parr densities were lower in 2007 (2.4 parr/100 m{sup 2}) than in all previous years since 2000. In 2008, we observed low-to-moderate flows prior to mid-May and relatively cold weather conditions throughout the spring migration season. These conditions moved half of the fish through Lower Granite Dam prior to mid-May; then high flows moved 50 to 90% of the fish through the dam in only 12 days. Clearly, complex interrelationships of several factors drive the annual migrational timing of the stocks.« less

Fall-to-Fall Testing versus Spring-to-Spring Testing: What Is the Impact on a Local Community's Chapter 1 Evaluation?

ERIC Educational Resources Information Center

Bushner, Diane E.

The impact of a decision by a local program under Chapter 1, the federally funded program of financial assistance to special educational needs of children, to test students fall-to-fall or spring-to-spring was studied. Students enrolled in a Chapter 1 reading program in 1988-89 were tested on a fall-to-spring basis, a spring-to-spring basis, and a…

Abundance, biomass, vertical migration and estimated development rate of the copepod Calanus finmarchicus in the southern Gulf of Maine during late spring

NASA Astrophysics Data System (ADS)

Durbin, Edward G.; Gilman, Sharon L.; Campbell, Robert G.; Durbin, Ann G.

Abundance, biomass, diel vertical migration and estimated in situ development in the copepod Calanus finmarchicus were investigated during late spring in 1988 and 1989 in the southern Gulf of Maine. This region is an important feeding ground for the planktivorous right whale, Eubalaena glacialis. The 1988 study took place during the declining spring bloom, with phytoplankton biomass variable, but relatively high. The 1989 study occurred after seasonal stratification, and phytoplankton biomass was low. During the 1988 cruise the dominant stage in C. finmarchicus shifted from C1-C2 to C4-C5. Stage durations during 1988 (4.0 days for C3 and 6.6 days for C4), estimated from the temporal change in stage distribution, were similar to maximal values observed in the laboratory. In contrast, during 1989 stages C4 and C5 were dominant throughout the study period and development rate was slow (estimated C4 stage duration about 24 days). Diel vertical migration patterns changed, from an absence of migration at the first two 1988 stations where younger stages predominated (C1-C3), to a very strong diel vertical migration at the later 1988 stations where stages C3-C3 predominated. This was not a simple ontogenetic change in migratory behavior since all copepodite stages at each station showed similar patterns. During 1989 dense aggregations of C. finmarchicus remained in the surface layer both day and night, and no diel vertical migration was observed. A small, nonmigratory population of late-stage C. finmarchicus was found at depth. Individual body size of these copepods was considerably greater than those found at the surface. Differences in development rate between years reflect differences in the food environment, brought about by seasonal hydrographic changes and the development of more intense stratification. Diel vertical migration patterns, however, did not show a simple relation with food availability, and it is suggested that predation may play an important role in regulating the behavior of the copepods.

Stopover ecology of neotropical migrants in central Veracruz, México

Treesearch

Ernesto Ruelas Inzunza; Stephen W. Hoffman; Laurie J. Goodrich

2005-01-01

Available information on the ecology of neotropical migrants during the winter season and especially during migration is far behind the existing knowledge of birds during the breeding season. This paper presents a stopover ecology case study. We document the occurrence of species, outline the prevailing weather patterns during spring and fall migration seasons, and...

Cerulean Warbler (Setophaga cerulea) spring migration stopover in northern Middle America

Treesearch

Melinda J. Welton; David L. Anderson; Gabriel J. Colorado; Paul B. Hamel; Diego Calderón-F.

2012-01-01

The Cerulean Warbler (Setophaga cerulea) has one of the longest migrations of any small passerine, traveling approximately 4,000 km between breeding grounds in eastern North America and nonbreeding residency in northern South America. However, unlike many migratory birds, little is known about this aspect of the ecology of this species. In 2004 –...

Migration Decision-Making among Mexican Youth: Individual, Family, and Community Influences

ERIC Educational Resources Information Center

Tucker, Christine M.; Torres-Pereda, Pilar; Minnis, Alexandra M.; Bautista-Arredondo, Sergio A.

2013-01-01

We explored migration decisions using in-depth, semistructured interviews with male and female youth ages 14 to 24 (n = 47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were nonmigrants with relatives in the United States. Migrant and nonmigrant youth expressed different…

Tracking of white-tailed deer migration by Global Positioning System

USGS Publications Warehouse

Nelson, M.E.; Mech, L.D.; Frame, P.F.

2004-01-01

Based on global positioning system (GPS) radiocollars in northeastern Minnesota, deer migrated 23-45 km in spring during 31-356 h, deviating a maximum 1.6-4.0 km perpendicular from a straight line of travel between their seasonal ranges. They migrated a minimum of 2.1-18.6 km/day over 11-56 h during 2-14 periods of travel. Minimum travel during 1-h intervals averaged 1.5 km/h. Deer paused 1-12 times, averaging 24 h/pause. Deer migrated similar distances in autumn with comparable rates and patterns of travel.

Contribution of landbird migration to the biological diversity of the northwest gulf coastal plain

USGS Publications Warehouse

Barrow, W.C.; Hamilton, R.B.; Powell, M.A.; Ouchley, K.

2000-01-01

This study examined seasonal diversity and feeding behavior of those avian species utilizing that region of the Northwest Gulf Coastal Plain known as the Chenier Plain. Field observations were conducted at three forested locations on coastal cheniers for three years (1993-95) in the spring and at one location for three years (1996-98) in autumn to determine species presence and diet. One hundred and twenty-eight species were present during the spring and 103 species in autumn. The majority of these species were migrants (103 species in spring and 89 species in autumn) and the majority of these were Nearctic/Neotropical species (73 species in spring and 66 species in autumn). The diet of these migrants was more variable than expected. Many insectivorous species were observed to consume seeds, fruit and nectar as well as insects. Because of these varied diets, many species serve as seed dispersers, occasional pollinators and important predators of herbivorus insects. Wooded areas were found to be important in providing food, cover and water for migrating species. A review of historical changes in the landscape of this area is presented and management practices designed to restore wooded habitat to this area are proposed.

Developing and Delivering National-Scale Gridded Phenology Data Products

NASA Astrophysics Data System (ADS)

Marsh, L.; Crimmins, M.; Crimmins, T. M.; Gerst, K.; Rosemartin, A.; Switzer, J.; Weltzin, J. F.

2016-12-01

The USA National Phenology Network (USA-NPN; www.usanpn.org) is now producing and freely delivering daily maps and short-term forecasts of accumulated growing degree days and spring onset dates (based on the Extended Spring Indices) at fine spatial scale for the conterminous United States. These data products have utility for a wide range of natural resource planning and management applications, including scheduling invasive species and pest detection and control activities, determining planting dates, anticipating allergy outbreaks and planning agricultural harvest dates. Accumulated growing degree day (AGDD) maps were selected because accumulated temperature is a strong driver of phenological transitions in plants and animals, including leaf-out, flowering, fruit ripening and migration. The Extended Spring Indices (SI-x) are based on predictive climate models for lilac and honeysuckle leaf and bloom; they have been widely used to summarize changes in the timing of spring onset. The SI-x is used as a national indicator of climate change impacts by the US Global Change Research Program and the Environmental Protection Agency. The USA-NPN is a national-scale program that supports scientific advancement and decision-making by collecting, storing, and sharing phenology data and information. To best serve various audiences, the AGDD and SI-x gridded maps are available in various formats through a range of access tools, including the USA-NPN online visualization tool as well as industry standards compliant web services. We plan to expand the suite of gridded map products offered by the USA-NPN to include predictive maps of phenological transitions for additional plant and animal species at fine spatial and temporal resolution in the near future. USA-NPN invites you to use freely available daily and short-term forecast maps of accumulated growing degree days and spring onset dates at fine spatial scale for the conterminous United States.

Geochemistry and migration of contaminants at the Weldon Spring chemical plant site, St. Charles County, Missouri, 1989-91

USGS Publications Warehouse

Schumacher, John G.

1993-01-01

The geochemistry of the shallow aquifer and geochemical controls on the migration of uranium and other constituents from raffinate pits were determined at the Weldon Spring chemical plant site. Surface-water samples from the raffinate pits con- tained large concentrations of calcium, magnesium, sodium, potassium, sulfate, nitrite, lithium, moly- bdenum, strontium, vanadium, and uranium. Analyses of interstitial-water samples from raffinate pit 3 indicated that concentrations of most constituents increased with increasing depth below the water- sediment interface. Nitrate and uranium were not chemically reduced and attenuated within the raffinate pits and can be expected to migrate into the overburden. Laboratory sorption experiments were performed to evaluate the effect of pH value on the sorption of several raffinate constituents by the overburden. No sorption of calcium, sodium, sulfate, nitrate, or lithium was observed. Sorption of molybdenum was dependent on solution pH and sorption of uranium was dependent on solution pH and carbonate concentration. The sorption of uranium and molybdenum was consistent with sorption controlled by oxyhydroxides. The quality of water collected in overburden lysimeters near raffinate pit 4 can be modeled as a mixture of water from raffinate pits 3 and 4, and an uncontaminated com- ponent in a system at equilibrium with ferrihydrite and calcite. Increased constituent concentrations in a perennial spring north of the site were the result of a subsurface connection between the spring and several losing stream segments receiving runoff from the site, in addition to seepage from the raffinate pits.

Supplemental feeding alters migration of a temperate ungulate.

PubMed

Jones, Jennifer D; Kauffman, Matthew J; Monteith, Kevin L; Scurlock, Brandon M; Albeke, Shannon E; Cross, Paul C

Conservation of migration requires information on behavior and environmental determinants. The spatial distribution of forage resources, which migration exploits, often are altered and may have subtle, unintended consequences. Supplemental feeding is a common management practice, particularly for ungulates in North America and Europe, and carryover effects on behavior of this anthropogenic manipulation of forage are expected in theory, but have received limited empirical evaluation, particularly regarding effects on migration. We used global positioning system (GPS) data to evaluate the influence of winter feeding on migration behavior of 219 adult female elk (Cervus elaphus) from 18 fed ranges and 4 unfed ranges in western Wyoming. Principal component analysis revealed that the migratory behavior of fed and unfed elk differed in distance migrated, and the timing of arrival to, duration on, and departure from summer range. Fed elk migrated 19.2 km less, spent 11 more days on stopover sites, arrived to summer range 5 days later, resided on summer range 26 fewer days, and departed in the autumn 10 days earlier than unfed elk. Time-to-event models indicated that differences in migratory behavior between fed and unfed elk were caused by altered sensitivity to the environmental drivers of migration. In spring, unfed elk migrated following plant green-up closely, whereas fed elk departed the feedground but lingered on transitional range, thereby delaying their arrival to summer range. In autumn, fed elk were more responsive to low temperatures and precipitation events, causing earlier departure from summer range than unfed elk. Overall, supplemental feeding disconnected migration by fed elk from spring green-up and decreased time spent on summer range, thereby reducing access to quality forage. Our findings suggest that ungulate migration can be substantially altered by changes to the spatial distribution of resources, including those of anthropogenic origin, and that management practices applied in one season may have unintended behavioral consequences in subsequent seasons.

Supplemental feeding alters migration of a temperate ungulate

USGS Publications Warehouse

Jones, Jennifer D; Kauffman, Matthew J.; Monteith, Kevin L.; Scurlock, Brandon M.; Albeke, Shannon E.; Cross, Paul C.

2014-01-01

Conservation of migration requires information on behavior and environmental determinants. The spatial distribution of forage resources, which migration exploits, often are altered and may have subtle, unintended consequences. Supplemental feeding is a common management practice, particularly for ungulates in North America and Europe, and carryover effects on behavior of this anthropogenic manipulation of forage are expected in theory, but have received limited empirical evaluation, particularly regarding effects on migration. We used global positioning system (GPS) data to evaluate the influence of winter feeding on migration behavior of 219 adult female elk (Cervus elaphus) from 18 fed ranges and 4 unfed ranges in western Wyoming. Principal component analysis revealed that the migratory behavior of fed and unfed elk differed in distance migrated, and the timing of arrival to, duration on, and departure from summer range. Fed elk migrated 19.2 km less, spent 11 more days on stopover sites, arrived to summer range 5 days later, resided on summer range 26 fewer days, and departed in the autumn 10 days earlier than unfed elk. Time-to-event models indicated that differences in migratory behavior between fed and unfed elk were caused by altered sensitivity to the environmental drivers of migration. In spring, unfed elk migrated following plant green-up closely, whereas fed elk departed the feedground but lingered on transitional range, thereby delaying their arrival to summer range. In autumn, fed elk were more responsive to low temperatures and precipitation events, causing earlier departure from summer range than unfed elk. Overall, supplemental feeding disconnected migration by fed elk from spring green-up and decreased time spent on summer range, thereby reducing access to quality forage. Our findings suggest that ungulate migration can be substantially altered by changes to the spatial distribution of resources, including those of anthropogenic origin, and that management practices applied in one season may have unintended behavioral consequences in subsequent seasons.

Climate and the complexity of migratory phenology: sexes, migratory distance, and arrival distributions

NASA Astrophysics Data System (ADS)

Macmynowski, Dena P.; Root, Terry L.

2007-05-01

The intra- and inter-season complexity of bird migration has received limited attention in climatic change research. Our phenological analysis of 22 species collected in Chicago, USA, (1979 2002) evaluates the relationship between multi-scalar climate variables and differences (1) in arrival timing between sexes, (2) in arrival distributions among species, and (3) between spring and fall migration. The early migratory period for earliest arriving species (i.e., short-distance migrants) and earliest arriving individuals of a species (i.e., males) most frequently correlate with climate variables. Compared to long-distance migrant species, four times as many short-distance migrants correlate with spring temperature, while 8 of 11 (73%) of long-distance migrant species’ arrival is correlated with the North Atlantic Oscillation (NAO). While migratory phenology has been correlated with NAO in Europe, we believe that this is the first documentation of a significant association in North America. Geographically proximate conditions apparently influence migratory timing for short-distance migrants while continental-scale climate (e.g., NAO) seemingly influences the phenology of Neotropical migrants. The preponderance of climate correlations is with the early migratory period, not the median of arrival, suggesting that early spring conditions constrain the onset or rate of migration for some species. The seasonal arrival distribution provides considerable information about migratory passage beyond what is apparent from statistical analyses of phenology. A relationship between climate and fall phenology is not detected at this location. Analysis of the within-season complexity of migration, including multiple metrics of arrival, is essential to detect species’ responses to changing climate as well as evaluate the underlying biological mechanisms.

Sexual selection predicts advancement of avian spring migration in response to climate change.

PubMed

Spottiswoode, Claire N; Tøttrup, Anders P; Coppack, Timothy

2006-12-22

Global warming has led to earlier spring arrival of migratory birds, but the extent of this advancement varies greatly among species, and it remains uncertain to what degree these changes are phenotypically plastic responses or microevolutionary adaptations to changing environmental conditions. We suggest that sexual selection could help to understand this variation, since early spring arrival of males is favoured by female choice. Climate change could weaken the strength of natural selection opposing sexual selection for early migration, which would predict greatest advancement in species with stronger female choice. We test this hypothesis comparatively by investigating the degree of long-term change in spring passage at two ringing stations in northern Europe in relation to a synthetic estimate of the strength of female choice, composed of degree of extra-pair paternity, relative testes size and degree of sexually dichromatic plumage colouration. We found that species with a stronger index of sexual selection have indeed advanced their date of spring passage to a greater extent. This relationship was stronger for the changes in the median passage date of the whole population than for changes in the timing of first-arriving individuals, suggesting that selection has not only acted on protandrous males. These results suggest that sexual selection may have an impact on the responses of organisms to climate change, and knowledge of a species' mating system might help to inform attempts at predicting these.

High Altitude Bird Migration at Temperate Latitudes: A Synoptic Perspective on Wind Assistance

PubMed Central

Dokter, Adriaan M.; Shamoun-Baranes, Judy; Kemp, Michael U.; Tijm, Sander; Holleman, Iwan

2013-01-01

At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed migratory passerines at mid-latitudes that selected high altitude wind optima on particular nights, leading to the formation of structured migration layers at varying altitude up to 3 km. Using long-term vertical profiling of bird migration by C-band Doppler radar in the Netherlands, we find that such migration layers occur nearly exclusively during spring migration in the presence of a high-pressure system. A conceptual analytic framework providing insight into the synoptic patterns of wind assistance for migrants that includes the altitudinal dimension has so far been lacking. We present a simple model for a baroclinic atmosphere that relates vertical profiles of wind assistance to the pressure and temperature patterns occurring at temperate latitudes. We show how the magnitude and direction of the large scale horizontal temperature gradient affects the relative gain in wind assistance that migrants obtain through ascending. Temperature gradients typical for northerly high-pressure systems in spring are shown to cause high altitude wind optima in the easterly sectors of anticyclones, thereby explaining the frequent observations of high altitude migration in these synoptic conditions. Given the recurring synoptic arrangements of pressure systems across temperate continents, the opportunities for exploiting high altitude wind will differ between flyways, for example between easterly and westerly oceanic coasts. PMID:23300969

Variable detours in long-distance migration across ecological barriers and their relation to habitat availability at ground

PubMed Central

Hahn, Steffen; Emmenegger, Tamara; Lisovski, Simeon; Amrhein, Valentin; Zehtindjiev, Pavel; Liechti, Felix

2014-01-01

Migration detours, the spatial deviation from the shortest route, are a widespread phenomenon in migratory species, especially if barriers must be crossed. Moving longer distances causes additional efforts in energy and time, and to be adaptive, this should be counterbalanced by favorable condition en route. We compared migration patterns of nightingales that travelled along different flyways from their European breeding sites to the African nonbreeding sites. We tested for deviations from shortest routes and related the observed and expected routes to the habitat availability at ground during autumn and spring migration. All individuals flew detours of varying extent. Detours were largest and seasonally consistent in western flyway birds, whereas birds on the central and eastern flyways showed less detours during autumn migration, but large detours during spring migration (eastern flyway birds). Neither migration durations nor the time of arrival at destination were related to the lengths of detours. Arrival at the breeding site was nearly synchronous in birds flying different detours. Flying detours increased the potential availability of suitable broad-scale habitats en route only along the western flyway. Habitat availability on observed routes remained similar or even decreased for individuals flying detours on the central or the eastern flyway as compared to shortest routes. Thus, broad-scale habitat distribution may partially explain detour performance, but the weak detour-habitat association along central and eastern flyways suggests that other factors shape detour extent regionally. Prime candidate factors are the distribution of small suitable habitat patches at local scale as well as winds specific for the region and altitude. PMID:25505540

When and where does mortality occur in migratory birds? Direct evidence from long-term satellite tracking of raptors.

PubMed

Klaassen, Raymond H G; Hake, Mikael; Strandberg, Roine; Koks, Ben J; Trierweiler, Christiane; Exo, Klaus-Michael; Bairlein, Franz; Alerstam, Thomas

2014-01-01

Information about when and where animals die is important to understand population regulation. In migratory animals, mortality might occur not only during the stationary periods (e.g. breeding and wintering) but also during the migration seasons. However, the relative importance of population limiting factors during different periods of the year remains poorly understood, and previous studies mainly relied on indirect evidence. Here, we provide direct evidence about when and where migrants die by identifying cases of confirmed and probable deaths in three species of long-distance migratory raptors tracked by satellite telemetry. We show that mortality rate was about six times higher during migration seasons than during stationary periods. However, total mortality was surprisingly similar between periods, which can be explained by the fact that risky migration periods are shorter than safer stationary periods. Nevertheless, more than half of the annual mortality occurred during migration. We also found spatiotemporal patterns in mortality: spring mortality occurred mainly in Africa in association with the crossing of the Sahara desert, while most mortality during autumn took place in Europe. Our results strongly suggest that events during the migration seasons have an important impact on the population dynamics of long-distance migrants. We speculate that mortality during spring migration may account for short-term annual variation in survival and population sizes, while mortality during autumn migration may be more important for long-term population regulation (through density-dependent effects). © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

High altitude bird migration at temperate latitudes: a synoptic perspective on wind assistance.

PubMed

Dokter, Adriaan M; Shamoun-Baranes, Judy; Kemp, Michael U; Tijm, Sander; Holleman, Iwan

2013-01-01

At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed migratory passerines at mid-latitudes that selected high altitude wind optima on particular nights, leading to the formation of structured migration layers at varying altitude up to 3 km. Using long-term vertical profiling of bird migration by C-band Doppler radar in the Netherlands, we find that such migration layers occur nearly exclusively during spring migration in the presence of a high-pressure system. A conceptual analytic framework providing insight into the synoptic patterns of wind assistance for migrants that includes the altitudinal dimension has so far been lacking. We present a simple model for a baroclinic atmosphere that relates vertical profiles of wind assistance to the pressure and temperature patterns occurring at temperate latitudes. We show how the magnitude and direction of the large scale horizontal temperature gradient affects the relative gain in wind assistance that migrants obtain through ascending. Temperature gradients typical for northerly high-pressure systems in spring are shown to cause high altitude wind optima in the easterly sectors of anticyclones, thereby explaining the frequent observations of high altitude migration in these synoptic conditions. Given the recurring synoptic arrangements of pressure systems across temperate continents, the opportunities for exploiting high altitude wind will differ between flyways, for example between easterly and westerly oceanic coasts.

Rock Island Dam Smolt Monitoring; 1994-1995 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Truscott, Keith B.; Fielder, Paul C.

1995-10-01

Downstream migrating salmon and steelhead trout (Oncorhynchus spp.) smolts were monitored at the Rock Island Dam bypass trap from April 1 - August 31, 1954. This was the tenth consecutive year that the bypass trap was monitored. Data collected included: (1) number of fish caught by species, (2) number of adipose clipped and/or Passive Integrated Transponder (PIT) tagged fish caught by species, (3) daily average riverflow, (4) daily average powerhouse No. 1 and No. 2 flows and daily average spill. These data were transmitted to the Fish Passage Center, which manages the Smolt Monitoring Program throughout the Columbia River Basin.more » The Smolt Monitoring Program is used to manage the {open_quotes}water budget{close_quotes}, releasing upstream reservoir water storage allocated to supplement river flows to enhance survival of downstream migrating juvenile salmonids. The Rock Island Dam trapping facility collected 37,795 downstream migrating salmonids in 1994. Collected fish included 4 yearling and 4 sub-yearling chinook salmon (O. tshawytscha) that had been previously PIT tagged to help determine migration rates. Additionally, 1,132 sub-yearling chinook, 4,185 yearling chinook, 6,627 steelhead, (O. mykiss) and 422 sockeye (O. nerka) with clipped adipose fins were collected. The middle 80% of the 1994 spring migration (excluding sub-yearling chinooks) passed Rock Island Dam during a 34 day period, April 25 - May 28. Passage rates of chinook and steelhead smolts released from hatcheries and the downstream migration timing of all salmonids are presented. The spring migration timing of juvenile salmonids is strongly influenced by hatchery releases above Rock Island Dam.« less

Arthropods of native and exotic vegetation and their association with willow flycatchers and Wilson's warblers

Treesearch

Linda S. DeLay; Deborah M. Finch; Sandra Brantley; Richard Fagerlund; Michael D. Means; Jeffrey F. Kelly

1999-01-01

We compared abundance of migrating Willow Flycatchers and Wilson's Warblers to the abundance of arthropods in exotic and native vegetation at Bosque del Apache National Wildlife Refuge. We trapped arthropods using glue-boards in 1996 and 1997 in the same cottonwood, saltcedar, and willow habitats where we mist-netted birds during spring and fall migration. There...

Seasonal migration to high latitudes results in major reproductive benefits in an insect

PubMed Central

Chapman, Jason W.; Bell, James R.; Burgin, Laura E.; Reynolds, Donald R.; Pettersson, Lars B.; Hill, Jane K.; Bonsall, Michael B.; Thomas, Jeremy A.

2012-01-01

Little is known of the population dynamics of long-range insect migrants, and it has been suggested that the annual journeys of billions of nonhardy insects to exploit temperate zones during summer represent a sink from which future generations seldom return (the “Pied Piper” effect). We combine data from entomological radars and ground-based light traps to show that annual migrations are highly adaptive in the noctuid moth Autographa gamma (silver Y), a major agricultural pest. We estimate that 10–240 million immigrants reach the United Kingdom each spring, but that summer breeding results in a fourfold increase in the abundance of the subsequent generation of adults, all of which emigrate southward in the fall. Trajectory simulations show that 80% of emigrants will reach regions suitable for winter breeding in the Mediterranean Basin, for which our population dynamics model predicts a winter carrying capacity only 20% of that of northern Europe during the summer. We conclude not only that poleward insect migrations in spring result in major population increases, but also that the persistence of such species is dependent on summer breeding in high-latitude regions, which requires a fundamental change in our understanding of insect migration. PMID:22927392

Niche dynamics of shorebirds in Delaware Bay: Foraging behavior, habitat choice and migration timing

NASA Astrophysics Data System (ADS)

Novcic, Ivana

2016-08-01

Niche differentiation through resource partitioning is seen as one of the most important mechanisms of diversity maintenance contributing to stable coexistence of different species within communities. In this study, I examined whether four species of migrating shorebirds, dunlins (Calidris alpina), semipalmated sandpipers (Calidris pusilla), least sandpipers (Calidris minutilla) and short-billed dowitchers (Limnodromus griseus), segregate by time of passage, habitat use and foraging behavior at their major stopover in Delaware Bay during spring migration. I tested the prediction that most of the separation between morphologically similar species will be achieved by differential migration timing. Despite the high level of overlap along observed niche dimensions, this study demonstrates a certain level of ecological separation between migrating shorebirds. The results of analyses suggest that differential timing of spring migration might be the most important dimension along which shorebird species segregate while at stopover in Delaware Bay. Besides differences in time of passage, species exhibited differences in habitat use, particularly least sandpipers that foraged in vegetated areas of tidal marshes more frequently than other species, as well as short-billed dowitchers that foraged in deeper water more often than small sandpipers did. Partitioning along foraging techniques was less prominent than segregation along temporal or microhabitat dimensions. Such ranking of niche dimensions emphasizes significance of temporal segregation of migratory species - separation of species by time of passage may reduce the opportunity for interspecific aggressive encounters, which in turn can have positive effects on birds' time and energy budget during stopover period.

Decision-Making in Agent-Based Models of Migration: State of the Art and Challenges.

PubMed

Klabunde, Anna; Willekens, Frans

We review agent-based models (ABM) of human migration with respect to their decision-making rules. The most prominent behavioural theories used as decision rules are the random utility theory, as implemented in the discrete choice model, and the theory of planned behaviour. We identify the critical choices that must be made in developing an ABM, namely the modelling of decision processes and social networks. We also discuss two challenges that hamper the widespread use of ABM in the study of migration and, more broadly, demography and the social sciences: (a) the choice and the operationalisation of a behavioural theory (decision-making and social interaction) and (b) the selection of empirical evidence to validate the model. We offer advice on how these challenges might be overcome.

Potential for an Arctic-breeding migratory bird to adjust spring migration phenology to Arctic amplification.

PubMed

Lameris, Thomas K; Scholten, Ilse; Bauer, Silke; Cobben, Marleen M P; Ens, Bruno J; Nolet, Bart A

2017-10-01

Arctic amplification, the accelerated climate warming in the polar regions, is causing a more rapid advancement of the onset of spring in the Arctic than in temperate regions. Consequently, the arrival of many migratory birds in the Arctic is thought to become increasingly mismatched with the onset of local spring, consequently reducing individual fitness and potentially even population levels. We used a dynamic state variable model to study whether Arctic long-distance migrants can advance their migratory schedules under climate warming scenarios which include Arctic amplification, and whether such an advancement is constrained by fuel accumulation or the ability to anticipate climatic changes. Our model predicts that barnacle geese Branta leucopsis suffer from considerably reduced reproductive success with increasing Arctic amplification through mistimed arrival, when they cannot anticipate a more rapid progress of Arctic spring from their wintering grounds. When geese are able to anticipate a more rapid progress of Arctic spring, they are predicted to advance their spring arrival under Arctic amplification up to 44 days without any reproductive costs in terms of optimal condition or timing of breeding. Negative effects of mistimed arrival on reproduction are predicted to be somewhat mitigated by increasing summer length under warming in the Arctic, as late arriving geese can still breed successfully. We conclude that adaptation to Arctic amplification may rather be constrained by the (un)predictability of changes in the Arctic spring than by the time available for fuel accumulation. Social migrants like geese tend to have a high behavioural plasticity regarding stopover site choice and migration schedule, giving them the potential to adapt to future climate changes on their flyway. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Walla Walla River Fish Passage Operations Program, 2003-2004 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bronson, James P.

2004-12-01

In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survivalmore » of migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2003-2004 project year, there were 379 adult summer steelhead (Oncorhynchus mykiss), 36 adult bull trout (Salvelinus confluentus); 108 adult and 3 jack spring chinook (O. tshawytscha) enumerated at the Nursery Bridge Dam fishway video counting window between December 21, 2003, and June 30, 2004. Summer steelhead and spring chinook were observed moving upstream while bull trout were observed moving both upstream and downstream of the facility. In addition, the old ladder trap was operated by the WWBNPME project in order to radio tag spring chinook adults. A total of 2 adult summer steelhead, 4 bull trout, and 23 adult spring chinook were enumerated at the west ladder at Nursery Bridge Dam during the trapping operations between May 6 and May 23, 2004. Operation of the Little Walla Walla River juvenile trap for trap and haul purposes was not necessary this year. The project transported adult spring chinook from Threemile Dam to the South Fork Walla Walla Brood Holding Facility. A total of 239 spring chinook were outplanted in August for natural spawning in the basin.« less

Capturing migration phenology of terrestrial wildlife using camera traps

USGS Publications Warehouse

Tape, Ken D.; Gustine, David D.

2014-01-01

Remote photography, using camera traps, can be an effective and noninvasive tool for capturing the migration phenology of terrestrial wildlife. We deployed 14 digital cameras along a 104-kilometer longitudinal transect to record the spring migrations of caribou (Rangifer tarandus) and ptarmigan (Lagopus spp.) in the Alaskan Arctic. The cameras recorded images at 15-minute intervals, producing approximately 40,000 images, including 6685 caribou observations and 5329 ptarmigan observations. The northward caribou migration was evident because the median caribou observation (i.e., herd median) occurred later with increasing latitude; average caribou migration speed also increased with latitude (r2 = .91). Except at the northernmost latitude, a northward ptarmigan migration was similarly evident (r2 = .93). Future applications of this method could be used to examine the conditions proximate to animal movement, such as habitat or snow cover, that may influence migration phenology.

Differential timing and latitudinal variation in sex ratio of Aquatic Warblers during the autumn migration.

PubMed

Wojczulanis-Jakubas, Katarzyna; Chrostek, Małgorzata E; Jiguet, Frédéric; Martínez, Carlos Zumalacárregui; Miguélez, David; Neto, Júlio M

2017-11-14

Differential migration has been extensively reported in spring, but less so in autumn, particularly in relation to sex in monomorphic bird species. Here, we analysed the autumn passage of a monomorphic, globally threatened passerine, the Aquatic Warbler Acrocephalus paludicola throughout Western Europe, with regard to age and sex. We showed that, overall, adults migrated earlier than first-year birds, and males migrated earlier than females during the autumn migration. This may be caused by an overall social dominance of adults over immatures, and differentiated migration strategy of males and females. In addition, we found male-skewed sex proportions, with a tendency to an equalised ratio in more southern stopover sites. This may indicate a male bias in the global population or different migration strategies of the sexes. Differential migration may cause the age and sex classes to be exposed differently to various threats affecting demographic structure of the species.

Differential timing and latitudinal variation in sex ratio of Aquatic Warblers during the autumn migration

NASA Astrophysics Data System (ADS)

Wojczulanis-Jakubas, Katarzyna; Chrostek, Małgorzata E.; Jiguet, Frédéric; Martínez, Carlos Zumalacárregui; Miguélez, David; Neto, Júlio M.

2017-12-01

Differential migration has been extensively reported in spring, but less so in autumn, particularly in relation to sex in monomorphic bird species. Here, we analysed the autumn passage of a monomorphic, globally threatened passerine, the Aquatic Warbler Acrocephalus paludicola throughout Western Europe, with regard to age and sex. We showed that, overall, adults migrated earlier than first-year birds, and males migrated earlier than females during the autumn migration. This may be caused by an overall social dominance of adults over immatures, and differentiated migration strategy of males and females. In addition, we found male-skewed sex proportions, with a tendency to an equalised ratio in more southern stopover sites. This may indicate a male bias in the global population or different migration strategies of the sexes. Differential migration may cause the age and sex classes to be exposed differently to various threats affecting demographic structure of the species.

The Motivators That Contribute to the Migration of African American Educators from Suburban School Districts to Urban School Districts

ERIC Educational Resources Information Center

McGary, Ostrova Dewayne

2012-01-01

The purpose of this qualitative study was to examine the perceived motivators contributing African American educators' decision to migrate from a suburban school district to an urban school district. The case study approach was used in an effort to capture the participants' voices and the motivators contributing to their decision to migrate to an…

Individual variation in staging and timing of spring migration of Pacific common eiders in Alaska

USGS Publications Warehouse

Petersen, Margaret R.

2005-01-01

Timing of migration and characterization of migration patterns of birds are usually based on dates of peak migration to and from staging, wintering, and breeding areas used by the bulk of a species. For Pacific common eiders (Somateria mollissima v-nigrum), as well as other species, the timing of migration into and through the Beaufort Sea is based on counts of birds past land or ice-based sites and radar observations, and arrival dates to colonies determined by influxes of birds seen by ground observers. With the continued and proposed development of nearshore and offshore waters of the Beaufort Sea, there is an expanding need to manage local populations. Observations of individual Pacific common eiders can provide a more complete understanding of local populations as well as variability among populations. This study was designed to determine factors influencing migration patterns of individuals nesting in the western Beaufort Sea from their wintering locations along the Chukotka Peninsula, through the eastern Chukchi and western Beaufort seas, until their arrival to their nesting area. The Simpson Lagoon/Maguire Island nesting colonies are 1300-1400 km from the primary winter area. Eiders enter the Beaufort Sea at Point Barrow then move east 300-350 km to their nesting colonies. Nesting adult females were marked with satellite transmitters during summer then followed the next spring and early summer. Transmitters were programmed to provide location data every 3 days (2001, n = 12) or daily (2002 and 2004, n = 7 and 18, respectively) beginning 15 April. I expected the dates of arrival to the colony to vary with weather during migration (Point. Barrow to the colony) and general conditions in spring (early or late year based on differences in temperatures from the long term norm for April, May, and June). All individuals returned to the colony area they were marked the previous year. Data were consistent with other “short” distance migrants. There were no correlations of the dates of arrival to the dates birds left the wintering area, the total days spent staging, wind speed or direction, temperature, weather, or seasonal differences in temperature from the long term average, a plethora of non-significant results. However, two patterns emerged: some birds migrated about 550 km and staged in the eastern Chukchi Sea before migrating to the colonies, while others went directly either to the colony area (1300 km) or elsewhere within the western  Beaufort. I will present preliminary analysis and several hypotheses regarding these two strategies. 

Gender differences in socioeconomic returns to family migration in Malaysia: the role of family decision making versus labor market stratification.

PubMed

Chattopadhyay, A

2000-01-01

In this article the author examines gender differences in the effect of family migration on socioeconomic attainment in Malaysia. The analysis discerns the relative importance of gender roles in household migration decisions, compared to gender stratification in the labor market. The Malaysian economy has undergone rapid industrialization and great structural changes which have opened up new economic opportunities, particularly for women. Despite the somewhat advantaged position of women compared to men in the Malaysian labor market, the author finds that men experience much greater socioeconomic gains than women from family migration. Hence indicating that family migration decisions in Malaysia, rather than optimizing family gains, compensate for the gender effect in the labor market. However, the gains of Malaysian men are more assured when they move alone. Data for the study come from the second round of the Malaysian Family Life Survey.

Trophic ecology of mullets during their spring migration in a European saltmarsh: A stable isotope study

NASA Astrophysics Data System (ADS)

Lebreton, Benoit; Richard, Pierre; Parlier, Emmanuel P.; Guillou, Gaël; Blanchard, Gérard F.

2011-03-01

Mullet populations are abundant in littoral waters throughout the world and play a significant role in organic matter fluxes. Mullets are opportunistic feeders: adults have frequently been shown to feed on primary producers (e.g. fresh or detrital plant material, microphytobenthos) but they may also feed on meiofauna. The population structure and stomach contents of mullets that colonize saltmarsh creeks in Aiguillon Bay (French Atlantic coast) were studied to determine if they use saltmarshes as a feeding ground in spring. Stable isotope analyses were carried out on mullets sampled to assess their diet during their spring migration. The mullet population was primarily composed of young-of-the-year (G0), 1 year-old (G1) of both Liza ramada and Liza aurata species and 3 year-old or older (G3+) L. ramada individuals. G0 and G3+ population densities increased during the spring period: catch per unit effort (CPUE) increased from 0.22 to 1.49 ind min -1 for the G0 age group; but stomach content analyses revealed that only G1 and G3+ feed in the saltmarsh. Isotopic signatures of G1 (spring: δ 13C: -14.8‰, δ 15N: 14.1‰) and G3+ mullets (spring: δ 13C: -16.9‰, δ 15N: 13.8‰) indicate that mullet growth is supported largely by primary consumers, such as benthic meiofauna or small macrofauna. Mullets are thus positioned at a much higher trophic level than true primary consumers.

Habitat selection of woodchat shrikes Lanius senator during spring stopover is related to foraging strategy

PubMed Central

Barboutis, Christos; Kassara, Christina; Giokas, Sinos

2017-01-01

Abstract Every spring a huge number of passerines cross the Sahara Desert and the Mediterranean Sea on their way to their breeding grounds. Stopover sites after such extended barriers where birds can rest, refuel, and find shelter from adverse weather, are of crucial importance for the outcome of their migration. Stopover habitat selection used by migrating birds depends on landscape context, habitat patch characteristics, as well as on the particular energetic conditions and needs of individual birds, but it is still poorly investigated. We focused on a long-distance migrating passerine, the woodchat shrike, in order to investigate for the first time the species’ habitat selection at a spring stopover site (island of Antikythira, Greece) after the crossing of the Sahara Desert and Mediterranean Sea. We implemented radio-tracking, color-ringing, and visual behavioral observations to collect data on microhabitat use. Generalized Linear Mixed Models were developed to identify the species’ most preferred microhabitat during its stopover on this low human disturbed island. We found that high maquis vegetation surrounded by low vegetation was chosen as perches for hunting. Moreover, high maquis vegetation appeared to facilitate hunting attempts toward the ground, the most frequently observed foraging strategy. Finally, we discuss our findings in the context of conservation practices for the woodchat shrike and their stopover sites on Mediterranean islands. PMID:29491971

Use of Electromyogram Telemetry to Assess Swimmng Activity of Adult Spring Chinook Salmon Migrating Past a Columbia River Dam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Richard S.; Geist, David R.; Mesa, Matthew G.

Electromyogram (EMG) radiotelemetry was used to examine the amount of energy expended by spring Chinook salmon Oncorhynchus tshawytscha migrating upstream past a Columbia River dam. Electrodes from EMG transmitters were surgically implanted in the red muscle of fish captured at Bonneville Dam and output from the tags was calibrated to defined swim speeds for each fish in a tunnel respirometer. The fish were then released below Bonneville Dam and radio-tracked as they migrated through the tailraces, fishways, and forebays of the dam. On average, the rate of aerobic energy used by spring Chinook salmon was significantly higher when they weremore » moving through tailraces (1.27 kcal•kg-1•h-1) than when they were moving through other parts of the dam. Specifically, the rate of aerobic energy use for fish in tailraces was 14% higher than that used by fish in fishways (1.11 kcal•kg-1•h-1) and 27% higher than the rate used by fish in forebays (1.00 kcal•kg-1•h-1). Most (80%) of the aerobic energy used by fish to pass this dam was expended in the tailrace (25.5 kcal/kg), while only 18% (5.6 kcal/kg) and 2% (0.6 kcal/kg) were used in the fishways and forebays.« less

Avian cholera in Nebraska's Rainwater Basin

USGS Publications Warehouse

Windingstad, R.M.; Hurt, J.J.; Trout, A.K.; Cary, J.

1984-01-01

The first report of avian cholera in North America occurred in northwestern Texas in winter 1944 (Quortrup et al. 1946). In 1975, mortality from avian cholera occurred for the first time in waterfowl in the Rainwater Basin of Nebraska when an estimated 25,000 birds died (Zinkl et al. 1977). Avian cholera has continued to cause mortality in wild birds in specific areas of the Basin each spring since. Losses of waterfowl from avian cholera continue to be much greater in some of the wetlands in the western part of the Basin than in the east. Several wetlands in the west have consistently higher mortality and are most often the wetlands where initial mortality is noticed each spring (Figure 1). The establishment of this disease in Nebraska is of considerable concern because of the importance of the Rainwater Basin as a spring staging area for waterfowl migrating to their breeding grounds. The wetlands in this area are on a major migration route used by an estimated 5 to 9 million ducks and several hundred thousand geese. A large portion of the western mid-continental greater white-fronted goose (Anser albifrons) population stage in the Basin each spring. Occasionally, whooping cranes (Grus americana) use these wetlands during migration, and lesser sandhill cranes (Grus canadensis) staging on the nearby Platte River sometimes use wetlands where avian cholera occurs (Anonymous 1981). Our objectives were to determine whether certain water quality variables in the Rainwater Basin differed between areas of high and low avian cholera incidence. These results would then be used for laboratory studies involving the survivability of Pasteurella multocida, the causative bacterium of avian cholera. Those studies will be reported elsewhere.

Arab Spring, "Favelas," Borders, and the Artistic Transnational Migration: Toward a Curriculum for a Global Hip-Hop Nation

ERIC Educational Resources Information Center

Ibrahim, Awad

2017-01-01

Straddling between the purely political and the poetically artistic, I am arguing, is a Global Hip-Hop Nation (GHHN), which is yet to be charted and its cartography is yet to be demarcated. Taking two examples, the first a Hip-Hop song from within the Arab Spring and the second from the "favelas" in Brazil, my intent is to show what…

Supplement Analysis for the Grande Ronde Basin Endemic Spring Chinook Salmon Supplementation Program EA (DOE/EA-1173/SA-01)

DOE Office of Scientific and Technical Information (OSTI.GOV)

N /A

2003-12-18

The CTUIR and ODFW propose to expand their monitoring and evaluation for the Grande Ronde spring chinook supplementation program to take additional data on summer steelhead that are trapped at the existing adult collection weirs on the upper Grande Ronde River and Catherine Creek. The weirs are a movable design and are operated seasonally during the adult chinook migration. Bull trout and summer steelhead have been trapped at the weirs since 1997 incidental to the spring chinook broodstock collection activities. Minimal data is recorded on both species as a requirement of the ESA permits, and reported to USFWS and NOAAmore » Fisheries. This supplement analysis covers a minor expansion of the program to collect more extensive life history data on summer steelhead. The weir and trap will be installed 2-3 weeks earlier (early to mid-March) than was previously needed for the spring chinook broodstock collection in order to monitor the summer steelhead migration period. The adult steelhead will be captured in the traps, anesthetized, and measured. Data will be recorded on the date of capture, fork length, sex, markings, and maturity of the fish, and scale and punch tissue samples will be taken for genetic analyses.« less

Habitat use and movement patterns of Northern Pintails during spring in northern Japan: the importance of agricultural lands

USGS Publications Warehouse

Yamaguchi, Noriyuki M.; Hupp, Jerry W.; Flint, Paul L.; Pearce, John M.; Shigeta, Yusuke; Shimada, Tetsuo; Hiraoka, Emiko N.; Higuchi, Hiroyoshi

2012-01-01

From 2006 to 2009, we marked 198 Northern Pintails (Anas acuta) with satellite transmitters on their wintering areas in Japan to study their migration routes and habitat use in spring staging areas. We hypothesized that the distribution of pintails during spring staging was influenced by patterns of land use and expected that the most frequently used areas would have more agricultural habitat than lesser-used areas. We obtained 3031 daily locations from 163 migrant pintails marked with satellite transmitters and identified 524 stopover sites. Based on a fixed kernel home range analysis of stopover utilization distribution (UD), core staging areas (areas within the 50% UD) were identified in northern Honshu and western Hokkaido, and were used by 71% of marked pintails. Core staging areas had a greater proportion of rice fields than peripheral (51–95% UD) and rarely used (outside the 95% UD) staging areas. Stopover sites also contained more rice fields and other agricultural land than were available at regional scales, indicating that pintails selected rice and other agricultural habitats at regional and local scales. Pintails remained at spring staging areas an average of 51 d. Prolonged staging in agricultural habitats of northern Japan was likely necessary for pintails to prepare for transoceanic migration to Arctic nesting areas in eastern Russia.

Forage plants of an Arctic-nesting herbivore show larger warming response in breeding than wintering grounds, potentially disrupting migration phenology.

PubMed

Lameris, Thomas K; Jochems, Femke; van der Graaf, Alexandra J; Andersson, Mattias; Limpens, Juul; Nolet, Bart A

2017-04-01

During spring migration, herbivorous waterfowl breeding in the Arctic depend on peaks in the supply of nitrogen-rich forage plants, following a "green wave" of grass growth along their flyway to fuel migration and reproduction. The effects of climate warming on forage plant growth are expected to be larger at the Arctic breeding grounds than in temperate wintering grounds, potentially disrupting this green wave and causing waterfowl to mistime their arrival on the breeding grounds. We studied the potential effect of climate warming on timing of food peaks along the migratory flyway of the Russian population of barnacle geese using a warming experiment with open-top chambers. We measured the effect of 1.0-1.7°C experimental warming on forage plant biomass and nitrogen concentration at three sites along the migratory flyway (temperate wintering site, temperate spring stopover site, and Arctic breeding site) during 2 months for two consecutive years. We found that experimental warming increased biomass accumulation and sped up the decline in nitrogen concentration of forage plants at the Arctic breeding site but not at temperate wintering and stop-over sites. Increasing spring temperatures in the Arctic will thus shorten the food peak of nitrogen-rich forage at the breeding grounds. Our results further suggest an advance of the local food peak in the Arctic under 1-2°C climate warming, which will likely cause migrating geese to mistime their arrival at the breeding grounds, particularly considering the Arctic warms faster than the temperate regions. The combination of a shorter food peak and mistimed arrival is likely to decrease goose reproductive success under climate warming by reducing growth and survival of goslings after hatching.

An assessment of spatio-temporal relationships between nocturnal bird migration traffic rates and diurnal bird stopover density.

PubMed

Horton, Kyle G; Shriver, W Gregory; Buler, Jeffrey J

2016-01-01

Daily magnitudes and fluxes of landbird migration are often measured via nocturnal traffic rates aloft or diurnal densities within terrestrial habitats during stopover. However, these measures are not consistently correlated and at times reveal opposing trends. For this reason we sought to determine how comparison methods (daily magnitude or daily flux), nocturnal monitoring tools (weather surveillance radar, WSR; thermal imaging, TI), and temporal scale (preceding or following diurnal sampling) influenced correlation strength from stopover densities estimated by daily transect counts. We quantified nocturnal traffic rates at two temporal scales; averaged across the entire night and within individual decile periods of the night, and at two spatial scales; within 1 km of airspace surrounding the site via WSR and directly overhead within the narrow beam of a TI. Overall, the magnitude of daily bird density during stopover was positively related to the magnitude of broad-scale radar traffic rates of migrants on preceding and following nights during both the spring and fall. These relationships were strongest on the following night, and particularly from measures early in the night. Only during the spring on the following nights did we find positive correlations between the daily flux of transect counts and migration traffic rates (both WSR and TI). This indicates that our site likely had a more consistent daily turnover of migrants compared to the fall. The lack of general correlations between seasonal trends or daily flux in fine-scale TI traffic rates and stopover densities across or within nights was unexpected and likely due to poor sampling of traffic rates due to the camera's narrow beam. The order (preceding or following day) and metric of comparisons (magnitude or flux), as well as the tool (WSR or TI) used for monitoring nocturnal migration traffic can have dramatic impacts when compared with ground-based estimates of migrant density. WSR provided measures of the magnitude and daily flux in nocturnal migration traffic rates that related to daily stopover counts of migrants during spring and fall. Relationships among migrating bird flux measures are more complex than simple measures of magnitude of migration. Care should be given to address these complexities when comparing data among methods.

Distribution and migration chronology of Eastern population sandhill cranes

USGS Publications Warehouse

Fronczak, David L.; Andersen, David; Hanna, Everett E.; Cooper, Thomas R.

2017-01-01

The Eastern Population (EP) of greater sandhill cranes (Antigone canadensis tabida; cranes) is expanding in size and geographic range. Little information exists regarding the geographic extent of breeding, migration, and wintering ranges, migration chronology, or use of staging areas for cranes in the EP. To obtain these data, we attached solar global positioning system (GPS) platform transmitting terminals (PTTs) to 42 sandhill cranes and monitored daily locations from December 2009 through August 2014. On average, tagged cranes settled in summer areas during late‐March in Minnesota (7%), Wisconsin (29%), Michigan, USA (21%), and Ontario, Canada (38%) and arrived at their winter terminus beginning mid‐December in Indiana (15%), Kentucky (3%), Tennessee (45%), Georgia (5%), and Florida (32%). Cranes initiated spring migration beginning mid‐February to their respective summer areas on routes similar to those used during fall migration. Twenty‐five marked cranes returned to the same summer area after a second spring migration, of which 19 (76%) settled <3 km from the estimated mean center of the summer area of the previous year. During the 2010–2012 United States Fish and Wildlife Service (USFWS) Cooperative Fall Abundance Survey for cranes in the EP, we estimated that approximately 29–31% of cranes that summered in both Wisconsin and the Lower Peninsula of Michigan were not in areas included in the survey. The information we collected on crane movements provides insight into distribution and migration chronology that will aid in assessment of the current USFWS fall survey. In addition, information on specific use sites can assist state and federal managers to identify and protect key staging and winter areas particularly during current and future recreational harvest seasons.

Robust Spring Drying in the Southwestern U.S. and Seasonal Migration of Wet/Dry Patterns in a Warmer Climate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Yang; Leung, Lai-Yung R.; Lu, Jian

2014-03-16

This study compares climate simulations over the United States produced by a regional climate model with the driving global climate simulations as well as a large multi-model ensemble of global climate simulations to investigate robust changes in water availability (precipitation (P) – evapotranspiration (E)). A robust spring dry signal across multiple models is identified in the Southwest that results from a decrease in P and an increase in E in the future. In the boreal winter and summer, the prominent changes in P – E are associated with a north – south dipole pattern, while in spring, the prominent changesmore » in P – E appear as an east – west dipole pattern. The progression of the north – south and east – west dipole patterns through the seasons manifests clearly as a seasonal “clockwise” migration of wet/dry patterns, which is shown to be a robust feature of water availability changes in the US consistent across regional and global climate simulations.« less

Residency patterns of migrating sandpipers at a midcontinental stopover

USGS Publications Warehouse

Skagen, Susan K.; Knopf, Fritz L.

1994-01-01

Arctic-nesting shorebirds require several refueling stops during their long migrations between breeding grounds and Central and South American wintering areas. The protection of stopover habitats for transcontinental migrants depends on whether birds fly long distances between a few select sites or fly short distances and stop at several wetlands. Although the Great Plains historically provided a vast array of wetlands for use by migrants, wetland loss and conversion have reduced the availability of stopover sites in recent decades. In this study, we examined (1) residency periods, (2) fat dynamics, and (3) migration chronology of two shorebird species, the Semipalmated Sandpiper (Calidris pusilla) and White-rumped Sandpiper (C. fuscicollis) at Quivira National Wildlife Refuge (NWR), Kansas. Semipalmated Sandpipers had prolonged periods of species residency with overlapping arrivals and departures. Individual residency periods were highly variable and were unrelated to lipid reserves upon arrival. In contrast, White-rumped Sandpipers arrived and departed more synchronously. Birds that arrived in poor condition stayed longer than those with more body fat in 1991, but not in 1992. Wind direction did not influence patterns of departures of either species. We hypothesize that Semipalmated Sandpipers are ecologically eurytopic when migrating across the Great Plains in the spring. Highly variable patterns in arrival, residency, and lipid levels indicate that spring migration of this species is relaxed and opportunistic. White-rumped Sandpipers showed a pattern of reduced flexibility. Flight range estimates suggest that most birds require intermediate stopovers before reaching the breeding grounds. Interior wetlands appear to function as migration stopovers rather than staging areas for shorebirds.

Sensory basis of lepidopteran migration: Focus on the monarch butterfly

PubMed Central

Guerra, Patrick A.; Reppert, Steven M.

2015-01-01

In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compasses and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources. PMID:25625216

Sensory basis of lepidopteran migration: focus on the monarch butterfly.

PubMed

Guerra, Patrick A; Reppert, Steven M

2015-10-01

In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compass and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

Climate Induced Spillover and Implications for U.S. Security.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tidwell, Vincent C.; Naugle, Asmeret Bier; Backus, George A.

Developing nations incur a greater risk to climate change than the developed world due to poorly managed human/natural resources, unreliable infrastructure and brittle governing/economic institutions. These vulnerabilities often give rise to a climate induced “domino effect” of reduced natural resource production-leading to economic hardship, social unrest, and humanitarian crises. Integral to this cascading set of events is increased human migration, leading to the “spillover” of impacts to adjoining areas with even broader impact on global markets and security. Given the complexity of factors influencing human migration and the resultant spill-over effect, quantitative tools are needed to aid policy analysis. Towardmore » this need, a series of migration models were developed along with a system dynamics model of the spillover effect. The migration decision models were structured according to two interacting paths, one that captured long-term “chronic” impacts related to protracted deteriorating quality of life and a second focused on short-term “acute” impacts of disaster and/or conflict. Chronic migration dynamics were modeled for two different cases; one that looked only at emigration but at a national level for the entire world; and a second that looked at both emigration and immigration but focused on a single nation. Model parameterization for each of the migration models was accomplished through regression analysis using decadal data spanning the period 1960-2010. A similar approach was taken with acute migration dynamics except regression analysis utilized annual data sets limited to a shorter time horizon (2001-2013). The system dynamics spillover model was organized around two broad modules, one simulating the decision dynamics of migration and a second module that treats the changing environmental conditions that influence the migration decision. The environmental module informs the migration decision, endogenously simulating interactions/changes in the economy, labor, population, conflict, water, and food. A regional model focused on Mali in western Africa was used as a test case to demonstrate the efficacy of the model.« less

The Rest of the Story: A Qualitative Study of Chinese and Indian Women's Graduate Education Migration

ERIC Educational Resources Information Center

Yakaboski, Tamara

2013-01-01

Previous migration discourse views educational migration through narrowly defined push-pull forces, which ignores overseas graduate education as a path for maneuvering through restrictive gendered and cultural experiences. The purpose of this exploratory research is to expand migration research and view women's migration decisions as employing…

Evaluating predictors of local dabbling duck abundance during migration: Managing the spectrum of conditions faced by migrants

USGS Publications Warehouse

Aagaard, Kevin; Crimmins, Shawn M.; Thogmartin, Wayne E.; Tavernia, Brian G.; Lyons, James E.

2015-01-01

The development of robust modelling techniques to derive inferences from large-scale migratory bird monitoring data at appropriate scales has direct relevance to their management. The Integrated Waterbird Management and Monitoring programme (IWMM) represents one of the few attempts to monitor migrating waterbirds across entire flyways using targeted local surveys. This dataset included 13,208,785 waterfowl (eight Anas species) counted during 28,000 surveys at nearly 1,000 locations across the eastern United States between autumn 2010 and spring 2013 and was used to evaluate potential predictors of waterfowl abundance at the wetland scale. Mixed-effects, log-linear models of local abundance were built for the Atlantic and Mississippi flyways during spring and autumn migration to identify factors relating to habitat structure, forage availability, and migration timing that influence target dabbling duck species abundance. Results indicated that migrating dabbling ducks responded differently to environmental factors. While the factors identified demonstrated a high degree of importance, they were inconsistent across species, flyways and seasons. Furthermore, the direction and magnitude of the importance of each covariate group considered here varied across species. Given our results, actionable policy recommendations are likely to be most effective if they consider species-level variation within targeted taxonomic units and across management areas. The methods implemented here can easily be applied to other contexts, and serve as a novel investigation into local-level population patterns using data from broad-scale monitoring programmes.

Results of the Utah-Arizona stage-by-stage migrations

USGS Publications Warehouse

Ellis, D.H.; Mellon, C.; Kinloch, M.; Dolbeare, T.; Ossi, D.P.

2001-01-01

In an effort to find a safer means of teaching cranes new migration routes, each year (in 1998 and 1999) we transported a group of greater sandhill cranes (Grus canadensis tabida) stage-by-stage, in a horse trailer, with stops for brief flights at about 30-km intervals, along a 1300-1400-km fall migration route from Fish Springs National Wildlife Refuge (Fish Springs) in west-central Utah to the vicinity of Gila Bend, Arizona. Thereafter, we released them into a wild flock of sandhill cranes. All stage-by-stage birds were hand-reared with both a plastic crane decoy (to encourage them to roost in water) and a costume-draped humanoid form (called a scare-eagle and used for its namesake purpose). When these 2 teaching aids were placed in water, our cranes readily roosted nearby. All but 4 of our cranes proved cooperative (i.e., catchable at each of the ca 25-36 stops) during the migration. All were efficiently released into a wild flock and experienced good survival. The stage-by-stage method proved to be a safe means of transporting cranes south and giving them experience along the route. Some cranes apparently learned their route from the limited experience afforded by releasing them at intervals, and the 1999 cranes have made repealed migrations to or near our chosen northern terminus. However, after 1 winter in our chosen area, the birds have moved elsewhere to winter.

A Foraging Cost of Migration for a Partially Migratory Cyprinid Fish

PubMed Central

Chapman, Ben B.; Eriksen, Anders; Baktoft, Henrik; Brodersen, Jakob; Nilsson, P. Anders; Hulthen, Kaj; Brönmark, Christer; Hansson, Lars-Anders; Grønkjær, Peter; Skov, Christian

2013-01-01

Migration has evolved as a strategy to maximise individual fitness in response to seasonally changing ecological and environmental conditions. However, migration can also incur costs, and quantifying these costs can provide important clues to the ultimate ecological forces that underpin migratory behaviour. A key emerging model to explain migration in many systems posits that migration is driven by seasonal changes to a predation/growth potential (p/g) trade-off that a wide range of animals face. In this study we assess a key assumption of this model for a common cyprinid partial migrant, the roach Rutilus rutilus, which migrates from shallow lakes to streams during winter. By sampling fish from stream and lake habitats in the autumn and spring and measuring their stomach fullness and diet composition, we tested if migrating roach pay a cost of reduced foraging when migrating. Resident fish had fuller stomachs containing more high quality prey items than migrant fish. Hence, we document a feeding cost to migration in roach, which adds additional support for the validity of the p/g model of migration in freshwater systems. PMID:23723967

Survival and migration behavior of juvenile salmonids at Lower Granite Dam, 2006

USGS Publications Warehouse

Beeman, John W.; Fielding, Scott D.; Braatz, Amy C.; Wilkerson, Tamara S.; Pope, Adam C.; Walker, Christopher E.; Hardiman, Jill M.; Perry, Russell W.; Counihan, Timothy D.

2008-01-01

We described behavior and estimated passage and survival parameters of juvenile salmonids during spring and summer migration periods at Lower Granite Dam in 2006. During the spring, the study was designed to examine the effects of the Behavioral Guidance Structure (BGS) by using a randomized-block BGS Stored / BGS Deployed treatment design. The summer study was designed to compare passage and survival through Lower Granite Dam using a randomized-block design during two spill treatments while the BGS was in the stored position. We used the Route Specific Survival Model to estimate survival and passage probabilities of hatchery yearling Chinook salmon, hatchery juvenile steelhead, and hatchery and wild subyearling Chinook salmon. We also estimated fish guidance efficiency (FGE), fish passage efficiency (FPE), Removable Spillway Weir passage effectiveness (RPE), spill passage effectiveness (SPY), and combined spill and RSW passage effectiveness.

Measured flow and tracer-dye data for spring 1996 and 1997 for the south Sacramento-San Joaquin Delta, California

USGS Publications Warehouse

Oltmann, Richard N.

1999-01-01

During the spring of years when the flow of the San Joaquin River is less than 7,000 cubic feet per second (ft3/s) a temporary rock barrier is installed by the California Department of Water Resources (DWR) at the head of Old River (HOR) in the south Sacramento-San Joaquin Delta to prevent out migrating salmon in the San Joaquin River from entering Old River and being drawn to the State and federal pumping facilities (Figure 1). The export rate of the pumping facilities also is reduced during these migration periods to minimize the draw of fish to the export facilities through the other channels connected to the San Joaquin River north of the HOR such as Turner Cut, Columbia Cut, and Middle River.

Downstream migration of recently transformed sea lampreys before and after treatment of a Lake Michigan tributary with a lampricide

USGS Publications Warehouse

Hodges, John W.

1972-01-01

After the Pere Marquette River was treated with a lampricide in May 1964, the number of recently transformed sea lampreys (Petromyzon marinus) collected in the water-intake structure of a chemical plant near the mouth of the stream dropped 99.5%, from 13,913 (average for 1962-63 and 1963-64) to 76 (average for the next four migration seasons). Average length of the lampreys caught increased markedly after the treatment. In five of the six migration seasons, the catch of downstream migrants was higher in the fall than in the spring.

Hepatic element concentrations of lesser scaup (Aythya affinis) during spring migration in the upper Midwest

USGS Publications Warehouse

Pillatzki, Angela E.; Neiger, Regg D.; Chipps, Steven R.; Higgins, Kenneth F.; Thiex, Nancy; Afton, Alan D.

2011-01-01

High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 μg/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 μg/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction.

Hepatic element concentrations of lesser scaup (aythya affinis) during spring migration in the upper midwest

USGS Publications Warehouse

Pillatzki, A.E.; Neiger, R.D.; Chipps, S.R.; Higgins, K.F.; Thiex, N.; Afton, A.D.

2011-01-01

High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 ??g/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 ??g/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction. ?? 2010 Springer Science+Business Media, LLC.

Rural migration in Nevada: Lincoln County. Phase 1, 1992--1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soden, D.L.; Carns, D.E.; Mosser, D.

1993-12-31

The principal objective of this project was to develop insight into the scope of migration of working age Nevadans out of their county of birth; including the collection of data on their skill levels, desire to out or in-migrate, interactions between families of migratory persons, and the impact that the proposed high-level nuclear waste repository at Yucca mountain might have on their individual, and collective, decisions to migrate and return. The initial phase of this project reported here was conducted in 1992 and 1993 in Lincoln County, Nevada, one of the counties designated as ``affected`` by the proposed repository program.more » The findings suggest that a serious out-migration problem exists in Lincoln County, and that the Yucca mountain project will likely affect decisions relating to migration patterns in the future.« less

Conserving migratory land birds in the New World: Do we know enough?

USGS Publications Warehouse

Faaborg, John; Holmes, Richard T.; Anders, A.D.; Bildstein, K.L.; Dugger, K.M.; Gauthreaux, S.A.; Heglund, P.; Hobson, K.A.; Jahn, A.E.; Johnson, D.H.; Latta, S.C.; Levey, D.J.; Marra, P.P.; Merkord, C.L.; Nol, E.; Rothstein, S.I.; Sherry, T.W.; Scott, Sillett T.; Thompson, F. R.; Warnock, N.

2010-01-01

Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas. Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird's life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk, Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human population growth, acid deposition, climate change, and exotic diseases are global concerns with uncertain consequences to migratory birds and even lesscertain remedies. Despite enormous gaps in our understanding of these birds, research, much of it occurring in the past 30 years, has provided sufficient information to make intelligent conservation efforts but needs to expand to handle future challenges. ?? 2010 by the Ecological Society of America.

Conserving migratory land birds in the new world: do we know enough?

PubMed

Faaborg, John; Holmes, Richard T; Anders, Angela D; Bildstein, Keith L; Dugger, Katie M; Gauthreaux, Sidney A; Heglund, Patricia; Hobson, Keith A; Jahn, Alex E; Johnson, Douglas H; Latta, Steven C; Levey, Douglas J; Marra, Peter P; Merkord, Christopher L; Nol, Erica; Rothstein, Stephen I; Sherry, Thomas W; Sillett, T Scott; Thompson, Frank R; Warnock, Nils

2010-03-01

Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas, Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird's life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk. Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human population growth, acid deposition, climate change, and exotic diseases are global concerns with uncertain consequences to migratory birds and even less-certain remedies. Despite enormous gaps in our understanding of these birds, research, much of it occurring in the past 30 years, has provided sufficient information to make intelligent conservation efforts but needs to expand to handle future challenges.

Assessing spring direct mortality to avifauna from wind energy facilities in the Dakotas

USGS Publications Warehouse

Graff, Brianna J.; Jenks, Jonathan A.; Stafford, Joshua D.; Jensen, Kent C.; Grovenburg, Troy W.

2016-01-01

The Northern Great Plains (NGP) contains much of the remaining temperate grasslands, an ecosystem that is one of the most converted and least protected in the world. Within the NGP, the Prairie Pothole Region (PPR) provides important habitat for >50% of North America's breeding waterfowl and many species of shorebirds, waterbirds, and grassland songbirds. This region also has high wind energy potential, but the effects of wind energy developments on migratory and resident bird and bat populations in the NGP remains understudied. This is troubling considering >2,200 wind turbines are actively generating power in the region and numerous wind energy projects have been proposed for development in the future. Our objectives were to estimate avian and bat fatality rates for wind turbines situated in cropland- and grassland-dominated landscapes, document species at high risk to direct mortality, and assess the influence of habitat variables on waterfowl mortality at 2 wind farms in the NGP. From 10 March to 7 June 2013–2014, we completed 2,398 searches around turbines for carcasses at the Tatanka Wind Farm (TAWF) and the Edgeley-Kulm Wind Farm (EKWF) in South Dakota and North Dakota. During spring, we found 92 turbine-related mortalities comprising 33 species and documented a greater diversity of species (n = 30) killed at TAWF (predominately grassland) than at EKWF (n = 9; predominately agricultural fields). After accounting for detection rates, we estimated spring mortality of 1.86 (SE = 0.22) deaths/megawatt (MW) at TAWF and 2.55 (SE = 0.51) deaths/MW at EKWF. Waterfowl spring (Mar–Jun) fatality rates were 0.79 (SE = 0.11) and 0.91 (SE = 0.10) deaths/MW at TAWF and EKWF, respectively. Our results suggest that future wind facility siting decisions consider avoiding grassland habitats and locate turbines in pre-existing fragmented and converted habitat outside of high densities of breeding waterfowl and major migration corridors.

A Spring Forward for Human Evolution in East Africa?

NASA Astrophysics Data System (ADS)

Cuthbert, M. O.; Ashley, G. M.

2014-12-01

The current consensus is that humans evolved in Africa and then migrated in waves to other parts of the world starting as early as 2 Ma. The climate was both cooling and drying. One of the major unknowns connected with human survival in this climatically turbulent environment is the availability of resources, particularly water. A growing body of geological evidence shows an association between springs, stone tools and hominin fossils at a number of sites in the East African Rift System (EARS) during a critical period for hominin evolution (from 1.8 Ma). The springs may have been vulnerable to climate variability, thus the role that groundwater availability may have played in human evolution and migration to other continents is not known. Using palaeogeological reconstruction and groundwater modelling of the paleo-catchment of one such EARS site, Olduvai Gorge (3°S), we show how spring discharge was likely linked to climate variability of annual to Milankovitch cycle timescales. Under decadal to centennial timescales, spring flow would have been relatively invariant providing good water resource resilience through long droughts. For multi-millennial periods, modelled spring flows lag groundwater recharge by 100s to 1000 years. Our results show how groundwater would have provided 'drought proof' water supply and habitats during arid phases as potable surface water from rivers or lakes became increasingly scarce. Localized groundwater systems are likely to have been widespread within the EARS providing refugia and intense competition during dry periods. Thus, springs and associated wetlands may have been important factors in natural selection and evolution, as well as a vital resource during dispersal within and out of Africa. While further exploration is needed to test the geographical extent of groundwater use by early humans, we propose that groundwater flow systems produced in the EARS played a significant role in the evolution and dispersal of early humans.

Tonawanda Creek, Genesee County, New York, Regional Flood Control. Final Environmental Impact Statement.

DTIC Science & Technology

1981-11-01

sedges, rushes, cattails, and iris and some woody shrub species, have established within or around the periphery of these areas that help to pro- vide...extensively in spring and fall. Shrub swamps are comprised of woody species such as red-osier dogwood, silky dogwood, arrow-wood, buckthorn, slippery...valuable to wildlife and are used extensively by migrating waterfowl during the spring and summer. Shrub swamps are dominated by woody species, including

Lower Granite Dam Smolt Monitoring Program, 1998 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verhey, Peter; Ross, Doug; Morrill, Charles

1998-12-01

The 1998 fish collection season at Lower Granite was characterized by relatively moderate spring flows and spill, moderate levels of debris, cool spring, warm summer and fall water temperatures, and increased chinook numbers, particularly wild subyearling chinook collected and transported. The Fish Passage Center's Smolt Monitoring Program is designed to provide a consistent, real-time database on fish passage and document the migrational characteristics of the many stocks of salmon and steelhead in the Columbia Basin.

Altered expression of pectoral myosin heavy chain isoforms corresponds to migration status in the white-crowned sparrow (Zonotrichia leucophrys gambelii)

PubMed Central

Welch, Kenneth C.; Ramenofsky, Marilyn

2016-01-01

Birds undergo numerous changes as they progress through life-history stages, yet relatively few studies have examined how birds adapt to both the dynamic energetic and mechanical demands associated with such transitions. Myosin heavy chain (MyHC) expression, often linked with muscle fibre type, is strongly correlated with a muscle's mechanical power-generating capability, thus we examined several morphological properties, including MyHC expression of the pectoralis, in a long-distance migrant, the white-crowned sparrow (Zonotrichia leucophrys gambelii) throughout the progression from winter, spring departure and arrival on breeding grounds. White-crowned sparrows demonstrated significant phenotypic flexibility throughout the seasonal transition, including changes in prealternate moult status, lipid fuelling, body condition and flight muscle morphology. Pectoral MyHC expression also varied significantly over the course of the study. Wintering birds expressed a single, newly classified adult fast 2 isoform. At spring departure, pectoral isoform expression included two MyHC isoforms: the adult fast 2 isoform along with a smaller proportion of a newly present adult fast 1 isoform. By spring arrival, both adult fast isoforms present at departure remained, yet expression had shifted to a greater relative proportion of the adult fast 1 isoform. Altering pectoral MyHC isoform expression in preparation for and during spring migration may represent an adaptation to modulate muscle mechanical output to support long-distance flight. PMID:28018664

Associations of intestinal helminth infections with health parameters of spring-migrating female lesser scaup (Aythya affinis) in the upper Midwest, USA.

PubMed

Conner England, J; Levengood, Jeffrey M; Osborn, Josh M; Yetter, Aaron P; Suski, Cory D; Cole, Rebecca A; Hagy, Heath M

2018-06-01

Thousands of lesser scaup (Aythya affinis) die during spring and fall migrations through the upper Midwest, USA, from infections with Cyathocotyle bushiensis and Sphaeridiotrema spp. (Class: Trematoda) after ingesting infected intermediate hosts, such as non-native faucet snails (Bithynia tentaculata). The lesser scaup is a species of conservation concern and is highly susceptible to these infections. We collected female lesser scaup from spring migratory stopover locations throughout Illinois and Wisconsin and assessed biochemical and morphological indicators of health in relation to intestinal helminth loads. Helminth species diversity, total trematode abundance, and the infection intensities of the trematodes C. bushiensis and Sphaeridiotrema spp. were associated with percent body fat, blood metabolites, hematological measures, and an index of foraging habitat quality. Helminth diversity was negatively associated with percent body fat, albumin concentrations, and monocytes, whereas glucose concentrations displayed a slight, positive association. Total trematode abundance was negatively associated with blood concentrations of non-esterified fatty acids and albumin. Infections of C. bushiensis were positively related to basophil levels, whereas Sphaeridiotrema spp. infection intensity was negatively associated with packed cell volume and foraging habitat quality. Thus, commonly measured health metrics may indicate intestinal parasite infections and help waterfowl managers understand overall habitat quality. Intestinal parasitic loads offer another plausible mechanism underlying the spring condition hypothesis.

On marriage and migration.

PubMed

Stark, O

1988-09-01

Marriage, migration, and related phenomena such as marital stability, fertility, and investment in human capital may be better explained by studying marriage and migration jointly. This paper examines the role of migration in obtaining joint labor market and marriage market equilibrium. When broadly interpreted, marriage and migration share a number of common features. Both involve search and its resolution (pairing of mates in the former and matching of labor and firms in the latter). In both cases, success in finding a partner is sensitive to the availability of partners and to the distribution of their endowments and traits. Almost always, and along with separation and divorce, marriage mandates spatial relocation which may translate into migration. Both involve a movement that is associated with adjustment costs from 1 state into another. The decisions to enter marriage and undertake employment or the decisions to divorce and quit a job depend on exogenous parameters, some of which are determined by the marriage market and the labor market. Since both marriage and divorce take place in the context of broadly defined markets, they may and often are analyzed applying market concepts, theorems, and solutions. Yet the authors could not pinpoint 1 single, systematic attempt that checks through the interactions between marriage and migration, so this paper attempts to rectify this state of research. Essentially, this paper 1) discusses individual decision making pending possible migration prior to or following marriage, 2) examines whether it is easier for a married couple or a single person to migrate, and 3) considers whether marriage dissolution could cause migration when marriage is the only reason that has kept a spouse from moving. This integrated research agenda for both marriage and migration can delineate interesting new implications to examine.

Bird migration patterns in the arid southwest-Final report

USGS Publications Warehouse

Ruth, Janet M.; Felix, Rodney K.; Dieh, Robert H.

2010-01-01

To ensure full life-cycle conservation, we need to understand migrant behavior en route and how migrating species use stopover and migration aerohabitats. In the Southwest, birds traverse arid and mountainous landscapes in migration. Migrants are known to use riparian stopover habitats; we know less about how migrant density varies across the Southwest seasonally and annually, and how migrants use other habitat types during migratory stopover. Furthermore, we lack information about migrant flight altitudes, speeds, and directions of travel, and how these patterns vary seasonally and annually across the Southwest. Using weather surveillance radar data, we identified targets likely dominated by nocturnally migrating birds and determined their flight altitudes, speeds, directions over ground, and variations in abundance. Migrating or foraging bats likely are present across the region in some of these data, particularly in central Texas. We found that migrants flew at significantly lower altitudes and significantly higher speeds in spring than in fall. In all seasons migrants maintained seasonally appropriate directions of movement. We detected significant differences in vertical structure of migrant densities that varied both geographically within seasons and seasonally within sites. We also found that in fall there was a greater and more variable passage of migrants through the central part of the borderlands (New Mexico and west Texas); in spring there was some suggestion of greater and more variable passage of migrants in the eastern borderlands (central and south Texas). Such patterns are consistent with the existence of at least two migration systems through western North America and the use of different migration routes in spring and fall for at least some species. Using radar data and satellite land cover data, we determined the habitats with which migrants are associated during migration stopover. There were significant differences in bird densities among habitat types at all sites in at least one season. Upland forest habitat in parts of Arizona and New Mexico supported high migrant densities, especially in fall. Developed habitats in areas with little upland forest habitat also supported high migrant densities. Scrub/shrub and grassland habitats supported low to intermediate migrant densities, but because these habitat types dominate the region, they may support large numbers of migratory birds. This may be especially true for species that do not use forested habitats during migration. Target identity remains a challenge for radar-based studies. Presence of bats in the data complicates interpretation of some observations, particularly from central Texas. Based on our results it is simplistic to: (1) consider the arid west as a largely inhospitable landscape in which there are only relatively small oases of habitat that provide the resources needed by all migrants; (2) think of western riparian and upland forest habitat as supporting the majority of migrants in all cases; or (3) consider a particular habitat type unimportant migrant stopover habitat based solely on migrant densities.

Evaluation of energy expenditure in adult spring Chinook salmon migrating upstream in the Columbia River Basin: an assessment based on sequential proximate analysis

USGS Publications Warehouse

Mesa, M.G.; Magie, C.D.

2006-01-01

The upstream migration of adult anadromous salmonids in the Columbia River Basin (CRB) has been dramatically altered and fish may be experiencing energetically costly delays at dams. To explore this notion, we estimated the energetic costs of migration and reproduction of Yakima River-bound spring Chinook salmon Oncorhynchus tshawytscha using a sequential analysis of their proximate composition (i.e., percent water, fat, protein, and ash). Tissues (muscle, viscera, and gonad) were sampled from fish near the start of their migration (Bonneville Dam), at a mid point (Roza Dam, 510 km upstream from Bonneville Dam) and from fresh carcasses on the spawning grounds (about 100 km above Roza Dam). At Bonneville Dam, the energy reserves of these fish were remarkably high, primarily due to the high percentage of fat in the muscle (18-20%; energy content over 11 kJ g-1). The median travel time for fish from Bonneville to Roza Dam was 27 d and ranged from 18 to 42 d. Fish lost from 6 to 17% of their energy density in muscle, depending on travel time. On average, fish taking a relatively long time for migration between dams used from 5 to 8% more energy from the muscle than faster fish. From the time they passed Bonneville Dam to death, these fish, depending on gender, used 95-99% of their muscle and 73-86% of their viscera lipid stores. Also, both sexes used about 32% of their muscular and very little of their visceral protein stores. However, we were unable to relate energy use and reproductive success to migration history. Our results suggest a possible influence of the CRB hydroelectric system on adult salmonid energetics.

Patterns of testosterone in three Nearctic-Neotropical migratory songbirds during spring passage.

PubMed

Covino, Kristen M; Morris, Sara R; Moore, Frank R

2015-12-01

Preparation for breeding may overlap extensively with vernal migration in long-distance migratory songbirds. Testosterone plays a central role in mediating this transition into breeding condition by facilitating changes to physiology and behavior. While changes in testosterone levels are well studied in captive migrants, these changes are less well known in free-living birds. We examined testosterone levels in free-living Nearctic-Neotropical migrants of three species during their vernal migration. Testosterone levels increased during the migratory period in males of all three species but significantly so in only two. Testosterone levels in females remained the same throughout their migration. Our results support the extensive overlap between vernal migration and breeding preparation in male songbirds. The pattern of testosterone changes during vernal migration is far from clear in females. Copyright © 2015 Elsevier Inc. All rights reserved.

Sulfolobus islandicus meta-populations in Yellowstone National Park hot springs

USGS Publications Warehouse

Campbell, Kate M.; Kouris, Angela; England, Whitney; Anderson, Rika E.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Whitaker, Rachel J.

2017-01-01

Abiotic and biotic forces shape the structure and evolution of microbial populations. We investigated forces that shape the spatial and temporal population structure of Sulfolobus islandicus by comparing geochemical and molecular analysis from seven hot springs in five regions sampled over 3 years in Yellowstone National Park. Through deep amplicon sequencing, we uncovered 148 unique alleles at two loci whose relative frequency provides clear evidence for independent populations in different hot springs. Although geography controls regional geochemical composition and population differentiation, temporal changes in population were not explained by corresponding variation in geochemistry. The data suggest that the influence of extinction, bottleneck events and/or selective sweeps within a spring and low migration between springs shape these populations. We suggest that hydrologic events such as storm events and surface snowmelt runoff destabilize smaller hot spring environments with smaller populations and result in high variation in the S. islandicus population over time. Therefore, physical abiotic features such as hot spring size and position in the landscape are important factors shaping the stability and diversity of the S. islandicus meta-population within Yellowstone National Park.

Convergence of broad-scale migration strategies in terrestrial birds.

PubMed

La Sorte, Frank A; Fink, Daniel; Hochachka, Wesley M; Kelling, Steve

2016-01-27

Migration is a common strategy used by birds that breed in seasonal environments. Selection for greater migration efficiency is likely to be stronger for terrestrial species whose migration strategies require non-stop transoceanic crossings. If multiple species use the same transoceanic flyway, then we expect the migration strategies of these species to converge geographically towards the most optimal solution. We test this by examining population-level migration trajectories within the Western Hemisphere for 118 migratory species using occurrence information from eBird. Geographical convergence of migration strategies was evident within specific terrestrial regions where geomorphological features such as mountains or isthmuses constrained overland migration. Convergence was also evident for transoceanic migrants that crossed the Gulf of Mexico or Atlantic Ocean. Here, annual population-level movements were characterized by clockwise looped trajectories, which resulted in faster but more circuitous journeys in the spring and more direct journeys in the autumn. These findings suggest that the unique constraints and requirements associated with transoceanic migration have promoted the spatial convergence of migration strategies. The combination of seasonal atmospheric and environmental conditions that has facilitated the use of similar broad-scale migration strategies may be especially prone to disruption under climate and land-use change. © 2016 The Author(s).

Make Development Decisions Predictable and Fair: Green Tape Program, Silver Spring, Maryland

EPA Pesticide Factsheets

Montgomery County's Green Tape program is making redevelopment in Silver Spring, Maryland, faster and more cost effective by speeding the permitting process for development in the mixed-use city center.

Intra-household conflicts in migration decisionmaking: return and pendulum migration in Morocco.

PubMed

De Haas, Hein; Fokkema, Tineke

2010-01-01

By analyzing the migration behavior and transnational residential strategies of first-generation, aging migrants from a particular Moroccan sending region, this study contributes to a conceptual critique of migration theories that identify the household as the most relevant decisionmaking unit. It highlights the role of intra-household power inequalities and conflicts in migration decisionmaking as well as the effects of migration decisions for intra-household power relations. Many labor migrants who left Morocco to work in Europe in the 1960s and 1970s did not realize their wish to return but instead ended up reunifying their families at the destination. An increasing proportion adopts a pendulum migration strategy to reconcile their own wish to retain strong ties with Morocco with the reluctance of children and spouses to return. Migrants who unilaterally decided not to reunify their families usually return after their active working life. However, this unilateral decision also blocks legal entry into Europe for their children, which has generated considerable intergenerational tensions.

Patterns of migration and residency in coastal cutthroat trout Oncorhynchus clarkii clarkii from two tributaries of the lower Columbia River

USGS Publications Warehouse

Zydlewski, G.B.; Zydlewski, Joseph D.; Johnson, J.

2009-01-01

Coastal cutthroat trout Onchorhynchus clarkii clarkii life-history variants, migration and freshwater residency were monitored using stationary passive integrated transponder (PIT) tag arrays in two tributaries of the Columbia River from 2001 to 2005 (Abernathy Creek, river kilometre, rkm 76) and from 2002 to 2005 (Chinook River, rkm 6). In 2001-2003 and 2002-2003 (Abernathy and Chinook, respectively), 300-500 coastal O. c. clarkii were captured in each tributary by electrofishing and implanted with 23 mm PIT tags. PIT arrays monitored movements from the initiation of tagging through the spring of 2005. Rotary screw traps were also operated on both tributaries. In Abernathy Creek, 28% of tagged individuals were observed through either active capture or passive interrogation. Of these, 32% were identified as migrants and 68% were identified as residents. In the Chinook River, 48% of tagged fish were observed subsequent to tagging; 92% of these fish were migrants and only 8% were resident. In both tributaries, a greater proportion of resident fish were in the upper reaches. The majority of migrants (78-93%) moved the spring following tagging. Migrants leaving at age 2+ years tended to grow faster than those that migrated at age 3+ years or residents. Patterns of growth or growth opportunities may influence both patterns of life-history expression and the timing of migration. ?? 2009 The Fisheries Society of the British Isles.

The greenscape shapes surfing of resource waves in a large migratory herbivore

USGS Publications Warehouse

Aikens, Ellen O.; Kauffman, Matthew J.; Merkle, Jerod A.; Dwinnell, Samantha P.H.; Fralick, Gary L.; Monteith, Kevin L.

2017-01-01

The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e. green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that migratory routes are more than a link between seasonal ranges, and they provide an important, but often overlooked, foraging habitat. In addition, the spatiotemporal configuration of forage resources that propagate along migratory routes shape animal movement and presumably, energy gains during migration.

Emigration of Natural and Hatchery Chinook Salmon and Steelhead Smolts from the Imnaha River, Oregon, Progress Report 2000-2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleary, Peter; Kucera, Paul; Blenden, Michael

This report summarizes the emigration studies of the Nez Perce Tribe in the Imnaha River subbasin during the 2001 and 2002 migration years. A migration year for the Imnaha River is defined here as beginning July 31 of the previous year and ending July 30 the following year. The conclusion of the studies at the end of migration year 2002 marked the 11th year of the Nez Perce Tribe's Lower Snake River Emigration Studies. The Nez Perce Tribe has participated in the Fish Passage Center's Smolt Monitoring Program for nine of the 11 years. These studies collect and tag juvenilemore » chinook salmon and steelhead at two locations in the fall, rkm 74 and rkm 7, and at rkm 7 during the spring. Data from captured and tagged fish provide an evaluation of hatchery production and releases strategies, post release survival of hatchery chinook salmon, abundance of natural chinook salmon, and downstream survival and arrival timing of natural and hatchery chinook salmon and steelhead. The hydrologic conditions that migrating fish encountered in 2001 were characterized as a drought and conditions in 2002 were characterized as below average. Hatchery chinook salmon had a mean fork length that was 34 mm greater in 2001 and 35 mm greater in 2002 than the mean fork length of natural chinook smolts. Hatchery steelhead smolt mean fork lengths were 39 mm greater than natural steelhead smolts in 2001 and 44 mm greater than natural steelhead smolt fork lengths in 2002. A significant difference (p < 0.05) between hatchery and natural chinook salmon and steelhead fork lengths has been documented by these emigration studies from 1997 to 2002. Hatchery chinook salmon were volitionally released in 2001 and 2002 and the 90% arrivals for 2001 and 2002 at the lower rkm 7 trap were within the range of past observations of 22 to 38 days observed in 1999 and 2000. We estimated that 93.9% of the 123,014 hatchery chinook salmon released in 2001 survived to the lower trap and 90.2% of the 303,769 hatchery chinook salmon released in 2002 survived to the lower trap. Post release survival estimates for hatchery chinook salmon were within the range of past estimates; 88.4% in 1998 to 100.9% in 1994. An estimated 7,646 to 23,249 (95% C.I.) natural chinook salmon smolts migrated past the lower Imnaha River trap from April 4 to April 22. An additional 6,767 to 14,706 (95% C.I.) natural chinook salmon smolts migrated past the lower Imnaha River trap from April 23 to May 14, 2002. Natural chinook salmon captured and tagged at the upper rkm 74 trap survived to Lower Granite Dam (LGR) at a rate of 28.8% during migration year 2001 and 21.9% during migration year 2002. The survival estimate for fall tagged natural chinook salmon from the lower trap to LGR was 41.9% in 2001 and 33.3% in 2002. Differences between survival from release to LGR for fall tagged natural chinook salmon from the lower trap have been 5.9% to 16.9% higher than for fall tagged natural chinook salmon from the upper trap from 1994 to 2002. Spring PIT tag release groups of natural chinook salmon, hatchery chinook salmon, and hatchery steelhead produced estimates of survival from the trap to LGR within the range of past estimates since 1993. Estimated survival from release to LGR for 2001 and 2002 were as follows: 83.7% and 86.9% for natural chinook salmon, 80.3% and 77.3% for hatchery chinook salmon, 82.7% and 81.8% for natural steelhead, and 82.0% and 83.0% for hatchery steelhead. Estimates of survival for spring tagged fish from the trap to Lower Monumental Dam (LMO) during the drought of 2001 were the lowest estimates of survival from 1998 to 2002 for natural chinook salmon, and from1997 to 2002 for natural and hatchery steelhead. Estimates of migration year 2001 survival from the trap to LMO were as follows: 65.6% - natural chinook salmon, 68.9% - hatchery chinook salmon, 49.7% natural steelhead, and 42.9% - hatchery steelhead. Estimates of migration year 2002 survival from the trap to LMO were as follows: 76.8% - natural chinook salmon, 68.1% - hatchery chinook salmon, 69.9% natural steelhead, and 78.0% - hatchery steelhead. A smolt-to-adult return rate (SAR) index from LGR to LGR was calculated for migrating pre-smolt and smolt natural chinook salmon, that were PIT tagged in the fall and spring at the lower trap, for brood years 1996 to 1998 (migration years 1998 to 2000). The SARs are representative of in-river Imnaha natural chinook salmon. The LGR to LGR SAR index for presmolt chinook salmon is as follows: 3.08% (BY 1996), 2.41% (BY 1997), and 2.98% (BY 1998). Smolt-to-adult return rate index for spring tagged smolts was lower: 1.75% (BY 1996), 2.24% (BY 1997) and 2.94% (BY 1998). Fall tagged natural chinook salmon from the upper and lower trap and spring tagged natural chinook salmon from the lower trap all had significantly different (p < 0.05) median and cumulative arrival timing at LGR during migration year 2001.« less

Home on the Range: Factors Explaining Partial Migration of African Buffalo in a Tropical Environment

PubMed Central

Naidoo, Robin; Du Preez, Pierre; Stuart-Hill, Greg; Jago, Mark; Wegmann, Martin

2012-01-01

Partial migration (when only some individuals in a population undertake seasonal migrations) is common in many species and geographical contexts. Despite the development of modern statistical methods for analyzing partial migration, there have been no studies on what influences partial migration in tropical environments. We present research on factors affecting partial migration in African buffalo (Syncerus caffer) in northeastern Namibia. Our dataset is derived from 32 satellite tracking collars, spans 4 years and contains over 35,000 locations. We used remotely sensed data to quantify various factors that buffalo experience in the dry season when making decisions on whether and how far to migrate, including potential man-made and natural barriers, as well as spatial and temporal heterogeneity in environmental conditions. Using an information-theoretic, non-linear regression approach, our analyses showed that buffalo in this area can be divided into 4 migratory classes: migrants, non-migrants, dispersers, and a new class that we call “expanders”. Multimodel inference from least-squares regressions of wet season movements showed that environmental conditions (rainfall, fires, woodland cover, vegetation biomass), distance to the nearest barrier (river, fence, cultivated area) and social factors (age, size of herd at capture) were all important in explaining variation in migratory behaviour. The relative contributions of these variables to partial migration have not previously been assessed for ungulates in the tropics. Understanding the factors driving migratory decisions of wildlife will lead to better-informed conservation and land-use decisions in this area. PMID:22570722

Effects of the light goose conservation order on non-target waterfowl distribution during spring migration

USGS Publications Warehouse

Dinges, Andrew J.; Webb, Elisabeth B.; Vrtiska, Mark P.

2015-01-01

The Light Goose Conservation Order (LGCO) was initiated in 1999 to reduce mid-continent populations of light geese (lesser snow geese Chen caerulescens and Ross's geese C. rossi). However, concern about potential for LGCO activities (i.e. hunting activities) to negatively impact non-target waterfowl species during spring migration in the Rainwater Basin (RWB) of Nebraska prompted agency personnel to limit the number of hunt days each week and close multiple public wetlands to LGCO activities entirely. To evaluate the effects of the LGCO in the RWB, we quantified waterfowl density at wetlands open and closed to LGCO hunting and recorded all hunter encounters during springs 2011 and 2012. We encountered a total of 70 hunting parties on 22 study wetlands, with over 90% of these encounters occurring during early season when the majority of waterfowl used the RWB region. We detected greater overall densities of dabbling ducks Anas spp., as well as for mallards A. platyrhynchos and northern pintails A. acuta on wetlands closed to the LGCO. We detected no effects of hunt day in the analyses of dabbling duck densities. We detected no differences in mean weekly dabbling duck densities among wetlands open to hunting, regardless of weekly or cumulative hunting encounter frequency throughout early season. Additionally, hunting category was not a predictor for the presence of greater white-fronted geese Anser albifronsin a logistic regression model. Given that dabbling duck densities were greater on wetlands closed to hunting, providing wetlands free from hunting disturbance as refugia during the LGCO remains an important management strategy at migration stopover sites. However, given that we did not detect an effect of hunt day or hunting frequency on dabbling duck density, our results suggest increased hunting frequency at sites already open to hunting would likely have minimal impacts on the distribution of non-target waterfowl species using the region for spring staging.

Smolt Monitoring Program Comparative Survival Rate Study (CSS); Oregon Department of Fish and Wildlife, Annual Report 2001-2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jonasson, Brian; Carmichael, Richard

2003-05-01

We PIT-tagged juvenile spring chinook salmon reared at Lookingglass Hatchery in October 2001 as part of the Comparative Survival Rate Study (CSS) for migratory year (MY) 2002. We tagged 20,998 Imnaha stock spring chinook salmon, and after mortality and tag loss, we allowed the remaining 20,920 fish to leave the acclimation pond at our Imnaha River satellite facility beginning 21 March 2002 to begin their seaward migration. The fish remaining in the pond were forced out on 17 April 2002. We tagged 20,973 Catherine Creek stock captive brood progeny spring chinook salmon, and after mortality and tag loss, we allowedmore » the remaining 20,796 fish to leave the acclimation ponds at our Catherine Creek satellite facility beginning 1 April 2001 to begin their seaward migration. The fish remaining in the ponds were forced out on 15 April 2001. We estimated survival rates, from release to Lower Granite Dam in MY 2002, for three stocks of hatchery spring chinook salmon tagged at Lookingglass Hatchery to determine their relative migration performance. Imnaha River stock and Lostine River stock survival rates were similar and were higher than the survival rate of Catherine Creek stock. We PIT-tagged 20,950 BY 2001 Imnaha River stock and 20,820 BY 2001 Catherine Creek stock captive brood progeny in October 2002 as part of the CSS for MY 2003. At the time the fish were transferred from Lookingglass Hatchery to the acclimation site, the rates of mortality and tag loss for Imnaha River stock were 0.14% and 0.06%, respectively. Catherine Creek stock, during the same period, had rates of mortality and tag loss of 0.57% and 0.31%, respectively. There was slightly elevated mortality, primarily from BKD, in one raceway of Catherine Creek stock at Lookingglass Hatchery for BY 2001.« less

Sexually Dimorphic Patterns of Cell Proliferation in the Brain Are Linked to Seasonal Life-History Transitions in Red-Sided Garter Snakes.

PubMed

Lutterschmidt, Deborah I; Lucas, Ashley R; Karam, Ritta A; Nguyen, Vicky T; Rasmussen, Meghann R

2018-01-01

Seasonal rhythms in physiology and behavior are widespread across diverse taxonomic groups and may be mediated by seasonal changes in neurogenesis, including cell proliferation, migration, and differentiation. We examined if cell proliferation in the brain is associated with the seasonal life-history transition from spring breeding to migration and summer foraging in a free-ranging population of red-sided garter snakes ( Thamnophis sirtalis ) in Manitoba, Canada. We used the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) to label newly proliferated cells within the brain of adult snakes collected from the den during the mating season or from a road located along their migratory route. To assess rates of cell migration, we further categorized BrdU-labeled cells according to their location within the ventricular zone or parenchymal region of the nucleus sphericus (homolog of the amygdala), preoptic area/hypothalamus, septal nucleus, and cortex (homolog of the hippocampus). We found that cell proliferation and cell migration varied significantly with sex, the migratory status of snakes, and reproductive behavior in males. In most regions of interest, patterns of cell proliferation were sexually dimorphic, with males having significantly more BrdU-labeled cells than females prior to migration. However, during the initial stages of migration, females exhibited a significant increase in cell proliferation within the nucleus sphericus, hypothalamus, and septal nucleus, but not in any subregion of the cortex. In contrast, migrating males exhibited a significant increase in cell proliferation within the medial cortex but no other brain region. Because it is unlikely that the medial cortex plays a sexually dimorphic role in spatial memory during spring migration, we speculate that cell proliferation within the male medial cortex is associated with regulation of the hypothalamus-pituitary-adrenal axis. Finally, the only brain region where cell migration into the parenchymal region varied significantly with sex or migratory status was the hypothalamus. These results suggest that the migration of newly proliferated cells and/or the continued division of undifferentiated cells are activated earlier or to a greater extent in the hypothalamus. Our data suggest that sexually dimorphic changes in cell proliferation and cell migration in the adult brain may mediate sex differences in the timing of seasonal life-history transitions.

Sexually Dimorphic Patterns of Cell Proliferation in the Brain Are Linked to Seasonal Life-History Transitions in Red-Sided Garter Snakes

PubMed Central

Lutterschmidt, Deborah I.; Lucas, Ashley R.; Karam, Ritta A.; Nguyen, Vicky T.; Rasmussen, Meghann R.

2018-01-01

Seasonal rhythms in physiology and behavior are widespread across diverse taxonomic groups and may be mediated by seasonal changes in neurogenesis, including cell proliferation, migration, and differentiation. We examined if cell proliferation in the brain is associated with the seasonal life-history transition from spring breeding to migration and summer foraging in a free-ranging population of red-sided garter snakes (Thamnophis sirtalis) in Manitoba, Canada. We used the thymidine analog 5-bromo-2′-deoxyuridine (BrdU) to label newly proliferated cells within the brain of adult snakes collected from the den during the mating season or from a road located along their migratory route. To assess rates of cell migration, we further categorized BrdU-labeled cells according to their location within the ventricular zone or parenchymal region of the nucleus sphericus (homolog of the amygdala), preoptic area/hypothalamus, septal nucleus, and cortex (homolog of the hippocampus). We found that cell proliferation and cell migration varied significantly with sex, the migratory status of snakes, and reproductive behavior in males. In most regions of interest, patterns of cell proliferation were sexually dimorphic, with males having significantly more BrdU-labeled cells than females prior to migration. However, during the initial stages of migration, females exhibited a significant increase in cell proliferation within the nucleus sphericus, hypothalamus, and septal nucleus, but not in any subregion of the cortex. In contrast, migrating males exhibited a significant increase in cell proliferation within the medial cortex but no other brain region. Because it is unlikely that the medial cortex plays a sexually dimorphic role in spatial memory during spring migration, we speculate that cell proliferation within the male medial cortex is associated with regulation of the hypothalamus-pituitary-adrenal axis. Finally, the only brain region where cell migration into the parenchymal region varied significantly with sex or migratory status was the hypothalamus. These results suggest that the migration of newly proliferated cells and/or the continued division of undifferentiated cells are activated earlier or to a greater extent in the hypothalamus. Our data suggest that sexually dimorphic changes in cell proliferation and cell migration in the adult brain may mediate sex differences in the timing of seasonal life-history transitions.

Use of electromyogram telemetry to assess swimming activity of adult spring Chinook salmon migrating past a Columbia River dam

USGS Publications Warehouse

Brown, R.S.; Geist, D.R.; Mesa, M.G.

2006-01-01

Electromyogram (EMG) radiotelemetry was used to estimate the swim speeds of spring Chinook salmon Oncorhynchus tshawytscha migrating upstream past a Columbia River dam. Electrodes from EMG transmitters were surgically implanted in the red muscle of fish captured at Bonneville Dam, and output from the tags was calibrated to defined swim speeds for each fish in a tunnel respirometer. The fish were then released below Bonneville Dam and radio-tracked as they migrated through the tailraces, fishways, and forebays of the dam. On average, swim speed was significantly higher when tagged salmon were moving through tailraces than when they were moving through other parts of the dam. Specifically, swim speeds for fish in tailraces (106.4 cm/s) were 23% higher than those of fish in fishways (84.9 cm/s) and 32% higher than those of fish in forebays (80.2 cm/s). Swim speeds were higher in fishways during the day than during the night, but there were no diel differences in swim speeds in tailraces and forebays. During dam passage, Chinook salmon spent the most time in tailraces, followed by fishways and forebays. ?? Copyright by the American Fisheries Society 2006.

Spring migration of Northern Pintails from Texas and New Mexico, USA

USGS Publications Warehouse

Haukos, D.A.; Miller, M.R.; Orthmeyer, D.L.; Takekawa, John Y.; Fleskes, J.P.; Casazza, Michael L.; Perry, W.M.; Moon, J.A.

2006-01-01

We used satellite transmitters (platform transmitting terminals or PTTs) during 2002 and 2003 to document spring migration timing, routes, stopover sites, and nesting sites of adult female Northern Pintails (Anas acuta) from major wintering areas of the Gulf Coast (N = 20) and Playa Lakes Regions (PLR, N = 20) in Texas, and the Middle Rio Grande Valley, New Mexico (MRGV, N = 15). Some Pintails tagged in the MRGV continued movements into Mexico. Poor winter survival or PTT failure reduced sample size to 15 for PLR Pintails, 5 for Gulf Coast Pintails, and 11 for MRGV Pintails. Apparent winter survival was 66% lower for Texas Gulf Coast PTT-tagged Pintails than for those from the PLR and MRGV. Pintails from each area used different routes to their respective breeding grounds. PTT-tagged Pintails from the MRGV followed the Rio Grande Valley north to southern Colorado, before traveling on to the Dakotas and Canada or traveled northeast and joined the migration of PLR Pintails in Texas or Kansas. The latter made initial stops in Kansas, Nebraska, Colorado, or the Dakotas. Gulf Coast Pintails traveled through north-central Oklahoma or central Kansas. Pintails that had stopped first in Kansas or Nebraska tended to settle to nest in the United States. Wetland availability in the Prairie Pothole Region of the Northern Great Plains influenced nesting destinations of PTT-tagged Pintails, but individuals settled across a wide swath of northern North America. We did not detect any consistently-used spring staging areas. Therefore, negative impacts to any of the marked populations, or their wetland habitats, may have continental implications.

Geographic variation in migration chronology and winter distribution of midcontinent greater white-fronted geese

USGS Publications Warehouse

Ely, Craig R.; Nieman, Daniel J.; Alisauskas, Ray T.; Schmutz, Joel A.; Hines, James E.

2013-01-01

We evaluated spatial and temporal differences in migratory behavior among different breeding groups of midcontinent greater white-fronted geese (Anser albifrons) using band-recovery data and observations of neck collared geese during migration and winter. Birds from different breeding areas were initially delineated by geographic distance into 6 banding reference areas (BRAs): 1) interior Alaska, 2) North Slope of Alaska, 3) western Northwest Territories (NWT), 4) western Nunavut, 5) central Nunavut, and 6) eastern Nunavut. The banding groups also differed by breeding habitat, with geese from interior Alaska nesting in the boreal forest (taiga), and all other groups breeding in tundra habitats. Geese from interior Alaska migrated earlier during autumn, and were more likely to winter farther south (in Mexico) than geese from other breeding areas. Geese banded in central and eastern Nunavut (Queen Maud Gulf and Inglis River) wintered farther east (in Louisiana) than geese from other breeding areas. Small-scale (within-state) geographic segregation of wintering flocks was evidenced by the recent (post-1990) nearly exclusive use of a new wintering area in north central Texas by geese from interior Alaska. Segregation among BRAs was also apparent in Mexico, where taiga geese were found predominantly in the central Highlands (states of Zacatecas and Durango), whereas tundra geese mostly used states along the Gulf Coast (primarily Tamaulipas). Interior Alaska birds initiated spring migration earlier than geese from other areas, and were more likely than others to stop in the Rainwater Basin of Nebraska, a region where cholera outbreaks periodically kill thousands of geese. Geese from interior Alaska were the first to arrive at spring staging areas in prairie Canada where BRAs exhibited spatial delineation (a longitudinal cline) in relation to breeding areas. Our results show significant geographic and temporal variation among taiga and tundra breeding cohorts during autumn, winter, and spring. Temporal and spatial differences in migratory behavior may allow management practices that accommodate potential demographic differences between taiga and tundra populations.

Citizen Science Data and Scaling

NASA Astrophysics Data System (ADS)

Henderson, S.; Wasser, L. A.

2013-12-01

There is rapid growth in the collection of environmental data by non experts. So called ';citizen scientists' are collecting data on plant phenology, precipitation patterns, bird migration and winter feeding, mating calls of frogs in the spring, and numerous other topics and phenomena related to environmental science. This data is generally submitted to online programs (e.g Project BudBurst, COCORaHS, Project Feederwatch, Frogwatch USA, etc.)and is freely available to scientists, educators, land managers, and decisions makers. While the data is often used to address specific science questions, it also provides the opportunity to explore its utility in the context of ecosystem scaling. Citizen science data is being collected and submitted at an unprecedented rate and is of a spatial and temporal scale previously not possible. The amount of citizen science data vastly exceeds what scientists or land managers can collect on their own. As such, it provides opportunities to address scaling in the environmental sciences. This presentation will explore data from several citizen science programs in the context of scaling.

Animal migration and risk of spread of viral infections: Chapter 9

USGS Publications Warehouse

Prosser, Diann J.; Nagel, Jessica; Takekawa, John Y.; Edited by Singh, Sunit K.

2013-01-01

The potential contribution of migration towards the spread of disease is as varied as the ecology of the pathogens themselves and their host populations. This chapter outlines multiple examples of viral diseases in animal populations and their mechanisms of viral spread. Many species of insects, mammals, fish, and birds exhibit migratory behavior and have the potential to disperse diseases over long distances. The majority of studies available on viral zoonoses have focused on birds and bats, due to their highly migratory life histories. A number of studies have reported evidence of changes in the timing of animal migrations in response to climate change. The majority indicate an advancement of spring migration, with few or inconclusive results for fall migration. Predicting the combined effects of climate change on migratory patterns of host species and epidemiology of viral pathogens is complex and not fully realistic.

Three Levels of Push-Pull Dynamics among Chinese International Students' Decision to Study Abroad in the Canadian Context

ERIC Educational Resources Information Center

Chen, Jun Mian

2017-01-01

The extant literature on student migration flows generally focus on the traditional push-pull factors of migration at the individual level. Such a tendency excludes the broader levels affecting international student mobility. This paper proposes a hybrid of three levels of push-pull dynamics (micro-individual decision-making, meso-academic…

An evaluation of regression methods to estimate nutritional condition of canvasbacks and other water birds

USGS Publications Warehouse

Sparling, D.W.; Barzen, J.A.; Lovvorn, J.R.; Serie, J.R.

1992-01-01

Regression equations that use mensural data to estimate body condition have been developed for several water birds. These equations often have been based on data that represent different sexes, age classes, or seasons, without being adequately tested for intergroup differences. We used proximate carcass analysis of 538 adult and juvenile canvasbacks (Aythya valisineria ) collected during fall migration, winter, and spring migrations in 1975-76 and 1982-85 to test regression methods for estimating body condition.

Colonization and Containment of Hyalomma Marginatum Rufipes for Studies on the Transmission of Crimean-Congo Hemorrhagic Fever

DTIC Science & Technology

1987-07-31

tick-borne Crimean-Congo hemorrhagic fever in Asia, Europe and Africa. J. Med. Entomol. 15: 307-417. Hoogstraal, H., M. N. Kaiser, M. A. Taylor, S. Gaber ...N. Kaiser, M. A. Taylor, E. Guindy, and S. Gaber . 1963. Tick (Ixodoidea) on birds migrating from Europe and Asia to Africa, 1959-1961. IBID. Pegram...Hoogstraal, H Traylor, M.A., Gaber , S., Malakatis, G., Guindy, E. & Relmy, 1. 1964 ricks (Ixodidae) on migrating birds in Eg ypt, Spring and Fall

Prospect theory and the decision to move or stay.

PubMed

Clark, William A V; Lisowski, William

2017-09-05

Migration has always involved stress and risk. More risk-averse households are less likely to move, while less risk-averse households will seek out opportunities and migrate. We investigate how the theoretical contributions of prospect theory, and specifically the endowment effect, can provide new understanding about decisions whether to migrate or not. We test the hypothesis that risk aversion extends the length of stay in the dwelling and, by extension, in the local labor and housing markets. How long people remain in place is a function, we hypothesize, of their independently self-assessed propensity to take risks, after controlling for a range of demographic and socioeconomic characteristics. We use the theoretical insights of prospect theory and the endowment effect (the notion of the "use value" differing from the "exchange value") to explain the likelihood of staying after controlling for life-course events. The results confirm the explanatory power of self-assessed risk in the decision to migrate or stay and, equally important, confirm the role of the endowment effect.

Prospect theory and the decision to move or stay

PubMed Central

Clark, William A. V.

2017-01-01

Migration has always involved stress and risk. More risk-averse households are less likely to move, while less risk-averse households will seek out opportunities and migrate. We investigate how the theoretical contributions of prospect theory, and specifically the endowment effect, can provide new understanding about decisions whether to migrate or not. We test the hypothesis that risk aversion extends the length of stay in the dwelling and, by extension, in the local labor and housing markets. How long people remain in place is a function, we hypothesize, of their independently self-assessed propensity to take risks, after controlling for a range of demographic and socioeconomic characteristics. We use the theoretical insights of prospect theory and the endowment effect (the notion of the “use value” differing from the “exchange value”) to explain the likelihood of staying after controlling for life-course events. The results confirm the explanatory power of self-assessed risk in the decision to migrate or stay and, equally important, confirm the role of the endowment effect. PMID:28827341

Linking phenological events in migratory passerines with a changing climate: 50 years in the Laurel Highlands of Pennsylvania.

PubMed

McDermott, Molly E; DeGroote, Lucas W

2017-01-01

Advanced timing of both seasonal migration and reproduction in birds has been strongly associated with a warming climate for many bird species. Phenological responses to climate linking these stages may ultimately impact fitness. We analyzed five decades of banding data from 17 migratory bird species to investigate 1) how spring arrival related to timing of breeding, 2) if the interval between arrival and breeding has changed with increasing spring temperatures, and 3) whether arrival timing or breeding timing best predicted local productivity. Four of 17 species, all mid- to long-distance migrants, hatched young earlier in years when migrants arrived earlier to the breeding grounds (~1:1 day advancement). The interval between arrival on breeding grounds and appearance of juveniles shortened with warmer spring temperatures for 12 species (1-6 days for every 1°C increase) and over time for seven species (1-8 days per decade), suggesting that some migratory passerines adapt to climate change by laying more quickly after arrival or reducing the time from laying to fledging. We found more support for the former, that the rate of reproductive advancement was higher than that for arrival in warm years. Timing of spring arrival and breeding were both poor predictors of avian productivity for most migrants analyzed. Nevertheless, we found evidence that fitness benefits may occur from shifts to earlier spring arrival for the multi-brooded Song Sparrow. Our results uniquely demonstrate that co-occurring avian species are phenologically plastic in their response to climate change on their breeding grounds. If migrants continue to show a weaker response to temperatures during migration than breeding, and the window between arrival and optimal breeding shortens further, biological constraints to plasticity may limit the ability of species to adapt successfully to future warming.

One year of migration data for a western yellow-billed cuckoo

USGS Publications Warehouse

Sechrist, Juddson D.; Paxton, Eben H.; Ahlers, Darrell D.; Doster, Robert H.; Ryan, Vicky M.

2012-01-01

In 2009, we studied the migration of the Western Yellow-billed Cuckoo by capturing 13 breeding birds on the middle Rio Grande, New Mexico, and attaching a 1.5-g Mk 14-S British Antarctic Survey geolocator to each bird. In 2010, we recaptured one of the cuckoos, enabling us to download its geolocation data. The cuckoo had flown approximately 9500 km during its southward migration, traveling through Central America to winter in portions of Bolivia, Brazil, Paraguay, and Argentina. The spring migration route differed somewhat from the fall route, with the cuckoo bypassing Central America to migrate through the Caribbean. Additionally, it moved between New Mexico and Mexico at the end of summer in 2009 and again in 2010 before being recaptured at its breeding site. Our results, albeit from one individual, hint at a dynamic migration strategy and have broad implications for the ecology and conservation of the Western Yellow-billed Cuckoo, a species of conservation concern.

Corresponding long-term shifts in stream temperature and invasive fish migration

USGS Publications Warehouse

McCann, Erin L.; Johnson, Nicholas; Pangle, Kevin

2018-01-01

By investigating historic trapping records of invasive sea lamprey (Petromyzon marinus) throughout tributaries to the Laurentian Great Lakes, we found that upstream spawning migration timing was highly correlated with stream temperatures over large spatial and temporal scales. Furthermore, several streams in our study exceeded a critical spring thermal threshold (i.e., 15°C) and experienced peak spawning migration up to 30 days earlier since the 1980s, whereas others were relatively unchanged. Streams exhibiting warming trends and earlier migration were spatially clustered and generally found on the leeward side of the Great Lakes where the lakes most affect local climate. These findings highlight that all streams are not equally impacted by climate change and represent, to our knowledge, the first observation linking long-term changes in stream temperatures to shifts in migration timing of an invasive fish. Earlier sea lamprey migration in Great Lakes tributaries may improve young of the year growth and survival, but not limit their spatial distribution, making sea lamprey control more challenging.

Tracking Mallards (Anas platyrhynchos) with GPS Satellite Transmitters Along Their Migration Route Through Northeast Asia.

PubMed

Shin, Jeong-Hwa; Lee, Ki-Sup; Kim, Seol-Hee; Hwang, Jong-Kyung; Woo, Chanjin; Kim, Jiyeon; Kim, Jung-Hyun; Suh, Jae-Hwa; Jeong, Jipseol; Wang, Seung-Jun; Chung, Hyen-Mi; Yu, Seung-do; Choi, Kyung-Hee; Mo, In-Pil

2016-05-01

In this study, Global Positioning System satellite transmitters were attached to three mallards (Anas platyrhynchos) wintering in South Korea to track their migration routes, stopover sites, breeding sites, and migration patterns. We successfully tracked only one mallard (no. 108917) from November 15, 2011, to November 29, 2013, and determined separate migration routes in two cases of spring migration and one case of fall migration. The mallard repeatedly migrated to the same final destination, even though the travel path varied. We identified six stopover sites: Hunhe River, Liaohe River, Yinma River, Yalu River, Songjeon Bay, and Dahuofang Reservoir in China and South Korea. The wintering sites of two migration cases were discovered to be identical (Gokgyo River in Asan, South Korea). The terminal sites, which were presumed to be breeding grounds, were the same in both cases (Hinggan League in Inner Mongolia Autonomous Region, China). On the basis of the migration routes identified in this study, we suggest that future efforts to control highly pathogenic avian influenza (HPAI) should not only include avian influenza surveillance but also implement flyway-based strategies, with regard to all countries affected by potential HPAI outbreaks.

No Duck Left behind

ERIC Educational Resources Information Center

Cooper, Sandi; Thomas, Julie; Motley, Tammy

2011-01-01

Recently, a group of fourth graders joined "Pintail Partners"--a year-long collaborative research effort of scientists, students, classroom teachers, preservice teachers, museum educators, and university professors. Students and teachers followed satellite tracking data (marking the pintail duck's spring migration) and interacted with scientists…

Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2003-2004 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Steven G.; Muir, William D.; Zabel, Richard W.

2004-01-01

For juvenile chinook salmon Oncorhynchus tshawytscha, sockeye salmon O. nerka, and steelhead O. mykiss that migrate through reservoirs, hydroelectric projects, and free-flowing sections of the Snake and Columbia Rivers, survival estimates are essential to develop effective strategies for recovering depressed stocks. Many management strategies were based on estimates of system survival (Raymond 1979; Sims and Ossiander 1981) derived in a river system considerably different from today's (Williams and Matthews 1995; Williams et al. 2001). Knowledge of the magnitude, locations, and causes of smolt mortality under present passage conditions, and under conditions projected for the future, are necessary to develop strategiesmore » that will optimize smolt survival during migration. From 1993 through 2002, the National Marine Fisheries Service (NMFS) and the University of Washington (UW) demonstrated the feasibility of using three statistical models to estimate survival of PIT-tagged (Prentice et al. 1990a) juvenile salmonids passing through Snake River dams and reservoirs (Iwamoto et al. 1994; Muir et al. 1995, 1996, 2001a, 2003; Smith et al. 1998, 2000a,b; Hockersmith et al. 1999; Zabel et al. 2001, 2002). Evaluation of assumptions for these models indicated that all were generally satisfied, and accurate and precise survival estimates were obtained. In 2003, NMFS and UW completed the eleventh year of the study. Flow levels during the early portion of the 2003 spring migration were similar to 2002, and only slightly higher than in the drought conditions during 2001. However, flow levels were much greater during the later part of the migration in 2003. Spill levels were similar to 2002, much higher than in 2001. Research objectives were to: (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the performance of the survival-estimation models under prevailing operational and environmental conditions. Additionally, as adult return information becomes available, as part of this study we will evaluate relationships between juvenile survival and subsequent adult returns for fish with different juvenile migration histories.« less

Using a Convection Model to Predict Altitudes of White Stork Migration Over Central Israel

NASA Astrophysics Data System (ADS)

Shamoun-Baranes, Judy; Liechti, Olivier; Yom-Tov, Yoram; Leshem, Yossi

Soaring migrants such as storks, pelicans and large birds of prey rely on thermal convection during migration. The convection model ALPTHERM was designed to predict the onset, strength, duration and depth of thermal convection for varying topographies for glider pilots, based on atmospheric conditions at midnight. We tested ALPTHERM predictions as configured for two topographies of central Israel, the Coastal Plains and the Judean and Samarian Mountains in order to predict altitudes of migrating white storks (Ciconia ciconia). Migrating flocks of white storks were tracked with a motorized glider, to measure maximum altitudes of migration during spring 2000. A significant positive correlation was found between the maximum daily altitudes of migration measured and the predicted upper boundary of thermal convection for the Coastal Plains and Samarian Mountains. Thirty-minute predictions for the Coastal Plains and Samarian Mountains correlated positively with measured maximum migration altitudes per thermal. ALPTHERM forecasts can be used to alter flight altitudes in both civil and especially military aviation and reduce the hazard of serious aircraft collisions with soaring migrants.

The economics of amenities and migration in the Pacific Northwest: review of selected literature with implications for national forest management.

Treesearch

Brian E. Garber-Yonts

2004-01-01

This paper reviews literature on the influence of nonmarket amenity resources on population migration. Literature reviewed includes migration and demographic studies; urban and regional economics studies of amenities in labor markets, retirement migration, and firm location decisions; nonmarket valuation studies using hedonic price analysis of amenity resource values;...

Beyond greener pastures: exploring contexts surrounding Filipino nurse migration in Canada through oral history.

PubMed

Ronquillo, Charlene; Boschma, Geertje; Wong, Sabrina T; Quiney, Linda

2011-09-01

The history of immigrant Filipino nurses in Canada has received little attention, yet Canada is a major receiving country of a growing number of Filipino migrants and incorporates Filipino immigrant nurses into its healthcare workforce at a steady rate. This study aims to look beyond the traditional economic and policy analysis perspectives of global migration and beyond the push and pull factors commonly discussed in the migration literature. Through oral history, this study explores biographical histories of nine Filipino immigrant nurses currently working in British Columbia and Alberta, Canada. Narratives reveal the instrumental role of the deeply embedded culture of migration in the Philippines in influencing Filipino nurses to migrate. Additionally, the stories illustrate the weight of cultural pressures and societal constructs these nurses faced that first colored their decision to pursue a career in nursing and ultimately to pursue emigration. Oral history is a powerful tool for examining migration history and sheds light on nuances of experience that might otherwise be neglected. This study explores the complex connections between various factors motivating Filipino nurse migration, the decision-making process, and other pre-migration experiences. © 2011 Blackwell Publishing Ltd.

[The breaking down of imaginary socio-cultural perceptions in the migration process].

PubMed

Aruj, R

1998-01-01

This is a general study of migration and of the reasons why people decide to migrate. The author develops a theoretical approach to the study of the causes of migration, which suggests that the decision to migrate is the result of a conflict which has taken place in the minds of potential migrants and their families in which traditional social and cultural values are questioned and found wanting. (ANNOTATION)

Corrective action investigation plan: Cactus Spring Waste Trenches. Revision 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This Correction Action Investigation Plan (CAIP) contains environmental sample collection objectives and logic for the CAU No. 426, which includes the Cactus Spring Waste Trenches, CAS No. RG-08-001-RG-CS. The Cactus Spring Waste Trenches are located at the Tonopah Test Range (TTR) which is part of the Nellis Air Force Range, approximately 255 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada, by air. The purpose of this investigation is to generate sufficient data to establish the types of waste buried in the trenches, identify the presence and nature of contamination, determine the vertical extent of contaminant migration below themore » Cactus Spring Waste Trenches, and determine the appropriate course of action for the site. The potential courses of action for the site are clean closure, closure in place (with or without remediation), or no further action.« less

Fish Passage Center; Columbia Basin Fish and Wildlife Authority, 2002 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeHart, Michele; Berggren, Thomas J.; Filardo, Margaret

2003-09-01

The runoff volumes in 2002 were near average for the January to July period above Lower Granite Dam (80%) and The Dalles Dam (97%). The year 2002 hydrosystem operations and runoff conditions resulted in flows that were less than the seasonal Biological Opinion (Opinion) flow objectives at Lower Granite Dam for both the spring and summer period. The seasonal flow objectives for Priest Rapids and McNary dams were exceeded for the spring period, but at McNary Dam summer flow objectives were not met. While seasonal flow objectives were exceeded for the spring at McNary Dam, the 2002 season illustrated thatmore » Biological Opinion management to seasonal flow targets can result in conditions where a major portion of the juvenile fish migration migrates in conditions that are less than the flow objectives. The delay in runoff due to cool weather conditions and the inability of reservoirs to augment flows by drafting lower than the flood control elevations, resulted in flows less than the Opinion objectives until May 22, 2002. By this time approximately 73% of the yearling chinook and 56% of steelhead had already passed the project. For the most part, spill in 2002 was managed below the gas waiver limits for total dissolved gas levels and the NMFS action criteria for dissolved gas signs were not exceeded. The exception was at Lower Monumental Dam where no Biological Opinion spill occurred due to the need to conduct repairs in the stilling basin. Survival estimates obtained for PIT tagged juveniles were similar in range to those observed prior to 2001. A multi-year analysis of juvenile survival and the factors that affect it was conducted in 2002. A water transit time and flow relation was demonstrated for spring migrating chinook and steelhead of Snake River and Mid Columbia River origin. Returning numbers of adults observed at Bonneville Dam declined for spring chinook, steelhead and coho, while summer and fall chinook numbers increased. However, all numbers were far greater than observed in the past ten years averaged together. In 2002, about 87 million juvenile salmon were released from Federal, State, Tribal or private hatcheries into the Columbia River Basin above Bonneville Dam. This represents an increase over the past season, when only 71 million juvenile fish were released into the same area.« less

Inferring the rules of social interaction in migrating caribou.

PubMed

Torney, Colin J; Lamont, Myles; Debell, Leon; Angohiatok, Ryan J; Leclerc, Lisa-Marie; Berdahl, Andrew M

2018-05-19

Social interactions are a significant factor that influence the decision-making of species ranging from humans to bacteria. In the context of animal migration, social interactions may lead to improved decision-making, greater ability to respond to environmental cues, and the cultural transmission of optimal routes. Despite their significance, the precise nature of social interactions in migrating species remains largely unknown. Here we deploy unmanned aerial systems to collect aerial footage of caribou as they undertake their migration from Victoria Island to mainland Canada. Through a Bayesian analysis of trajectories we reveal the fine-scale interaction rules of migrating caribou and show they are attracted to one another and copy directional choices of neighbours, but do not interact through clearly defined metric or topological interaction ranges. By explicitly considering the role of social information on movement decisions we construct a map of near neighbour influence that quantifies the nature of information flow in these herds. These results will inform more realistic, mechanism-based models of migration in caribou and other social ungulates, leading to better predictions of spatial use patterns and responses to changing environmental conditions. Moreover, we anticipate that the protocol we developed here will be broadly applicable to study social behaviour in a wide range of migratory and non-migratory taxa.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Authors.

Spring migratory pathways and migration chronology of Canada geese (Branta canadensis interior) wintering at the Santee National Wildlife Refuge, South Carolina

USGS Publications Warehouse

Giles, Molly M.; Jodice, Patrick G.R.; Baldwin, Robert F.; Stanton, John D.; Epstein, Marc

2013-01-01

We assessed the migratory pathways, migration chronology, and breeding ground affiliation of Canada Geese (Branta canadensis interior) that winter in and adjacent to the Santee National Wildlife Refuge in Summerton, South Carolina, United States. Satellite transmitters were fitted to eight Canada Geese at Santee National Wildlife Refuge during the winter of 2009–2010. Canada Geese departed Santee National Wildlife Refuge between 5 and 7 March 2010. Six Canada Geese followed a route that included stopovers in northeastern North Carolina and western New York, with three of those birds completing spring migration to breeding grounds associated with the Atlantic Population (AP). The mean distance between stopover sites along this route was 417 km, the mean total migration distance was 2838 km, and the Canada Geese arrived on AP breeding grounds on the eastern shore of Hudson Bay between 20 and 24 May 2010. Two Canada Geese followed a different route from that described above, with stopovers in northeastern Ohio, prior to arriving on the breeding grounds on 9 June 2010. Mean distance between stopover sites was 402 and 365 km for these two birds, and total migration distance was 4020 and 3650 km. These data represent the first efforts to track migratory Canada Geese from the southernmost extent of their current wintering range in the Atlantic Flyway. We did not track any Canada Geese to breeding grounds associated with the Southern James Bay Population. Caution should be used in the interpretation of this finding, however, because of the small sample size. We demonstrated that migratory Canada Geese wintering in South Carolina use at least two migratory pathways and that an affiliation with the Atlantic Population breeding ground exists.

Use of ultralight aircraft for introducing migratory crane populations

USGS Publications Warehouse

Clegg, K.R.; Lewis, J.C.; Ellis, D.H.; Urbanek, Richard P.; Stahlecker, Dale

1997-01-01

Objectives were to determine if captive-reared cranes could be led behind an ultralight aircraft (UL) along a migration route and, if after release on a wintering area, they would integrate with wild cranes and migrate north in spring to their natal area without assistance. Greater sandhill cranes (Grus canadensis tabida) were used as the research surrogate for whooping cranes (Grus americana). In 1995, the senior author raised 15 cranes to fledging and trained them to respond to his vocal imitation of a sandhill crane brood call. Chicks learned to follow him as he walked, drove an all-terrain vehicle (ATV), or piloted an UL. The caretakers were not in crane costumes. Cranes were tame but allowed to roam at will without accompanying humans part of the day and were penned at night. Daily excursions provided exposure to habitats, foods, and predators the birds would encounter after release into the wild. In mid-October 1995, 11 radio-tagged cranes were led in migration from Grade, Idaho to Bosque del Apache National Wildlife Refuge (BdANWR), central New Mexico, and released near wild wintering sandhill cranes. The 1,204km migration took 11 days, including 1 day when the aircraft were grounded due to a winter storm. Hazards encountered enroute included mountainous terrain, turbulent air, and attacks by gold eagles (Aquila chrysaetos). On the wintering ground, hazards included crane hunters and coyotes (Canis latrans). Within 2 days after release at the BdANWR wintering site, the research cranes were associating with and imitating the behavior of wild cranes. The 4 surviving birds migrated north in spring 1996 and at the time of this writing 2 were within 53 km of their natal area in Idaho.

Diel periodicity and chronology of upstream migration in yellow-phase American eels (Anguilla rostrata)

USGS Publications Warehouse

Aldinger, Joni L.; Welsh, Stuart A.

2017-01-01

Yellow-phase American eel (Anguilla rostrata) upstream migration is temporally punctuated, yet migration chronology within diel time periods is not well-understood. This study examined diel periodicity, chronology, and total length (TL) of six multi-day, high-count (285–1,868 eels) passage events of upstream migrant yellow-phase American eels at the Millville Dam eel ladder, lower Shenandoah River, West Virginia during 2011–2014. We categorized passage by diel periods (vespertine, nocturnal, matutinal, diurnal) and season (spring, summer, late summer/early fall, fall). We depicted passage counts as time-series histograms and used time-series spectral analysis (Fast Fourier Transformation) to identify cyclical patterns and diel periodicity of upstream migration. We created histograms to examine movement patterns within diel periods for each passage event and fit normal mixture models (2–9 mixtures) to describe multiple peaks of passage counts. Periodicity of movements for each passage event followed a 24-h activity cycle with mostly nocturnal movement. Multimodal models were supported by the data; most modes represented nocturnal movements, but modes at or near the transition between twilight and night were also common. We used mixed-model methodology to examine relationships among TL, diel period, and season. An additive-effects model of diel period + season was the best approximating model. A decreasing trend of mean TL occurred across diel movement periods, with the highest mean TL occurring during fall relative to similar mean values of TL for spring, summer, and late summer/early fall. This study increased our understanding of yellow-phase American eels by demonstrating the non-random nature of their upstream migration.

Long-Term Trends in Migration Timing Based on Thermal Response of a Temperate Forage Fish

NASA Astrophysics Data System (ADS)

Palamara, L. J.; Manderson, J.; Kohut, J. T.; Snow, A.

2016-02-01

The physiology of many marine animals is tightly coupled to their surrounding fluid environment. Several habitat features, most notably temperature, determine these animals' fitness by affecting their growth, survival, and reproductive success. In temperate regions, many species are mobile and able to track the specific temperatures encompassed by their thermal niches as the regional temperature distribution changes. Butterfish (Peprilus triacanthus), which demonstrate very strong seasonal and temperature-dependent migration patterns in the Mid-Atlantic Bight (MAB), a region exhibiting some of the highest seasonal and interannual temperature variability in the world, is an excellent example of this phenomenon. We developed a thermal niche model for butterfish based on the statistical relationship between catches and measured temperatures from spring and fall NMFS and NEAMAP surveys and several state inshore surveys, and fit parameters to the Boltzmann-Arrhenius function, a simple yet explanatory model of temperature dependence, so that the resulting curve closely matched the statistical relationship. This thermal relationship was coupled to over 30 years of daily shallow-water OI SST (optimal interpolation sea surface temperature) measured by satellite and various in situ platforms, and daily bottom temperatures estimated by a hydrodynamic hindcast ROMS (Regional Ocean Modeling System) model to examine long-term trends in thermal migration triggers into shallow inshore waters in the spring, and out of them to deep offshore wintering habitat in the fall. In many parts of the MAB, the "thermal fall" migration trigger was delayed during later decades of the time series compared to earlier decades. This suggests potential changes in butterfish productivity and life history stages, as well as potential changes in NMFS survey bias, as the ships are unable to tow in shallow waters and will catch most butterfish in deeper waters after the variable migration trigger.

Measured flow and tracer-dye data showing the anthropogenic effects on the hydrodynamics of south Sacramento-San Joaquin Delta, California, spring 1996 and 1997

USGS Publications Warehouse

Oltmann, Richard N.

1998-01-01

Tidal flows were measured using acoustic Doppler current profilers and ultrasonic velocity meters during spring 1996 and 1997 in south Sacramento-San Joaquin Delta, California, when (1) a temporary barrier was installed at the head of Old River to prevent the entrance of migrating San Joaquin River salmon smolts, (2) the rate of water export from the south Delta was reduced for an extended period of time, and (3) a 30-day pulse flow was created on the San Joaquin River to move salmon smolts north away from the export facilities during spring 1997. Tracer-dye measurements also were made under these three conditions.

Variation in wind and piscivorous predator fields affecting the survival of Atlantic salmon, Salmo salar, in the Gulf of Maine

USGS Publications Warehouse

Friedland, K.D.; Manning, J.P.; Link, Jason S.; Gilbert, J.R.; Gilbert, A.T.; O'Connell, A.F.

2012-01-01

Observations relevant to the North American stock complex of Atlantic salmon, Salmo salar L., suggest that marine mortality is influenced by variation in predation pressure affecting post-smolts during the first months at sea. This hypothesis was tested for Gulf of Maine (GOM) stocks by examining wind pseudostress and the distribution of piscivorous predator fields potentially affecting post-smolts. Marine survival has declined over recent decades with a change in the direction of spring winds, which is likely extending the migration of post-smolts by favouring routes using the western GOM. In addition to changes in spring wind patterns, higher spring sea surface temperatures have been associated with shifting distributions of a range of fish species. The abundance of several pelagic piscivores, which based on their feeding habits may predate on salmon post-smolts, has increased in the areas that serve as migration corridors for post-smolts. In particular, populations of silver hake, Merluccius bilinearis (Mitchell), red hake, Urophycis chuss (Walbaum), and spiny dogfish, Squalus acanthias L., increased in size in the portion of the GOM used by post-smolts. Climate variation and shifting predator distributions in the GOM are consistent with the predator hypothesis of recruitment control suggested for the stock complex.

Active elastic dimers: cells moving on rigid tracks.

PubMed

Lopez, J H; Das, Moumita; Schwarz, J M

2014-09-01

Experiments suggest that the migration of some cells in the three-dimensional extracellular matrix bears strong resemblance to one-dimensional cell migration. Motivated by this observation, we construct and study a minimal one-dimensional model cell made of two beads and an active spring moving along a rigid track. The active spring models the stress fibers with their myosin-driven contractility and α-actinin-driven extendability, while the friction coefficients of the two beads describe the catch and slip-bond behaviors of the integrins in focal adhesions. In the absence of active noise, net motion arises from an interplay between active contractility (and passive extendability) of the stress fibers and an asymmetry between the front and back of the cell due to catch-bond behavior of integrins at the front of the cell and slip-bond behavior of integrins at the back. We obtain reasonable cell speeds with independently estimated parameters. We also study the effects of hysteresis in the active spring, due to catch-bond behavior and the dynamics of cross linking, and the addition of active noise on the motion of the cell. Our model highlights the role of α-actinin in three-dimensional cell motility and does not require Arp2/3 actin filament nucleation for net motion.

Wetland use and feeding by lesser scaup during spring migration across the upper Midwest, USA

USGS Publications Warehouse

Anteau, M.J.; Afton, A.D.

2009-01-01

Low food availability and forage quality and concomitant decreased lipid reserves of lesser scaup (Aythya affinis; hereafter scaup) during spring migration in the upper Midwest may partially explain reductions in the continental population of scaup. In springs 20042005, we examined wetland use and feeding activity of scaup on 356 randomly-selected wetlands within 6 regions in Iowa, Minnesota, and North Dakota. We examined wetland characteristics that favor high scaup use in 286 of these wetlands. We found that probabilities of wetland use and feeding by scaup increased with turbidity up to 45 and 30 NTU, respectively, but then declined at higher turbidity levels. Wetland use was positively correlated with size of open-water zone and amphipod densities, but was not correlated with chironomid densities. Feeding increased with amphipod density up to 26 m-3 and then declined at higher amphipod densities; scaup seemingly forage most efficiently at amphipod densities above 26 m -3. Wetland use was higher in North Dakota than in southern Minnesota and Iowa. Our results indicate that effective wetland restoration efforts to benefit scaup require maintaining abundant populations of amphipods (generally near 26 m-3 landscape geometric mean) in wetlands with large (> 500 m diameter) open-water zones throughout the upper Midwest, but especially within Iowa and southern Minnesota.

Snow cover and snow goose Anser caerulescens caerulescens distribution during spring migration

USGS Publications Warehouse

Hupp, Jerry W.; Zacheis, Amy B.; Anthony, R. Michael; Robertson, Donna G.; Erickson, Wallace P.; Palacios, Kelly C.

2001-01-01

Arctic geese often use spring migration stopover areas when feeding habitats are partially snow covered. Melting of snow during the stopover period causes spatial and temporal variability in distribution and abundance of feeding habitat. We recorded changes in snow cover and lesser snow goose Anser caerulescens caerulescens distribution on a spring migration stopover area in south-central Alaska during aerial surveys in 1993-1994. Our objectives were to determine whether geese selected among areas with different amounts of snow cover and to assess how temporal changes in snow cover affected goose distribution. We also measured temporal changes in chemical composition of forage species after snow melt. We divided an Arc/Info coverage of the approximately 210 km2 coastal stopover area into 2-km2 cells, and measured snow cover and snow goose use of cells. Cells that had 10-49.9% snow cover were selected by snow geese, whereas cells that lacked snow cover were avoided. In both years, snow cover diminished along the coast between mid-April and early May. Flock distribution changed as snow geese abandoned snow-free areas in favour of cells where snow patches were interspersed with bare ground. Snow-free areas may have been less attractive to geese because available forage had been quickly exploited as bare ground was exposed, and because soils became drier making extraction of underground forage more difficult. Fiber content of two forage species increased whereas non-structural carbohydrate concentrations of forage plants appeared to diminish after snow melt, but changes in nutrient concentrations likely occurred too slowly to account for abandonment of snow-free areas by snow geese.

Walla Walla River Fish Passage Operations Program, 2000-2001 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimmerman, Brian C.; Duke, Bill B.

2004-02-01

In the late 1990's, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow measures, and initiating trap and haul efforts. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survival of migrating adultmore » and juvenile salmonids in the basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2000-2001 project year, there were 624 summer steelhead (Oncorhynchus mykiss), 24 bull trout (Salvelinus confluentus), and 47 spring chinook (O. tshawytscha) counted at the Nursery Bridge Dam adult trap between December 27, 2000 and June 7, 2001. The Little Walla Walla River juvenile trap was not operated this year. The project transported 1600 adult spring chinook from Ringold Springs Hatchery to the South Fork Walla Walla Brood Holding Facility and outplanted 1156 for natural spawning in the basin. The project also provided equipment for transportation of juveniles captured during the construction fish salvage at Nursery Bridge Dam.« less

Winter range arrival and departure of white-tailed deer in northeastern Minnesota

USGS Publications Warehouse

Nelson, M.E.

1995-01-01

I analyzed 364 spring and 239 fall migrations by 194 white-tailed deer (Odocoileus virginianus) from 1975 to 1993 in northeastern Minnesota to determine the proximate cause of arrivals on and departures from winter ranges. The first autumn temperatures below -7?C initiated fall migrations for 14% (95% confidence interval (CI) = 0-30) of female deer prior to snowfall in three autumns, but only 2% remained on winter ranges. During 14 autumns, the first temperatures below -7?C coincidental with snowfalls elicited migration in 45% (95% CI = 34-57) of females, and 91 % remained on winter ranges. Arrival dates failed to correlate with independent variables of temperature and snow depth, precluding predictive modeling of arrival on winter ranges. During 13 years, a mean of 80% of females permanently arrived on winter ranges by 31 December. Mean departure dates from winter ranges varied annually (19 March - 4 May) and between winter ranges (14 days) and according to snow depth (15-cm differences). Only 15 - 41 % of deer departed when snow depths were> 30 cm but 80% had done so by the time of lO-cm depths. Mean weekly snow depths in March (18-85 cm) and mean temperature in April (0.3 -8.1 ?c) explained most of the variation in mean departure dates from two winter ranges (Ely, R2 = 0.87, P < 0.0005, n = 19 springs; Isabella, R2 = 0.85, P = 0.0001, n = 12 springs). Mean differences between observed mean departure dates and mean departure dates predicted from equations ranged from 3 days (predictions within the study area) to 8 days (predictions for winter ranges 100-440 km distant).

Sex differences in the thermoregulation and evaporative water loss of a heterothermic bat, Lasiurus cinereus, during its spring migration

USGS Publications Warehouse

Cryan, P.M.; Wolf, B. O.

2003-01-01

This study quantifies sex differences in thermoregulation and water loss of a small (20-35 g) insectivorous heterothermic mammal, the hoary bat Lasiurus cinereus, during its spring migration. We measured body temperature, metabolic rate and evaporative water loss, and calculated wet thermal conductance, for bats exposed to air temperatures ranging from 0 to 40°C for periods of 2-5 h. Pregnant females maintained normothermic body temperatures (35.7±0.7°C; mean ± s.e.m.) independent of air temperature. In contrast, males became torpid during the majority (68%) of exposures to air temperatures <25°C. The thermal neutral zone (TNZ) ranged between approximately 30°C and 34°C in both sexes and, within the TNZ, females had lower mass-specific metabolic rates (6.1±0.2 mW g-1) than males (9.0±0.9 mW g-1). Wet thermal conductance values in torpid bats (0.7±0.5 mW g-1 deg.-1) were lower than those of normothermic individuals (1.1±0.3 mW g-1 deg.-1). Mass-specific rates of evaporative water loss in males were consistently higher than in females at most air temperatures and rates of water loss in torpid bats were 63±6% of normothermic values. These results suggest that male and pregnant female L. cinereus employ different thermoregulatory strategies during their spring migration. Females defend normothermic body temperatures, presumably to expedite embryonic growth, while males use torpor, presumably to minimize energy and water deficits. These variable thermoregulatory strategies may reflect continental differences in the summer distribution of the sexes.

Climate-induced trends in predator–prey synchrony differ across life-history stages of an anadromous salmonid

USGS Publications Warehouse

Bell, Donovan A.; Kovach, Ryan; Vulstek, Scott C.; Joyce, John E.; Tallmon, David A.

2017-01-01

Differential climate-induced shifts in phenology can create mismatches between predators and prey, but few studies have examined predator–prey mismatch across multiple life-history stages. We used long-term data from a warming stream with shifting salmonid migration timings to quantify intra-annual migration synchrony between predatory Dolly Varden (Salvelinus malma) and Pacific salmon prey and examined how predator–prey synchrony has been influenced by climate change. We demonstrate that Dolly Varden have become increasingly mismatched with spring downstream migrations of abundant pink salmon (Oncorhynchus gorbuscha) juveniles. However, Dolly Varden have remained matched with fall upstream migrations of spawning Pacific salmon, including coho (Oncorhynchus kisutch), sockeye (Oncorhynchus nerka), and pink salmon. Downstream predator–prey migration synchrony decreased over time and with higher temperatures, particularly with pink salmon. In contrast, upstream migration synchrony was temporally stable and increased with rising temperatures. Differing trends in Dolly Varden predator–prey synchrony may be explained by the direct use of salmon to cue upstream migration, but not downstream migration. Overall, we show that climate change can have differing impacts on predator–prey synchrony across life-history stages.

Development of Matched (migratory Analytical Time Change Easy Detection) Method for Satellite-Tracked Migratory Birds

NASA Astrophysics Data System (ADS)

Doko, Tomoko; Chen, Wenbo; Higuchi, Hiroyoshi

2016-06-01

Satellite tracking technology has been used to reveal the migration patterns and flyways of migratory birds. In general, bird migration can be classified according to migration status. These statuses include the wintering period, spring migration, breeding period, and autumn migration. To determine the migration status, periods of these statuses should be individually determined, but there is no objective method to define 'a threshold date' for when an individual bird changes its status. The research objective is to develop an effective and objective method to determine threshold dates of migration status based on satellite-tracked data. The developed method was named the "MATCHED (Migratory Analytical Time Change Easy Detection) method". In order to demonstrate the method, data acquired from satellite-tracked Tundra Swans were used. MATCHED method is composed by six steps: 1) dataset preparation, 2) time frame creation, 3) automatic identification, 4) visualization of change points, 5) interpretation, and 6) manual correction. Accuracy was tested. In general, MATCHED method was proved powerful to identify the change points between migration status as well as stopovers. Nevertheless, identifying "exact" threshold dates is still challenging. Limitation and application of this method was discussed.

The News. Spring 2006

ERIC Educational Resources Information Center

Giles, Ray, Ed.

2006-01-01

This Spring issue of the quarterly newsletter of the Community College League of California contains the following articles: (1) Enrollment Drops; Fees to Blame?; (2) Senate's Grad Proposal Triggers Debate on Mission, Access; (3) Compton Decision has Affected Perceptions of Commission (discussion with Barbara Beno); (4) Dynamic New Architectural…

Regulation of migration in Mythimna separata (Walker) in China: A review integrating environmental, physiological, hormonal, genetic, and molecular factors

USDA-ARS?s Scientific Manuscript database

Each year the oriental armyworm, Mythimna separata, undertakes a seasonal, long-distance, multigeneration roundtrip migration between Southern and Northern China. The developmental decision to migrate is facultative and controlled by environmental, physiological, hormonal, genetic, and molecular fac...

Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam 2008-2009

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Fenton; Johnson, Gary E.; Weiland, Mark A.

2009-09-01

This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam (TDA) sluiceway and turbines during fall/winter 2008 and early spring 2009, respectively. The study was conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE). Operating the sluiceway reduces the potential for hydropower production. However, this surface flow outlet may be the optimal non-turbine route for fallbacks in late fall after the sluiceway is typically closed for juvenile fish passage and for overwintering summer steelhead andmore » kelt passage in the early spring before the start of the voluntary spill season. The goal of this study was to characterize adult steelhead spatial and temporal distributions and passage rates at the sluiceway and turbines, and their movements in front of the sluiceway at TDA to inform fisheries managers’ and engineers’ decision-making relative to sluiceway operations. The study periods were from November 1 to December 15, 2008 (45 days) and from March 1 to April 9, 2009 (40 days). The study objectives were to 1) estimate the number and distribution of overwintering summer steelhead fallbacks and kelt-sized acoustic targets passing into the sluiceway and turbines at TDA during the two study periods, respectively, and 2) assess the behavior of these fish in front of sluice entrances. We obtained fish passage data using fixed-location hydroacoustics and fish behavior data using acoustic imaging. For the overwintering summer steelhead, fallback occurred throughout the 45-day study period. We estimated that a total of 1790 ± 250 (95% confidence interval) summer steelhead targets passed through the powerhouse intakes and operating sluices during November 1 to December 15, 2008. Ninety five percent of these fish passed through the sluiceway. Therefore, without the sluiceway as a route through the dam, a number of steelhead may have fallen back through turbines. Run timing peaked in late November, but fish continued to pass the dam until the end of the study. Horizontal distribution data indicated that sluice 1 is the preferred route for these fish during fallback through the dam. Diel distribution for overwintering steelhead fallbacks was variable with no apparent distinct patterns. Therefore, sluiceway operations should not be based on diel distribution. For the early spring study, overwintering summer steelhead and early out-migrating steelhead kelt downstream passage occurred throughout the 40-day study period. A total of 1766 ± 277 (95% confidence interval) kelt-size targets were estimated to have passed through the powerhouse intakes and operating sluices. Ninety five percent of these fish passed through the sluiceway. Therefore, as with steelhead fallback, not having the sluiceway as a route through the dam, a number of overwintering steelhead and kelts may use the turbines for downstream passage before the start of the spill season. Run timing peaked in late March; however, relatively large numbers of kelt-sized targets passed the dam on March 2 and March 6 (162 and 188 fish, respectively). Horizontal distribution indicated that sluice 1 is the preferred route for these adult salmonids as they migrate downstream through the dam. Again, no clear pattern was seen for diel distribution of overwintering steelhead and early out-migrating kelt passage.« less

North Atlantic Blue and Fin Whales Suspend Their Spring Migration to Forage in Middle Latitudes: Building up Energy Reserves for the Journey?

PubMed Central

Silva, Mónica A.; Prieto, Rui; Jonsen, Ian; Baumgartner, Mark F.; Santos, Ricardo S.

2013-01-01

The need to balance energy reserves during migration is a critical factor for most long-distance migrants and an important determinant of migratory strategies in birds, insects and land mammals. Large baleen whales migrate annually between foraging and breeding sites, crossing vast ocean areas where food is seldom abundant. How whales respond to the demands and constraints of such long migrations remains unknown. We applied a behaviour discriminating hierarchical state-space model to the satellite tracking data of 12 fin whales and 3 blue whales tagged off the Azores, to investigate their movements, behaviour (transiting and area-restricted search, ARS) and daily activity cycles during the spring migration. Fin and blue whales remained at middle latitudes for prolonged periods, spending most of their time there in ARS behaviour. While near the Azores, fin whale ARS behaviour occurred within a restricted area, with a high degree of overlap among whales. There were noticeable behavioural differences along the migratory pathway of fin whales tracked to higher latitudes: ARS occurred only in the Azores and north of 56°N, whereas in between these areas whales travelled at higher overall speeds while maintaining a nearly direct trajectory. This suggests fin whales may alternate periods of active migration with periods of extended use of specific habitats along the migratory route. ARS behaviour in blue whales occurred over a much wider area as whales slowly progressed northwards. The tracks of these whales terminated still at middle latitudes, before any behavioural switch was detected. Fin whales exhibited behavioural-specific diel rhythms in swimming speed but these varied significantly between geographic areas, possibly due to differences in the day-night cycle across areas. Finally, we show a link between fin whales seen in the Azores and those summering in eastern Greenland-western Iceland along a migratory corridor located in central Atlantic waters. PMID:24116112

Lesser scaup winter foraging and nutrient reserve acquisition in east-central Florida

USGS Publications Warehouse

Herring, G.; Collazo, J.A.

2006-01-01

Lesser scaup (Aythya affinis) populations have been declining since the late 1970s. One of the explanations to account for this decline, the spring-condition hypothesis (SCH), is based on the premise that scaup are limited by their ability to acquire or maintain nutrient reserves during migration to the breeding grounds, leading to an impairment of their reproductive potential. Available evidence suggests that endogenous reserves required for reproduction are obtained at a later stage of migration or after arrival at the breeding grounds, not wintering sites. However, only one study has addressed body-condition levels on a southern wintering site in the last decade, with results limited to the wintering grounds on the Mississippi Flyway. We documented foraging behavior, nutrient levels, and body mass of lesser scaup in east-central Florida, USA, where 62% of the Atlantic Flyway population overwinters, during the winters of 2002 and 2003. Diurnal foraging did not increase seasonally. Nocturnal foraging increased seasonally by 76% or 43 minutes per night in females and by 478% or 1.9 hours per night in males. Measures of body condition did not change seasonally during 2002 for either sex. Between early and later winter in 2003 corrected body mass (CBM) and lipid reserves of male scaup increased 77 g and 39 g, respectively. Our results suggest that lesser scaup maintain or may slightly improve their physiological condition in east-central Florida during winter. Lower body mass and differences in nutrient levels in east-central Florida, compared to a wintering site in Louisiana, likely stem from geographic variation and lower thermal requirements associated with the warmer Florida environment. Lesser scaup depart Florida with sufficient reserves to initiate spring migration, but they maximize nutrient reserves used during reproduction elsewhere during migration or on the breeding grounds. These results suggest that maintaining the ecological integrity of this wintering ground is critical in minimizing winter mortality and preventing it from becoming an ancillary factor in current declines. Future research should address understanding survival rates during spring migration and at critical staging areas to provide new insight into the ramifications of scaup leaving wintering habitats such as MINWR with lower body condition than at other wintering sites in other flyways.

Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study.

PubMed

Kishkinev, Dmitry; Heyers, Dominik; Woodworth, Bradley K; Mitchell, Greg W; Hobson, Keith A; Norris, D Ryan

2016-11-23

The ability to navigate implies that animals have the capability to compensate for geographical displacement and return to their initial goal or target. Although some species are capable of adjusting their direction after displacement, the environmental cues used to achieve this remain elusive. Two possible cues are geomagnetic parameters (magnetic map hypothesis) or atmospheric odour-forming gradients (olfactory map hypothesis). In this study, we examined both of these hypotheses by surgically deactivating either the magnetic or olfactory sensory systems in experienced white-throated sparrows (Zonotrichia albicollis) captured in southern Ontario, Canada, during spring migration. Treated, sham-treated, and intact birds were then displaced 2,200 km west to Saskatchewan, Canada. Tracking their initial post-displacement migration using an array of automated VHF receiving towers, we found no evidence in any of the groups for compensatory directional response towards their expected breeding grounds. Our results suggest that white-throated sparrows may fall back to a simple constant-vector orientation strategy instead of performing true navigation after they have been geographically displaced to an unfamiliar area during spring migration. Such a basic strategy may be more common than currently thought in experienced migratory birds and its occurrence could be determined by habitat preferences or range size.

Immune and endocrine responses of adult spring Chinook salmon during freshwater migration and sexual maturation

USGS Publications Warehouse

Maule, A.G.; Schrock, R.M.; Slater, C.; Fitzpatrick, M.S.; Schreck, C. B.

1996-01-01

The immune –endocrine responses in spring chinook salmon (Oncorhynchus tshawytscha) were examined during their freshwater migration and final maturation. In 1990, migrating fish had high plasma cortisol titres (means 200 ng ml−1) and generated relatively few antibody-producing cells (APC) from peripheral blood leukocytes (PBL) (100 –200 per culture). After three weeks acclimation in constant environmental conditions, plasma cortisol was reduced and APC increased. There were no changes in number or affinity of glucocorticoid receptors. Concentrations of several sex steroids correlated with APC in females, but there were no such correlations in males. In 1993, fish in a hatchery had significantly greater cortisol concentrations in primary circulation than in secondary circulation, but sex steroid concentrations did not differ between circulations. Mean lysozyme activity in the primary and secondary circulation did not differ in June. In August, activity in the primary circulation was significantly less than that of the secondary, perhaps the result of acute stress associated with sampling. While some sex steroids correlated with lysozyme activity, the fact that in both years all endocrine and immune variables that correlated with each other also correlated with the date of sample, raises the question as to whether or not these are cause-and-effect relations.

Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study

PubMed Central

Kishkinev, Dmitry; Heyers, Dominik; Woodworth, Bradley K.; Mitchell, Greg W.; Hobson, Keith A.; Norris, D. Ryan

2016-01-01

The ability to navigate implies that animals have the capability to compensate for geographical displacement and return to their initial goal or target. Although some species are capable of adjusting their direction after displacement, the environmental cues used to achieve this remain elusive. Two possible cues are geomagnetic parameters (magnetic map hypothesis) or atmospheric odour-forming gradients (olfactory map hypothesis). In this study, we examined both of these hypotheses by surgically deactivating either the magnetic or olfactory sensory systems in experienced white-throated sparrows (Zonotrichia albicollis) captured in southern Ontario, Canada, during spring migration. Treated, sham-treated, and intact birds were then displaced 2,200 km west to Saskatchewan, Canada. Tracking their initial post-displacement migration using an array of automated VHF receiving towers, we found no evidence in any of the groups for compensatory directional response towards their expected breeding grounds. Our results suggest that white-throated sparrows may fall back to a simple constant-vector orientation strategy instead of performing true navigation after they have been geographically displaced to an unfamiliar area during spring migration. Such a basic strategy may be more common than currently thought in experienced migratory birds and its occurrence could be determined by habitat preferences or range size. PMID:27876843

77 FR 33703 - Newspapers Used for Publication of Legal Notices by the Intermountain Region; Utah, Idaho, Nevada...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-07

... Express District Ranger decisions for Duchesne, Roosevelt: Uintah Basin Standard Flaming Gorge District... Teton Basin: Post Register District Ranger decisions for Montpelier, Soda Springs and Westside: Idaho... decisions: Idaho Mountain Express Sawtooth National Recreation Area: The Challis Messenger Uinta-Wasatch...

Environmental Guide to the Virginia Capes Operating Area

DTIC Science & Technology

1973-03-01

invertebrates occupy the waters over the shelf. Among fishes found here are croakers, sea robins, sea bass, sharks, rays, bluefish , alewives, and...pelagic forms such as tuna, billfish, and bluefish migrate seasonally, occurring in greatest abun- dance along the Gulf Stream boundary in spring and

The greenscape shapes surfing of resource waves in a large migratory herbivore.

PubMed

Aikens, Ellen O; Kauffman, Matthew J; Merkle, Jerod A; Dwinnell, Samantha P H; Fralick, Gary L; Monteith, Kevin L

2017-06-01

The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e. green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that migratory routes are more than a link between seasonal ranges, and they provide an important, but often overlooked, foraging habitat. In addition, the spatiotemporal configuration of forage resources that propagate along migratory routes shape animal movement and presumably, energy gains during migration. © 2017 John Wiley & Sons Ltd/CNRS.

Navigating north: how body mass and winds shape avian flight behaviours across a North American migratory flyway.

PubMed

Horton, Kyle G; Van Doren, Benjamin M; La Sorte, Frank A; Fink, Daniel; Sheldon, Daniel; Farnsworth, Andrew; Kelly, Jeffrey F

2018-05-07

The migratory patterns of birds have been the focus of ecologists for millennia. What behavioural traits underlie these remarkably consistent movements? Addressing this question is central to advancing our understanding of migratory flight strategies and requires the integration of information across levels of biological organisation, e.g. species to communities. Here, we combine species-specific observations from the eBird citizen-science database with observations aggregated from weather surveillance radars during spring migration in central North America. Our results confirm a core prediction of migration theory at an unprecedented national scale: body mass predicts variation in flight strategies across latitudes, with larger-bodied species flying faster and compensating more for wind drift. We also find evidence that migrants travelling northward earlier in the spring increasingly compensate for wind drift at higher latitudes. This integration of information across biological scales provides new insight into patterns and determinants of broad-scale flight strategies of migratory birds. © 2018 John Wiley & Sons Ltd/CNRS.

Prevalence of West Nile virus in migratory birds during spring and fall migration

USGS Publications Warehouse

Dusek, Robert J.; McLean, R.G.; Kramer, L.D.; Ubico, S.R.; Dupuis, A.P.; Ebel, G.D.; Guptill, S.C.

2009-01-01

To investigate the role of migratory birds in the dissemination of West Nile virus (WNV), we measured the prevalence of infectious WNV and specific WNV neutralizing antibodies in birds, principally Passeriformes, during spring and fall migrations in the Atlantic and Mississippi flyways from 2001-2003. Blood samples were obtained from 13,403 birds, representing 133 species. Specific WNV neutralizing antibody was detected in 254 resident and migratory birds, representing 39 species, and was most commonly detected in northern cardinals (Cardinalis cardinalis) (9.8%, N = 762) and gray catbirds (Dumetella carolinensis) (3.2%,N = 3188). West Nile virus viremias were detected in 19 birds, including 8 gray catbirds, and only during the fall migratory period. These results provide additional evidence that migratory birds may have been a principal agent for the spread of WNV in North America and provide data on the occurrence of WNV in a variety of bird species. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.

Acoustic effects of oil-production activities on bowhead and white whales visible during spring migration near Pt. Barrow, Alaska-1990 phase: sound propagation and whale responses to playbacks of continuous drilling noise from an ice platform, as studied in pack ice conditions. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson, W.J.; Greene, C.R.; Koski, W.R.

1991-10-01

The report concerns the effects of underwater noise from simulated oil production operations on the movements and behavior of bowhead and white whales migrating around northern Alaska in spring. An underwater sound projector suspended from pack ice was used to introduce recorded drilling noise and other test sounds into leads through the pack ice. These sounds were received and measured at various distances to determine the rate of sound attenuation with distance and frequency. The movements and behavior of bowhead and white whales approaching the operating projector were studied by aircraft- and ice-based observers. Some individuals of both species weremore » observed to approach well within the ensonified area. However, behavioral changes and avoidance reactions were evident when the received sound level became sufficiently high. Reactions to aircraft are also discussed.« less

Return Migration among Elderly, Chronically Ill Bosnian Refugees: Does Health Matter?

PubMed Central

Handlos, Line Neerup; Olwig, Karen Fog; Bygbjerg, Ib Christian; Kristiansen, Maria; Norredam, Marie Louise

2015-01-01

Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from Denmark and the role of health issues in their decision to return. It is based on semi-structured interviews with 33 elderly, chronically ill Bosnian refugees who have moved back to Bosnia and Herzegovina, and 10 elderly, chronically ill Bosnian refugees who have remained in Denmark. The interviews show that physical health, in the sense of the absence of illness and easy access to necessary health-care services and medicines, was not highly prioritized when the decision was made whether or not to return. However, if health is regarded more broadly as involving more than mere physical health and the absence of illness, health did matter. Viewed as physical, social and mental well-being in line with WHO’s definition of health, health was indeed one of the most important factors when the decision to return was made. PMID:26473899

Return Migration among Elderly, Chronically Ill Bosnian Refugees: Does Health Matter?

PubMed

Handlos, Line Neerup; Olwig, Karen Fog; Bygbjerg, Ib Christian; Kristiansen, Maria; Norredam, Marie Louise

2015-10-12

Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from Denmark and the role of health issues in their decision to return. It is based on semi-structured interviews with 33 elderly, chronically ill Bosnian refugees who have moved back to Bosnia and Herzegovina, and 10 elderly, chronically ill Bosnian refugees who have remained in Denmark. The interviews show that physical health, in the sense of the absence of illness and easy access to necessary health-care services and medicines, was not highly prioritized when the decision was made whether or not to return. However, if health is regarded more broadly as involving more than mere physical health and the absence of illness, health did matter. Viewed as physical, social and mental well-being in line with WHO's definition of health, health was indeed one of the most important factors when the decision to return was made.

Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam, 2009-2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Fenton; Johnson, Gary E.; Weiland, Mark A.

2010-07-31

This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam (TDA) sluiceway and turbines during fall/winter 2009 through early spring 2010. The study was conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE). The goal of this study was to characterize adult steelhead spatial and temporal distributions and passage rates at the sluiceway and turbines for fisheries managers and engineers to use in decision-making relative to sluiceway operations. The study was from November 1, 2009more » to April 10, 2010. The study was divided into three study periods: Period 1, November 1 - December 15, 2009 for a fall/winter sluiceway and turbine study; Period 2, December 16, 2009 - February 28, 2010 for a turbine only study; Period 3, March 1 - April 10, 2010 for a spring sluiceway and turbine study. Sluiceway operations were scheduled to begin on March 1 for this study; however, because of an oil spill cleanup near the sluice outfall, sluiceway operations were delayed until March 8, 2010, therefore the spring study period did not commence until March 8. The study objectives were to (1) estimate the number and distribution of overwintering summer steelhead fallbacks and kelt-sized acoustic targets passing into the sluiceway and turbines at TDA between November 1 and December 15, 2009 and March 1 and April 10, 2010, and (2) estimate the numbers and distribution of adult steelhead and kelt-sized targets passing into turbine units between December 16, 2009 and February 28, 2010. We obtained fish passage data using fixed-location hydroacoustics. For Period 1, overwintering summer steelhead fallback occurred throughout the 45-day study period. A total of 879 {+-} 165 (95% CI) steelhead targets passed through the powerhouse and sluiceway during November 1 to December 15, 2009. Ninety two percent of these fish passed through the sluiceway. Run timing peaked in early December, but fish continued to pass the dam until the end of the study. Horizontal distribution data indicated that Sluice 1 is the preferred route for these fish during fallback through the dam. Diel distribution for steelhead was variable with no apparent distinct patterns. For Period 2, adult steelhead passage occurred on January 14 and 31 and February 2, 22, and 24. A total of 62 {+-} 40 (95% CI) steelhead targets passed through the powerhouse intakes during December 16, 2009 to March 7, 2010. Horizontal distribution data indicated turbine unit 18 passed the majority of fish. Fish passage occurred during morning periods. Passage did not occur during afternoon or nighttime. For Period 3, the early spring study period, overwintering summer steelhead and early out-migrating steelhead kelt downstream passage occurred throughout the 34-day study period. A total of 1,985 {+-} 234 (95% CI) kelt-size targets were estimated to have passed through the powerhouse sluiceway. Ninety-nine percent of these fish passed through the sluiceway. Run timing peaked in late March and again in early April. Horizontal distribution indicated that Sluice 1 is the preferred route for these adult salmonids as they migrate downstream through the dam. Diel distribution for steelhead was variable with no apparent distinct patterns. The results of this study strongly suggest that operating the TDA sluiceway for steelhead passage (fallbacks and kelts) during the late fall, winter, and early spring months will provide an optimal, non-turbine route for these fishes to pass the dam.« less

Aerial Surveys of Endangered Whales in the Beaufort Sea, Chukchi Sea, and Northern Bering Sea.

DTIC Science & Technology

1981-06-01

migration pattern from that of the 1979 season . Unusual and distinctively marked whales were noted during the spring and fall migrations, and a stranding was...during September and October was latitude 71o30󈧄" N. SIGHTINGS BY OUR SURVEY TEAM The first sightings for the fall season were on 9 September at...when eight bowheads were seen north of the Joint State-Federal lease area. The final sighting of the season was of a cow accompanied by a calf on 9

Place characteristics and residential location choice among the retirement-age population.

PubMed

Duncombe, William; Robbins, Mark; Wolf, Douglas A

2003-07-01

We investigate the association between an extensive set of location-specific factors and the propensity of retirement-age individuals to remain in, or relocate to, those locations. In particular we investigate whether state and local fiscal factors influence the migration decisions of retirees, and we study the relative importance of fiscal and other factors in these decisions. We place decisions regarding whether to move and where to locate in a single discrete-choice framework. We estimate an individual-level location-choice model by using a combination of place-characteristics data and Census county-to-county migration data for the period 1985-1990. We find that levels of tax burdens and public services can affect location decisions. Of the fiscal variables, income taxes have the largest relative effects. However, other factors, including climate, economic conditions, and population characteristics, appear to play much larger roles in migration and location decisions. Although income tax reductions might influence the location decisions of recent retirees, whether or not the economic benefits associated with these population gains outweigh the accompanying revenue losses is an important area for further research. A more cost-effective strategy may be for states to focus on marketing their amenities rather than using fiscal policy to recruit retirees.

Behavioural thermoregulation and bioenergetics of riverine smallmouth bass associated with ambient cold-period thermal refuge

USGS Publications Warehouse

Westhoff, Jacob T.; Paukert, Craig P.; Ettinger-Dietzel, Sarah; Dodd, H.R.; Siepker, Michael

2016-01-01

Smallmouth bass in thermally heterogeneous streams may behaviourally thermoregulate during the cold period (i.e., groundwater temperature greater than river water temperature) by inhabiting warm areas in the stream that result from high groundwater influence or springs. Our objectives were to determine movement of smallmouth bass (Micropterus dolomieu) that use thermal refuge and project differences in growth and consumption among smallmouth bass exhibiting different thermal-use patterns. We implanted radio transmitters in 29 smallmouth bass captured in Alley Spring on the Jacks Fork River, Missouri, USA, during the winter of 2012. Additionally, temperature archival tags were implanted in a subset of nine fish. Fish were tracked using radio telemetry monthly from January 2012 through January of 2013. The greatest upstream movement was 42.5 km, and the greatest downstream movement was 22.2 km. Most radio tagged fish (69%) departed Alley Spring when daily maximum river water temperature first exceeded that of the spring (14 °C) and during increased river discharge. Bioenergetic modelling predicted that a 350 g migrating smallmouth bass that used cold-period thermal refuge would grow 16% slower at the same consumption level as a fish that did not seek thermal refuge. Contrary to the bioenergetics models, extrapolation of growth scope results suggested migrating fish grow 29% more than fish using areas of stream with little groundwater influence. Our results contradict previous findings that smallmouth bass are relatively sedentary, provide information about potential cues for migratory behaviour, and give insight to managers regarding use and growth of smallmouth bass in thermally heterogeneous river systems.

Spring bird migration in Mississippi Alluvial Valley forests

USGS Publications Warehouse

Wilson, R. Randy; Twedt, Daniel J.

2003-01-01

We surveyed forest songbirds during migration in bottomland hardwood forest stands and managed cottonwood (Populus deltoides) plantations in northeast Louisiana and west-central Mississippi between 24 March and 24 May 1996 and 1997. We detected more bird species in bottomland hardwood stands than in cottonwood stands. Within hardwood stands, we detected more individuals in stands subjected to uneven-aged timber harvest than in unmanaged stands. Early in migration, avian species composition was similar in both forest types, being comprised mainly of short-distance migrants. Bird species composition in these forest types became increasingly disparate as long-distance neotropical-nearctic migrants arrived. Ten bird species were characteristic of bottomland hardwood forests, whereas eight different species were characteristic of managed cottonwood plantations. Because these two forest types supported different bird communities, both forest types provide important inland stopover habitat during migration. Silvicultural management of bottomland hardwood forests that increases their understory vegetation will provide forested habitat for a more species rich and abundant population of songbirds during migration.

Migration strategies of Swan Geese Anser cygnoides from northeast Mongolia

USGS Publications Warehouse

Batbayar, Nyambayar; Takekawa, John Y.; Newman, Scott H.; Prosser, Diann J.; Natsagdorj, Tseveenmyadag; Xiao, Xiangming

2011-01-01

In 2006–2008, 25 Swan Geese Anser cygnoides were marked with solar-powered GPS satellite transmitters in northeast Mongolia to examine the timing and pathways of their migration. Most geese began their autumn migration in August, flying southeast toward a staging area at the Yalu River Estuary on the China-North Korea border. After staging for several weeks, the Swan Geese continued to their wintering grounds at wetlands along the Yangtze River Basin of eastern China in December. Spring migration commenced in late February, and the birds following either a same-route or loop migration to arrive at the breeding grounds in mid April. Swan Geese used a larger number of staging areas for a longer duration when they were north of 42°N latitude; they seemed to avoid staging for extended periods in the highly urbanised areas of eastern China. Further research should examine threats and disturbances to the geese in relation to human population growth and increasing urbanisation.

Mites (family Trombiculidae) parasitizing birds migrating from Africa to Europe

PubMed Central

Varma, M. G. R.

1964-01-01

The mechanisms of dissemination of arthropod-borne human and animal pathogens are of considerable interest to the epidemiologist, veterinarian and biologist. Birds which are hosts to such pathogens and their arthropod vectors could transport them over long distances during their spring and autumn migratory flights. In April 1961, birds migrating from Africa to Europe were collected in south-western Spain and examined for ectoparasites and antibodies to arboviruses. Fully engorged larvae of two species of trombiculid mites unknown in Europe (genera Neoschoengastia and Blankaartia) but found in Africa were collected from two of the migrating birds (redstart and little bittern), suggesting that the birds were carrying the mites from Africa to Europe. Trombiculid mites are the proven vectors of scrub typhus; they have also been implicated in the transmission of human haemorrhagic nephroso-nephritis. The finding of the mite larvae on migrating birds is therefore of some epidemiological interest and underlines the importance of obtaining more data on the dispersal of trombiculids by migrating birds. PMID:14267750

Seasonal changes in partial, reverse diel vertical migrations of cisco Coregonus artedi.

PubMed

Ahrenstorff, T D; Hrabik, T R

2016-09-01

The objectives of this study were to (1) document changes in partial, reverse diel vertical migrations (DVM) patterns of cisco Coregonus artedi in Ten Mile Lake, MN, U.S.A., throughout the year and (2) evaluate the mechanisms that may cause shifts in migration behaviour. Results indicated that C. artedi vertical distributions remained deep in the water column during the day and night of the spring and autumn, which was related to a low risk, low reward strategy. During summer, a partial migration occurred where a portion of the population remained deeper according to the low risk, low reward strategy, while the other portion performed a more extensive high risk, high reward reverse DVM. In winter, C. artedi did not migrate because there were only low risk, low reward conditions present at all depths. The extensive partial, reverse DVM during summer probably increased the growth potential of C. artedi, helping individuals survive in a lake with low zooplankton prey resources. © 2016 The Fisheries Society of the British Isles.

Costs of migratory decisions: A comparison across eight white stork populations

PubMed Central

Flack, Andrea; Fiedler, Wolfgang; Blas, Julio; Pokrovsky, Ivan; Kaatz, Michael; Mitropolsky, Maxim; Aghababyan, Karen; Fakriadis, Ioannis; Makrigianni, Eleni; Jerzak, Leszek; Azafzaf, Hichem; Feltrup-Azafzaf, Claudia; Rotics, Shay; Mokotjomela, Thabiso M.; Nathan, Ran; Wikelski, Martin

2016-01-01

Annual migratory movements can range from a few tens to thousands of kilometers, creating unique energetic requirements for each specific species and journey. Even within the same species, migration costs can vary largely because of flexible, opportunistic life history strategies. We uncover the large extent of variation in the lifetime migratory decisions of young white storks originating from eight populations. Not only did juvenile storks differ in their geographically distinct wintering locations, their diverse migration patterns also affected the amount of energy individuals invested for locomotion during the first months of their life. Overwintering in areas with higher human population reduced the stork’s overall energy expenditure because of shorter daily foraging trips, closer wintering grounds, or a complete suppression of migration. Because migrants can change ecological processes in several distinct communities simultaneously, understanding their life history decisions helps not only to protect migratory species but also to conserve stable ecosystems. PMID:26844294

Numbers and distribution of Double-crested Cormorants on the upper Mississippi river

USGS Publications Warehouse

Kirsch, E.M.

1997-01-01

Historic records indicate that Double-crested Cormorants (Phalacrocorax auritus) were common breeders and abundant during migration on the Upper Mississippi River from St. Paul, Minnesota, to St. Louis, Missouri, during the 1940s and 1950s. Their numbers declined in the mid- to late-1950s, remained low through the 1970s, and began to increase somewhat in the late 1980s. Aerial surveys of migrating cormorants and ground surveys at cormorant colonies during 1991-1993, indicate that numbers have not returned to historic levels. Only 500-2,000 cormorants were seen during spring migration 1992-1993; and 5,000-7,000 during fall migration 1991-1992; whereas, tens of thousands were reported in the 1940s and 1950s. Four hundred ninety-six nests were counted at 4 colonies in 1992, and 545 nests were counted in 9 colonies in 1993; whereas, during the 1940s and 1950s, about 2,500 birds were reported nesting in 4 locations. Pools 6 and 13 have always attracted breeding and migrating cormorants, currently attract the largest numbers of cormorants during migration, and still support breeding colonies.

Numbers and distribution of double-crested cormorants on the upper Mississippi River

USGS Publications Warehouse

Kirsch, E.M.

1997-01-01

Historic records indicate that Double-crested Cormorants (Phalacrocorax auritus) were common breeders and abundant during migration on the Upper Mississippi River from St. Paul, Minnesota, to St. Louis, Missouri, during the 1940s and 1950s. Their numbers declined in the mid-to late-1950s, remained low through the 1970s, and began to increase somewhat in the late 1980s. Aerial surveys of migrating cormorants and ground surveys at cormorant colonies during 1991-1993, indicate that numbers have not returned to historic levels. Only 500-2,000 cormorants were seen during spring migration 1992-1993; and 5,000-7,000 during fall migration 1991-1992; whereas, tens of thousands were reported in the 1940s and 1950s. Four hundred ninety-six nests were counted at 4 colonies in 1992, and 545 nests were counted in 9 colonies in 1993; whereas, during the 1940s and 1950s, about 2,500 birds were reported nesting in 4 locations. Pools 6 and 13 have always attracted breeding and migrating cormorants, currently attract the largest numbers of cormorants during migration, and still support breeding colonies.

Fall armyworm: Management of a genetically complicated migratory pest

USDA-ARS?s Scientific Manuscript database

Fall armyworm (Spodoptera frugiperda) (Lepidoptera: Noctuidae) is a neotropical pest that migrates each spring from locations in south Texas and south Florida to the central and eastern U.S. Management of this pest in Florida sweet corn involves tactics such as chemical control, host plant manageme...

[Transcatheter embolization for huge pulmonary arteriovenous fistula using metallic "spider" and spring embolus--application of hand-made metallic "spider" using partial monorail technique].

PubMed

Hirota, S; Sako, M; Fujita, Y; Hasegawa, Y; Sugimoto, K; Suzuki, Y; Kono, M

1992-07-25

We performed transcatheter embolization in two cases with huge pulmonary arteriovenous fistula (AVF) using a metallic "spider" and spring embolus. Conventional spring embolus or detachable balloon could not be used in these cases. Metallic spider was indicated for pulmonary AVF with a feeding artery diameter of more than 16 mm to prevent embolus passing through the AVF. In the first case, we used large handmade metallic spiders of 25 mm in diameter followed by embolization by numerous spring coils. At that time, a partial monorail technique was newly devised to carry the large metallic spider into the feeding artery, otherwise the spider could not pass into a 9F catheter. After embolization, symptoms and PaO2 in arterial blood improved remarkably in both cases. In the second case, a spring coil migrated into the normal pulmonary artery, but no infarction resulted. In conclusion, the metallic spider was very useful for embolization of hugee pulmonary AVF to avoid the embolus passing through and to tangle spring coils together with it. If commercially available "spiders" are too small, ones can be made easily.

Understanding Migration as an Adaptation in Deltas Using a Bayesian Network Model

NASA Astrophysics Data System (ADS)

Lázár, A. N.; Adams, H.; de Campos, R. S.; Mortreux, C. C.; Clarke, D.; Nicholls, R. J.; Amisigo, B. A.

2016-12-01

Deltas are hotspots of high population density, fertile lands and dramatic environmental and anthropogenic pressures and changes. Amongst other environmental factors, sea level rise, soil salinization, water shortages and erosion threaten people's livelihoods and wellbeing. As a result, there is a growing concern that significant environmental change induced migration might occur from these areas. Migration, however, is already happening for economic, education and other reasons (e.g. livelihood change, marriage, planned relocation, etc.). Migration hence has multiple, interlinked drivers and depending on the perspective, can be considered as a positive or negative phenomenon. The DECCMA project (Deltas, Vulnerability & Climate Change: Migration & Adaptation) studies migration as part of a suite of adaptation options available to the coastal populations in the Ganges delta in Bangladesh, the Mahanadi delta in India and the Volta delta in Ghana. It aims to develop a holistic framework of analysis that assesses the impact of climate and environmental change on the migration patterns of these areas. This assessment framework will couple environmental, socio-economics and governance dimensions in an attempt to synthesise drivers and barriers and allow testing of plausible future scenarios. One of the integrative methods of DECCMA is a Bayesian Belief Network (BBN) model describing the decision-making of a coastal household. BBN models are built on qualitative and quantitative observations/expert knowledge and describe the probability of different events/responses etc. BBN models are especially useful to capture uncertainties of large systems and engaging with stakeholders. The DECCMA BBN model is based on household survey results from delta migrant sending areas. This presentation will describe model elements (livelihood sensitivity to climate change, local and national adaptation options, household characteristics/attitude, social networks, household decision) and initial outputs on migration and in-situ adaptation. In doing so we illustrate some key causal relationships between changes in the environment, livelihoods and migration decision.

Hybrid songbirds employ intermediate routes in a migratory divide.

PubMed

Delmore, Kira E; Irwin, Darren E

2014-10-01

Migratory divides are contact zones between populations that use different routes to navigate around unsuitable areas on seasonal migration. Hybrids in divides have been predicted to employ intermediate and potentially inferior routes. We provide the first direct test of this hypothesis, using light-level geolocators to track birds breeding in a hybrid zone between Swainson's thrushes in western Canada. Compared to parental forms, hybrids exhibited increased variability in their migratory routes, with some using intermediate routes that crossed arid and mountainous regions, and some using the same routes as one parental group on fall migration and the other on spring migration. Hybrids also tended to use geographically intermediate wintering sites. Analysis of genetic variation across the hybrid zone suggests moderately strong selection against hybrids. These results indicate that seasonal migratory behaviour might be a source of selection against hybrids, supporting a possible role for migration in speciation. © 2014 John Wiley & Sons Ltd/CNRS.

The Far East taiga forest: unrecognized inhospitable terrain for migrating Arctic-nesting waterbirds?

PubMed

Wang, Xin; Cao, Lei; Bysykatova, Inga; Xu, Zhenggang; Rozenfeld, Sonia; Jeong, Wooseog; Vangeluwe, Didier; Zhao, Yunlin; Xie, Tianhe; Yi, Kunpeng; Fox, Anthony David

2018-01-01

The degree of inhospitable terrain encountered by migrating birds can dramatically affect migration strategies and their evolution as well as influence the way we develop our contemporary flyway conservation responses to protect them. We used telemetry data from 44 tagged individuals of four large-bodied, Arctic breeding waterbird species (two geese, a swan and one crane species) to show for the first time that these birds fly non-stop over the Far East taiga forest, despite their differing ecologies and migration routes. This implies a lack of suitable taiga refuelling habitats for these long-distance migrants. These results underline the extreme importance of northeast China spring staging habitats and of Arctic areas prior to departure in autumn to enable birds to clear this inhospitable biome, confirming the need for adequate site safeguard to protect these populations throughout their annual cycle.

The Far East taiga forest: unrecognized inhospitable terrain for migrating Arctic-nesting waterbirds?

PubMed Central

Wang, Xin; Bysykatova, Inga; Xu, Zhenggang; Rozenfeld, Sonia; Jeong, Wooseog; Vangeluwe, Didier; Zhao, Yunlin; Xie, Tianhe; Yi, Kunpeng; Fox, Anthony David

2018-01-01

The degree of inhospitable terrain encountered by migrating birds can dramatically affect migration strategies and their evolution as well as influence the way we develop our contemporary flyway conservation responses to protect them. We used telemetry data from 44 tagged individuals of four large-bodied, Arctic breeding waterbird species (two geese, a swan and one crane species) to show for the first time that these birds fly non-stop over the Far East taiga forest, despite their differing ecologies and migration routes. This implies a lack of suitable taiga refuelling habitats for these long-distance migrants. These results underline the extreme importance of northeast China spring staging habitats and of Arctic areas prior to departure in autumn to enable birds to clear this inhospitable biome, confirming the need for adequate site safeguard to protect these populations throughout their annual cycle. PMID:29479493

Epidemic spread in coupled populations with seasonally varying migration rates

NASA Astrophysics Data System (ADS)

Muzyczyn, Adam; Shaw, Leah B.

2009-03-01

The H5N1 strain of avian influenza has spread worldwide, and this spread may be due to seasonal migration of birds and mixing of birds from different regions in the wintering grounds. We studied a multipatch model for avian influenza with seasonally varying migration rates. The bird population was divided into two spatially distinct patches, or subpopulations. Within each patch, the disease followed the SIR (susceptible-infected-recovered) model for epidemic spread. Migration rates were varied periodically, with a net flux toward the breeding grounds during the spring and towards the wintering grounds during the fall. The case of two symmetric patches reduced to single-patch SIR dynamics. However, asymmetry in the birth and contact rates in the breeding grounds and wintering grounds led to bifurcations to longer period orbits and chaotic dynamics. We studied the bifurcation structure of the model and the phase relationships between outbreaks in the two patches.

The role of body size versus growth on the decision to migrate: a case study with Salmo trutta

NASA Astrophysics Data System (ADS)

Acolas, M. L.; Labonne, J.; Baglinière, J. L.; Roussel, J. M.

2012-01-01

In a population exhibiting partial migration (i.e. migration and residency tactics occur in the same population), the mechanisms underlying the tactical choice are still unclear. Empirical studies have highlighted a variety of factors that could influence the coexistence of resident and migratory individuals, with growth and body size considered to be key factors in the decision to migrate. Most studies suffer from at least one of the two following caveats: (1) survival and capture probabilities are not taken into account in the data analysis, and (2) body size is often used as a proxy for individual growth. We performed a capture-mark-recapture experiment to study partial migration among juvenile brown trout Salmo trutta at the end of their first year, when a portion of the population emigrate from the natal stream while others choose residency tactic. Bayesian multistate capture-recapture models accounting for survival and recaptures probabilities were used to investigate the relative role of body size and individual growth on survival and migration probabilities. Our results show that, despite an apparent effect of both size and growth on migration, growth is the better integrative parameter and acts directly on migration probability whereas body size acts more strongly on survival. Consequently, we recommend caution if size is used as a proxy for growth when studying the factors that drive partial migration in juvenile salmonid species.

An empirical evaluation of landscape energetic models: Mallard and American black duck space use during the non-breeding period

USGS Publications Warehouse

Beatty, William S.; Webb, Elisabeth B.; Kesler, Dylan C.; Naylor, Luke W.; Raedeke, Andrew H.; Humburg, Dale D.; Coluccy, John M.; Soulliere, G.

2015-01-01

Bird conservation Joint Ventures are collaborative partnerships between public agencies and private organizations that facilitate habitat management to support waterfowl and other bird populations. A subset of Joint Ventures has developed energetic carrying capacity models (ECCs) to translate regional waterfowl population goals into habitat objectives during the non-breeding period. Energetic carrying capacity models consider food biomass, metabolism, and available habitat to estimate waterfowl carrying capacity within an area. To evaluate Joint Venture ECCs in the context of waterfowl space use, we monitored 33 female mallards (Anas platyrhynchos) and 55 female American black ducks (A. rubripes) using global positioning system satellite telemetry in the central and eastern United States. To quantify space use, we measured first-passage time (FPT: time required for an individual to transit across a circle of a given radius) at biologically relevant spatial scales for mallards (3.46 km) and American black ducks (2.30 km) during the non-breeding period, which included autumn migration, winter, and spring migration. We developed a series of models to predict FPT using Joint Venture ECCs and compared them to a biological null model that quantified habitat composition and a statistical null model, which included intercept and random terms. Energetic carrying capacity models predicted mallard space use more efficiently during autumn and spring migrations, but the statistical null was the top model for winter. For American black ducks, ECCs did not improve predictions of space use; the biological null was top ranked for winter and the statistical null was top ranked for spring migration. Thus, ECCs provided limited insight into predicting waterfowl space use during the non-breeding season. Refined estimates of spatial and temporal variation in food abundance, habitat conditions, and anthropogenic disturbance will likely improve ECCs and benefit conservation planners in linking non-breeding waterfowl habitat objectives with distribution and population parameters. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Transfer of fallout radionuclides derived from Fukushima NPP accident: 1 year study on transfer of radionuclides through hydrological processes

NASA Astrophysics Data System (ADS)

Onda, Yuichi; Kato, Hiroaki; Patin, Jeremy; Yoshimura, Kazuya; Tsujimura, Maki; Wakahara, Taeko; Fukushima, Takehiko

2013-04-01

Previous experiences such as Chernobyl Nuclear Power Plant accident have confirmed that fallout radionuclides on the ground surface migrate through natural environment including soils and rivers. Therefore, in order to estimate future changes in radionuclide deposition, migration process of radionuclides in forests, soils, ground water, rivers should be monitored. However, such comprehensive studies on migration through forests, soils, ground water and rivers have not been conducted so far. Here, we present the following comprehensive investigation was conducted to confirm migration of radionuclides through natural environment including soils and rivers. 1)Study on depth distribution of radiocaesium in soils within forests, fields, and grassland 2)Confirmation of radionuclide distribution and investigation on migration in forests 3)Study on radionuclide migration due to soil erosion under different land use 4)Measurement of radionuclides entrained from natural environment including forests and soils 5)Investigation on radionuclide migration through soil water, ground water, stream water, spring water under different land use 6)Study on paddy-to-river transfer of radionuclides through suspended sediments 7)Study on river-to-ocean transfer of radionuclides via suspended sediments 8)Confirmation of radionuclide deposition in ponds and reservoirs

Space-based ornithology: studying bird migration and environmental change in North America

NASA Astrophysics Data System (ADS)

Smith, James A.; Deppe, Jill L.

2008-10-01

Natural fluctuations in the availability of critical stopover sites coupled with anthropogenic destruction of wetlands, land-use change, and anticipated losses due to climate change present migratory birds with a formidable challenge. Space based technology in concert with bird migration modeling and geographical information analysis yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At the NASA Goddard Space Flight Center, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. We use an individual-based bird biophysical migration model, driven by remotely sensed land surface data, climate and hydrologic data, and biological field observations to study migratory bird responses to environmental change in North America. Simulation allows us to study bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. We illustrate our approach by simulating the spring migration of pectoral sandpipers from the Gulf of Mexico to Alaska. Mean stopover length and trajectory patterns are consistent with field observations.

Space-Based Ornithology - Studying Bird Migration and Environmental Change in North America

NASA Technical Reports Server (NTRS)

Smith, James A.; Deppe, Jill L.

2008-01-01

Natural fluctuations in the availability of critical stopover sites coupled with anthropogenic destruction of wetlands, land-use change, and anticipated losses due to climate change present migratory birds with a formidable challenge. Space based technology in concert with bird migration modeling and geographical information analysis yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At the NASA Goddard Space Flight Center, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. We use an individual-based bird biophysical migration model, driven by remotely sensed land surface data, climate and hydrologic data, and biological field observations to study migratory bird responses to environmental change in North America. Simulation allows us to study bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. We illustrate our approach by simulating the spring migration of pectoral sandpipers from the Gulf of Mexico to Alaska. Mean stopover length and trajectory patterns are consistent with field observations.

Flyway-scale variation in plasma triglyceride levels as an index of refueling rate in spring-migrating western sandpipers (Calidris mauri)

USGS Publications Warehouse

Williams, T.D.; Warnock, N.; Takekawa, John Y.; Bishop, M.A.

2007-01-01

We combined radiotelemetry, plasma metabolite analyses, and macro-invertebrate prey sampling to investigate variation in putative fattening rates (estimated as plasma triglyceride levels) at the flyway scale in Western Sandpipers (Calidris mauri) migrating between Punta Banda, Mexico (31°N), and Hartney Bay, Alaska (60°N), a distance of 4,240 km. Birds were caught at a wintering site (San Francisco Bay) and eight stopover sites along this Pacific Flyway. Body mass was higher in females than in males at six sites, but variation was not correlated with latitude for either sex, and the relationship of change in mass by date within sites was uninformative with regard to possible latitudinal variation in fattening rates. At San Francisco Bay, triglyceride levels were higher in the spring than in the winter. Mean plasma triglyceride varied among stopover sites, and there was a significant linear trend of increasing triglyceride levels with latitude as birds migrated north. At San Francisco Bay, length of stay was negatively related to triglyceride levels. However, plasma triglyceride levels at wintering or initial stopover sites (San Francisco and Punta Banda) did not predict individual variation in subsequent rates of travel during migration. We found no significant relationship between triglyceride levels and prey biomass at different stopover sites, which suggests that the latitudinal pattern is not explained by latitudinal changes in food availability. Rather, we suggest that differences in physiology of migratory birds at southern versus northern stopover sites or behavioral differences may allow birds to sustain higher fattening rates closer to the breeding grounds.

Associations between body composition and helminths of lesser snow geese during winter and spring migration.

PubMed

Shutler, Dave; Alisauskas, Ray T; Daniel McLaughlin, J

2012-07-01

Costs of parasitism are predicted to be higher with greater parasite intensities and higher inter-parasite competition (diversity). We tested whether greater helminth intensities and diversity were associated with poorer body composition (whole-body fat, protein, mineral and true body mass) in lesser snow geese, Chen caerulescens caerulescens. As part of a larger study on nutritional ecology, 828 wintering or migrating geese were shot between January and May 1983 in 27 different date-locations (samples) during their northward migration through mid-continental North America. A large proportion of overall variation in body composition and parasite communities was among samples, so we analyzed data within each of the 27 samples, controlling for structural body size (the first principal component of 10 body size measurements), sex and the age of geese. There was no compelling evidence that cestodes, trematodes or helminth diversity were associated with variation in body composition but nematodes had several negative associations with fat reserves. However, negative associations between fat reserves and nematodes occurred most often in geese collected between March and May when nematode prevalences and intensities were relatively low. This suggests several possibilities: that the most common nematodes (Heterakis dispar and Trichostrongylus tenuis) were more virulent at this time, that infected individuals had been chronically infected and suffered cumulative nutrient deficits that lasted until late in the spring migration, or that geese became more vulnerable to the effects of parasites at this time of year, possibly because they redirected resources away from immunity toward fat storage in preparation for reproduction. Copyright © 2012 Australian Society for Parasitology Inc. All rights reserved.

Implementation of a framework for multi-species, multi-objective adaptive management in Delaware Bay

USGS Publications Warehouse

McGowan, Conor P.; Smith, David R.; Nichols, James D.; Lyons, James E.; Sweka, John A.; Kalasz, Kevin; Niles, Lawrence J.; Wong, Richard; Brust, Jeffrey; Davis, Michelle C.; Spear, Braddock

2015-01-01

Decision analytic approaches have been widely recommended as well suited to solving disputed and ecologically complex natural resource management problems with multiple objectives and high uncertainty. However, the difference between theory and practice is substantial, as there are very few actual resource management programs that represent formal applications of decision analysis. We applied the process of structured decision making to Atlantic horseshoe crab harvest decisions in the Delaware Bay region to develop a multispecies adaptive management (AM) plan, which is currently being implemented. Horseshoe crab harvest has been a controversial management issue since the late 1990s. A largely unregulated horseshoe crab harvest caused a decline in crab spawning abundance. That decline coincided with a major decline in migratory shorebird populations that consume horseshoe crab eggs on the sandy beaches of Delaware Bay during spring migration. Our approach incorporated multiple stakeholders, including fishery and shorebird conservation advocates, to account for diverse management objectives and varied opinions on ecosystem function. Through consensus building, we devised an objective statement and quantitative objective function to evaluate alternative crab harvest policies. We developed a set of competing ecological models accounting for the leading hypotheses on the interaction between shorebirds and horseshoe crabs. The models were initially weighted based on stakeholder confidence in these hypotheses, but weights will be adjusted based on monitoring and Bayesian model weight updating. These models were used together to predict the effects of management actions on the crab and shorebird populations. Finally, we used a dynamic optimization routine to identify the state dependent optimal harvest policy for horseshoe crabs, given the possible actions, the stated objectives and our competing hypotheses about system function. The AM plan was reviewed, accepted and implemented by the Atlantic States Marine Fisheries Commission in 2012 and 2013. While disagreements among stakeholders persist, structured decision making enabled unprecedented progress towards a transparent and consensus driven management plan for crabs and shorebirds in Delaware Bay.

Two Trees: Migrating Fault Trees to Decision Trees for Real Time Fault Detection on International Space Station

NASA Technical Reports Server (NTRS)

Lee, Charles; Alena, Richard L.; Robinson, Peter

2004-01-01

We started from ISS fault trees example to migrate to decision trees, presented a method to convert fault trees to decision trees. The method shows that the visualizations of root cause of fault are easier and the tree manipulating becomes more programmatic via available decision tree programs. The visualization of decision trees for the diagnostic shows a format of straight forward and easy understands. For ISS real time fault diagnostic, the status of the systems could be shown by mining the signals through the trees and see where it stops at. The other advantage to use decision trees is that the trees can learn the fault patterns and predict the future fault from the historic data. The learning is not only on the static data sets but also can be online, through accumulating the real time data sets, the decision trees can gain and store faults patterns in the trees and recognize them when they come.

40 CFR 148.24 - Termination of approved petition.

Code of Federal Regulations, 2014 CFR

2014-07-01

... relevant to the Director's decision on the petition; (2) A determination that there has been migration from... the Director may at his discretion decide not to terminate where: (i) The migration resulted from a...

40 CFR 148.24 - Termination of approved petition.

Code of Federal Regulations, 2012 CFR

2012-07-01

... relevant to the Director's decision on the petition; (2) A determination that there has been migration from... the Director may at his discretion decide not to terminate where: (i) The migration resulted from a...

40 CFR 148.24 - Termination of approved petition.

Code of Federal Regulations, 2013 CFR

2013-07-01

... relevant to the Director's decision on the petition; (2) A determination that there has been migration from... the Director may at his discretion decide not to terminate where: (i) The migration resulted from a...

40 CFR 148.24 - Termination of approved petition.

Code of Federal Regulations, 2010 CFR

2010-07-01

... relevant to the Director's decision on the petition; (2) A determination that there has been migration from... the Director may at his discretion decide not to terminate where: (i) The migration resulted from a...

40 CFR 148.24 - Termination of approved petition.

Code of Federal Regulations, 2011 CFR

2011-07-01

... relevant to the Director's decision on the petition; (2) A determination that there has been migration from... the Director may at his discretion decide not to terminate where: (i) The migration resulted from a...

Springs of Great Britain

NASA Astrophysics Data System (ADS)

Day, J. B. W.

1996-03-01

Predictably, in a country such as Britain, with its preponderance of consolidated, sedimentary, mainly fissure-flow aquifers, there is a very large number of springs, many of which are, or have been, used for public supply. Migratory springs are a feature of the British (Ur. Cretaceous) Chalk, the most important British aquifer. The Chalk's low specific yield and high capillary moisture retention together give rise to very considerable fluctuations (more than 33 m in some areas) of the unconfined water table. Along the gentle dip slopes of the Chalk (North and South Downs of southern and southeastern England) springs may migrate laterally for several miles, giving rise to seasonal streams locally known as “bournes” or “lavants”. However, springs such as at Duncton, West Sussex, at the base of the much steeper scarp slopes of the Chalk, form point sources, the flows from which tend to be relatively steady; such springs commonly supply and are the original reason for the existence of many of the small towns and villages which nestle along the bases of the chalk scarps of Sussex and Kent. Where the Chalk forms coastal cliffs, a number of springs break out at the base of the cliff between high and low tide levels; there are major chalk coastal springs, for instance, at St. Margaret's Bay (Kent) and at Arish Mells, east of Lulworth Cove, Dorset. Such springs are not used for direct supply (their salinity is usually too high) but are indicators of the presence of local reserves of groundwater for possible future development.

Early Childhood Education in Turkish Gecekondu.

ERIC Educational Resources Information Center

Savas-Ulkuer, Nurper

A longitudinal research project was initiated in the spring of 1988 in Ankara, Turkey in selected gecekondu settlements. A gecekondu is a hastily constructed dwelling used to house newcomers to large cities. Gecekondu dwellers are predominantly disadvantaged, rural people who have migrated to the fringes of urban areas and whose children usually…

Gastro-intestinal microbiota of two migratory shorebird species during spring migration staging in Delaware Bay, USA

EPA Science Inventory

Migratory birds travel long distances and use diverse habitats, potentially exposing them to a broad range of microbes that could negatively affect their health and survival. Gut microbiota composition has been shown to be closely related to organismal health through interactions...

Modeling seasonal migration of fall armyworm moths

USDA-ARS?s Scientific Manuscript database

Fall armyworm, Spodoptera frugiperda (J. E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature, but must repeat a series of northward migratory flights each spring if it is to re-infest ...

Energy Reserves, Information Need and a Pinch of Personality Determine Decision-Making on Route in Partially Migratory Blue Tits.

PubMed

Nilsson, Anna L K; Nilsson, Jan-Åke; Mettke-Hofmann, Claudia

2016-01-01

In facultative partial migrants some individuals in a population are migratory and others are resident and individuals decide each year anew which strategy to choose. While the proportion of birds migrating is in part determined by environmental conditions and competitive abilities, the timing of individual departure and behaviours on route are little understood. Individuals encounter different environmental conditions when migrating earlier or later. Based on cost/ benefit considerations we tested whether behaviours on route were affected by time constraints, personality and/or age in a partially migrating population of Blue tits (Cyanistes caeruleus). We captured female Blue tits on migration at the Southern tip of Sweden during early, peak and late migration and measured latency to feed in an unfamiliar environment, exploration of a novel object and hesitation to feed beside a novel object (neophobia). Lean birds and birds with long wings started feeding earlier when released into the cage indicating that foraging decisions were mainly determined by energetic needs (lean and large birds). However, juveniles commenced feeding later with progression of the migratory season in concordance with predictions about personality effects. Furthermore, lean birds started to explore earlier than birds with larger fat reserves again indicating an effect of maintaining threshold energy reserves. Moreover, late migrating juveniles, started to explore earlier than early migrating juveniles possibly due to time constraints to find high-quality foraging patches or a suitable winter home. Finally, neophobia did not change over the migratory season indicating that this behaviour is not compromised by time constraints. The results overall indicate that decisions on route are mainly governed by energetic requirements and current needs to learn about the environment and only to a small extent by differences in personality.

Energy Reserves, Information Need and a Pinch of Personality Determine Decision-Making on Route in Partially Migratory Blue Tits

PubMed Central

Nilsson, Jan-Åke; Mettke-Hofmann, Claudia

2016-01-01

In facultative partial migrants some individuals in a population are migratory and others are resident and individuals decide each year anew which strategy to choose. While the proportion of birds migrating is in part determined by environmental conditions and competitive abilities, the timing of individual departure and behaviours on route are little understood. Individuals encounter different environmental conditions when migrating earlier or later. Based on cost/ benefit considerations we tested whether behaviours on route were affected by time constraints, personality and/or age in a partially migrating population of Blue tits (Cyanistes caeruleus). We captured female Blue tits on migration at the Southern tip of Sweden during early, peak and late migration and measured latency to feed in an unfamiliar environment, exploration of a novel object and hesitation to feed beside a novel object (neophobia). Lean birds and birds with long wings started feeding earlier when released into the cage indicating that foraging decisions were mainly determined by energetic needs (lean and large birds). However, juveniles commenced feeding later with progression of the migratory season in concordance with predictions about personality effects. Furthermore, lean birds started to explore earlier than birds with larger fat reserves again indicating an effect of maintaining threshold energy reserves. Moreover, late migrating juveniles, started to explore earlier than early migrating juveniles possibly due to time constraints to find high-quality foraging patches or a suitable winter home. Finally, neophobia did not change over the migratory season indicating that this behaviour is not compromised by time constraints. The results overall indicate that decisions on route are mainly governed by energetic requirements and current needs to learn about the environment and only to a small extent by differences in personality. PMID:27732602

Migration of Florida sub-adult Bald Eagles

USGS Publications Warehouse

Mojica, E.K.; Meyers, J.M.; Millsap, B.A.; Haley, K.L.

2008-01-01

We used satellite telemetry locations accurate within 1 km to identify migration routes and stopover sites of 54 migratory sub-adult Bald Eagles (Haliaeetus leucocephalus) hatched in Florida from 1997 to 2001. We measured number of days traveled during migration, path of migration, stopover time and locations, and distance traveled to and from winter and summer areas for each eagle (1?5 years old). Eagles used both Coastal Plain (n = 24) and Appalachian Mountain (n = 26) routes on their first migration north. Mountain migrants traveled farther (X = 2,112 km; 95% CI: 1,815-2,410) than coastal migrants (X = 1,397 km; 95% CI: 1,087?1,706). Eagles changed between migration routes less often on northbound and southbound movements as they matured (X2 = 13.22, df = 2, P < 0.001). One-year-old eagles changed routes between yearly spring and fall migrations 57% of the time, 2-year-olds 30%, and 3-5-year-olds changed only 17% of the time. About half (n = 25, 46%) used stopovers during migration and stayed 6-31 days (X = 14.8 days; 95% CI: 12.8-16.8). We recommend that migratory stopover site locations be added to GIS data bases for improving conservation of Bald Eagles in the eastern United States.

Sources and Chronology of Nitrate Contamination of Spring Waters: Integrating Science and Policy Decisions

NASA Astrophysics Data System (ADS)

Katz, B. G.; Stevenson, J. A.

2002-12-01

Human health and ecological concerns have arisen regarding spring waters in Florida as a steady increase in nitrate concentrations has been observed during the past 30 years. The extensive aesthetic, cultural, and recreational value of these springs, which also supply water for human consumption and support critical ecological habitats, could be threatened by the presence of nitrate. As part of the response to these concerns by the State of Florida, several research studies have used various chemical and isotopic tracers to determine sources of nitrate contamination and age of ground water discharging from springs. Since 1997, 60 water samples have been collected from 44 springs and analyzed for isotopic (15N, 3H/3He, 18O, 2H, 13C) and other chemical tracers (CFCs, major ions, dissolved gases, SF6). Delta 15N values of nitrate ranged from 2.6 to 12.9 per mil (median = 5.8 per mil) and indicated that nitrate in most spring waters originated from synthetic fertilizers. CFCs, 3H/3He, and SF6, used to estimate the residence time of ground water discharging from springs, indicated that spring-water ages ranged from 5 to 39 years. Concentrations of these multiple transient tracers are consistent with a two-component hydrologic model with mixtures of varying proportions of young water (less than 8 years) from the shallow part of the aquifer system and older water (20-50 years) from the deeper part of the flow system. Given residence times of 20-40 years for ground water discharging from most springs, it could take decades for nitrate concentrations to decrease to near background levels, even with immediate reductions in nitrogen inputs to the land surface. These research results are being used by the State of Florida to inform elected officials, water-resource mangers, and planners that decisions about land use today will affect the quality of ground water in springs for decades.

Development of decision tools to assess migration from plastic materials in contact with food.

PubMed

Gillet, G; Vitrac, O; Tissier, D; Saillard, P; Desobry, S

2009-12-01

Testing the specific migration limits of all substances intentionally added to polymer material according to European Union (EU) regulation is a time-consuming and expensive task. Although mathematical modeling offers an interesting alternative, it can significantly overestimate the migration in situations which are strongly conservative due to significant uncertainty in transport properties. In addition, its application is of little use for end-users or enforcement laboratories, which do not have access to the formulation. This paper revises the paradigm of migration modeling by combining modeling with deformulation experiments and iterative modeling in the framework of decision theory. The complete approach is illustrated for polyolefins in contact with 50% ethanol for eight typical migrants, including hindered phenolic antioxidants and low molecular weight surrogates. Results from a French ACTIA project on the identification of formulation fingerprints and on the prediction of partition coefficients with alcoholic and aqueous stimulants is described. When the true migration was close but still lower than the limit of concern, the proposed compact decision tree, including up to four sources of uncertainty, showed that the chance of demonstrating compliance was about 3 : 4 in the presence of one source of uncertainty, whereas it fell below 2 : 4 and 1 : 4 with two and three sources of uncertainty, respectively. The recommendations for further food packaging safety surveys and future developments are discussed.

Migration in Deltas: An Integrated Analysis

NASA Astrophysics Data System (ADS)

Nicholls, Robert J.; Hutton, Craig W.; Lazar, Attila; Adger, W. Neil; Allan, Andrew; Arto, Inaki; Vincent, Katharine; Rahman, Munsur; Salehin, Mashfiqus; Sugata, Hazra; Ghosh, Tuhin; Codjoe, Sam; Appeaning-Addo, Kwasi

2017-04-01

Deltas and low-lying coastal regions have long been perceived as vulnerable to global sea-level rise, with the potential for mass displacement of exposed populations. The assumption of mass displacement of populations in deltas requires a comprehensive reassessment in the light of present and future migration in deltas, including the potential role of adaptation to influence these decisions. At present, deltas are subject to multiple drivers of environmental change and often have high population densities as they are accessible and productive ecosystems. Climate change, catchment management, subsidence and land cover change drive environmental change across all deltas. Populations in deltas are also highly mobile, with significant urbanization trends and the growth of large cities and mega-cities within or adjacent to deltas across Asia and Africa. Such migration is driven primarily by economic opportunity, yet environmental change in general, and climate change in particular, are likely to play an increasing direct and indirect role in future migration trends. The policy challenges centre on the role of migration within regional adaptation strategies to climate change; the protection of vulnerable populations; and the future of urban settlements within deltas. This paper reviews current knowledge on migration and adaptation to environmental change to discern specific issues pertinent to delta regions. It develops a new integrated methodology to assess present and future migration in deltas using the Volta delta in Ghana, Mahanadi delta in India and Ganges-Brahmaputra-Meghna delta across India and Bangladesh. The integrated method focuses on: biophysical changes and spatial distribution of vulnerability; demographic changes and migration decision-making using multiple methods and data; macro-economic trends and scenarios in the deltas; and the policies and governance structures that constrain and enable adaptation. The analysis is facilitated by a range of consistent scenarios from global to delta scales, developed in consultation with major stakeholders. Initial results suggest that migration decision-making strongly interacts with diverse measures for adaptation of land, water and agricultural management. A key normative challenge is to identify the parameters of successful migration and adaptation across delta regions, to inform policy analysis and formulation. Key words: Deltas, sea-level rise, migration and adaptation Acknowledgement: DECCMA (Deltas, Vulnerability & Climate Change: Migration & Adaptation) project is part of the Collaborative ADAPTATION Research Initiative in Africa and Asia (CARIAA), with financial support from the UK Government's Department for International Development (DFID) and the International Development Research Centre (IDRC), Canada.

Migratory bird hunter opinions regarding potential management strategies for controlling light goose populations

USGS Publications Warehouse

Dinges, Andrew J.; Webb, Elisabeth B.; Vrtiska, Mark P.; Nilon, Charles H.; Wilhelm Stanis, Sonja A.

2014-01-01

We expanded the Nebraska Light Goose Conservation Order (LGCO) harvest survey (NE, USA) in spring 2012 to assess migratory bird hunter opinions regarding future management strategies for controlling light goose populations. Although hunters strongly agreed that population control of light geese was an important wildlife management issue, they were generally unsupportive of wildlife officials using forms of direct control methods to control light goose populations. Respondents who indicated participation in the 2012 LGCO were also less supportive of any form of direct control compared with migratory bird hunters who did not participate in the LGCO. When presented with alternative methods by wildlife officials for future light goose population control, respondents were most supportive of wildlife agencies selectively shooting light geese on migration and wintering areas and least supportive of wildlife officials using bait with approved chemicals to euthanize light geese. A clear understanding of public perception of various potential direct-control options will likely assist wildlife biologists in making informed decisions on how to proceed with population control of light geese.

Direct migration motion estimation and mode decision to decoder for a low-complexity decoder Wyner-Ziv video coding

NASA Astrophysics Data System (ADS)

Lei, Ted Chih-Wei; Tseng, Fan-Shuo

2017-07-01

This paper addresses the problem of high-computational complexity decoding in traditional Wyner-Ziv video coding (WZVC). The key focus is the migration of two traditionally high-computationally complex encoder algorithms, namely motion estimation and mode decision. In order to reduce the computational burden in this process, the proposed architecture adopts the partial boundary matching algorithm and four flexible types of block mode decision at the decoder. This approach does away with the need for motion estimation and mode decision at the encoder. The experimental results show that the proposed padding block-based WZVC not only decreases decoder complexity to approximately one hundredth that of the state-of-the-art DISCOVER decoding but also outperforms DISCOVER codec by up to 3 to 4 dB.

Corticosterone secretion patterns prior to spring and autumn migration differ in free-living barn swallows (Hirundo rustica L.).

PubMed

Raja-aho, Sari; Lehikoinen, Esa; Suorsa, Petri; Nikinmaa, Mikko; Vainio, Minna; Vosloo, Dalene; Eeva, Tapio

2013-11-01

Recent studies of long-distance migratory birds show that behavioural and physiological changes associated with predictable or unpredictable challenges during the annual cycle are distinctively regulated by hormones. Corticosterone is the primary energy regulating hormone in birds. Corticosterone levels are elevated during stresses but they are also modulated seasonally according to environmental conditions and life-history demands. We measured the baseline and stress-induced levels of corticosterone in the barn swallow (Hirundo rustica L.) just before spring and autumn migrations in South Africa and Finland, respectively. Barn swallows completing their pre-breeding moult had low body condition (residual body mass) and high baseline corticosterone levels in the wintering grounds. In contrast, baseline corticosterone levels in Finland were low and not related to residual mass. These data contradict the first prediction of the migration modulation hypothesis (MMH) by showing no association with baseline corticosterone levels and pre-migratory fuelling. Yet, the adrenocortical response to the capture and handling stress was notably blunted in South Africa compared to a strong response in Finland. Further, individuals that had started fuelling in Finland showed a reduced response to the handling stress. Taken together, elevated baseline corticosterone levels and high residual mass may blunt the adrenocortical response in long-distance migrants and aerial feeders such as the barn swallow. This observation lends support to the second prediction of the MMH.

Use of a Florida Gulf Coast Barrier Island by Spring Trans-Gulf Migrants and the Projected Effects of Sea Level Rise on Habitat Availability.

PubMed

Lester, Lori A; Gutierrez Ramirez, Mariamar; Kneidel, Alan H; Heckscher, Christopher M

2016-01-01

Barrier islands on the north coast of the Gulf of Mexico are an internationally important coastal resource. Each spring hundreds of thousands of Nearctic-Neotropical songbirds crossing the Gulf of Mexico during spring migration use these islands because they provide the first landfall for individuals following a trans-Gulf migratory route. The effects of climate change, particularly sea level rise, may negatively impact habitat availability for migrants on barrier islands. Our objectives were (1) to confirm the use of St. George Island, Florida by trans-Gulf migrants and (2) to determine whether forested stopover habitat will be available for migrants on St. George Island following sea level rise. We used avian transect data, geographic information systems, remote sensing, and simulation modelling to investigate the potential effects of three different sea level rise scenarios (0.28 m, 0.82 m, and 2 m) on habitat availability for trans-Gulf migrants. We found considerable use of the island by spring trans-Gulf migrants. Migrants were most abundant in areas with low elevation, high canopy height, and high coverage of forests and scrub/shrub. A substantial percentage of forest (44%) will be lost by 2100 assuming moderate sea level rise (0.82 m). Thus, as sea level rise progresses, less forests will be available for migrants during stopover. Many migratory bird species' populations are declining, and degradation of barrier island stopover habitat may further increase the cost of migration for many individuals. To preserve this coastal resource, conservation and wise management of migratory stopover areas, especially near ecological barriers like the Gulf of Mexico, will be essential as sea levels rise.

Use of a Florida Gulf Coast Barrier Island by Spring Trans-Gulf Migrants and the Projected Effects of Sea Level Rise on Habitat Availability

PubMed Central

Lester, Lori A.; Gutierrez Ramirez, Mariamar; Kneidel, Alan H.; Heckscher, Christopher M.

2016-01-01

Barrier islands on the north coast of the Gulf of Mexico are an internationally important coastal resource. Each spring hundreds of thousands of Nearctic-Neotropical songbirds crossing the Gulf of Mexico during spring migration use these islands because they provide the first landfall for individuals following a trans-Gulf migratory route. The effects of climate change, particularly sea level rise, may negatively impact habitat availability for migrants on barrier islands. Our objectives were (1) to confirm the use of St. George Island, Florida by trans-Gulf migrants and (2) to determine whether forested stopover habitat will be available for migrants on St. George Island following sea level rise. We used avian transect data, geographic information systems, remote sensing, and simulation modelling to investigate the potential effects of three different sea level rise scenarios (0.28 m, 0.82 m, and 2 m) on habitat availability for trans-Gulf migrants. We found considerable use of the island by spring trans-Gulf migrants. Migrants were most abundant in areas with low elevation, high canopy height, and high coverage of forests and scrub/shrub. A substantial percentage of forest (44%) will be lost by 2100 assuming moderate sea level rise (0.82 m). Thus, as sea level rise progresses, less forests will be available for migrants during stopover. Many migratory bird species’ populations are declining, and degradation of barrier island stopover habitat may further increase the cost of migration for many individuals. To preserve this coastal resource, conservation and wise management of migratory stopover areas, especially near ecological barriers like the Gulf of Mexico, will be essential as sea levels rise. PMID:26934343

Ireland's medical brain drain: migration intentions of Irish medical students.

PubMed

Gouda, Pishoy; Kitt, Kevin; Evans, David S; Goggin, Deirdre; McGrath, Deirdre; Last, Jason; Hennessy, Martina; Arnett, Richard; O'Flynn, Siun; Dunne, Fidelma; O'Donovan, Diarmuid

2015-03-12

To provide the optimum level of healthcare, it is important that the supply of well-trained doctors meets the demand. However, despite many initiatives, Ireland continues to have a shortfall of physicians, which has been projected to persist. Our study aimed to investigate the migration intentions of Irish medical students and identify the factors that influence their decisions in order to design appropriate interventions to sustain the supply of trained doctors in order to maintain a viable medical system. An online cross-sectional survey was undertaken of all Irish medical students studying in the Republic of Ireland. The survey included nominal, ordinal, and scale items to determine migration intentions, factors influencing their decisions, and understanding of the Irish healthcare system. A total of 2 273 medical students responded (37% response rate), of whom 1 519 were classified as Irish medical students (having completed secondary school in Ireland). Of these, 88% indicated they were either definitely migrating or contemplating migrating following graduation or completion of the pre-registration intern year. Forty percent expressed an intention of returning to Ireland within 5 years. The factors most influencing their decision to leave were career opportunities (85%), working conditions (83%), and lifestyle (80%). The migration intentions expressed in this study predict an immediate and severe threat to the sustainability of the Irish healthcare service. Urgent interventions such as providing information about career options and specialty training pathways are required. These must begin in the undergraduate phase and continue in postgraduate training and are needed to retain medical school graduates.

Data on the migration of health-care workers: sources, uses, and challenges.

PubMed Central

Diallo, Khassoum

2004-01-01

The migration of health workers within and between countries is a growing concern worldwide because of its impact on health systems in developing and developed countries alike. Policy decisions need to be made at the national, regional and international levels to manage more effectively this phenomenon, but those decisions will be effective and correctly implemented and evaluated only if they are based on adequate statistical data. Most statistics on the migration of health-care workers are neither complete nor fully comparable, and they are often underused, limited (because they often give only a broad description of the phenomena) and not as timely as required. There is also a conflict between the wide range of potential sources of data and the poor statistical evidence on the migration of health personnel. There are two major problems facing researchers who wish to provide evidence on this migration: the problems commonly faced when studying migration in general, such as definitional and comparability problems of "worker migrations" and those related to the specific movements of the health workforce. This paper presents information on the uses of statistics and those who use them, the strengths and limitations of the main data sources, and other challenges that need to be met to obtain good evidence on the migration of health workers. This paper also proposes methods to improve the collection, analysis, sharing, and use of statistics on the migration of health workers. PMID:15375450

Modelling and simulating decision processes of linked lives: An approach based on concurrent processes and stochastic race.

PubMed

Warnke, Tom; Reinhardt, Oliver; Klabunde, Anna; Willekens, Frans; Uhrmacher, Adelinde M

2017-10-01

Individuals' decision processes play a central role in understanding modern migration phenomena and other demographic processes. Their integration into agent-based computational demography depends largely on suitable support by a modelling language. We are developing the Modelling Language for Linked Lives (ML3) to describe the diverse decision processes of linked lives succinctly in continuous time. The context of individuals is modelled by networks the individual is part of, such as family ties and other social networks. Central concepts, such as behaviour conditional on agent attributes, age-dependent behaviour, and stochastic waiting times, are tightly integrated in the language. Thereby, alternative decisions are modelled by concurrent processes that compete by stochastic race. Using a migration model, we demonstrate how this allows for compact description of complex decisions, here based on the Theory of Planned Behaviour. We describe the challenges for the simulation algorithm posed by stochastic race between multiple concurrent complex decisions.

Why sub-Saharan African health workers migrate to European countries that do not actively recruit: a qualitative study post-migration.

PubMed

Poppe, Annelien; Jirovsky, Elena; Blacklock, Claire; Laxmikanth, Pallavi; Moosa, Shabir; De Maeseneer, Jan; Kutalek, Ruth; Peersman, Wim

2014-01-01

Many studies have investigated the migration intentions of sub-Saharan African medical students and health professionals within the context of a legacy of active international recruitment by receiving countries. However, many health workers migrate outside of this recruitment paradigm. This paper aims to explore the reasons for migration of health workers from sub-Saharan Africa to Belgium and Austria; European countries without a history of active recruitment in sub-Saharan Africa. Data were collected using semistructured interviews. Twenty-seven health workers were interviewed about their migration experiences. Included participants were born in sub-Saharan Africa, had trained as health workers in sub-Saharan Africa, and were currently living in Belgium or Austria, though not necessarily currently working as a health professional. Both Austria and Belgium were shown not to be target countries for the health workers, who instead moved there by circumstance, rather than choice. Three principal reasons for migration were reported: 1) educational purposes; 2) political instability or insecurity in their country of origin; and 3) family reunification. In addition, two respondents mentioned medical reasons and, although less explicit, economic factors were also involved in several of the respondents' decision to migrate. These results highlight the importance of the broader economic, social, and political context within which migration decisions are made. Training opportunities proved to be an important factor for migration. A further development and upgrade of primary care might help to counter the common desire to specialize and improve domestic training opportunities.

Moving BASISplus and TECHLIBplus from VAX/VMS to UNIX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dominiak, R.

1993-12-31

BASISplus is used at the Laboratory by the Technical Information Services (TIS) Department which is part of the Information and Publishing Division at ARGONNE. TIS operates the Argonne Information Management System (AIM). The AIM System consists of the ANL Libraries On-Line Database (a TECHLIBplus database), the Current Journals Database (IDI`s current contents search), the ANL Publications Tracking Database (a TECHLIBplus database), the Powder Diffraction File Database, and several CD-ROM databases available through a Novell network. The AIM System is available from the desktop of ANL staff through modem and network connections, as well as from the 10 science libraries atmore » ARGONNE. TIS has been a BASISplus and TECHLIBplus site from the start, and never migrated from BASIS K. The decision to migrate from the VAX/VMS platform to a UNIX platform. Migrating a product from one platform to another involves many decisions and considerations. These justifications, decisions, and considerations are explored in this report.« less

Strategic Studies Quarterly. Volume 3, Number 1, Spring 2009

DTIC Science & Technology

2009-01-01

elaborated in Sharon Behn and Seth Rosen, “US Urged to Focus More on Nation-Building,” Washington Times, 28 July 2005, 15. 2. Daryl Kimball, “Of...Third World Quarterly 25, no. 6 (2004): 1131–54. 45. Ben Watkins and Michael L. Fleisher, “Tracking Pastoralist Migration: Lessons from the Ethiopian

Seasonal changes in the vocal behavior of bowhead whales (Balaena mysticetus) in Disko Bay, Western-Greenland.

PubMed

Tervo, Outi M; Parks, Susan E; Miller, Lee A

2009-09-01

Singing behavior has been described from bowhead whales in the Bering Sea during their annual spring migration and from Davis Strait during their spring feeding season. It has been suggested that this spring singing behavior is a remnant of the singing during the winter breeding season, though no winter recordings are available. In this study, the authors describe recordings made during the winter and spring months of bowhead whales in Disko Bay, Western-Greenland. A total of 7091 bowhead whale sounds were analyzed to describe the vocal repertoire, the singing behavior, and the changes in vocal behavior from February to May. The vocal signals could be divided into simple (frequency-modulated) calls (n=483), complex (amplitude-modulated) calls (n=635), and song notes (n=5973). Recordings from the end of February to middle of March were characterized by higher call rates with a greater diversity of call types than recordings made later in the season. This study is the first description of bowhead song from the stock in Western-Greenland during both the winter and spring months, and provides support for the hypothesis that song during the winter months contains more song notes than song from the spring making the winter song more variable.

Seasonal and annual survival of adult Pacific brant

USGS Publications Warehouse

Ward, David H.; Rexstad, Eric A.; Sedinger, James S.; Lindberg, Mark S.; Dawe, Neil K.

1997-01-01

Declining mid-winter counts of Pacific brant (Branta bernicla nigricans) and reduced numbers of nesting birds on their main breeding grounds prompted us to assess factors that may be limiting recovery of this population. We estimated seasonal and annual survival rates of adult brant in 1986-93 from resightings of leg-banded birds. Brant were banded at a major colony on the Yukon-Kuskokwim Delta, Alaska (Y-K Delta) in 1986-92, and resighted there in 1987-93 as well as at major fall and spring migration and wintering areas in 1990-93. Seasonal survival was the same for males and females. Mean monthly survival rate was lowest (P ≤ 0.05) in late spring migration (15 Apr-1 Jun), the period of greatest subsistence harvest on the breeding grounds, and highest in winter (1 Jan-1 Mar), the period of greatest sport harvest. Annual survival rate did not vary among years (F = 0.51; 5, 718 df; P = 0.91) and averaged 0.840 (SE = 0.031) from 1986 to 1993. Subsistence harvest has contributed to low population levels of Pacific brant.

Animal migration amid shifting patterns of phenology and predation: lessons from a Yellowstone elk herd.

PubMed

Middleton, Arthur D; Kauffman, Matthew J; McWhirter, Douglas E; Cook, John G; Cook, Rachel C; Nelson, Abigail A; Jimenez, Michael D; Klaver, Robert W

2013-06-01

Migration is a striking behavioral strategy by which many animals enhance resource acquisition while reducing predation risk. Historically, the demographic benefits of such movements made migration common, but in many taxa the phenomenon is considered globally threatened. Here we describe a long-term decline in the productivity of elk (Cervus elaphus) that migrate through intact wilderness areas to protected summer ranges inside Yellowstone National Park, USA. We attribute this decline to a long-term reduction in the demographic benefits that ungulates typically gain from migration. Among migratory elk, we observed a 21-year, 70% reduction in recruitment and a 4-year, 19% depression in their pregnancy rate largely caused by infrequent reproduction of females that were young or lactating. In contrast, among resident elk, we have recently observed increasing recruitment and a high rate of pregnancy. Landscape-level changes in habitat quality and predation appear to be responsible for the declining productivity of Yellowstone migrants. From 1989 to 2009, migratory elk experienced an increasing rate and shorter duration of green-up coincident with warmer spring-summer temperatures and reduced spring precipitation, also consistent with observations of an unusually severe drought in the region. Migrants are also now exposed to four times as many grizzly bears (Ursus arctos) and wolves (Canis lupus) as resident elk. Both of these restored predators consume migratory elk calves at high rates in the Yellowstone wilderness but are maintained at low densities via lethal management and human disturbance in the year-round habitats of resident elk. Our findings suggest that large-carnivore recovery and drought, operating simultaneously along an elevation gradient, have disproportionately influenced the demography of migratory elk. Many migratory animals travel large geographic distances between their seasonal ranges. Changes in land use and climate that disparately influence such seasonal ranges may alter the ecological basis of migratory behavior, representing an important challenge for, and a powerful lens into, the ecology and conservation of migratory taxa.

Do birds of like feather flock together? The use of a novel 13C+D combustion isotope analyzer to track bird migration

NASA Astrophysics Data System (ADS)

Saad, N.

2011-12-01

Information on spring migration routes, geographic linkages among winter, spring, and breeding locations, and potential geographic effects on arrival body condition of a variety of avian species is so far little known. Stable isotope ratios are exquisitely sensitive to the biochemistry of living organisms and the nutrients available to them. Isotope ratios provide detailed knowledge useful in a variety of fields, including birds migration, through a combination of stable-isotope measurements of carbon (13C/12C) and hydrogen (D/H) isotopes of flight feathers and breast feathers of tissues representing different periods of dietary integration and body composition analyses. Associations among specific geographic areas, habitat use, and arrival condition can be elucidated through the measurement of these dual isotopes. We report here on the development of a novel laser spectroscopy based system for the simultaneous analysis of the stable isotope ratios of carbon (13C/12C) and hydrogen (D/H) that is robust, easy-to-use, and is the first stable isotope ratio analysis system to combine the measurement of 13C/12C and D/H in one simple analysis from a bulk organic sample with an application to bird migration. The system comprises a combustion module to convert the organic sample into CO2 and H2O and a Cavity Ring-Down Spectrometer (CRDS) that analyzes the combustion species inside an optical cavity based on the molecular absorption of individual isotopomers. This CRDS uses dual lasers to target the four isotpomers of interest: 12CO2, 13CO2, H2O and HDO. The system delivers a typical precision of 0.1 permil for δ13C and 1.5 permil for δD that parallels that achieved by IRMS, but with an unprecedented simplicity that allows ecologists to leverage the science and elucidate the avian migration patterns.

Possible linkage between neuronal recruitment and flight distance in migratory birds

PubMed Central

Barkan, Shay; Roll, Uri; Yom-Tov, Yoram; Wassenaar, Leonard I.; Barnea, Anat

2016-01-01

New neuronal recruitment in an adult animal’s brain is presumed to contribute to brain plasticity and increase the animal’s ability to contend with new and changing environments. During long-distance migration, birds migrating greater distances are exposed to more diverse spatial information. Thus, we hypothesized that greater migration distance in birds would correlate with the recruitment of new neurons into the brain regions involved with migratory navigation. We tested this hypothesis on two Palearctic migrants - reed warblers (Acrocephalus scirpaceus) and turtle doves (Streptopelia turtur), caught in Israel while returning from Africa in spring and summer. Birds were injected with a neuronal birth marker and later inspected for new neurons in brain regions known to play a role in navigation - the hippocampus and nidopallium caudolateral. We calculated the migration distance of each individual by matching feather isotopic values (δ2H and δ13C) to winter base-maps of these isotopes in Africa. Our findings suggest a positive correlation between migration distance and new neuronal recruitment in two brain regions - the hippocampus in reed warblers and nidopallium caudolateral in turtle doves. This multidisciplinary approach provides new insights into the ability of the avian brain to adapt to different migration challenges. PMID:26905978

Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha

USGS Publications Warehouse

Dolan, Brian P.; Fisher, Kathleen M.; Colvin, Michael E.; Benda, Susan E.; Peterson, James T.; Kent, Michael L.; Schreck, Carl B.

2016-01-01

Adult Chinook salmon (Oncorhynchus tshawytscha) migrate from salt water to freshwater streams to spawn. Immune responses in migrating adult salmon are thought to diminish in the run up to spawning, though the exact mechanisms for diminished immune responses remain unknown. Here we examine both adaptive and innate immune responses as well as pathogen burdens in migrating adult Chinook salmon in the Upper Willamette River basin. Messenger RNA transcripts encoding antibody heavy chain molecules slightly diminish as a function of time, but are still present even after fish have successfully spawned. In contrast, the innate anti-bacterial effector proteins present in fish plasma rapidly decrease as spawning approaches. Fish also were examined for the presence and severity of eight different pathogens in different organs. While pathogen burden tended to increase during the migration, no specific pathogen signature was associated with diminished immune responses. Transcript levels of the immunosuppressive cytokines IL-10 and TGF beta were measured and did not change during the migration. These results suggest that loss of immune functions in adult migrating salmon are not due to pathogen infection or cytokine-mediated immune suppression, but is rather part of the life history of Chinook salmon likely induced by diminished energy reserves or hormonal changes which accompany spawning.

Seasonal Variability in Vadose zone biodegradation at a crude oil pipeline rupture site

USGS Publications Warehouse

Sihota, Natasha J.; Trost, Jared J.; Bekins, Barbara; Berg, Andrew M.; Delin, Geoffrey N.; Mason, Brent E.; Warren, Ean; Mayer, K. Ulrich

2016-01-01

Understanding seasonal changes in natural attenuation processes is critical for evaluating source-zone longevity and informing management decisions. The seasonal variations of natural attenuation were investigated through measurements of surficial CO2 effluxes, shallow soil CO2 radiocarbon contents, subsurface gas concentrations, soil temperature, and volumetric water contents during a 2-yr period. Surficial CO2 effluxes varied seasonally, with peak values of total soil respiration (TSR) occurring in the late spring and summer. Efflux and radiocarbon data indicated that the fractional contributions of natural soil respiration (NSR) and contaminant soil respiration (CSR) to TSR varied seasonally. The NSR dominated in the spring and summer, and CSR dominated in the fall and winter. Subsurface gas concentrations also varied seasonally, with peak values of CO2 and CH4 occurring in the fall and winter. Vadose zone temperatures and subsurface CO2 concentrations revealed a correlation between contaminant respiration and temperature. A time lag of 5 to 7 mo between peak subsurface CO2 concentrations and peak surface efflux is consistent with travel-time estimates for subsurface gas migration. Periods of frozen soils coincided with depressed surface CO2 effluxes and elevated CO2 concentrations, pointing to the temporary presence of an ice layer that inhibited gas transport. Quantitative reactive transport simulations demonstrated aspects of the conceptual model developed from field measurements. Overall, results indicated that source-zone natural attenuation (SZNA) rates and gas transport processes varied seasonally and that the average annual SZNA rate estimated from periodic surface efflux measurements is 60% lower than rates determined from measurements during the summer.

Fish Research Project Oregon; Aspects of Life History and Production of Juvenile Oncorhynchus Mykiss in the Grande Ronde River Basin, Northeast Oregon, 1995-1999 Summary Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Dyke, Erick S.; Jonnasson, Brian C.; Carmichael, Richard W.

2001-07-01

Rotary screw traps, located at four sites in the Grande Ronde River basin, were used to characterize aspects of early life history exhibited by juvenile Onchorhychus mykiss during migration years 1995-99. The Lostine, Catherine Creek and upper Grande Ronde traps captured fish as they migrated out of spawning areas into valley rearing habitats. The Grande Ronde Valley trap captured fish as they left valley habitats downstream of Catherine Creek and upper Grande Ronde River rearing habitats. Dispersal downstream of spawning areas was most evident in fall and spring, but movement occurred during all seasons that the traps were fished. Seawardmore » migration occurred primarily in spring when O. mykiss smolts left overwintering area located in both spawning area and valley habitats. Migration patterns exhibited by O. mykiss suggest that Grande Ronde Valley habitats are used for overwintering and should be considered critical rearing habitat. We were unable to positively differentiate anadromous and resident forms of O. mykiss in the Grande Ronde River basin because both forms occur in our study area. The Grande Ronde Valley trap provided the best information on steelhead production in the basin because it fished below valley habitats where O. mykiss overwinter. Length frequency histograms of O. mykiss captured below upper spawning and rearing habitats showed a bimodal distribution regardless of the season of capture. Scale analyses suggested that each mode represents a different brood year. Length frequency histograms of O. mykiss captured in the Grande Ronde Valley trap were not bimodal, and primarily represented a size range consistent with other researchers' accounts of anadromous smolts.« less

Life history diversity of Snake River finespotted cutthroat trout: managing for persistence in a rapidly changing environment

USGS Publications Warehouse

Homel, Kristen M.; Gresswell, Robert E.; Kershner, Jeffrey L.

2015-01-01

Over the last century, native trout have experienced dramatic population declines, particularly in larger river systems where habitats associated with different spawning life history forms have been lost through habitat degradation and fragmentation. The resulting decrease in life history diversity has affected the capacity of populations to respond to environmental variability and disturbance. Unfortunately, because few large rivers are intact enough to permit full expression of life history diversity, it is unclear what patterns of diversity should be a conservation target. In this study, radiotelemetry was used to identify spawning and migration patterns of Snake River Finespotted Cutthroat Trout Oncorhynchus clarkii behnkei in the upper Snake River. Individuals were implanted with radio tags in October 2007 and 2008, and monitored through October 2009. Radio-tagged cutthroat trout in the upper Snake River exhibited variation in spawning habitat type and location, migration distance, spawn timing, postspawning behavior, and susceptibility to mortality sources. Between May and July, Cutthroat Trout spawned in runoff-dominated tributaries, groundwater-dominated spring creeks, and side channels of the Snake River. Individuals migrated up to 101 km from tagging locations in the upper Snake River to access spawning habitats, indicating that the upper Snake River provided seasonal habitat for spawners originating throughout the watershed. Postspawning behavior also varied; by August each year, 28% of spring-creek spawners remained in their spawning location, compared with 0% of side-channel spawners and 7% of tributary spawners. These spawning and migration patterns reflect the connectivity, habitat diversity, and dynamic template of the Snake River. Ultimately, promoting life history diversity through restoration of complex habitats may provide the most opportunities for cutthroat trout persistence in an environment likely to experience increased variability from climate change and disturbance from invasive species.

Migratory preparation associated alterations in pectoralis muscle biochemistry and proteome in Palearctic-Indian emberizid migratory finch, red-headed bunting, Emberiza bruniceps.

PubMed

Banerjee, Somanshu; Chaturvedi, Chandra Mohini

2016-03-01

Avian migration is an exceptionally high-energy-demanding process, which is met by the accumulation and utilization of fuel stores as well as the alterations in muscle physiology prior to their flight. Pre-migratory fattening coupled with changes in flight muscle metabolic enzymes and proteome is required to provide the necessary fuel and muscle performance required for migration. We studied how the serum metabolites (urea, uric acid, and creatinine), pectoralis muscle metabolites (glycogen, glucose, and cholesterol), muscle metabolic enzymes (CPT, HOAD, CS, MDH, CCO, CK, LDH, PFK, MLPL, and PK), liver lipogenic enzyme (FAS), and pectoralis muscle proteins get altered in pre-migratory and non-migratory buntings. Significantly increased pectoralis muscle fatty acid oxidation (CPT and HOAD activity), aerobic/anaerobic capacity (CS, CCO, and MDH activity), glycolytic capacity (PFK and PK activity), lipolysis (muscle LPL), and burst power (CK activity) were observed prior to the spring migration in pre-migratory buntings, whereas significantly increased pectoralis muscle anaerobic capacity (LDH activity) was observed in non-migratory buntings. Significant increase in the liver FAS showed profound lipogenesis prior to the spring migration. In this study, we have also investigated whether muscle has differential protein content during the pre-migratory and non-migratory phases of the annual migratory cycle. Twenty-nine proteins are identified and well characterized varying in expression significantly during the pre-migratory and non-migratory phases. These findings indicate that significant pre-migratory fattening and alterations in flight (pectoralis) muscle biochemistry and proteome in between the non- and pre-migratory phases may play a significant role in pre-migratory flight muscle preparation in these long-route migrants. Copyright © 2015 Elsevier Inc. All rights reserved.

The potential of fruit trees to enhance converted habitats for migrating birds in southern Mexico

USGS Publications Warehouse

Foster, M.S.

2007-01-01

Migration routes used by Nearctic migrant birds can cover great distances; they also differ among species, within species, and between years and seasons. As a result, migration routes for an entire migratory avifauna can encompass broad geographic areas, making it impossible to protect continuous stretches of habitat sufficient to connect the wintering and breeding grounds for most species. Consequently, ways to enhance habitats converted for human use (i.e. for pasture, crop cultivation, human settlement) as stopover sites for migrants are especially important. Shelterbelts around pastures and fields, if planted with species targeted to support migrant (and resident) bird species that naturally occupy mature forest habitats and that are at least partially frugivorous, could be a powerful enhancement tool for such species, if the birds will enter the converted areas to feed. I tested this approach for Nearctic migrant birds during the spring migration through an area in Chiapas, Mexico. Mature forest tree species whose fruits are eaten by birds were surveyed. Based on life form, crop size and fruit characteristics, I selected three tree species for study: Cymbopetalum mayanum (Annonaceae), Bursera simaruba (Burseraceae) and Trophis racemosa (Moraceae). I compared the use of fruits of these species by migrants and residents in forest with their use of the fruits of isolated individuals of the same species in pasture and cropland. All three plant species were useful for enhancing converted habitats for forest-occupying spring migrants, although species differed in the degree to which they entered disturbed areas to feed on the fruits. These tree species could probably enhance habitats for migrants at sites throughout the natural geographic ranges of the plants; in other geographic areas for other target bird groups, other tree species might be more appropriate.

The causes of international labor migrations--a demand-determined approach.

PubMed

Straubhaar, T

1986-01-01

The author first studies the reasons why people migrate using a neoclassical approach concerning income differentials. He tests this approach empirically and demonstrates its limits. A demand-determination approach based on human capital theory is then outlined to overcome these limits and to take into account restrictive immigration controls. Migration from Italy, Spain, Greece, Portugal, and Turkey to the European Community destination countries is examined. It is concluded that "the demand for immigrants in the destination country is the decisive condition for the phenomenon of international labor migration, and the supply of migration-willing workers is only a necessary condition." excerpt

Evaluating indices of lipid and protein content in lesser snow and Ross's geese during spring migration

USGS Publications Warehouse

Webb, Elisabeth B.; Fowler, Drew N.; Woodall, Brendan A.; Vrtiska, Mark P.

2018-01-01

Assessing nutrient stores in avian species is important for understanding the extent to which body condition influences success or failure in life‐history events. We evaluated predictive models using morphometric characteristics to estimate total body lipids (TBL) and total body protein (TBP), based on traditional proximate analyses, in spring migrating lesser snow geese (Anser caerulescens caerulescens) and Ross's geese (A. rossii). We also compared performance of our lipid model with a previously derived predictive equation for TBL developed for nesting lesser snow geese. We used external and internal measurements on 612 lesser snow and 125 Ross's geese collected during spring migration in 2015 and 2016 within the Central and Mississippi flyways to derive and evaluate predictive models. Using a validation data set, our best performing lipid model for snow geese better predicted TBL (root mean square error [RMSE] of 23.56) compared with a model derived from nesting individuals (RMSE = 48.60), suggesting the importance of season‐specific models for accurate lipid estimation. Models that included body mass and abdominal fat deposit best predicted TBL determined by proximate analysis in both species (lesser snow goose, R2 = 0.87, RMSE = 23.56: Ross's geese, R2 = 0.89, RMSE = 13.75). Models incorporating a combination of external structural measurements in addition to internal muscle and body mass best predicted protein values (R2 = 0.85, RMSE = 19.39 and R2 = 0.85, RMSE = 7.65, lesser snow and Ross's geese, respectively), but protein models including only body mass and body size were also competitive and provided extended utility to our equations for field applications. Therefore, our models indicated the importance of specimen dissection and measurement of the abdominal fat pad to provide the most accurate lipid estimates and provide alternative dissection‐free methods for estimating protein.

Shortnose sturgeon in the Gulf of Maine: Use of spawning habitat in the Kennebec System and response to dam removal

USGS Publications Warehouse

Wippelhauser, Gail S.; Zydlewski, Gayle B.; Kieffer, Micah; Sulikowski, James; Kinnison, Michael T.

2015-01-01

Evidence has become available in this century indicating that populations of the endangered Shortnose Sturgeon Acipenser brevirostrum migrate outside their natal river systems, but the full extent and functional basis of these migrations are not well understood. Between 2007 and 2013, 40 Shortnose Sturgeon captured and tagged in four Gulf of Maine river systems migrated long distances in coastal waters to reach the Kennebec System where their movements were logged by an acoustic receiver array. Twenty-one (20%) of 104 Shortnose Sturgeon tagged in the Penobscot River, two (50%) of four tagged in the Kennebec System, one (50%) of two tagged in the Saco River, and 16 (37%) of 43 tagged in the Merrimack River moved to a previously identified spawning site or historical spawning habitat in the Kennebec System in spring. Most (65%) moved in early spring from the tagging location directly to a spawning site in the Kennebec System, whereas the rest moved primarily in the fall from the tagging location to a wintering site in that system and moved to a spawning site the following spring. Spawning was inferred from the location, behavior, and sexual status of the fish and from season, water temperature, and discharge, and was confirmed by the capture of larvae in some years. Tagged fish went to a known spawning area in the upper Kennebec Estuary (16 events) or the Androscoggin Estuary (14 events), an historical spawning habitat in the restored Kennebec River (8 events), or two spawning areas in a single year (7 events). We have provided the first evidence indicating that Shortnose Sturgeon spawn in the restored Kennebec River in an historical habitat that became accessible in 1999 when Edwards Dam was removed, 162 years after it was constructed. These results highlight the importance of the Kennebec System to Shortnose Sturgeon throughout the Gulf of Maine.

Synergistic and singular effects of river discharge and lunar illumination on dam passage of upstream migrant yellow-phase American eels

USGS Publications Warehouse

Welsh, Stuart A.; Aldinger, Joni L.; Braham, Melissa A.; Zimmerman, Jennifer L.

2016-01-01

Monitoring of dam passage can be useful for management and conservation assessments of American eel, particularly if passage counts can be examined over multiple years. During a 7-year study (2007–2013) of upstream migration of American eels within the lower Shenandoah River (Potomac River drainage), we counted and measured American eels at the Millville Dam eel pass, where annual study periods were determined by the timing of the eel pass installation during spring or summer and removal during fall. Daily American eel counts were analysed with negative binomial regression models, with and without a year (YR) effect, and with the following time-varying environmental covariates: river discharge of the Shenandoah River at Millville (RDM) and of the Potomac River at Point of Rocks, lunar illumination (LI), water temperature, and cloud cover. A total of 17 161 yellow-phase American eels used the pass during the seven annual periods, and length measurements were obtained from 9213 individuals (mean = 294 mm TL, s.e. = 0.49, range 183–594 mm). Data on passage counts of American eels supported an additive-effects model (YR + LI + RDM) where parameter estimates were positive for river discharge (β = 7.3, s.e. = 0.01) and negative for LI (β = −1.9, s.e. = 0.34). Interestingly, RDM and LI acted synergistically and singularly as correlates of upstream migration of American eels, but the highest daily counts and multiple-day passage events were associated with increased RDM. Annual installation of the eel pass during late spring or summer prevented an early spring assessment, a period with higher RDM relative to those values obtained during sampling periods. Because increases in river discharge are climatically controlled events, upstream migration events of American eels within the Potomac River drainage are likely linked to the influence of climate variability on flow regime.

Trans-equatorial migration routes, staging sites and wintering areas of a high-Arctic avian predator: the long-tailed Skua (Stercorarius longicaudus).

PubMed

Gilg, Olivier; Moe, Børge; Hanssen, Sveinn Are; Schmidt, Niels Martin; Sittler, Benoît; Hansen, Jannik; Reneerkens, Jeroen; Sabard, Brigitte; Chastel, Olivier; Moreau, Jérôme; Phillips, Richard A; Oudman, Thomas; Biersma, Elisabeth M; Fenstad, Anette A; Lang, Johannes; Bollache, Loïc

2013-01-01

The Long-tailed Skua, a small (<300 g) Arctic-breeding predator and seabird, is a functionally very important component of the Arctic vertebrate communities in summer, but little is known about its migration and winter distribution. We used light-level geolocators to track the annual movements of eight adult birds breeding in north-east Greenland (n = 3) and Svalbard (n = 5). All birds wintered in the Southern Hemisphere (mean arrival-departure dates on wintering grounds: 24 October-21 March): five along the south-west coast of Africa (0-40°S, 0-15°E), in the productive Benguela upwelling, and three further south (30-40°S, 0-50°E), in an area extending into the south-west Indian Ocean. Different migratory routes and rates of travel were documented during post-breeding (345 km d(-1) in late August-early September) and spring migrations (235 km d(-1) in late April) when most birds used a more westerly flyway. Among the different staging areas, a large region off the Grand Banks of Newfoundland appears to be the most important. It was used in autumn by all but one of the tracked birds (from a few days to three weeks) and in spring by five out of eight birds (from one to more than six weeks). Two other staging sites, off the Iberian coast and near the Azores, were used by two birds in spring for five to six weeks. Over one year, individuals travelled between 43,900 and 54,200 km (36,600-45,700 when excluding staging periods) and went as far as 10,500-13,700 km (mean 12,800 km) from their breeding sites. This study has revealed important marine areas in both the south and north Atlantic Ocean. Sustainable management of these ocean basins will benefit Long-tailed Skuas as well as other trans-equatorial migrants from the Arctic.

Supporting evaluation for the proposed plan for final remedial action for the groundwater operable unit at the chemical plant area of the Weldon Spring Site, Weldon Spring, Missouri.

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2003-08-06

This report presents the technical information developed since the interim record of decision (IROD) was issued in September 2000 (U.S. Department of Energy [DOE] 2000). The information was incorporated into the evaluation that was performed in selecting the preferred alternative for the Chemical Plant groundwater operable unit (GWOU) of the Weldon Spring site. The contaminants of concern (COCs) in groundwater and springs are trichloroethylene (TCE), nitrate, uranium, and nitroaromatic compounds. The preferred alternative of monitored natural attenuation (MNA) coupled with institutional controls (ICs) and contingency activities is described in the ''Proposed Plan (PP) for Final Remedial Action for the Groundwatermore » Operable Unit at the Chemical Plant Area of the Weldon Spring Site, Weldon Spring, Missouri'' (DOE 2003b).« less

Using avian radar to examine relationships among avian activity, bird strikes, and meteorological factors

USGS Publications Warehouse

Coates, Peter S.; Casazza, Michael L.; Halstead, Brian J.; Fleskes, Joseph P.; Laughlin, James A.

2011-01-01

Radar systems designed to detect avian activity at airfields are useful in understanding factors that influence the risk of bird and aircraft collisions (bird strikes). We used an avian radar system to measure avian activity at Beale Air Force Base, California, USA, during 2008 and 2009. We conducted a 2-part analysis to examine relationships among avian activity, bird strikes, and meteorological and time-dependent factors. We found that avian activity around the airfield was greater at times when bird strikes occurred than on average using a permutation resampling technique. Second, we developed generalized linear mixed models of an avian activity index (AAI). Variation in AAI was first explained by seasons that were based on average migration dates of birds at the study area. We then modeled AAI by those seasons to further explain variation by meteorological factors and daily light levels within a 24-hour period. In general, avian activity increased with decreased temperature, wind, visibility, precipitation, and increased humidity and cloud cover. These effects differed by season. For example, during the spring bird migration period, most avian activity occurred before sunrise at twilight hours on clear days with low winds, whereas during fall migration, substantial activity occurred after sunrise, and birds generally were more active at lower temperatures. We report parameter estimates (i.e., constants and coefficients) averaged across models and a relatively simple calculation for safety officers and wildlife managers to predict AAI and the relative risk of bird strike based on time, date, and meteorological values. We validated model predictability and assessed model fit. These analyses will be useful for general inference of avian activity and risk assessment efforts. Further investigation and ongoing data collection will refine these inference models and improve our understanding of factors that influence avian activity, which is necessary to inform management decisions aimed at reducing risk of bird strikes.

Lessons from the motorized migrations

USGS Publications Warehouse

Ellis, D.H.; Gee, G.F.; Clegg, K.R.; Duff, J.W.; Lishman, W.A.; Sladen, William J. L.

2001-01-01

Ten experiments have been conducted to determine if cranes can be led on migration and if those so trained will repeat migrations on their own. Results have been mixed as we have experienced the mishaps common to pilot studies. Nevertheless, we have learned many valuable lessons. Chief among these are that cranes can be led long distances behind motorized craft (air and ground), and those led over most or the entire route will return north come spring and south in fall to and from the general area of training. However, they will follow their own route. Groups transported south and flown at intervals along the route will migrate but often miss target termini. If certain protocol restrictions are followed, it is possible to make the trained cranes wild, however, the most practical way of so doing is to introduce them into a flock of wild cranes. We project that it is possible to create or restore wild migratory flocks of cranes by first leading small groups from chosen northern to southern termini.

Influence of multiple dam passage on survival of juvenile Chinook salmon in the Columbia River estuary and coastal ocean

PubMed Central

Rechisky, Erin L.; Welch, David W.; Porter, Aswea D.; Jacobs-Scott, Melinda C.; Winchell, Paul M.

2013-01-01

Multiple dam passage during seaward migration is thought to reduce the subsequent survival of Snake River Chinook salmon. This hypothesis developed because juvenile Chinook salmon from the Snake River, the Columbia River’s largest tributary, migrate >700 km through eight hydropower dams and have lower adult return rates than downstream populations that migrate through only 3 or 4 dams. Using a large-scale telemetry array, we tested whether survival of hatchery-reared juvenile Snake River spring Chinook salmon is reduced in the estuary and coastal ocean relative to a downstream, hatchery-reared population from the Yakima River. During the initial 750-km, 1-mo-long migration through the estuary and coastal ocean, we found no evidence of differential survival; therefore, poorer adult returns of Snake River Chinook may develop far from the Columbia River. Thus, hydrosystem mitigation efforts may be ineffective if differential mortality rates develop in the North Pacific Ocean for reasons unrelated to dam passage. PMID:23576733

Critically endangered western gray whales migrate to the eastern North Pacific.

PubMed

Mate, Bruce R; Ilyashenko, Valentin Yu; Bradford, Amanda L; Vertyankin, Vladimir V; Tsidulko, Grigory A; Rozhnov, Vyacheslav V; Irvine, Ladd M

2015-04-01

Western North Pacific gray whales (WGWs), once considered extinct, are critically endangered with unknown migratory routes and reproductive areas. We attached satellite-monitored tags to seven WGWs on their primary feeding ground off Sakhalin Island, Russia, three of which subsequently migrated to regions occupied by non-endangered eastern gray whales (EGWs). A female with the longest-lasting tag visited all three major EGW reproductive areas off Baja California, Mexico, before returning to Sakhalin Island the following spring. Her 22 511 km round-trip is the longest documented mammal migration and strongly suggests that some presumed WGWs are actually EGWs foraging in areas historically attributed to WGWs. The observed migration routes provide evidence of navigational skills across open water that break the near-shore north-south migratory paradigm of EGWs. Despite evidence of genetic differentiation, these tagging data indicate that the population identity of whales off Sakhalin Island needs further evaluation. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Hemispheric-scale wind selection facilitates bar-tailed godwit circum-migration of the Pacific

USGS Publications Warehouse

Gill, Robert E.; Douglas, David C.; Handel, Colleen M.; Tibbitts, T. Lee; Hufford, Gary; Piersma, Theunis

2014-01-01

The annual 29 000 km long migration of the bar-tailed godwit, Limosa lapponica baueri, around the Pacific Ocean traverses what is arguably the most complex and seasonally structured atmospheric setting on Earth. Faced with marked variation in wind regimes and storm conditions across oceanic migration corridors, individuals must make critical decisions about when and where to fly during nonstop flights of a week's duration or longer. At a minimum, their decisions will affect wind profitability and thus reduce energetic costs of migration; in the extreme, poor decisions or unpredictable weather events will risk survival. We used satellite telemetry to track the annual migration of 24 bar-tailed godwits and analysed their flight performance relative to wind conditions during three major migration legs between nonbreeding grounds in New Zealand and breeding grounds in Alaska. Because flight altitudes of birds en route were unknown, we modelled flight efficiency at six geopotential heights across each migratory segment. Birds selected departure dates when atmospheric conditions conferred the greatest wind assistance both at departure and throughout their flights. This behaviour suggests that there exists a cognitive mechanism, heretofore unknown among migratory birds, that allows godwits to assess changes in weather conditions that are linked (i.e. teleconnected) across widely separated atmospheric regions. Godwits also showed adaptive flexibility in their response not only to cues related to seasonal changes in macrometeorology, such as spatial shifting of storm tracks and temporal periods of cyclogenesis, but also to cues associated with stochastic events, especially at departure sites. Godwits showed limits to their response behaviours, however, especially relative to rapidly developing stochastic events while en route. We found that flight efficiency depended significantly upon altitude and hypothesize that godwits exhibit further adaptive flexibility by varying flight altitude en route to optimize flight efficiency.

Spousal Mobility and Earnings

PubMed Central

MCKINNISH, TERRA

2008-01-01

An important finding in the literature on migration has been that the earnings of married women typically decrease with a move, while the earnings of married men often increase with a move, suggesting that married women are more likely to act as the “trailing spouse.” This article considers a related but largely unexplored question: what is the effect of having an occupation that is associated with frequent migration on the migration decisions of a household and on the earnings of the spouse? Further, how do these effects differ between men and women? The Public Use Microdata Sample from the 2000 U.S. decennial census is used to calculate migration rates by occupation and education. The analysis estimates the effects of these occupational mobility measures on the migration of couples and the earnings of married individuals. I find that migration rates in both the husband’s and wife’s occupations affect the household migration decision, but mobility in the husband’s occupation matters considerably more. For couples in which the husband has a college degree (regardless of the wife’s educational level), a husband’s mobility has a large, significant negative effect on his wife’s earnings, whereas a wife’s mobility has no effect on her husband’s earnings. This negative effect does not exist for college-educated wives married to non-college-educated husbands. PMID:19110900

Chemistry & migration mysteries: Fur holds clues to previous journeys

USGS Publications Warehouse

Cryan, Paul M.

2004-01-01

The bat was not only pregnant but downright angry as I snipped a bit of fur from her back. Within a few seconds, however, she flapped her powerful wings, took off from my hand and disappeared into the night, rejoining thousands of female hoary bats (Lasiurus cinereus) on their migration through the mountains of New Mexico.Every spring, hundreds of these expectant mothers pass through this small stream drainage on their way to birthing grounds farther east. Their annual passage was first reported here more than 30 years ago, and it is still one of the few known migration corridors in the area.My task that night was simple: catch hoary bats and snip tiny samples of fur from their thick coats, then let them continue on their way. The explanation, however, is a bit more complicated.

Long-Term Phenological Shifts in Raptor Migration and Climate

PubMed Central

Jaffré, Mikaël; Beaugrand, Grégory; Goberville, Éric; Jiguet, Frédéric; Kjellén, Nils; Troost, Gerard; Dubois, Philippe J.; Leprêtre, Alain; Luczak, Christophe

2013-01-01

Climate change is having a discernible effect on many biological and ecological processes. Among observed changes, modifications in bird phenology have been widely documented. However, most studies have interpreted phenological shifts as gradual biological adjustments in response to the alteration of the thermal regime. Here we analysed a long-term dataset (1980-2010) of short-distance migratory raptors in five European regions. We revealed that the responses of these birds to climate-induced changes in autumn temperatures are abrupt and synchronous at a continental scale. We found that when the temperatures increased, birds delayed their mean passage date of autumn migration. Such delay, in addition to an earlier spring migration, suggests that a significant warming may induce an extension of the breeding-area residence time of migratory raptors, which may eventually lead to residency. PMID:24223888

Seasonal migration and homing of channel catfish in the lower Wisconsin River, Wisconsin

USGS Publications Warehouse

Pellett, Thomas D.; Van Dyck, Gene J.; Adams, Jean V.

1998-01-01

A multiyear tag and recapture study was conducted to determine whether channel catfishIctalurus punctatus were migratory and if they had strong homing tendencies. Over 10,000 channel catfish were tagged from the lower Wisconsin River and adjacent waters of the upper Mississippi River during the 3-year sampling period. Data on movements were obtained from study recaptures and through tag returns and harvest information provided by sport anglers and commercial fishers. Channel catfish occupied relatively small home ranges during summer, migrated downstream to the upper Mississippi River in autumn, then migrated back up the Wisconsin River in spring to spawn and to occupy the same summer home sites they had used in previous summers. Fish size was a factor in the degree of fidelity to summer home sites, with larger fish showing greater fidelity.

A new device for collecting time-integrated water samples from springs and surface water bodies

USGS Publications Warehouse

Panno, S.V.; Krapac, I.G.; Keefer, D.A.

1998-01-01

A new device termed the 'seepage sampler' was developed to collect representative water samples from springs, streams, and other surface-water bodies. The sampler collects composite, time-integrated water samples over short (hours) or extended (weeks) periods without causing significant changes to the chemical composition of the samples. The water sample within the sampler remains at the ambient temperature of the water body and does not need to be cooled. Seepage samplers are inexpensive to construct and easy to use. A sampling program of numerous springs and/or streams can be designed at a relatively low cost through the use of these samplers. Transient solutes migrating through such flow systems, potentially unnoticed by periodic sampling, may be detected. In addition, the mass loading of solutes (e.g., agrichemicals) may be determined when seepage samplers are used in conjunction with discharge measurements.

EXAMPLES OF LANDFILL-GENERATED PLUMES IN LOW-RELIEF AREAS, SOUTHEAST FLORIDA.

USGS Publications Warehouse

Russell, Gary M.; Stewart, Mark; Higer, Aaron L.

1987-01-01

Examples of effects of low topographic relief are noted in southeast Florida where water-table gradients are 7 multiplied by 10** minus **4 to 5 multiplied by 10** minus **4 feet per foot. Water-table mounding beneath the landfill and the drainage effects of nearby ditches and well have created multiple leachate plumes in Stuart where one plume migrated in a direction opposite to the apparent regional gradient. In Coral Springs analysis suggests a bifurcating plume migrating along two narrow zones. In Fort Pierce it was difficult to detect leachate because of mineralized irrigation water and fertilizer runoff from an adjacent citrus grove.

Preliminary examination of oxidative stress in juvenile spring Chinook salmon (Oncorhynchus tshawytscha) of wild origin sampled from transport barges

USDA-ARS?s Scientific Manuscript database

Migrating juvenile wild Chinook salmon (Oncorhynchus tshawytscha), collected and loaded onto transport barges at Lower Granite Dam on the Snake River, were sampled from barges at John Day Dam, 348 km downstream, at five-day intervals beginning late April and ending late May. An increase in lipid per...

Intercontinental spread of Asian-origin H5N8 to North America through Beringia by migratory birds

USDA-ARS?s Scientific Manuscript database

Phylogenetic analysis and understanding of the waterfowl migration patterns suggests that Eurasian H5N8 clade 2.3.4.4 viruses moved to the Russian Far East/Beringia via migratory birds in spring 2014, evolved into 2 subgroups and subsequently spread along different flyways during fall 2014 into Euro...

Arthropod abundance and seasonal bird use of bottomland forest harvest gaps

Treesearch

Christopher E. Moorman; Liessa T. Woen; John C. Kilgo; James L. Hanula; Scott Horn; Michael D. Ulyshen

2012-01-01

We investigated the influence of arthropod abundance and vegetation structure on shifts in avian use of canopy gap, gap edge, and surrounding forest understory in a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. We compared captures of foliage-gleaning birds among locations during four periods (spring migration, breeding, post-breeding, and...

Reconstruction and analysis of spring rainfall over the southeastern US for the past 1000 years

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stahle, D.W.; Cleaveland, M.K.

1992-12-01

Tree-ring chronologies can provide surprisingly accurate estimates of the natural variability of important climate parameters such as precipitation and temperature during the centuries prior to the industrial Revolution. Bald cypress tree-ring chronologies have been used to reconstruct spring rainfall for the past 1000 years in North Carolina, South Carolina, and Georgia. These rainfall reconstructions explain from 54% to 68% of the spring rainfall variance in each state, and are well verified against independent rainfall measurements. In fact, these tree-ring data explain only 6% to 13% less statewide rainfall variance than is explained by the same number of instrumental raingage records.more » The reconstructions indicate that the spring rainfall extremes and decade-long regimes witnessed during the past century of instrumental observation have been a prominent feature of southeastern United States climate over the past millennium. These spring rainfall regimes are linked in part to anomalies in the seasonal expansion and migration of the subtropical anticyclone over the North Atlantic. The western sector of the Bermuda high often ridges strongly westward into the southeastern United States during dry springs, but during wet springs it is usually located east of its mean position and well offshore. Similar anomalies in the western sector of the Bermuda high occurred during multidecadal regimes of spring rainfall over the Southeast. During the relatively dry springs from 1901 to 1939, the high often ridged into the Southeast, but the western periphery of the high was more frequently located offshore during the relatively wet period from 1940 to 1980. Spring and summer rainfall extremes and decade-long regimes over the Southeast are frequently out of phase, and the tendency for wet (dry) springs to be followed by dry (wet) summers also appears to reflect anomalies in the zonal position of the Bermuda high during spring and summer.« less

77 FR 60101 - Newspapers To Be Used for Publication of Legal Notice of Appealable Decisions and Publication of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-02

...: Baldwin-White Cloud Districts: Lake County Star, published weekly in Baldwin, Lake County, Michigan..., Missouri District Ranger Decisions: Ava/Cassville/Willow Springs District: Springfield News-Leader... Virginia Marlinton-White Sulphur District: The Pocahontas Times, published weekly In Marlinton, Pocahontas...

76 FR 34034 - Newspapers Used for Publication of Legal Notices by the Intermountain Region; Utah, Idaho, Nevada...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-10

... Express District Ranger decisions for Duchesne, Roosevelt: Uintah Basin Standard Flaming Gorge District... Teton Basin: Post Register District Ranger decisions for Montpelier, Soda Springs and Westside: Idaho...: Idaho Mountain Express Sawtooth National Recreation Area: The Challis Messenger Uinta-Wasatch-Cache...

Spatiotemporal distributions of intestinal helminths in female lesser scaup Aythya affinis during spring migration from the upper Midwest, USA

USGS Publications Warehouse

England, J. C.; Levengood, J.M.; Osborn, J. M.; Yetter, A. P.; Kinsella, J.M.; Cole, Rebecca A.; Cory D. Suski,; Hagy, Heath M.

2017-01-01

We examined the associations between intestinal helminth infracommunity structure and infection parameters and the age, size, and year and region of collection of 130 female lesser scaup (Aythya affinis) during their 2014–2015 spring migrations through the upper Midwest, USA. We identified a total of 647,174 individual helminths from 40 taxa, including 20 trematodes, 14 cestodes, 4 nematodes and 2 acanthocephalans parasitizing lesser scaup within the study area. Lesser scaup were each infected with 2–23 helminth taxa. One digenean, Plenosoma minimum, is reported for the first time in lesser scaup and in the Midwest. Mean trematode abundance and total helminth abundance was significantly less in 2015 than 2014, and we suspect that colder weather late in 2015 impacted the intermediate host fauna and caused the observed differences. Brillouin's species diversity of helminths was greatest in the northernmost region of the study area, which coincides with the range of a non-indigenous snail that indirectly causes annual mortality events of lesser scaup. While host age and size were not determined to be influential factors of helminth infracommunity structure, non-parametric ordination and permutational analysis of co-variance revealed that year and region of collection explained differences in helminth infracommunities. Our results suggest that spatiotemporal variations play an important role in the structure of intestinal helminth infracommunities found in migrating lesser scaup hosts, and may therefore impact host ability to build endogenous reserves at certain stopover locations in the Midwest.

Spatiotemporal distributions of intestinal helminths in female lesser scaup Aythya affinis during spring migration from the upper Midwest, USA.

PubMed

England, J C; Levengood, J M; Osborn, J M; Yetter, A P; Kinsella, J M; Cole, R A; Suski, C D; Hagy, H M

2017-07-01

We examined the associations between intestinal helminth infracommunity structure and infection parameters and the age, size, and year and region of collection of 130 female lesser scaup (Aythya affinis) during their 2014-2015 spring migrations through the upper Midwest, USA. We identified a total of 647,174 individual helminths from 40 taxa, including 20 trematodes, 14 cestodes, 4 nematodes and 2 acanthocephalans parasitizing lesser scaup within the study area. Lesser scaup were each infected with 2-23 helminth taxa. One digenean, Plenosoma minimum, is reported for the first time in lesser scaup and in the Midwest. Mean trematode abundance and total helminth abundance was significantly less in 2015 than 2014, and we suspect that colder weather late in 2015 impacted the intermediate host fauna and caused the observed differences. Brillouin's species diversity of helminths was greatest in the northernmost region of the study area, which coincides with the range of a non-indigenous snail that indirectly causes annual mortality events of lesser scaup. While host age and size were not determined to be influential factors of helminth infracommunity structure, non-parametric ordination and permutational analysis of co-variance revealed that year and region of collection explained differences in helminth infracommunities. Our results suggest that spatiotemporal variations play an important role in the structure of intestinal helminth infracommunities found in migrating lesser scaup hosts, and may therefore impact host ability to build endogenous reserves at certain stopover locations in the Midwest.

Seasonal diets of insectivorous birds using canopy gaps in a bottomland forest.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moorman, Christopher, E.; Bowen, Liessa, T.; Kilgo, John, C.

2007-07-01

ABSTRACT. Little is known about how insectivorous bird diets are influenced by arthropod availability and about how these relationships vary seasonally. We captured birds in forest-canopy gaps and adjacent mature forest during 2001 and 2002 at the Savannah River Site in Barnwell County, South Carolina, and flushed their crops to gather information about arthropods eaten during four periods: spring migration, breeding, postbreeding, and fall migration. Arthropod availability for foliage- and ground-gleaning birds was examined by leaf clipping and pitfall trapping. Coleopterans and Hemipterans were used by foliage- and ground-gleaners more than expected during all periods, whereas arthropods in the ordersmore » Araneae and Hymenoptera were used as, or less than, expected based on availability during all periods. Ground-gleaning birds used Homopterans and Lepidopterans in proportions higher than availability during all periods. Arthropod use by birds was consistent from spring through all migration, with no apparent seasonal shift in diet. Based on concurrent studies, heavily used orders of arthropods were equally abundant or slightly less abundant in canopy gaps than in the surrounding mature forest, but bird species were most frequently detected in gaps. Such results suggest that preferential feeding on arthropods by foliage-gleaning birds in p p habitats reduced arthropod densities or, alternatively, that bird use of gap and forest habitat was not determined y food resources. The abundance of arthropods across the stand may have allowed birds to remain in the densely vegetated gaps where thick cover provides protection from predators.« less

International migration patterns of Red-throated Loons (Gavia stellata) from four breeding populations in Alaska

USGS Publications Warehouse

McCloskey, Sarah E.; Uher-Koch, Brian D.; Schmutz, Joel A.; Fondell, Thomas F.

2018-01-01

Identifying post-breeding migration and wintering distributions of migratory birds is important for understanding factors that may drive population dynamics. Red-throated Loons (Gavia stellata) are widely distributed across Alaska and currently have varying population trends, including some populations with recent periods of decline. To investigate population differentiation and the location of migration pathways and wintering areas, which may inform population trend patterns, we used satellite transmitters (n = 32) to describe migration patterns of four geographically separate breeding populations of Red-throated Loons in Alaska. On average (± SD) Red-throated Loons underwent long (6,288 ± 1,825 km) fall and spring migrations predominantly along coastlines. The most northern population (Arctic Coastal Plain) migrated westward to East Asia and traveled approximately 2,000 km farther to wintering sites than the three more southerly populations (Seward Peninsula, Yukon-Kuskokwim Delta, and Copper River Delta) which migrated south along the Pacific coast of North America. These migration paths are consistent with the hypothesis that Red-throated Loons from the Arctic Coastal Plain are exposed to contaminants in East Asia. The three more southerly breeding populations demonstrated a chain migration pattern in which the more northerly breeding populations generally wintered in more northerly latitudes. Collectively, the migration paths observed in this study demonstrate that some geographically distinct breeding populations overlap in wintering distribution while others use highly different wintering areas. Red-throated Loon population trends in Alaska may therefore be driven by a wide range of effects throughout the annual cycle.

Monitoring and Evaluation of Supplemented Spring Chinook Salmon and Life Histories of Wild Summer Steelhead in the Grande Ronde Basin, 2007 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boe, Stephen J.; Crump, Carrie A.; Weldert, Rey L.

2009-04-10

This is the ninth annual report for a multi-year project designed to monitor and evaluate supplementation of endemic spring Chinook salmon in Catherine Creek and the upper Grande Ronde River. These two streams historically supported anadromous fish populations that provided significant tribal and non-tribal fisheries, but in recent years, have experienced severe declines in abundance. Conventional and captive broodstock supplementation methods are being used to restore these spring Chinook salmon populations. Spring Chinook salmon populations in Catherine Creek and the upper Grande Ronde River, and other streams in the Snake River Basin have experienced severe declines in abundance over themore » past two decades (Nehlsen et al. 1991). A supplementation program was initiated in Catherine Creek and the upper Grande Ronde River, incorporating the use of both captive and conventional broodstock methods, in order to prevent extinction in the short term and eventually rebuild populations. The captive broodstock component of the program (BPA Project 199801001) uses natural-origin parr collected by seining and reared to maturity at facilities near Seattle, Washington (Manchester Marine Laboratory) and Hood River, Oregon (Bonneville Hatchery). Spawning occurs at Bonneville Hatchery, and resulting progeny are reared in hatcheries. Shortly before outmigration in the spring, juveniles are transferred to acclimation facilities. After an acclimation period of about 2-4 weeks, volitional release begins. Any juveniles remaining after the volitional release period are forced out. The conventional broodstock component uses returning adults collected at traps near the spawning areas, transported to Lookingglass Hatchery near Elgin, Oregon, held, and later spawned. The resulting progeny are reared, acclimated, and released similar to the captive broodstock component. All progeny released receive one or more marks including a fin (adipose) clip, codedwire tag, PIT tag, or visual implant elastomer tag. The numbers of adults used for conventional broodstock are determined by an agreement among comanagers (Zimmerman and Patterson 2002). Activities for this project focus on two life stages of spring Chinook salmon: juveniles during the migration from freshwater to the ocean and adults during prespawning migration through the end of spawning. Life history, production, and genetics are monitored and used to evaluate program effectiveness.« less

Geologic map of the Vigo NE quadrangle, Lincoln County, Nevada

USGS Publications Warehouse

Scott, Robert B.; Harding, Anne E.

2006-01-01

This map of the Vigo NE quadrangle, Lincoln County, Nevada records the distribution, stratigraphy, and structural relationships of Tertiary intracaldera lavas and tuffs in the southeastern part of the Kane Springs Wash caldera, extracaldera Tertiary and upper Paleozoic rocks, and late Cenozoic surficial deposits both within and outside the caldera. The alkaline to peralkaline Kane Springs Wash caldera is the youngest (14 Ma) of three chemically related metaluminous to peralkaline calderas (Boulder Canyon caldera, 15 Ma; Narrow Canyon caldera, 16 Ma) of the nested Kane Springs Wash caldera complex. The chemistry of this caldera complex became progressively more alkalic with time, in contrast to the older calc-alkalic calderas and caldera complexes to the north that migrated progressively southward in eastern Nevada. The increasingly peralkaline eruptions from the Kane Springs Wash caldera complex reached a climax that was simultaneous with the end of both rapid extension and magmatism in this part of the Basin and Range. Using the assumption that degree of tilting is related to the degree of extension, the rate of extension increased until the abrupt halt at about 14 Ma. Silicic volcanism terminated at the Kane Springs Wash caldera followed only by local sporadic basaltic eruptions that ended by about 8 Ma. The northern boundary of an east-west-trending amagmatic corridor appears in the Vigo NE quadrangle south of the Kane Springs Wash caldera.

Transfer of fallout radionuclides derived from Fukushima NPP accident: 1 year study on transfer of radionuclides through geomorphic processes

NASA Astrophysics Data System (ADS)

Onda, Y.; Kato, H.; Fukushima, T.; Wakahara, T.; Kita, K.; Takahashi, Y.; Sakaguchi, A.; Tanaka, K.; Yamashiki, Y.; Yoshida, N.

2012-12-01

After the Fukushima Daiichi Nuclear Power Plant acciden, fallout radionuclides on the ground surface will transfer through geomorphic processes. Therefore, in order to estimate future changes in radionuclide deposition, migration process of radionuclides in forests, soils, ground water, rivers, and entrainment from trees and soils should be confirmed. We (FMWSE group) was funded by MEXT, Japanese government, and 1 year following monitoring has been conducted about 1 year. 1 Migration study of radionuclides in natural environment including forests and rivers 1) Study on depth distribution of radiocaesium in soils within forests, fields, and grassland. 2) Confirmation of radionuclide distribution and investigation on migration in forests. 3) Study on radionuclide migration due to soil erosion under different land use. 4) Measurement of radionuclides entrained from natural environment including forests and soils. 2 Migration study of radionuclides through hydrological cycle such as soil water, rivers, lakes and ponds, ground water. 1) Investigation on radionuclide migration through soil water, ground water, stream water, spring water under different land use. 2) Study on paddy-to-river transfer of radionuclides through suspended sediment. 3) Study on river-to-ocean transfer of radionuclides via suspended sediment. 4) Confirmation of radionuclide deposition in ponds and reservoirs. We will present how and where the fallout radionulides transfter through geomorphic processes.

Movement, migration, and smolting of Atlantic salmon (Salmo salar)

USGS Publications Warehouse

McCormick, S.D.; Hansen, Lonnie P.; Quinn, T.P.; Saunders, R.L.

1998-01-01

A variety of movements characterize the behavioral plasticity of Atlantic salmon (Salmo salar) in fresh water, including movements of fry from redds, establishment of feeding territories, spawning movements of sexually mature male parr, movement to and from winter habitat, and smolt migration in spring. Smolting is an adaptive specialization for downstream migration, seawater entry, and marine residence. While still in fresh water, smolts become silvery and streamlined, lose their positive rheotaxis and territoriality, and begin schooling. Physiological changes include increased salinity tolerance, olfactory sensitivity, metabolic rate, scope for growth, and altered hemoglobin and visual pigments. Through their impact on the neuroendocrine system, photoperiod and temperature regulate physiological changes, whereas temperature and water flow may initiate migration. Smolt survival is affected by a limited period of readiness (a physiological 'smolt window') and the timing of seawater entry with environmental conditions such as temperature, food, and predators (an ecological 'smolt window'). Smolt development is adversely affected by acidity, pollutants, and improper rearing conditions, and is often more sensitive than other life stages. Unfortunately, the migration corridor of smolts (mainstems of rivers and estuaries) are the most heavily impacted by pollution, dams, and other anthropogenic activities that may be directly lethal or increase mortality by delaying or inhibiting smolt migration.

Spring hunting changes the regional movements of migrating greater snow geese

USGS Publications Warehouse

Bechet, A.; Giroux, J.-F.; Gauthier, G.; Nichols, J.D.; Hines, J.E.

2003-01-01

1. Human-induced disturbance such as hunting may influence the migratory behaviour of long-distance migrants. In 1999 and 2000 a spring hunt of greater snow geese Anser caerulescens atlanticus occurred for the first time in North America since 1916, aimed at stopping population growth to protect natural habitats. 2. We evaluated the impact of this hunt on the staging movements of geese along a 600-km stretch of the St. Lawrence River in southern Quebec, Canada. 3. We tracked radio-tagged female geese in three contiguous regions of the staging area from the south-west to the north-east: Lake St Pierre, Upper Estuary and Lower Estuary, in spring 1997 (n = 37) and 1998 (n = 70) before the establishment of hunting, and in 1999 (n = 60) and 2000 (n = 59) during hunting. 4. We used multi-state capture-recapture models to estimate the movement probabilities of radio-tagged females among these regions. To assess disturbance level, we tracked geese during their feeding trips and estimated the probability of completing a foraging bout without being disturbed. 5. In the 2 years without hunting, migration was strongly unidirectional from the south-west to the north-east, with very low westward movement probabilities. Geese gradually moved from Lake St Pierre to Upper Estuary and then from Upper Estuary to Lower Estuary. 6. In contrast, during the 2 years with hunting westward movement was more than four times more likely than in preceding years. Most of these backward movements occurred shortly after the beginning of the hunt, indicating that geese moved back to regions where they had not previously experienced hunting. 7. Overall disturbance level increased in all regions in years with hunting relative to years without hunting. 8. Synthesis and applications. We conclude that spring hunting changed the stopover scheduling of this long-distance migrant and might further impact population dynamics by reducing prenuptial fattening. The spring hunt may also have increased crop damage. We propose that staggered hunt opening dates could attenuate secondary effects of such management actions.

Feeding ecology of arctic-nesting sandpipers during spring migration through the prairie pothole region

USGS Publications Warehouse

Eldridge, J.L.; Krapu, G.L.; Johnson, D.H.

2009-01-01

We evaluated food habits of 4 species of spring-migrant calidrid sandpipers in the Prairie Pothole Region (PPR) of North Dakota. Sandpipers foraged in several wetland classes and fed primarily on aquatic dipterans, mostly larvae, and the midge family Chironomidae was the primary food eaten. Larger sandpiper species foraged in deeper water and took larger larvae than did smaller sandpipers. The diverse wetland habitats that migrant shorebirds use in the PPR suggest a landscape-level approach be applied to wetland conservation efforts. We recommend that managers use livestock grazing and other tools, where applicable, to keep shallow, freshwater wetlands from becoming choked with emergent vegetation limiting chironomid production and preventing shorebird use.

Migration and Environmental Hazards

PubMed Central

Hunter, Lori M.

2011-01-01

Losses due to natural hazards (e.g., earthquakes, hurricanes) and technological hazards (e.g., nuclear waste facilities, chemical spills) are both on the rise. One response to hazard-related losses is migration, with this paper offering a review of research examining the association between migration and environmental hazards. Using examples from both developed and developing regional contexts, the overview demonstrates that the association between migration and environmental hazards varies by setting, hazard types, and household characteristics. In many cases, however, results demonstrate that environmental factors play a role in shaping migration decisions, particularly among those most vulnerable. Research also suggests that risk perception acts as a mediating factor. Classic migration theory is reviewed to offer a foundation for examination of these associations. PMID:21886366

Behavior and dam passage of juvenile Chinook salmon and juvenile steelhead at Detroit Reservoir and Dam, Oregon, March 2012-February 2013

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Evans, Scott D.; Haner, Philip V.; Hatton, Tyson W.; Kofoot, Eric E.; Sprando, Jamie M.; Smith, Collin D.

2014-01-01

The in-reservoir movements and dam passage of individual juvenile Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) were studied at Detroit Reservoir and Dam, near Detroit, Oregon, during 2012 and 2013. The goal of the study was to provide data to inform decisions about future downstream passage alternatives and factors affecting downstream passage rates with the existing dam configuration. In 2012, 468 juvenile Chinook salmon and 200 juvenile steelhead were tagged and released during a 3-month period in the spring, and another 514 juvenile Chinook salmon were tagged and released during a 3-month period in the fall. The fish were surgically implanted with a small acoustic transmitter with an expected life of about 3 months and a passive integrated transponder tag with an indefinite life, and were released into the two main tributaries several kilometers upstream of the reservoir. Juvenile Chinook salmon migrated from the release sites to the reservoir in a greater proportion than juvenile steelhead, but once in the reservoir, juvenile steelhead migrated to the forebay faster and had a higher dam passage rate than juvenile Chinook salmon. The routes available for passing water and fish varied throughout the year, with low reservoir elevations in winter and high reservoir elevations in summer in accordance with the flood-control purpose of the dam. Most dam passage was through the spillway during the spring and summer, when the reservoir elevation was high and the spillway and powerhouse were the most common routes in operation, and via the powerhouse during the fall and winter period, when the reservoir elevation was low and the regulating outlet and powerhouse were the most common routes in operation. Few tagged fish passed when the powerhouse was the only route in operation. Dam passage rates during the spring and summer were greatest at night, increased with dam discharge, and were greater when water was passed freely over the spillway compared to when it was controlled by the spillway Tainter gates. Dam passage rates during the fall and winter, when the reservoir elevation usually was too low for spillway operation, were lower than during the spring and summer, negatively related to reservoir elevation, and positively related to dam discharge, though the latter relation diminished as reservoir elevation decreased. Fish locations near the dam from estimates of three-dimensional positions often were near the locations of dam discharge and fish depths were surface oriented relative to the depth of the forebay. Fish passage rates with the existing dam configuration were greatest when the spillway was in operation and were lowest when the powerhouse was the only route in operation; the latter result may be related to the relatively low magnitude or variability in discharge during that condition. The available data suggest that a properly designed surface outlet could be a viable passage route for juvenile Chinook salmon and juvenile steelhead at Detroit Dam. A second year of data collection based on a similar study design was complete at the time of this report.

Spatial and temporal variability in the trans-Pacific migration of Pacific bluefin tuna (Thunnus orientalis) revealed by archival tags

NASA Astrophysics Data System (ADS)

Fujioka, Ko; Fukuda, Hiromu; Tei, Yaoki; Okamoto, Suguru; Kiyofuji, Hidetada; Furukawa, Seishiro; Takagi, Junichi; Estess, Ethan; Farwell, Charles J.; Fuller, Daniel W.; Suzuki, Nobuaki; Ohshimo, Seiji; Kitagawa, Takashi

2018-03-01

Archival electronic tags were internally implanted in 713 age-0 Pacific bluefin tuna (PBF) caught in their nursery waters off the southern coast of Japan and in the East China Sea over an extended study period (1995-2015) to clarify the spatial and temporal variability of their trans-Pacific migration. Two hundred twenty-five of these tagged tuna were recaptured by fisheries (31.6%), and we successfully retrieved tag data from 14 of 21 individuals recovered in the Eastern pacific. Furthermore, one archival tag recovered in the Western Pacific revealed that the individual had performed a trans-Pacific migration, so in total 21 tagged PBF were shown to have migrated to the Eastern Pacific (2.9% of the total tags released). We successfully downloaded data from 15 of these 21 archival tags, which revealed that some age-1 PBF migrate rapidly (123.9 ± 82.8 km day-1) and directly from waters offshore of Japan to the eastern Pacific (160.0°E to 130.0°W), a journey that takes an average of 2.5 months (ranging from 1.2 to 5.5 months) through relatively cool waters (14.7 ± 2.0 °C). All juvenile PBF began their trans-Pacific migration shortly after exposure to cooler water temperatures (<14 °C), suggesting that sustained residence in lower water temperatures presents a physiological challenge for this age class. Three patterns were identified in the timing of the departure of juvenile PBF from the western Pacific: departing 12-14 months post-hatch (N = 7) in early summer (May-July), departing 17-19 months post-hatch (N = 7) in late autumn (October-December), and departing 21 months post-hatch (N = 1) in late winter (February). The PBF tagged along the southern coast of Japan (SCJ) arrived in the eastern Pacific earlier than those tagged in the East China Sea (ECS), most likely due to the shorter travel distance. Additionally, the PBF that began their trans-Pacific migration in the earlier period remained in an offshore foraging zone (the Kuroshio-Oyashio transition region) for shorter periods (2.8 months on average) and at lower latitudes (35.0°N) during the spring, while the PBF that delayed their migration spent more time (6.7 months on average) in the productive waters between 35.0 and 45.0°N during the spring-autumn months. The variability in the departure timing of the trans-Pacific migration of age-1 PBF may be related to geographic differences between nursery areas in addition to oceanographic conditions and foraging opportunities encountered by the tuna in the offshore waters of Japan during their first year.

Fault Networks in the Northwestern Albuquerque Basin and Their Potential Role in Controlling Mantle CO2 Degassing and Fluid Migration from the Valles Caldera

NASA Astrophysics Data System (ADS)

Smith, J. R.; Crossey, L. J.; Karlstrom, K. E.; Fischer, T. P.; Lee, H.; McGibbon, C. J.

2015-12-01

The Rio Grande rift (RGR) has Quaternary and active volcanism and faulting that provide a field laboratory for examining links between mantle degassing and faults as fluid conduits. Diffuse and spring CO2 flux measurements were taken at 6 sites in the northwestern Albuquerque Basin (NWAB) and Valles caldera geothermal system. All sites progress to the southwest from the 1.25 Ma Valles caldera, down the rift-related Jemez fault network, to intersect with the Nacimiento fault system. Mantle CO2 and He degassing are well documented at 5 of 6 sites, with decreasing 3He/4He ratios away from the caldera. The instrument used to measure CO2 flux was an EGM-4 CO2 gas analyzer (PP systems) with an accumulation chamber. Carbonic springs at Penasco Springs (PS) and San Ysidro (SY), and the carbonate-cemented Sand Hill Fault (SHF) were targeted, all near the western border of the RGR. The SHF has no spring activity, had the smallest maximum flux of all the sites (8 g/m2d), but carbonate along the fault zone (<2 m wide) attest to past CO2 flux. The other two sites are equal distance (30-40 km) between the SHF site and Valles caldera sites. These sites have active carbonic springs that precipitate travertine mounds. Our work suggests these sites reflect intersections of the Nacimiento fault with NE trending faults that connect to the Jemez fault network. The maximum diffuse flux recorded at SY (297 g/m2d) and PS (25 g/m2d) are high, especially along the fault and near springs. At SY and PS the instruments capacity was exceeded (2,400 g/m2d) at 6 of 9 springs. Interpretations indicate a direct CO2 flux through a fault-related artesian aquifer system that is connected to magmatic gases from the caldera. Maximum diffuse flux measurements of Alamo Canyon (20,906 g/m2d), Sulphur Springs (2,400 g/m2d) and Soda Dam (1,882 g/m2d) at Valles caldera geothermal sites are comparable to Yellowstone geothermal systems. We use geospatial analysis and local geologic mapping to examine relationships of CO2 flux to structure. Travertine mounds can create impermeable barriers that modify near-surface degassing patterns, making it difficult to decipher where CO2 and fluids preferentially migrate up the damage zones in the hanging-wall or footwall. Future work will utilize grids to more accurately assess the localized affect fault zones have on CO2 flux rates.

System Migration in ARL Libraries. SPEC Kit 185.

ERIC Educational Resources Information Center

Pattie, Ling-yuh W.; Lach, Michael

This publication reports results of a survey of 83 ARL (Association of Research Libraries) member libraries that examined the decision making process in migration from one automated library system to another. Data are reported on planning; implementation; workflow redesign; and training, publicity, and evaluation. Supplemental materials include:…

Elderly Care and Intrafamily Resource Allocation when Children Migrate.

PubMed

Antman, Francisca M

2012-01-01

This paper considers the intrafamily allocation of elderly care in the context of international migration where migrant children may be able to provide financial assistance to their parents, but are unable to offer physical care. To investigate the interaction between siblings, I take a non-cooperative view of family decision-making and estimate best response functions for individual physical and financial contributions as a function of siblings' contributions. I address the endogeneity of siblings' contributions and individual migration decisions by using siblings' characteristics as instrumental variables as well as models including family fixed effects. For both migrants and non-migrants, I find evidence that financial contributions function as strategic complements while siblings' time contributions operate as strategic substitutes. This suggests that children's contributions toward elderly care may be based on both strategic bequest and public good motivations.

Elderly Care and Intrafamily Resource Allocation when Children Migrate *

PubMed Central

Antman, Francisca M.

2012-01-01

This paper considers the intrafamily allocation of elderly care in the context of international migration where migrant children may be able to provide financial assistance to their parents, but are unable to offer physical care. To investigate the interaction between siblings, I take a non-cooperative view of family decision-making and estimate best response functions for individual physical and financial contributions as a function of siblings’ contributions. I address the endogeneity of siblings’ contributions and individual migration decisions by using siblings’ characteristics as instrumental variables as well as models including family fixed effects. For both migrants and non-migrants, I find evidence that financial contributions function as strategic complements while siblings’ time contributions operate as strategic substitutes. This suggests that children’s contributions toward elderly care may be based on both strategic bequest and public good motivations. PMID:22518064

Inertial migration of elastic particles in a pressure-driven power-law fluid

NASA Astrophysics Data System (ADS)

Bowie, Samuel; Alexeev, Alexander

2016-11-01

Using three-dimensional computer simulations, we study the cross-stream migration of deformable particles in a channel filled with a non-Newtonian fluid driven by a pressure gradient. Our numerical approach integrates lattice Boltzmann method and lattice spring method in order to model fluid structural interactions of the elastic particle and the surrounding power fluid in the channel. The particles are modeled as elastic shells filled with a viscous fluid that are initially spherical. We focus on the regimes where the inertial effects cannot be neglected and cause cross-stream drift of particles. We probe the flow with different power law indexes including both the shear thickening and thinning fluids. We also examine migration of particles of with different elasticity and relative size. To isolate the non-Newtonian effects on particle migration, we compare the results with the inertial migration results found in the case where the channel is filled with a simple Newtonian fluid. The results can be useful for applications requiring high throughput separation, sorting, and focusing of both synthetic particles and biological cells in microfluidic devices. Financial support provided by National Science Foundation (NSF) Grant No. CMMI1538161.

Gender Discrimination in the Allocation of Migrant Household Resources.

PubMed

Antman, Francisca M

2015-07-01

This paper considers the relationship between international migration and gender discrimination through the lens of decision-making power over intrahousehold resource allocation. The endogeneity of migration is addressed with a difference-in-differences style identification strategy and a model with household fixed effects. The results suggest that while a migrant household head is away, a greater share of resources is spent on girls relative to boys and his spouse commands greater decision-making power. Once the head returns home, however, a greater share of resources goes to boys and there is suggestive evidence of greater authority for the head of household.

How Do Cultural Producers Make Creative Decisions? Lessons from the Catwalk

ERIC Educational Resources Information Center

Godart, Frederic C. Mears, Ashley

2009-01-01

Faced with high uncertainty, how do producers in the cultural economy make creative decisions? We present a case study of the fashion modeling industry. Using participant observation, interviews and network analysis of the Spring/Summer 2007 Fashion Week collections, we explain how producers select models for fashion shows. While fashion producers…

Supreme Court Decision Could Help Efforts to Block Animal Research.

ERIC Educational Resources Information Center

Jaschik, Scott

1991-01-01

A decision in the case involving the "Silver Spring Monkeys" and National Institutes of Health research left open the possibility of suing the federal agency in state courts, possibly making it easier for animal-rights groups to block some animal research. However, the ruling addresses only a narrow jurisdictional question. (MSE)

Phenological synchrony of bird migration with tree flowering at desert riparian stopover sites

USGS Publications Warehouse

Kellermann, Jherime L.; van Riper, Charles

2015-01-01

Small-bodied songbirds replenish fat reserves during migration at stopover sites where they continually encounter novel and often unpredictable environmental conditions. The ability to select and utilize high quality habitats is critical to survival and fitness. Vegetation phenology is closely linked with emergence of insect prey and may provide valid cues of food availability for stopover habitat selection. Climate change is disrupting phenological synchrony across trophic levels with negative impacts on bird populations. However, whether synchrony or mismatch indicates historic or disrupted systems remains unclear. Many Neotropical migratory songbirds of western North America must cross arid regions where drought conditions related to climate change and human water use are expected to increase. We studied migrant abundance and the diversity (niche breadth) and proportional use of vegetation species as foraging substrates and their synchrony with vegetation flowering during spring migration along the lower Colorado River in the Sonoran Desert of the U.S. and Mexico.

Outward migration may alter population dynamics and income inequality

NASA Astrophysics Data System (ADS)

Shayegh, Soheil

2017-11-01

Climate change impacts may drive affected populations to migrate. However, migration decisions in response to climate change could have broader effects on population dynamics in affected regions. Here, I model the effect of climate change on fertility rates, income inequality, and human capital accumulation in developing countries, focusing on the instrumental role of migration as a key adaptation mechanism. In particular, I investigate how climate-induced migration in developing countries will affect those who do not migrate. I find that holding all else constant, climate change raises the return on acquiring skills, because skilled individuals have greater migration opportunities than unskilled individuals. In response to this change in incentives, parents may choose to invest more in education and have fewer children. This may ultimately reduce local income inequality, partially offsetting some of the damages of climate change for low-income individuals who do not migrate.

PROGRESS IN MEETING PROBLEMS OF MIGRATORY LABOR IN MARYLAND, FOURTH ANNUAL REPORT.

ERIC Educational Resources Information Center

NYSTROM, PAUL E.; AND OTHERS

THE VEGETABLE AND FRUIT INDUSTRIES OF MARYLAND HAVE LONG BEEN DEPENDENT UPON MIGRATORY LABOR FOR THE SEASONAL LABOR REQUIRED IN HARVESTING AND PROCESSING OPERATIONS. THIS LABOR FORCE COMES TO THE STATE IN THE SPRING OR SUMMER, IS EMPLOYED IN VARIOUS CAMPS IN MARYLAND AND STATES IN THE NORTH, AND MIGRATES SOUTH FOLLOWING THE HARVEST OF LATE…

Cultural and Economic Mediation Among Spanish Speaking Migrant Farm Workers in Dade County, Florida.

ERIC Educational Resources Information Center

Ferster, Lucian Edward

Based on the study "Migrant Children in Florida", this paper discusses the Spanish speaking farm workers who migrate to Dade County yearly to harvest the tomato and fresh vegetable crops. During the fall of 1969 and the spring of 1970, questionnaires were given to a random sample of 9,065 adult migrant workers in Florida counties with…

Partners in Flight: past, present, and future: prospects for neotropical migratory bird conservation in Canada

Treesearch

J. S. Wendt

1993-01-01

The plan for conservation of Neotropical Migratory Birds - Partners in Flight - appeals to many Canadians. The birds themselves are loved for their beauty, their song, their mysterious migration, and their faithful return each spring. They are valued as members of healthy ecosystems, especially when they gorge themselves on caterpillars. Canadians recognize that the...

Long distance commutes by lesser long-nosed bats (Leptonycteris yerbabuenae) to visit residential hummingbird feeders

Treesearch

Debbie C. Buecher; Ronnie Sidner

2013-01-01

Each spring, thousands of female lesser long-nosed bats (Leptonycteris yerbabuenae) migrate from southern Mexico to northern Sonora and southern Arizona to have their young and take advantage of seasonably available forage resources, including nectar, pollen, and fruit of columnar cacti. Once the pups are volant, the population begins to disperse across the grasslands...

American Avocet (Recurvirostra americana)

USGS Publications Warehouse

Ackerman, Joshua T.; Hartman, C. Alex; Herzog, Mark P.; Takekawa, John Y.; Robinson, Julie A.; Oring, Lewis W.; Skorupa, Joseph P.; Boettcher, Ruth; Poole, A.

2013-01-01

This large, striking shorebird with long bluish-gray legs, a long recurved bill, and a black-and-white chevron pattern on its back and wings is one of four Avocet species in the world, the only one with distinct breeding and non-breeding plumages -- its grayish-white head and neck feathers become cinnamon in early spring as birds begin to form pairs and migrate to breeding areas.

Activity of the mangrove snail Cerithidea decollata (Gastropoda: Potamididae) in a warm temperate South African estuary

NASA Astrophysics Data System (ADS)

Hodgson, Alan N.; Dickens, John

2012-08-01

A population of Cerithidea decollata, an intertidal marine gastropod usually found within mangroves, was studied within an area of Juncus kraussii in the upper reaches of the warm temperate Knysna estuary, which is at the southern-most limit of the recorded distribution of this snail. Activity (migratory and homing behaviour, distances travelled during foraging) of the snails was monitored over spring and neap tides in four seasons. Migratory patterns of the snails were affected by season, time of low tide (day vs night), tidal magnitude (spring vs neap) and zonation. In the summer and spring, a greater proportion of snails migrated from J. kraussii leaves onto the mud during the day at spring low tide. During neap tides in these two seasons, most snails did not climb J. kraussii leaves and remained on the mud, which was nearly always exposed. In autumn a few snails only were active and in winter snails were almost completely inactive, probably due to low air temperatures. Snails travelled greater distances on the mud on spring tides, during the diurnal low tides, and in the summer. No snails were found to home to individual J. kraussii leaves; however, homing behaviour was recorded to wooden poles within the Juncus wetland.

Trends and natural variability of North American spring onset as evaluated by a new gridded dataset of spring indices

USGS Publications Warehouse

Ault, Toby R.; Schwartz, Mark D.; Zurita-Milla, Raul; Weltzin, Jake F.; Betancourt, Julio L.

2015-01-01

Climate change is expected to modify the timing of seasonal transitions this century, impacting wildlife migrations, ecosystem function, and agricultural activity. Tracking seasonal transitions in a consistent manner across space and through time requires indices that can be used for monitoring and managing biophysical and ecological systems during the coming decades. Here a new gridded dataset of spring indices is described and used to understand interannual, decadal, and secular trends across the coterminous United States. This dataset is derived from daily interpolated meteorological data, and the results are compared with historical station data to ensure the trends and variations are robust. Regional trends in the first leaf index range from 20.8 to 21.6 days decade21, while first bloom index trends are between20.4 and 21.2 for most regions. However, these trends are modulated by interannual to multidecadal variations, which are substantial throughout the regions considered here. These findings emphasize the important role large-scale climate modes of variability play in modulating spring onset on interannual to multidecadal time scales. Finally, there is some potential for successful subseasonal forecasts of spring onset, as indices from most regions are significantly correlated with antecedent large-scale modes of variability.

Trends and Natural Variability of Spring Onset in the Coterminous United States as Evaluated by a New Gridded Dataset of Spring Indices

NASA Astrophysics Data System (ADS)

Ault, T.; Schwartz, M. D.; Zurita-Milla, R.; Weltzin, J. F.; Betancourt, J. L.

2015-12-01

Climate change is expected to modify the timing of seasonal transitions this century, impacting wildlife migrations, ecosystem function, and agricultural activity. Tracking seasonal transitions in a consistent manner across space and through time requires indices that can be used for monitoring and managing biophysical and ecological systems during the coming decades. Here a new gridded dataset of spring indices is described and used to understand interannual, decadal, and secular trends across the coterminous US. This dataset is derived from daily interpolated meteorological data, and results are compared with historical station data to ensure the trends and variations are robust. Regional trends in the first leaf index range from -0.8 to -1.6 days per decade, while first bloom index trends are between -0.4 and -1.2 for most regions. However, these trends are modulated by interannual to multidecadal variations, which are substantial throughout the regions considered here. These findings emphasize the important role large-scale climate modes of variability play in modulating spring onset on interannual to multidecadal timescales. Finally, there is some potential for successful sub-seasonal forecasts of spring onset, as indices from most regions are significantly correlated with antecedent large-scale modes of variability.

Residency Patterns and Migration Dynamics of Adult Bull Sharks (Carcharhinus leucas) on the East Coast of Southern Africa

PubMed Central

Daly, Ryan; Smale, Malcolm J.; Cowley, Paul D.; Froneman, Pierre W.

2014-01-01

Bull sharks (Carcharhinus leucas) are globally distributed top predators that play an important ecological role within coastal marine communities. However, little is known about the spatial and temporal scales of their habitat use and associated ecological role. In this study, we employed passive acoustic telemetry to investigate the residency patterns and migration dynamics of 18 adult bull sharks (195–283 cm total length) tagged in southern Mozambique for a period of between 10 and 22 months. The majority of sharks (n = 16) exhibited temporally and spatially variable residency patterns interspersed with migration events. Ten individuals undertook coastal migrations that ranged between 433 and 709 km (mean  = 533 km) with eight of these sharks returning to the study site. During migration, individuals exhibited rates of movement between 2 and 59 km.d−1 (mean  = 17.58 km.d−1) and were recorded travelling annual distances of between 450 and 3760 km (mean  = 1163 km). Migration towards lower latitudes primarily took place in austral spring and winter and there was a significant negative correlation between residency and mean monthly sea temperature at the study site. This suggested that seasonal change is the primary driver behind migration events but further investigation is required to assess how foraging and reproductive activity may influence residency patterns and migration. Results from this study highlight the need for further understanding of bull shark migration dynamics and suggest that effective conservation strategies for this vulnerable species necessitate the incorporation of congruent trans-boundary policies over large spatial scales. PMID:25295972

Distribution and habitat use of sora autumn migration in the Mississippi Flyway

USGS Publications Warehouse

Krementz, David G.; Asante, Kwasi; Naylor, Luke W.

2012-01-01

We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n  =  55), the average date when autumn migration began was October 23 (SE  =  2.62 d; range  =  September 17–December 7). For those mallards that stopped for >1 d during migration, the average stopover length was 15.4 d (SE  =  1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The total distance migrated per mallard averaged 1,407 km (SE  =  89.55 km; range  =  142–2,947 km). The average time spent on migration per individual between September 15 and December 15 was 27 d (SE  =  2.88 d; range  =  2–84 d). The state where most mallards were located on December 15 was Missouri (11) followed by Arkansas (8), while 5 mallards were still in Canada, and only 8 of 43 females and 0 of 10 males were present in Arkansas. The eastern Dakotas are a heavily utilized migration stopover for midcontinent mallards that may require more attention for migration habitat management. The reasons for so few mallards, especially male mallards, returning to Arkansas the following year deserves further research.

Autumn migration of of Mississippi Flyway mallards as determined by satellite telemetry

USGS Publications Warehouse

Krementz, David G.; Asante, Kwasi; Naylor, Luke W.

2012-01-01

We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallardsAnas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n  =  55), the average date when autumn migration began was October 23 (SE  =  2.62 d; range  =  September 17–December 7). For those mallards that stopped for >1 d during migration, the average stopover length was 15.4 d (SE  =  1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The total distance migrated per mallard averaged 1,407 km (SE  =  89.55 km; range  =  142–2,947 km). The average time spent on migration per individual between September 15 and December 15 was 27 d (SE  =  2.88 d; range  =  2–84 d). The state where most mallards were located on December 15 was Missouri (11) followed by Arkansas (8), while 5 mallards were still in Canada, and only 8 of 43 females and 0 of 10 males were present in Arkansas. The eastern Dakotas are a heavily utilized migration stopover for midcontinent mallards that may require more attention for migration habitat management. The reasons for so few mallards, especially male mallards, returning to Arkansas the following year deserves further research..

PubMed

Cabieses, Báltica

2014-12-01

The relationship between socioeconomic position (SEP), migration and health is dynamic, difficult to predict, multifactorial and poorly studied in the Latin American region. Moreover, there are high levels of uncertainty about reasons, types, and consequences of migration to an individual, family, community, country of origin and the receiving country. To discuss the evidence about the complex relationship between SEP, migration and health outcomes. According to international evidence available, migration has a direct impact on health outcomes in a population and, in turn, on public health policy decisions in each locality. The available evidence on this issue affects multiple parts of the social sciences. The "healthy migrant" effect is not consistently observed among immigrant populations, particularly after adjusting for PSE. Moreover, the immigrant population tends to assimilate in terms of risk factors and morbidity to the local population after about 10 years of stay in the foreign country. Migration has consequences for international relations, economic productive capacity of a country, inequality, demographic changes and health outcomes, to mention a few. There is now the opportunity to generate better and more evidence longitudinal population-based around the relationship between SEP, migration status and health. This will contribute to reduce uncertainty about the health status of immigrants that is required for decision- making in public health in Chile and the region. © 2013 Published by International Society for Pharmacoeconomics and Outcomes Research (ISPOR) on behalf of International Society for Pharmacoeconomics and Outcomes Research (ISPOR).

Labor migration and risk aversion in less developed countries.

PubMed

Katz, E; Stark, O

1986-01-01

"In this paper we question the pioneering work of Todaro, which states that rural-to-urban labor migration in less developed countries (LDCs) is an individual response to a higher urban expected income. We demonstrate that rural-to-urban labor migration is perfectly rational even if urban expected income is lower than rural income. We achieve this under a set of fairly stringent conditions: an individual decision-making entity, a one-period planning horizon, and global risk aversion. We obtain the result that a small chance of reaping a high reward is sufficient to trigger rural-to-urban labor migration." excerpt

Comparative Survival Rate Study (CSS) of Hatchery PIT-tagged Chinook; Oregon Department of Fish and Wildlife, Annual Report 2002-2003.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jonasson, Brian

2004-02-01

We PIT-tagged juvenile spring chinook salmon reared at Lookingglass Hatchery in October 2002 as part of the Comparative Survival Rate Study (CSS) for migratory year (MY) 2003. We tagged 20,950 Imnaha stock spring chinook salmon, and after mortality and tag loss, we allowed the remaining 20,904 fish to leave the acclimation pond at our Imnaha River satellite facility beginning 1 April 2003 to begin their seaward migration. The fish remaining in the pond were forced out on 15 April 2003. We tagged 20,820 Catherine Creek stock captive and conventional brood progeny spring chinook salmon, and after mortality and tag loss,more » we allowed the remaining 20,628 fish to leave the acclimation ponds at our Catherine Creek satellite facility beginning during two acclimation periods. The volitional release for the early acclimation group began 12 March 2003, and all remaining fish were forced out of the ponds on 23 March 2003. The volitional release for the late acclimation group began 31 March 2003, and all remaining fish were forced out of the ponds on 14 April 2003. We estimated survival rates, from release to Lower Granite Dam in MY 2003, for three stocks of hatchery spring chinook salmon tagged at Lookingglass Hatchery to determine their relative migration performance. Survival rates for the Imnaha River, Lostine River, and Catherine Creek stocks were 0.714, 0.557, and 0.350, respectively. We PIT-tagged 20,944 BY 2002 Imnaha River stock and 20,980 BY 2002 Catherine Creek stock captive and conventional brood progeny in October and November 2003 as part of the CSS for MY 2004. From tagging to January 28, 2004, the rates of mortality and tag loss for Imnaha River stock were 0.16% and 0.04%, respectively. Catherine Creek stock, during the same period, had rates of mortality and tag loss of 0.19% and 0.06%, respectively.« less

Seasonal and annual variation in Chilean hake Merluccius gayi spawning locations and egg size off central Chile

NASA Astrophysics Data System (ADS)

Landaeta, Mauricio F.; Castro, Leonardo R.

2012-01-01

Variability in Chilean hake reproductive tactics off central Chile was assessed by analyzing ichthyoplankton samples from nine oceanographic cruises (1996-2005) and through experimental trials with early life stages (eggs, yolk-sac larvae) during the main (austral spring) and secondary (late summer-early autumn) spawning seasons. Abundant eggs in the plankton (1300-2000 eggs per 10 m 2) and historical adult reproductive data showed the highest reproductive activity in austral spring, with large egg aggregations near shelf break (50-100 m depth). Large, recently spawned eggs (1.15-1.20 mm diameter) were advected nearshore by coastward subsurface flows in the spring upwelling season. Experimental trials indicated that recently hatched larvae (3.4-3.5 mm) consumed their yolk-sac (0.17-0.41 mm 3) in 3-4 days at 10-12 °C; plankton sampling indicated that larval hake remained at mid-depth (50-100 m) without showing daily vertical migrations until completing their caudal fin formation (∼15 mm). During the secondary reproductive peak, hake spawned nearshore, when smaller eggs (0.95-1.13 mm) and recently hatched larvae (2.2-2.6 mm notochord length) occurred in surface waters (0-10 m depth). Their relatively large yolk-sac volumes (0.57 ± 0.11 mm 3) provided endogenous nourishment for at least 5 days at 10 °C, according to experiments. In the field, preflexion larvae occurred mainly in the mixed layer (0-25 m) and started ontogenetic daily vertical migrations at 7 mm. A strong decline occurred after 2002 in the adult Chilean hake biomass (estimated by hydroacoustic surveys) and body size, coinciding with variations in spawning locations (more coastward in early spring 2004 and 2005) and decline in egg size. Thus, recent variations in Chilean hake reproductive tactics may reflect an indirect effect of declines in the parental population size.

Documenting Uncertainty and Error in Gridded Growing Degree Day and Spring Onset Maps Generated by the USA National Phenology Network

NASA Astrophysics Data System (ADS)

Crimmins, T. M.; Switzer, J.; Rosemartin, A.; Marsh, L.; Gerst, K.; Crimmins, M.; Weltzin, J. F.

2016-12-01

Since 2016 the USA National Phenology Network (USA-NPN; www.usanpn.org) has produced and delivered daily maps and short-term forecasts of accumulated growing degree days and spring onset dates at fine spatial scale for the conterminous United States. Because accumulated temperature is a strong driver of phenological transitions in plants and animals, including leaf-out, flowering, fruit ripening, and migration, these data products have utility for a wide range of natural resource planning and management applications, including scheduling invasive species and pest detection and control activities, determining planting dates, anticipating allergy outbreaks and planning agricultural harvest dates. The USA-NPN is a national-scale program that supports scientific advancement and decision-making by collecting, storing, and sharing phenology data and information. We will be expanding the suite of gridded map products offered by the USA-NPN to include predictive species-specific maps of phenological transitions in plants and animals at fine spatial and temporal resolution in the future. Data products, such as the gridded maps currently produced by the USA-NPN, inherently contain uncertainty and error arising from multiple sources, including error propagated forward from underlying climate data and from the models implemented. As providing high-quality, vetted data in a transparent way is central to the USA-NPN, we aim to identify and report the sources and magnitude of uncertainty and error in gridded maps and forecast products. At present, we compare our real-time gridded products to independent, trustworthy data sources, such as the Climate Reference Network, on a daily basis and report Mean Absolute Error and bias through an interactive online dashboard.

The extra mile: Ungulate migration distance alters the use of seasonal range and exposure to anthropogenic risk

USGS Publications Warehouse

Sawyer, Hall; Middleton, Arthur D.; Hayes, Matthew M.; Kauffman, Matthew J.; Monteith, Kevin L.

2016-01-01

Partial migration occurs across a variety of taxa and has important ecological and evolutionary consequences. Among ungulates, studies of partially migratory populations have allowed researchers to compare and contrast performance metrics of migrants versus residents and examine how environmental factors influence the relative abundance of each. Such studies tend to characterize animals discretely as either migratory or resident, but we suggest that variable migration distances within migratory herds are an important and overlooked form of population structure, with potential consequences for animal fitness. We examined whether the variation in individual migration distances (20–264 km) within a single wintering population of mule deer (Odocoileus hemionus) was associated with several critical behavioral attributes of migration, including timing of migration, time allocation to seasonal ranges, and exposure to anthropogenic mortality risks. Both the timing of migration and the amount of time animals allocated to seasonal ranges varied with migration distance. Animals migrating long distances (150–250 km) initiated spring migration more than three weeks before than those migrating moderate (50–150 km) or short distances (<50 km). Across an entire year, long-distance migrants spent approximately 100 more days migrating compared to moderate- and short-distance migrants. Relatedly, winter residency of long-distance migrants was 71 d fewer than for animals migrating shorter distances. Exposure to anthropogenic mortality factors, including highways and fences, was high for long-distance migrants, whereas vulnerability to harvest was high for short- and moderate-distance migrants. By reducing the amount of time that animals spend on winter range, long-distance migration may alleviate intraspecific competition for limited forage and effectively increase carrying capacity. Clear differences in winter residency, migration duration, and risk of anthropogenic mortality among short-, moderate-, and long-distance migrants suggest fitness trade-offs may exist among migratory segments of the population. Future studies of partial migration may benefit from expanding comparisons of residents and migrants, to consider how variable migration distances of migrants may influence the costs and benefits of migration.

Semidiurnal Solar Tide during the Fall Transition in the Northern Hemisphere

NASA Astrophysics Data System (ADS)

Conte, J. F.; Chau, J. L.; Laskar, F.; Stober, G.; Schmidt, H.

2017-12-01

We present an analysis of the semidiurnal solar tide (S2) during the fall transition in the Northern Hemisphere mesosphere and lower thermosphere (MLT) region. The tidal information has been derived from wind measurements provided by meteor radars at Andenes (69°N) and Juliusruh (54°N). During the autumn, S2 is characterized by a sudden and pronounced decrease occurring around day 285, every year and at all height levels. The spring transition also shows a decrease of S2, but that progressively extends from lower to higher altitudes during an interval of 15 to 40 days whose starting date varies from one year to the next. Possible explanations for the differences observed between fall and spring time periods are investigated using Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA) simulations of zonal and meridional winds, as well as ozone concentrations. Our results indicate that both, the westward propagating wave number 2 migrating tide (SW2) and the westward propagating wave number 1 non-migrating tide (SW1) decrease significantly during the fall, which results in a pronounced decrease of S2, as seen in the observations. During the spring, SW2 also decreases while SW1 remains approximately constant or slightly increases, resulting in a not so pronounced and more extended in time decrease of S2. SW2 and ozone concentrations do not show significant differences from one year to the next. SW1 on the other hand, presents considerable variability, which suggests that its source might be connected to interaction with other waves, such as gravity and planetary waves.

Songbird use of floodplain and upland forests along the Upper Mississippi River corridor during spring migration

USGS Publications Warehouse

Kirsch, Eileen M.; Heglund, Patricia J.; Gray, Brian R.; Mckann, Patrick

2013-01-01

The Upper Mississippi River is thought to provide important stopover habitat for migrating landbirds because of its north-south orientation and floodplain forests. The river flows through the Driftless Area of southwestern Wisconsin and southeastern Minnesota where forests are plentiful, yet forests of the floodplain and Driftless Area uplands differ greatly in landscape setting, tree species composition, and topography. We compared landbird assemblages in these upland and floodplain forests over three springs, 2005–2007, using line-transect surveys at randomly selected areas in and within 16 km of the floodplain. We found more species of both transient and locally breeding migrants per survey in floodplain than in upland forest. Detections of transient neotropical migrants did not differ statistically by habitat. Detections of locally breeding neotropical and temperate-zone migrants and transient temperate-zone migrants were greater in floodplain than in upland forest. Between floodplain and upland forest, assemblages of locally breeding species, including neotropical and temperate-zone migrants (of which some individuals were in transit), differed substantially, but assemblages of transients (including both neotropical and temperate-zone migrants) did not differ as much. Only two species of transient migrants had clear affinities for floodplain forest, and none had an affinity for upland forest, whereas most locally breeding migrants had an affinity for either upland or floodplain forest. Within each spring, however, detections of transient neotropical migrants shifted from being greater in floodplain to greater in upland forests. This intraseasonal shift may be related to the phenology of certain tree species.

Current Ethnic and Migration Issues in the Former USSR.

ERIC Educational Resources Information Center

Shamshur, Oleg V.

1994-01-01

Discusses the interactions between different ethnic groups in the former Soviet Union and the factors that may affect their migration decisions. The reluctance of Russian speakers to learn the languages of the peoples amongst whom they have lived has left them vulnerable in nation states where knowledge of the national language is required. (VWL)

Case Study: Pepperdine University Libraries' Migration to OCLC's Worldshare

ERIC Educational Resources Information Center

Dula, Michael W.; Ye, Gan

2012-01-01

In this case study the authors describe Pepperdine University Libraries' migration to OCLC's WorldShare Management Services. They elaborate on the rationale for the decision, review some of the challenges and lessons encountered along the way, and briefly discuss some effects of the new system on our libraries. The focus is on technical services…

Circuits of Education, Rural Gentrification, and Family Migration from the Global City

ERIC Educational Resources Information Center

Smith, Darren P.; Higley, Rebecca

2012-01-01

Although there is recurring empirical evidence of gentrifier families with young children, the importance of education-related factors in the migration and residential decision-making of rural gentrifiers have yet to be fully examined. Using the case study of Cranbrook, Kent, processes of education-led rural gentrification are revealed that are…

Avian influenza virus wild bird surveillance in the Azov and Black Sea regions of Ukraine (2010-2011).

PubMed

Muzyka, Denys; Pantin-Jackwood, Mary; Spackman, Erica; Stegniy, Borys; Rula, Oleksandr; Shutchenko, Pavlo

2012-12-01

The Azov and Black Sea basins are part of the transcontinental wild bird migration routes from Northern Asia and Europe to the Mediterranean, Africa, and Southwest Asia. These regions constitute an area of transit, stops during migration, and nesting for many different bird species. From September 2010 to September 2011, a wild bird surveillance study was conducted in these regions to identify avian influenza viruses. Biological samples consisting of cloacal and tracheal swabs and fecal samples were collected from wild birds of different ecological groups, including waterfowl and sea- and land-based birds, in places of mass bird accumulations in Sivash Bay and the Utlyuksky and Molochniy estuaries. The sampling covered the following wild bird biological cycles: autumn migration, wintering, spring migration, nesting, and postnesting seasons. A total of 3634 samples were collected from 66 different species of birds. During the autumn migration, 19 hemagglutinating viruses were isolated, 14 of which were identified as low pathogenicity avian influenza (LPAI) virus subtypes H1N?, H3N8, H5N2, H7N?, H8N4, H10N7, and H11N8. From the wintering samples, 45 hemagglutinating viruses were isolated, 36 of which were identified as LPAI virus subtypes H1N1, H1N? H1N2, H4N?, H6N1, H7N3, H7N6, H7N7, H8N2, H9N2, H10N7, H10N4, H11N2, H12N2, and H15N7. Only three viruses were isolated during the spring migration, nesting, and postnesting seasons (serotypes H6, H13, and H16). The HA and NA genes were sequenced from the isolated H5 and N1 viruses, and the phylogenetic analysis revealed possible ecological connections between the Azov and Black Sea regions and Europe. The LPAI viruses were isolated mostly from mallard ducks, but also from shellducks, shovelers, teals, and white-fronted geese. The rest of the 14 hemagglutinating viruses isolated were identified as different serotypes of avian paramyxoviruses (APMV-1, APMV-4, APMV-6, and APMV-7). This information furthers our understanding of the ecology of avian influenza viruses in wild bird species.

Rod Migration Into the Spinal Canal After Posterior Instrumented Fusion Causing Late-Onset Neurological Symptoms.

PubMed

Canavese, Federico; Dmitriev, Petru; Deslandes, Jacques; Samba, Antoine; Dimeglio, Alain; Mansour, Mounira; Rousset, Marie; Dubousset, Jean

2017-01-01

Rod migration into the spinal canal after posterior instrumented fusion is a rare complication causing late-onset neurological symptoms. The purpose of the present study is to report a case of a 13-year-old boy with spastic cerebral palsy and related neuromuscular kyphoscoliosis who developed late-onset neurological deterioration secondary to progressive implant migration into the spinal canal over a 5-year period. A decision was made to remove both rods to achieve decompression. Intraoperative findings were consistent with information gained from preoperative imaging. The rods were found to have an intracanal trajectory at T9-T10 for the right rod and T12-L2 for the left rod. The cause of implant migration, with progressive laminar erosion slow enough to generate a solid mass behind, was progressive kyphosis in a skeletally immature patient with neuromuscular compromise. Fixation type, early surgery, and spasticity management contributed significantly to the presenting condition. Mechanical factors and timing of surgery played a decisive role in this particular presentation. Level IV--Case report and review of the literature.

Size differences in migrant sandpiper flocks: ghosts in ephemeral guilds

USGS Publications Warehouse

Eldridge, J.L.; Johnson, D.H.

1988-01-01

Scolopacid sandpipers were studied from 1980 until 1984 during spring migration in North Dakota. Common species foraging together in mixed-species flocks differed in bill length most often by 20 to 30 percent (ratios from 1.2:1 to 1.3:1). Observed flocks were compared to computer generated flocks drawn from three source pools of Arctic-nesting sandpipers. The source pools included 51 migrant species from a global pool, 33 migrant species from a Western Hemisphere pool, and 13 species that migrated through North Dakota. The observed flocks formed randomly from the available species that used the North Dakota migration corridor but the North Dakota species were not a random selection from the Western Hemisphere and global pools of Arctic-nesting scolopacid sandpipers. In short, the ephemeral, mixed-species foraging flocks that we observed in North Dakota were random mixes from a non-random pool. The size-ratio distributions were consistent with the interpretation that use of this migration corridor by sandpipers has been influenced by some form of size-related selection such as competition.

Teaching migration routes to canada geese and trumpeter swans using ultralight aircraft, 1990-2001

USGS Publications Warehouse

Sladen, William J. L.; Lishman, W.A.; Ellis, D.H.; Shire, G.G.; Rininger, D.L.; Rees, Eileen C.; Earnst, Susan L.; Coulson, John C.

2002-01-01

This paper summarizes eleven years (1990-2001) of experiments to teach Canada Geese (Branta canadensis) and Trumpeter Swans (Cygnus buccinator) pre-selected migration routes using ultralight aircraft. When Canada Geese were trained to follow an ultralight aircraft for southward autumn migrations of 680 or 1,320 km, 81% (83/103) returned on their own in the next spring to near their place of training. In contrast, none returned of 21 similarly raised geese that were transported south in a closed truck over a route of 680 km. Trumpeter Swans have proven more difficult to train. However, in two experiments in which Trumpeter Swans followed an ultralight for the entire pre-selected route, one of three and two of four returned close to their training area. A stage-by-stage method, in which swans were transported in trucks between stops, flown in the vicinity and penned with a view of the night sky, has shown some promise. So far an established migration route (north and south twice) has been confirmed in only two geese

Integrating urban recharge uncertainty into standard groundwater modeling practice: A case study on water main break predictions for the Barton Springs segment of the Edwards Aquifer, Austin, Texas

NASA Astrophysics Data System (ADS)

Sinner, K.; Teasley, R. L.

2016-12-01

Groundwater models serve as integral tools for understanding flow processes and informing stakeholders and policy makers in management decisions. Historically, these models tended towards a deterministic nature, relying on historical data to predict and inform future decisions based on model outputs. This research works towards developing a stochastic method of modeling recharge inputs from pipe main break predictions in an existing groundwater model, which subsequently generates desired outputs incorporating future uncertainty rather than deterministic data. The case study for this research is the Barton Springs segment of the Edwards Aquifer near Austin, Texas. Researchers and water resource professionals have modeled the Edwards Aquifer for decades due to its high water quality, fragile ecosystem, and stakeholder interest. The original case study and model that this research is built upon was developed as a co-design problem with regional stakeholders and the model outcomes are generated specifically for communication with policy makers and managers. Recently, research in the Barton Springs segment demonstrated a significant contribution of urban, or anthropogenic, recharge to the aquifer, particularly during dry period, using deterministic data sets. Due to social and ecological importance of urban water loss to recharge, this study develops an evaluation method to help predicted pipe breaks and their related recharge contribution within the Barton Springs segment of the Edwards Aquifer. To benefit groundwater management decision processes, the performance measures captured in the model results, such as springflow, head levels, storage, and others, were determined by previous work in elicitation of problem framing to determine stakeholder interests and concerns. The results of the previous deterministic model and the stochastic model are compared to determine gains to stakeholder knowledge through the additional modeling

Emigration of Natural and Hatchery Naco x (Chinook salmon; Oncorhynchus tshawytscha) and Heeyey (Steelhead; Oncorhynchus mykiss) Smolts from the Imnaha River, Oregon from 5 October 2006 to 21 June 2007, Annual Report 2007.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michaels, Brian; Espinosa, Neal

2009-02-18

This report summarizes the Nez Perce Tribe (NPT) Department of Fisheries Resources Management (DFRM) results for the Lower Snake River Compensation Plan (LSRCP) Hatchery Evaluation studies and the Imnaha River Smolt Monitoring Program (SMP) for the 2007 smolt migration from the Imnaha River, Oregon. These studies are closely coordinated and provide information about juvenile natural and hatchery spring/summer Naco x (Chinook Salmon; Oncorhynchus tshawytscha) and Heeyey (steelhead; O. mykiss) biological characteristics, emigrant timing, survival, arrival timing and travel time to the Snake River dams and McNary Dam (MCD) on the Columbia River. These studies provide information on listed Naco xmore » (Chinook salmon) and Heeyey (steelhead) for the Federal Columbia River Power System (FCRPS) Biological Opinion (NMFS 2000). The Lower Snake River Compensation Plan program's goal is to maintain a hatchery production program of 490,000 Naco x (Chinook salmon) and 330,000 Heeyey (steelhead) for annual release in the Imnaha River (Carmichael et al. 1998, Whitesel et al. 1998). These hatchery releases occur to compensate for fish losses due to the construction and operation of the four lower Snake River hydroelectric facilities. One of the aspects of the LSRCP hatchery evaluation studies in the Imnaha River is to determine natural and hatchery Naco x (Chinook salmon) and Heeyey (steelhead) smolt performance, emigration characteristics and survival (Kucera and Blenden 1998). A long term monitoring effort was established to document smolt emigrant timing and post release survival within the Imnaha River, estimate smolt survival downstream to McNary Dam, compare natural and hatchery smolt performance, and collect smolt-to-adult return information. This project collects information for, and is part of, a larger effort entitled Smolt Monitoring by Federal and Non-Federal Agencies (BPA Project No. 198712700). This larger project provides data on movement of smolts out of major drainages and past dams on the Snake River and Columbia River. In season indices of migration strength and migration timing are provided for the run-at large at key monitoring sites. Marked smolts are utilized to measure travel time and estimate survival through key index reaches. Fish quality and descaling measures are recorded at each monitoring site and provide indicators of the health of the run. Co-managers in the Imnaha River subbasin (Ecovista 2004) have identified the need to collect information on life history, migration patterns, juvenile emigrant abundance, reach specific smolt survivals, and Smolt-to-Adult Return rates (SAR's) for both Heeyey (steelhead) and Naco x (Chinook salmon) smolts. The current study provides information related to the majority of the high priority data needs. Current funding does not allow for determination of a total (annual) juvenile emigrant abundance and lack of adult passive integrated transponder (PIT) tag detectors at the mouth of the Imnaha River results in the inability to calculate tributary specific SAR's. Information is shared with the Fish Passage Center (FPC) on a real time basis during the spring emigration period. The Bonneville Power Administration (BPA) and the United States Fish and Wildlife Service (USFWS) contracted the NPT to monitor emigration timing and tag up to 19,000 emigrating natural and hatchery Naco x (Chinook salmon) and Heeyey (steelhead) smolts from the Imnaha River with passive integrated transponder (PIT) tags. The completion of trapping in the spring of 2007 marked the 16th year of emigration studies on the Imnaha River, and the 14th year of participating in the FPC smolt monitoring program. Monitoring and evaluation objectives were to: (1) Evaluate effects of flow, temperature and other environmental factors on juvenile migration timing. (2) Determine emigration timing, travel time, and in-river survival of PIT tagged hatchery Naco x (Chinook salmon) smolts released at the Imnaha River acclimation facility to the Imnaha River juvenile migration trap. (3) Monitor the daily catch and biological characteristics of juvenile Naco x (Chinook salmon) and Heeyey (steelhead) smolts collected at the Imnaha River screw trap. (4) Determine spring emigration timing of Naco x (Chinook salmon) and Heeyey (steelhead) smolts collected at the Imnaha River juvenile migration trap. (5) Compare emigration characteristics and survival rates of natural fall and spring tagged juvenile Naco x (Chinook salmon). (6) Determine arrival timing, travel time and estimated survival of PIT tagged natural and hatchery Naco x (Chinook salmon) and natural and hatchery Heeyey (steelhead) smolts from the Imnaha River to Snake and Columbia River dams.« less

[The Lebanese in France: population trends and characteristics].

PubMed

Abdulkarim, A

1993-01-01

Demographic characteristics, population trends, and the spatial distribution of Lebanese migrants to France are examined and compared with those of migrants from other countries. The focus is on the decision to migrate and its effect on life in France. The author concludes that Lebanese migration is primarily labor migration, even during times of political upheaval and war, and that this motivation contributes to the assimilation of the Lebanese into the middle and upper socioeconomic classes. (SUMMARY IN ENG AND SPA)

Cues, corticosterone and departure decisions in a partial migrant.

PubMed

Eikenaar, Cas; Ballstaedt, Elmar; Hessler, Sven; Klinner, Thomas; Müller, Florian; Schmaljohann, Heiko

2018-05-15

Most migrating birds make multiple stopovers to fuel and/or rest. The decision to resume migration from stopover is based on various cues, such as time within the season and wind conditions. There are hints that the strength of these departure cues shapes corticosterone level, which in its turn appears to regulate the timing of departure. We here provide results that very strongly indicate that indeed departure cues jointly shape corticosterone level of migrants at stopover. We compared corticosterone level between migrating and sedentary common blackbirds (Turdus merula) sampled simultaneously at the same location during autumn migration. As expected, in migrating individuals corticosterone level was positively associated with time within the season and with current wind conditions. The latter was only apparent in adult birds and not in 1st year migrants, thus matching the observation that 1st year autumnal migrants are less wind selective than adults. In contrast to the migrants, in sedentary blackbirds these "cues" did not explain variation in corticosterone level. Furthermore, stopover departure seemed more likely and to occur earlier in the night in migrants with high corticosterone level. Our unique comparative study thus supports the newly developed concept that corticosterone mediates between departure cues and stopover departure timing in avian migrants. Copyright © 2018 Elsevier Inc. All rights reserved.

Profiling agricultural land cover change in the North Central U.S. using ten years of the Cropland Data Layer

NASA Astrophysics Data System (ADS)

Sandborn, A.; Ebinger, L.

2016-12-01

The Cropland Data Layer (CDL), produced by the USDA/National Agricultural Statistics Service, provides annual, georeferenced crop specific land cover data over the contiguous United States. Several analyses were performed on ten years (2007-2016) of CDL data in order to visualize and quantify agricultural change over the North Central region (North Dakota, South Dakota, and Minnesota). Crop masks were derived from the CDL and layered to produce a ten-year time stack of corn, soybeans, and spring wheat at 30m spatial resolution. Through numerous image analyses, a temporal profile of each crop type was compiled and portrayed cartographically. For each crop, analyses included calculating the mean center of crop area over the ten year sequence, identifying the first and latest year the crop was grown on each pixel, and distinguishing crop rotation patterns and replacement statistics. Results show a clear north-western expansion trend for corn and soybeans, and a western migration trend for spring wheat. While some change may be due to commonly practiced crop rotation, this analysis shows that crop footprints have extended into areas that were previously other crops, idle cropland, and pasture/rangeland. Possible factors contributing to this crop migration pattern include profit advantages of row crops over small grains, improved crop genetics, climate change, and farm management program changes. Identifying and mapping these crop planting differences will better inform agricultural best practices, help to monitor the latest crop migration patterns, and present researchers with a way to quantitatively measure and forecast future agricultural trends.

Reproductive strategies of northern geese: Why wait?

USGS Publications Warehouse

Ely, Craig R.; Bollinger, K.S.; Densmore, R.V.; Rothe, T.C.; Petrula, M.J.; Takekawa, John Y.; Orthmeyer, D.L.

2007-01-01

Migration and reproductive strategies in waterbirds are tightly linked, with timing of arrival and onset of nesting having important consequences for reproductive success. Whether migratory waterbirds are capital or income breeders is predicated by their spring migration schedule, how long they are on breeding areas before nesting, and how adapted they are to exploiting early spring foods at northern breeding areas. However, for most species, we know little about individual migration schedules, arrival times, and duration of residence on breeding areas before nesting. To document these relationships in a northern nesting goose, we radiotracked winter-marked Tule Greater White-fronted Geese (Anser albifrons elgasi; hereafter “Tule Geese”; n = 116) from the time of their arrival in Alaska through nesting. Tule Geese arrived on coastal feeding areas in mid-April and moved to nesting locations a week later. They initiated nests 15 days (range: 6–24 days) after arrival, a period roughly equivalent to the duration of rapid follicle growth. Tule Geese that arrived the earliest were more likely to nest than geese that arrived later; early arrivals also spent more time on the breeding grounds and nested earlier than geese that arrived later. The length of the prenesting period was comparable to that of other populations of this species, but longer than for goose species that initiate rapid follicle growth before arrival on the breeding grounds. We suggest that Tule Geese nesting in more temperate climates are more likely to delay breeding to exploit local food resources than Arctic-nesting species that may be constrained by short growing seasons.

Songbirds are resilient to hurricane disturbed habitats during spring migration

USGS Publications Warehouse

Lain, Emily; Zenzal, Theodore J.; Moore, Frank R.; Barrow, Wylie C.; Diehl, Robert H.

2017-01-01

The Gulf of Mexico is a conspicuous feature of the Neotropical–Nearctic bird migration system. Traveling long distances across ecological barriers comes with considerable risks, and mortality associated with intercontinental migration may be substantial, including that caused by storms or other adverse weather events. However, little, if anything, is known about how migratory birds respond to disturbance-induced changes in stopover habitat. Isolated, forested cheniere habitat along the northern coast of the Gulf of Mexico often concentrate migrants, during weather conditions unfavorable for northward movement or when birds are energetically stressed. We expected hurricane induced degradation of this habitat to negatively affect the abundance, propensity to stopover, and fueling trends of songbirds that stopover in coastal habitat. We used spring banding data collected in coastal Louisiana to compare migrant abundance and fueling trends before (1993–1996 and 1998–2005) and after hurricanes Rita (2006) and Ike (2009). We also characterized changes in vegetative structure before (1995) and after (2010) the hurricanes. The hurricanes caused dramatic changes to the vegetative structure, which likely decreased resources. Surprisingly, abundance, propensity to stopover, and fueling trends of most migrant species were not influenced by hurricane disturbance. Our results suggest that: 1) the function of chenieres as a refuge for migrants after completing a trans-Gulf flight may not have changed despite significant changes to habitat and decreases in resource availability, and 2) that most migrants may be able to cope with habitat disturbance during stopover. The fact that migrants use disturbed habitat points to their conservation value along the northern coast of the Gulf of Mexico.

Detecting mismatches of bird migration stopover and tree phenology in response to changing climate

USGS Publications Warehouse

Kellermann, Jherime L.; van Riper, Charles

2015-01-01

Migratory birds exploit seasonal variation in resources across latitudes, timing migration to coincide with the phenology of food at stopover sites. Differential responses to climate in phenology across trophic levels can result in phenological mismatch; however, detecting mismatch is sensitive to methodology. We examined patterns of migrant abundance and tree flowering, phenological mismatch, and the influence of climate during spring migration from 2009 to 2011 across five habitat types of the Madrean Sky Islands in southeastern Arizona, USA. We used two metrics to assess phenological mismatch: synchrony and overlap. We also examined whether phenological overlap declined with increasing difference in mean event date of phenophases. Migrant abundance and tree flowering generally increased with minimum spring temperature but depended on annual climate by habitat interactions. Migrant abundance was lowest and flowering was highest under cold, snowy conditions in high elevation montane conifer habitat while bird abundance was greatest and flowering was lowest in low elevation riparian habitat under the driest conditions. Phenological synchrony and overlap were unique and complementary metrics and should both be used when assessing mismatch. Overlap declined due to asynchronous phenologies but also due to reduced migrant abundance or flowering when synchrony was actually maintained. Overlap declined with increasing difference in event date and this trend was strongest in riparian areas. Montane habitat specialists may be at greatest risk of mismatch while riparian habitat could provide refugia during dry years for phenotypically plastic species. Interannual climate patterns that we observed match climate change projections for the arid southwest, altering stopover habitat condition.

Political motivations for intra-European migration

PubMed Central

Flipo, Aurore

2016-01-01

Motivations for migrating within the European Union have mainly been attributed to economic, career and lifestyle choices. This article suggests that political dissatisfaction is also an important motivator of recent intra-European migration. In our analysis of in-depth interviews with Romanian migrants in Spain and with Spanish migrants in Norway, we found a common emphasis on the political dimensions of their decision to migrate. In the interviews, the economic component of migration was often related to bad governance and negative perceptions of the state. The similarities of Spanish and Romanian migration narratives are especially striking because Spain and Romania represent substantially different migratory, political and economic contexts. However, migration is more obviously intertwined with conventional acts of political protest in the Spanish case. We suggest that differences in democratic contexts are pivotal in people’s reactions to and framing of their deep dissatisfaction with domestic politics, as found in many European countries today. PMID:28751786

Political motivations for intra-European migration.

PubMed

Bygnes, Susanne; Flipo, Aurore

2017-08-01

Motivations for migrating within the European Union have mainly been attributed to economic, career and lifestyle choices. This article suggests that political dissatisfaction is also an important motivator of recent intra-European migration. In our analysis of in-depth interviews with Romanian migrants in Spain and with Spanish migrants in Norway, we found a common emphasis on the political dimensions of their decision to migrate. In the interviews, the economic component of migration was often related to bad governance and negative perceptions of the state. The similarities of Spanish and Romanian migration narratives are especially striking because Spain and Romania represent substantially different migratory, political and economic contexts. However, migration is more obviously intertwined with conventional acts of political protest in the Spanish case. We suggest that differences in democratic contexts are pivotal in people's reactions to and framing of their deep dissatisfaction with domestic politics, as found in many European countries today.

Correlations between El Niño Southern Oscillation and changes in Nearctic-Neotropic migrant condition in Central America

Treesearch

J.D. Wolfe; C.J. Ralph

2009-01-01

Climatic changes induced by the El Niño–Southern Oscillation (ENSO) commonly influence biological systems; however, climatic variability and multitrophic interactions within tropical latitudes remain poorly understood. We examined relationships between migrant condition and ENSO during spring migration in Costa Rica. Our study is based on correlating an ENSO index with...

Rural Sociology in the South: 1980. Proceedings of the Rural Sociology Section of the Southern Association of Agricultural Scientists (Hot Springs, Arkansas, February 3-6, 1980).

ERIC Educational Resources Information Center

Frese, Wolfgang, Ed.

A total of 47 papers representing the broad research and extension interests related to rural areas are included in this volume. The 13 sessions are entitled Rural Structure and Process, Industrialization, Migration, Health and Alcohol, Quality of Life, Occupations and Work, Applied Sociology, Education, Network Analysis, Poverty, Status…

Patterns of lake occupancy by fish indicate different adaptations to life in a harsh Arctic environment

USGS Publications Warehouse

Haynes, Trevor B.; Rosenberger, Amanda E.; Lindberg, Mark S.; Whitman, Matthew; Schmutz, Joel A.

2014-01-01

Based on these patterns, we propose an overall model of primary controls on the distribution of fish on the Arctic Coastal Plain of Alaska. Harsh conditions, including lake freezing, limit occupancy in winter through extinction events while lake occupancy in spring and summer is driven by directional migration (large-bodied species) and undirected dispersal (small-bodied species).

Gender Discrimination in the Allocation of Migrant Household Resources*

PubMed Central

Antman, Francisca M.

2016-01-01

This paper considers the relationship between international migration and gender discrimination through the lens of decision-making power over intrahousehold resource allocation. The endogeneity of migration is addressed with a difference-in-differences style identification strategy and a model with household fixed effects. The results suggest that while a migrant household head is away, a greater share of resources is spent on girls relative to boys and his spouse commands greater decision-making power. Once the head returns home, however, a greater share of resources goes to boys and there is suggestive evidence of greater authority for the head of household. PMID:27546986

Cold adaptation recorded in tree rings highlights risks associated with climate change and assisted migration.

PubMed

Montwé, David; Isaac-Renton, Miriam; Hamann, Andreas; Spiecker, Heinrich

2018-04-23

With lengthening growing seasons but increased temperature variability under climate change, frost damage to plants may remain a risk and could be exacerbated by poleward planting of warm-adapted seed sources. Here, we study cold adaptation of tree populations in a wide-ranging coniferous species in western North America to inform limits to seed transfer. Using tree-ring signatures of cold damage from common garden trials designed to study genetic population differentiation, we find opposing geographic clines for spring frost and fall frost damage. Provenances from northern regions are sensitive to spring frosts, while the more productive provenances from central and southern regions are more susceptible to fall frosts. Transferring the southern, warm-adapted genotypes northward causes a significant loss of growth and a permanent rank change after a spring frost event. We conclude that cold adaptation should remain an important consideration when implementing seed transfers designed to mitigate harmful effects of climate change.

Counterintuitive roles of experience and weather on migratory performance

USGS Publications Warehouse

Rus, Adrian I.; Duerr, Adam E.; Miller, Tricia A.; Belthoff, James R.; Katzner, Todd E.

2017-01-01

Migration allows animals to live in resource-rich but seasonally variable environments. Because of the costs of migration, there is selective pressure to capitalize on variation in weather to optimize migratory performance. To test the degree to which migratory performance (defined as speed of migration) of Golden Eagles (Aquila chrysaetos) was determined by age- and season-specific responses to variation in weather, we analyzed 1,863 daily tracks (n = 83 migrant eagles) and 8,047 hourly tracks (n = 83) based on 15 min GPS telemetry data from Golden Eagles and 277 hourly tracks based on 30 s data (n = 37). Spring migrant eagles traveled 139.75 ± 82.19 km day−1 (mean ± SE; n = 57) and 25.59 ± 11.75 km hr−1 (n = 55). Autumn migrant eagles traveled 99.14 ± 59.98 km day−1 (n = 26) and 22.18 ± 9.18 km hr−1 (n = 28). Weather during migration varied by season and by age class. During spring, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by downward solar radiation and that older birds benefited less from flow assistance (tailwinds). During autumn, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by south–north winds and by flow assistance, again less strongly for older birds. In contrast, models for hourly performance based on data collected at 30 s intervals were not well described by a single model, likely reflecting eagles' rapid responses to the many weather conditions they experienced. Although daily speed of travel was similar for all age classes, younger birds traveled at faster hourly speeds than did adults. Our analyses uncovered strong, sometimes counterintuitive, relationships among weather, experience, and migratory flight, and they illustrate the significance of factors other than age in determining migratory performance.

Corrective action investigation plan: Cactus Spring Waste Trenches. Revision 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This Correction Action Investigation Plan (CAIP) contains environmental sample collection objectives and logic for the Corrective Action Unit No. 426, which includes the Cactus Spring Waste Trenches, located at the Tonopah Test Range. The purpose of this investigation is to generate sufficient data to establish the types of waste buried in the trenches, identify the presence and nature of contamination, determine the vertical extent of contaminant migration below the Cactus Spring Waste Trenches, and determine the appropriate course of action for the site. The potential courses of action for the site are clean closure, closure in place (with or withoutmore » remediation), or no further action. The scope of this investigation will include drilling and collecting subsurface samples from within and below the trenches. Sampling locations will be biased toward the areas most likely to be contaminated. The Cactus Spring Waste Trenches Site is identified as one of three potential locations for buried, radioactively contaminated materials from the Double Tracks Test. This test was the first of four storage-transportation tests conducted in 1963 as part of Operation Roller Coaster. The experiment involved the use of live animals to assess the inhalation intake of a plutonium aerosol.« less

Response of Marine Taxa to Climate Variability in the Southeast U.S.

NASA Astrophysics Data System (ADS)

Morley, J. W.; Pinsky, M. L.; Batt, R. D.

2016-02-01

Climate change has led to large-scale redistributions of marine taxa in many coastal regions around North America. Specifically, marine populations respond to spatial shifts in their preferred temperature conditions, or thermal envelope, as they shift across a seascape. The influence of climate change on the coastal fisheries of the southeast U.S. has been largely unexplored. We analyzed 25 years of trawl survey data (1990-2014) from the Southeast Area Monitoring and Assessment Program (SEAMAP), which samples the nearshore continental shelf of the South Atlantic Bight during spring, summer, and fall. Bottom temperatures exhibited no trend over this period and the assemblage showed no net shift north or south. However, taxa distributions were sensitive to interannual temperature variation. Annual projections of taxa thermal envelopes explained variation in centroid location for many species, particularly during spring. Accordingly, long-term latitudinal shifts in taxa-specific thermal envelopes, which trended to the north or south depending on the species, were highly correlated with centroid shifts during spring. One explanation for our results is that the phenology of taxa migration is adaptable to temperature variation. In particular, the inshore-offshore movement of species during spring and fall appears quite responsive to interannual temperature variability.

Comparing models of Red Knot population dynamics

USGS Publications Warehouse

McGowan, Conor P.

2015-01-01

Predictive population modeling contributes to our basic scientific understanding of population dynamics, but can also inform management decisions by evaluating alternative actions in virtual environments. Quantitative models mathematically reflect scientific hypotheses about how a system functions. In Delaware Bay, mid-Atlantic Coast, USA, to more effectively manage horseshoe crab (Limulus polyphemus) harvests and protect Red Knot (Calidris canutus rufa) populations, models are used to compare harvest actions and predict the impacts on crab and knot populations. Management has been chiefly driven by the core hypothesis that horseshoe crab egg abundance governs the survival and reproduction of migrating Red Knots that stopover in the Bay during spring migration. However, recently, hypotheses proposing that knot dynamics are governed by cyclical lemming dynamics garnered some support in data analyses. In this paper, I present alternative models of Red Knot population dynamics to reflect alternative hypotheses. Using 2 models with different lemming population cycle lengths and 2 models with different horseshoe crab effects, I project the knot population into the future under environmental stochasticity and parametric uncertainty with each model. I then compare each model's predictions to 10 yr of population monitoring from Delaware Bay. Using Bayes' theorem and model weight updating, models can accrue weight or support for one or another hypothesis of population dynamics. With 4 models of Red Knot population dynamics and only 10 yr of data, no hypothesis clearly predicted population count data better than another. The collapsed lemming cycle model performed best, accruing ~35% of the model weight, followed closely by the horseshoe crab egg abundance model, which accrued ~30% of the weight. The models that predicted no decline or stable populations (i.e. the 4-yr lemming cycle model and the weak horseshoe crab effect model) were the most weakly supported.

Migratory bird pathways and the Gulf of Mexico: Importance of Louisiana's coast

USGS Publications Warehouse

Smith, Gregory J.; Barrow, Wylie

2005-01-01

Because of its geographic position, Louisiana plays an important role in the hemispheric-scale phenomenon known as the Nearctic-Neotropical bird migration system. Each year millions of landbirds migrate across or near to the coast of the Gulf of Mexico. Birds migrate in large, broad fronts that sometimes exceed 2 million individuals, and there is an advantage for them to take a direct north-south route (the shortest distance).During migration seasons, nearly all of the migratory landbird species of the eastern United States, as well as many western species, use the coastal plains of the western gulf.Spring migrants arrive with depleted energy reserves and depend on Louisiana's coastal habitats to provide food and cover after long gulf crossings.Fall migrants depend on Louisiana’s coastal habitats for food to store fat reserves just prior to gulf crossings in autumn.Mortality during the migratory period can be high. Recent research on the black-throated blue warbler (Dendroica caerulescens) indicates that more than 85% of the annual mortality for the species occurs during migration.Migrants en route tend to concentrate in habitats adjacent to ecological barriers; DOI land managers need to identify key coastal landscape features that are important to these birds.Because of the vastness of the North American continent, it is nearly impossible to delineate movement patterns and migration pathways by using traditional ground-based surveys.

Student and Graduate Migration and Its Effect on the Financing of Higher Education

ERIC Educational Resources Information Center

Haussen, Tina; Uebelmesser, Silke

2016-01-01

In higher education systems that are partly tax funded, a country might not be willing to subsidize the education of international students who might leave after graduation. This paper analyzes how student migration affects governmental decisions regarding the private funding share of higher education for 22 OECD countries for the period of…

The Causes of Rural to Urban Migration Among the Poor. Final Report, March 1970.

ERIC Educational Resources Information Center

Hamilton, William L.; And Others

Focusing on individual decisions, the study examined why the rural poor migrated to urban areas. Rural-to-urban migrants were those persons having lived in places of less than 25,000 population and currently residing in major cities. Southeastern blacks, Appalachian whites, and Southwestern Spanish Americans were interviewed in two…

Health, Information, and Migration: Geographic Mobility of Union Army Veterans, 1860–1880

PubMed Central

Lee, Chulhee

2009-01-01

This article explores how injuries, sickness, and the geographic mobility of Union Army veterans while in service affected their postservice migrations. Wartime wounds and illnesses significantly diminished the geographic mobility of veterans after the war. Geographic moves while carrying out military missions had strong positive effects on their postservice geographic mobility. Geographic moves while in service also influenced the choice of destination among the migrants. I discuss some implications of the results for the elements of self-selection in migration, the roles of different types of information in migration decisions, and the overall impact of the Civil War on geographic mobility. PMID:20234796

A general equilibrium model of guest-worker migration: the source-country perspective.

PubMed

Djajic, S; Milbourne, R

1988-11-01

"This paper examines the problem of guest-worker migration from an economy populated by identical, utility-maximizing individuals with finite working lives. The decision to migrate, the rate of saving while abroad, as well as the length of a migrant's stay in the foreign country, are all viewed as part of a solution to an intertemporal optimization problem. In addition to studying the microeconomic aspects of temporary migration, the paper analyses the determinants of the equilibrium flow of migrants, the corresponding domestic wage, and the level of welfare enjoyed by a typical worker. Effects of an emigration tax are also investigated." excerpt

Influence of Riparian Tree Phenology on Lower Colorado River Spring-Migrating Birds: Implications of Flower Cueing

USGS Publications Warehouse

McGrath, Laura J.; van Riper, Charles

2005-01-01

Executive Summary Neotropical migrant birds make choices about which habitats are most likely to provide successful foraging locations during migration, but little is known about how these birds recognize and process environmental clues that indicate the presence of prey species. Aspects of tree phenology, notably flowering of trees along the lower Colorado River corridor, coincide with the migratory stopovers of leaf-gleaning insectivorous songbirds and may be an important indicator of arthropod prey species availability. Shifting tree flowering and leaf flush during the spring migration period presents avian insectivores with an assortment of foraging opportunities. During two field seasons at Cibola National Wildlife Refuge in southwestern Arizona, we examined riparian tree species to test whether leaf-gleaning insectivorous birds are attracted to the flowering condition of trees in choosing foraging sites. We predicted that flowering trees would host more insect prey resources, would thus show increased visit rates, length of stays and attack ratios of migrant avian insectivores, and that those arthropods would be found in the stomach contents of the birds. Paired trees of honey mesquite (Prosopis glandulosa), displaying heavy and light degrees of flowering were observed to test these predictions. To test whether birds are tracking arthropods directly or are using flowers as a proximate cue, we removed flowers from selected trees and paired these treated trees with neighboring high flowering trees, which served as controls. Avian foraging behavior, avian diets, arthropods, and phenology data were collected at the same time to control for temporal differences in insect availability, plant phenology, and differences in stopover arrivals of birds. We documented five patterns from this study: 1) Higher abundance and richness of arthropods were found on honey mesquite trees with greater numbers of flowers. 2) Arthropod abundance and richness increased as flowering level increased. 3) The subset of migrant avian insectivores selected for study disproportionately foraged among honey mesquite trees with significantly greater amounts of flower coverage than they did on trees with less than average flower coverage. 4) Paired field experiments demonstrated that migrant avian insectivores more often visited, stayed longer, and had higher attack rates on insect prey in honey mesquite trees with greater numbers of flowers. 5) Diet analyses of selected avian insectivores showed over half of their diet consisted of prey significantly associated with honey mesquite flowering. Combined, these results suggest that honey mesquite flowering condition is an important cue used by avian insectivores that enables birds to quickly find arthropod prey at stop-over locations, while in transit during spring migration.

[Distribution and seasonal dynamics of meiofauna in intertidal zone of Qingdao sandy beaches, Shandong Province of East China].

PubMed

Li, Ha; Hua, Er; Zhang, Zhi-Nan

2012-12-01

An investigation was conducted on the abundance, group composition, and distribution of meiofauna at the Second Beach of Taiping Bay and the Shilaoren Beach in Qingdao in January, April, July, and October 2008, aimed to analyze the distribution and seasonal dynamics of meiofauna in the intertidal zone of Qingdao sandy beaches. The measurements of environmental factors, including sediment grain size, interstitial water salinity, interstitial water temperature, organic matter content (TOC), and chlorophyll a (Chl a) content, were made simultaneously. There existed obvious seasonal differences in the environment factors, which could be clustered into two groups, i. e. , spring-winter group (January and April) and summer-autumn group (July and October). At the Second Beach of Taiping Bay, the mean annual abundance of meiofauna was (1167.3 +/- 768.3) ind x 10 cm(-2), and the most dominant group was Nematoda, accounting for 91% of the total. The meiofaunal group composition and abundance at the Second Beach differed horizontally, with the abundance ranked as high tide zone < middle tide zone < low tide zone. The meiofaunal group composition and abundance also varied seasonally, with high values in spring/winter and low values in summer/autumn (spring > winter > autumn > summer). The vertical distribution of the meiofauna in the high and middle tide zones of the Second Beach varied seasonally too. The meiofauna migrated downward with increasing temperature, concentrated in surface layer in winter and migrated downward in summer. At the Shilaoren Beach, the mean annual abundance of meiofauna was (1130.2 +/- 1419.1) ind x 10 cm(-2), and Nematoda accounted for 85% of the total. There was a great similarity of the environmental factors in the middle tide zone of the Second Beach and Shilaoren Beach, which led to no differences in the meiofaunal group composition and abundance. However, the vertical distribution of the meiofauna differed between the two beaches. When the temperature decreased, the meiofauna at Shilaoren Beach migrated downward. The ANOVA and BIOENV analyses showed that the TOC and MD phi were most responsible for the distribution of meiofauna among the tidal zones, the interstitial water temperature, MD phi, and TOC were the main causes of the seasonal variation of meiofaunal group composition and abundance, whereas the sediment Chl a affected the vertical migration of meiofauna. Tourism-induced sediment variation was another factor affecting the meiofaunal abundance, group composition, and distribution.

Peridote-water interaction generating migration pathways of H2-rich fluids in subduction context: Common processes in the ophiolites of Oman, New-Caledonia, Philippines and Turkey

NASA Astrophysics Data System (ADS)

Deville, E. P.; Prinzhofer, A.; Pillot, D.; Vacquand, C.; Sissmann, O.

2010-12-01

The occurrence of H2 flows which were punctually known notably in the ophiolites of Oman, Zambales (Philippines) and Antalya (Turkey) appears to be a widespread phenomenon in these major peridotite massifs associated with ancient or active subduction processes. Similar H2-rich gas flows have been discovered also in the peridotite of New-Caledonia. H2 concentrations are locally high (commonly 60 to90% in Oman). H2 is frequently degassing in hyperalkaline springs but the highest flows were found directly expelled from fractures in the peridotites. Obviously, within the fracture systems, gas and associated hyperalkaline water separate at shallow depth close to the top of the upper aquifer level. Locally high flows of gas migrate vertically in the fractures, whereas water with degassing H2 tends to migrate laterally in the fracture network toward the creeks where most of the hyperalkaline springs are found. The genesis of natural H2 is interpreted as the result of the interaction, at depth, between ultrabasic mantle rocks in the upper plate and water expelled by the subducted sediments by oxidation of metals (Fe2+, Mn2+) and reduction of water during serpentinisation. CH4 is commonly associated to the H2-rich fluids and it is interpreted as the result of the reduction of available CO2 at depth. N2 is also commonly associated to the H2-rich fluids in the ophiolites, whereas N2 flows (within H2) were found in the subducted sediments (below the sole décollement of the peridotite) where it can be observed (Oman and New-Caledonia). Within the peridotites, the hyperalkaline water is rich in ions OH- and Ca2+ and characterized by high pH (between 11 and 12). Most alkaline springs are found in the vicinity of major faults and/or lithological discontinuities like the basal décollement of the ophiolites and the peridotite-gabbro contact (Moho). This hyperalkaline water migration induces a chain of diagenetic reactions starting at depth within the fracture systems by the precipitation of Mg-carbonates (dolomite, magnesite) and continuing up to the surface where it leads mostly to the precipitation of Ca-carbonates (calcite, aragonite), and brucite. This chain of diagenetic reactions is associated with the capture and sequestration of the atmospheric CO2 during the precipitation of the carbonates.

Spring migration ecology of the mid-continent sandhill crane population with an emphasis on use of the Central Platte River Valley, Nebraska

USGS Publications Warehouse

Krapu, Gary L.; Brandt, David A.; Kinzel, Paul J.; Pearse, Aaron T.

2014-01-01

We conducted a 10-year study (1998–2007) of the Mid-Continent Population (MCP) of sandhill cranes (Grus canadensis) to identify spring-migration corridors, locations of major stopovers, and migration chronology by crane breeding affiliation (western Alaska–Siberia [WA–S], northern Canada–Nunavut [NC–N], west-central Canada–Alaska [WC–A], and east-central Canada–Minnesota [EC–M]). In the Central Platte River Valley (CPRV) of Nebraska, we evaluated factors influencing staging chronology, food habits, fat storage, and habitat use of sandhill cranes. We compared our findings to results from the Platte River Ecology Study conducted during 1978–1980. We determined spring migration corridors used by the breeding affiliations (designated subpopulations for management purposes) by monitoring 169 cranes marked with platform transmitter terminals (PTTs). We also marked and monitored 456 cranes in the CPRV with very high frequency (VHF) transmitters to evaluate length and pattern of stay, habitat use, and movements. An estimated 42% and 58% of cranes staging in the CPRV were greater sandhill cranes (G. c. tabida) and lesser sandhill cranes (G. c. canadensis), and they stayed for an average of 20 and 25 days (2000–2007), respectively. Cranes from the WA–S, NC–N, WC–A, and EC–M affiliations spent an average of 72, 77, 52, and 53 days, respectively, in spring migration of which 28, 23, 24, and 18 days occurred in the CPRV. The majority of the WA–S subpopulation settled in the CPRV apparently because of inadequate habitat to support more birds upstream, although WA–S cranes accounted for >90% of birds staging in the North Platte River Valley. Crane staging duration in the CPRV was negatively correlated with arrival dates; 92% of cranes stayed >7 days. A program of annual mechanical removal of mature stands of woody growth and seedlings that began in the early 1980s primarily in the main channel of the Platte River has allowed distribution of crane roosts to remain relatively stable over the past 2 decades. Most cranes returned to nocturnal roost sites used in previous years. Corn residues dominated the diet of sandhill cranes in the CPRV, as in the 1970s, despite a marked decline in standing crop of corn residues. Only 14% (10 of 74) of PTT-marked migrant cranes stayed at stopovers for ≥5 days before arriving in the CPRV, which limited the contribution of sites south of the CPRV for fat accumulation needed for migration and reproduction. Body masses of cranes (after adjusting for body size [an index of fat]) at arrival in the CPRV varied widely among years (1998–2006), indicating the importance of maintaining productive habitats on the wintering grounds to condition cranes for migration and reproduction. Average rates of fat gain by adult females while in the CPRV remained similar from 1978–1979 to 1998–1999 but declined among males. Distances cranes flew to feeding grounds in the CPRV increased as the percentage of cropland planted to soybeans increased and as density of cranes on nocturnal roosts increased. These results suggest that as habitats of limited or no value to cranes increase on the landscape, more flight time and higher maintenance costs may reduce fat storage. An estimated 40% of diurnal use occurred north of Interstate 80 (I-80) where ≤5% of lands dedicated to crane conservation are located. Seventy-four and 40% of PTT-marked EC–M and WC–A cranes had spring migrations that included staging in eastern South Dakota for an average of 11 and 10 days, respectively. Cranes of the NC–N, WA–S, and WC–A subpopulations staged an average of 25, 17, and 12 days in central and western Saskatchewan/eastern Alberta. Females in these affiliations increased their fat reserves after leaving Nebraska by an estimated 450, 451, and 452 g, respectively, underscoring the key role of these staging areas in preparing the 3 subpopulations for reproduction. After departing Nebraska, MCP cranes roosted primarily in basin wetlands. Most of these wetlands are in private ownership and lack adequate protection, emphasizing the need for effective laws and policies to ensure their long-term protection. The continued success of the current management goal of maintaining the MCP at approximately its current size and providing diverse recreational opportunities over a wide area of midcontinent and western North America is predicated on the ability of MCP cranes to continue to store large fat reserves in the CPRV in advance of breeding. For the CPRV to remain a key fat storage site, active channel maintenance (e.g., clearing of woody vegetation) likely will need to continue, along with establishing minimum stream flows. These actions would help ensure nocturnal roosting habitat remains sufficiently dispersed to provide cranes with daily intake of high-energy food adequate for major fat storage and limit risk of high mortality from storms and disease. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Stopover ecology of a migratory ungulate

USGS Publications Warehouse

Sawyer, Hall; Kauffman, Matthew J.

2011-01-01

1. Birds that migrate long distances use stopover sites to optimize fuel loads and complete migration as quickly as possible. Stopover use has been predicted to facilitate a time-minimization strategy in land migrants as well, but empirical tests have been lacking, and alternative migration strategies have not been considered. 2. We used fine-scale movement data to evaluate the ecological role of stopovers in migratory mule deer Odocoileus hemionus— a land migrant whose fitness is strongly influenced by energy intake rather than migration speed. 3. Although deer could easily complete migrations (range 18–144 km) in several days, they took an average of 3 weeks and spent 95% of that time in a series of stopover sites that had higher forage quality than movement corridors. Forage quality of stopovers increased with elevation and distance from winter range. Mule deer use of stopovers corresponded with a narrow phenological range, such that deer occupied stopovers 44 days prior to peak green-up, when forage quality was presumed to be highest. Mule deer used one stopover for every 5∙3 and 6∙7 km travelled during spring and autumn migrations, respectively, and used the same stopovers in consecutive years. 4. Study findings indicate that stopovers play a key role in the migration strategy of mule deer by allowing individuals to migrate in concert with plant phenology and maximize energy intake rather than speed. Our results suggest that stopover use may be more common among non-avian taxa than previously thought and, although the underlying migration strategies of temperate ungulates and birds are quite different, stopover use is important to both. 5. Exploring the role of stopovers in land migrants broadens the scope of stopover ecology and recognizes that the applied and theoretical benefits of stopover ecology need not be limited to avian taxa.

Net migration estimation in an extended, multiregional gravity model.

PubMed

Foot, D K; Milne, W J

1984-02-01

A multi-regional framework is developed in order to analyze net migration over time to all 10 Canadian provinces within an integrated system of equations. "An extended gravity model is the basis for the equation specification and the use of constrained econometric estimation techniques allows for the provincial interdependence of the migration decision while at the same time ensuring that an important system-wide requirement is respected." The model is estimated using official Canadian data for the 1960s and 1970s. "The results suggest the predominance of the push factor for interprovincial migration for most provinces, although net migration to the Atlantic provinces is also shown to be subject to pull forces from the rest of the country." The effects of wage rate variables, unemployment, and political disturbances in Quebec on inter-provincial migration are noted. excerpt

Cyclone Aila, livelihood stress, and migration: empirical evidence from coastal Bangladesh.

PubMed

Saha, Sebak Kumar

2017-07-01

This paper investigates why households migrated as a unit to Khulna City from the affected Upazilas of Dacope and Koyra in Khulna District, Bangladesh, following Cyclone Aila on 25 May 2009. The study reveals that households migrated primarily because of the livelihood stress that resulted from the failure to derive a secure income like before the event from the impacted areas-other push and pull factors also played a part in their migration decision. Despite all of the Aila-induced losses and problems, all households wanted to avoid migration, but they were unable to do so for this principal reason. The findings also demonstrate that, if livelihoods cannot be restored, some form of widespread migration is inevitable after a disaster such as this one. In addition, they show that migration has the potential to serve as a key adaptive response to environmental events, as evidenced by the improved economic conditions of a substantial number of the migrated households. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

Geologic context of large karst springs and caves in the Ozark National Scenic Riverways, Missouri

USGS Publications Warehouse

Weary, David J.; Orndorff, Randall C.

2016-01-01

The ONSR is a karst park, containing many springs and caves. The “jewels” of the park are large springs, several of first magnitude, that contribute significantly to the flow and water quality of the Current River and its tributaries. Completion of 1:24,000-scale geologic mapping of the park and surrounding river basin, along with synthesis of published hydrologic data, allows us to examine the spatial relationships between the springs and the geologic framework to develop a conceptual model for genesis of these springs. Based on their similarity to mapped spring conduits, many of the caves in the ONSR are fossil conduit segments. Therefore, geologic control on the evolution of the springs also applies to speleogenesis in this part of the southern Missouri Ozarks.Large springs occur in the ONSR area because: (1) the Ozark aquifer, from which they rise, is chiefly dolomite affected by solution via various processes over a long time period, (2) Paleozoic hypogenic fluid migration through these rocks exploited and enhanced flow-paths, (3) a consistent and low regional dip of the rocks off of the Salem Plateau (less than 2° to the southeast) allows integration of flow into large groundwater basins with a few discreet outlets, (4) the springs are located where the rivers have cut down into structural highs, allowing access to water from stratigraphic units deeper in the aquifer thus allowing development of springsheds that have volumetrically larger storage than smaller springs higher in the section, and (5) quartz sandstone and bedded chert in the carbonate stratigraphic succession that are locally to regionally continuous, serve as aquitards that locally confine groundwater up dip of the springs creating artesian conditions. This subhorizontal partitioning of the Ozark aquifer allows contributing areas for different springs to overlap, as evidenced by dye traces that cross adjacent groundwater basin boundaries, and possibly contributes to alternate flow routes under different groundwater flow regimes.A better understanding of the 3-dimensional hydrogeologic framework for the large spring systems in the ONSR allows more precise mapping of the contributing areas for those springs, will guide future studies of groundwater flow paths, and inform development of groundwater resource management strategies for the park.

Relationship of Teachers' Readiness for Change with Their Participation in Decision Making and School Culture

ERIC Educational Resources Information Center

Inandi, Yusuf; Giliç, Fahrettin

2016-01-01

The aim of this research is to study the relationship between primary school teachers' level of participation in decision making, school culture and their level of readiness for change. The data in the study were collected from 597 primary school teachers (304 men and 293 women) in central districts of Mersin in 2014 spring semester. Participation…

Space-based Ornithology-Studying Bird Migration and Environmental Change in North America

NASA Technical Reports Server (NTRS)

Smith, James; Deppe, Jill

2008-01-01

Natural fluctuations in the availability of critical stopover sites coupled with anthropogenic destruction of wetlands, land-use change, and anticipated losses due to climate change present migratory birds with a formidable challenge. We have developed an individual-based, spatially explicit bird migration model that simulates the migration routes, timing and energy budgets of individual birds under dynamic weather and land surface conditions. Our model incorporates biophysical constraints, individual bird energy status, bird behavior, and flight aerodynamics. We model the speed, direction, and timing of individual birds moving through a user specified Lagrangian grid. The model incorporates environmental properties including wind speed and direction, topography, dynamic hydrologic properties of the landscape, and environmental suitability. The model is driven by important variables estimated from satellite observations of the land surface, by data assimilation products from weather and climate models, and biological field data. We illustrate the use of the model to study the impact of both short- and long-term environmental variatios, e.g. climate, drought, anthropogenic, on migration timing (phenology), spatial pattern, and fitness (survival and reproductive success). We present several theoretical simulations of the spring migration of Pectoral Sandpiper (Calidris melanotos) in North America with emphasis on the Central flyway from the Gulf of Mexico to Alaska.

Genetic profiling links changing sea-ice to shifting beluga whale migration patterns

PubMed Central

Mahoney, Andrew R.; Suydam, Robert; Quakenbush, Lori; Whiting, Alex; Lowry, Lloyd; Harwood, Lois

2016-01-01

There is increasing concern over how Arctic fauna will adapt to climate related changes in sea-ice. We used long-term sighting and genetic data on beluga whales (Delphinapterus leucas) in conjunction with multi-decadal patterns of sea-ice in the Pacific Arctic to investigate the influence of sea-ice on spring migration and summer residency patterns. Substantial variations in sea-ice conditions were detected across seasons, years and sub-regions, revealing ice–ocean dynamics more complex than Arctic-wide trends suggest. This variation contrasted with a highly consistent pattern of migration and residency by several populations, indicating that belugas can accommodate widely varying sea-ice conditions to perpetuate philopatry to coastal migration destinations. However, a number of anomalous migration and residency events were detected and coincided with anomalous ice years, and in one case with an increase in killer whale (Orcinus orca) sightings and reported predation on beluga whales. The behavioural shifts were likely driven by changing sea-ice and associated changes in resource dispersion and predation risk. Continued reductions in sea-ice may result in increased predation at key aggregation areas and shifts in beluga whale behaviour with implications for population viability, ecosystem structure and the subsistence cultures that rely on them.

Comparative Study on Migration, Urbanization and Development in the ESCAP Region (RAS/P13/79). Rev. version.

PubMed

1982-01-01

Development of a study project by the UN Economic and Social Commission for Asia and the Pacific (ESCAP) on migration, urbanization, and development in the following countries is described: Indonesia, Malaysia, Pakistan, Philippines, Republic of Korea, Sri Lanka, and Thailand. The project's immediate goal is to assist decision makers in formulating population redistribution policies. It was recommended that ESCAP develop and test a migration questionnaire to assist member countries in undertaking surveys to study the interrelationships of migration and development. Upon completion of survey manuals to assist in the survey implementation, it was suggested that ESCAP run a series of in-country workshops to discuss the applications of survey results for policy formulation. A national migration survey will be taken in each country in the early 1980s in order to discern pattern and type of population mobility, factors that cause people to move or not to move, and the consequences of migration on places of origin and destination. A sample of 14,000 households in each country will be selected and 1 person of age 15-64 will be chosen as the respondent for each household. the following are some items which will be studied: 1) volume of migration streams within and between metropolitan areas and urban-rural areas; 2) decision making factors; 3) interactions between population movement and family structure, chages in fertility levels, employment, and education; 4) impact of agricultural systems on seasonal movements; 5) contributions of migrants to the cities; and 6) implications of international migration to and from the country. Leading family planning agencies will use these results to develop policy relating to population distribution, industry location, migration laws, regional economic planning, modern technology, and rural education. The management framework of the project is presented. After these results are published, government agencies can utilize them by incorporating direct questions on population movement into the national census, conducting demonstration projects to assess the impact of population movement programs, and training personnel.

Unlocking the secrets of Lake Clark sockeye salmon

USGS Publications Warehouse

Woody, Carol Ann

2003-01-01

Sockeye salmon are a cornerstone species in many Alaska watersheds. Each summer, adults lay eggs in rocky nests called “redds,” and they die soon after. In spring, their fry emerge from gravels and then rear in a nearby freshwater lake for one year or more before migrating as smolt to the sea. During this smolt phase, an olfactory map of their route is imprinted on their memories. Sockeye salmon spend one to four years in the ocean feeding and growing. Then, some innate cue sends them back in a mass migration to their natal lake systems, which they find using the olfactory map made years before. They complete their life cycle by spawning, then dying in habitats of their birth.

Ecohydrology of seepage springs in an urban National Park

NASA Astrophysics Data System (ADS)

Knee, K.; Melone, J.; Friedel, B.; Fong, D.

2014-12-01

Shallow groundwater-fed seepage springs, also known as hypotelminorheic habitats, are found around the Washington, DC area, including in the George Washington Parkway, a National Park unit in northern Virginia. These springs differ from better-known vernal pools both in their hydrology and their ecology: because they are groundwater-fed, they are more resistant to drying out than vernal pools, and they harbor cave-adapted arthropod species including amphipods of the genus Stygobroumus. This project seeks to understand the ecohydrology of the hypotelminorheic habitats that support these species, some of which are endangered, and which comprise an important but underappreciated component of biodiversity in DC-area National Parks. Our study focuses on two hypotelminorheic habitats in the GW Parkway area and consists of three main components: (1) a weekly population census of Stygobroumus using multiple mark-recapture methodology, (2) weekly monitoring of dissolved radon, a tracer of groundwater discharge, as well as conductivity, dissolved oxygen, and pH, and (3) continuous logging of spring water temperature. This poster presents preliminary data from the Stygobroumus population census and explores how these animals may be affected by spring hydrology. Specifically, we use temperature, conductivity, radon activity and precipitation data from a nearby weather station to understand how the springs respond to episodic and seasonal variation in temperature, precipitation and groundwater seepage and how this affects Stygobromus populations. We also explore whether variations in Stygobromus counts reflect (1) active migration between the surficial spring and the larger subterranean habitat, or (2) passive flushing driven by groundwater discharge. Our results provide basic hydrologic data about a little-understood habitat type and will help managers protect Stygobromus in the urban park environment.

Non-pathogenic microflora of a spring water with regenerative properties.

PubMed

Nicoletti, Giovanni; Corbella, Marta; Jaber, Omar; Marone, Piero; Scevola, Daniele; Faga, Angela

2015-11-01

The Comano spring water (Comano, Italy) has been demonstrated to improve skin regeneration, not only by increasing keratinocyte proliferation and migration, but also by modulating the regenerated collagen and elastic fibers in the dermis. However, such biological properties may not be entirely explained by its mineral composition only. As the non-pathogenic bacterial populations have demonstrated an active role in different biological processes, the potential presence of non-pathogenic bacterial species within the Comano spring water was investigated in order to identify any possible correlation between these bacterial populations and the demonstrated biological properties of this water. The water was collected at the spring using an aseptic procedure and multiple cultures were carried out. A total of 9 different strains were isolated, which were Aeromonas hydrophila , Brevundimonas vesicularis , Chromobacterium violaceum , Citrobacter youngae , Empedobacter brevis , Pantoea agglomerans , Pseudomonas putida , Pseudomonas stutzeri and Streptococcus mitis . All the isolated bacterial strains, although showing a rare potential virulence, demonstrated peculiar and favorable metabolic attitudes in controlling environmental pollution. The therapeutical effects of certain spring waters are currently being proven as correlated not only to their peculiar mineral composition, but also to the complex activity of their resident non-pathogenic bacterial populations. Although the present study provided only preliminary data, some of the non-pathogenic bacterial populations that were identified in the Comano spring water are likely to produce molecular mediators with a role in the wound healing process that, thus far, remain unknown. Numerous other unknown bacterial species, comprehensively termed DNA-rich 'dark matter', are likely to contribute to the Comano water regenerative properties as well. Therefore, the non-pathogenic bacterial populations of the Comano spring water are possibly credited for its demonstrated regenerative properties.

Hydrologic change in a coast redwood forest, Caspar Creek Experimental Watersheds: implications for salmonid survival

Treesearch

Elizabeth Keppeler

2016-01-01

The 52-year record of streamflow from the Caspar Creek Experimental Watersheds shows a trend toward decreasing rainfall and streamflow during the fall season when coho salmon (Oncorhynchus kisutch) migrate upstream to spawn. Rainfall records show a slight declining trend in fall totals and a slight increasing trend in spring totals since 1962, but only November shows a...

Importance of climatological downscaling and plant phenology for red deer in heterogeneous landscapes

PubMed Central

Pettorelli, Nathalie; Mysterud, Atle; Yoccoz, Nigel G; Langvatn, Rolf; Stenseth, Nils Chr

2005-01-01

Understanding how climate influences ecosystems represents a challenge in ecology and natural resource management. Although we know that climate affects plant phenology and herbivore performances at any single site, no study has directly coupled the topography–climate interaction (i.e. the climatological downscaling process) with large-scale vegetation dynamics and animal performances. Here we show how climatic variability (measured by the North Atlantic oscillation ‘NAO’) interacts with local topography in determining the vegetative greenness (as measured by the normalized difference vegetation index ‘NDVI’) and the body masses and seasonal movements of red deer (Cervus elaphus) in Norway. Warm springs induced an earlier onset of vegetation, resulting in earlier migration and higher body masses. Increasing values of the winter-NAO corresponded to less snow at low altitude (warmer, more precipitation results in more rain), but more snow at high altitude (colder, more precipitation corresponds to more snow) relative to winters with low winter-NAO. An increasing NAO thus results in a spatially more variable phenology, offering migrating deer an extended period with access to high-quality forage leading to increased body mass. Our results emphasize the importance of incorporating spring as well as the interaction between winter climate and topography when aiming at understanding how plant and animal respond to climate change. PMID:16243701

Re-calibration of the magnetic compass in hand-raised European robins (Erithacus rubecula)

PubMed Central

Alert, Bianca; Michalik, Andreas; Thiele, Nadine; Bottesch, Michael; Mouritsen, Henrik

2015-01-01

Migratory birds can use a variety of environmental cues for orientation. A primary calibration between the celestial and magnetic compasses seems to be fundamental prior to a bird’s first autumn migration. Releasing hand-raised or rescued young birds back into the wild might therefore be a problem because they might not have established a functional orientation system during their first calendar year. Here, we test whether hand-raised European robins that did not develop any functional compass before or during their first autumn migration could relearn to orient if they were exposed to natural celestial cues during the subsequent winter and spring. When tested in the geomagnetic field without access to celestial cues, these birds could orient in their species-specific spring migratory direction. In contrast, control birds that were deprived of any natural celestial cues throughout remained unable to orient. Our experiments suggest that European robins are still capable of establishing a functional orientation system after their first autumn. Although the external reference remains speculative, most likely, natural celestial cues enabled our birds to calibrate their magnetic compass. Our data suggest that avian compass systems are more flexible than previously believed and have implications for the release of hand-reared migratory birds. PMID:26388258

Dynamic malaria hotspots in an open cohort in western Kenya.

PubMed

Platt, Alyssa; Obala, Andrew A; MacIntyre, Charlie; Otsyula, Barasa; Meara, Wendy Prudhomme O'

2018-01-12

Malaria hotspots, defined as areas where transmission intensity exceeds the average level, become more pronounced as transmission declines. Targeting hotspots may accelerate reductions in transmission and could be pivotal for malaria elimination. Determinants of hotspot location, particularly of their movement, are poorly understood. We used spatial statistical methods to identify foci of incidence of self-reported malaria in a large census population of 64,000 people, in 8,290 compounds over a 2.5-year study period. Regression models examine stability of hotspots and identify static and dynamic correlates with their location. Hotspot location changed over short time-periods, rarely recurring in the same area. Hotspots identified in spring versus fall season differed in their stability. Households located in a hotspot in the fall were more likely to be located in a hotspot the following fall (RR = 1.77, 95% CI: 1.66-1.89), but the opposite was true for compounds in spring hotspots (RR = 0.15, 95% CI: 0.08-0.28). Location within a hotspot was related to environmental and static household characteristics such as distance to roads or rivers. Human migration into a household was correlated with risk of hotspot membership, but the direction of the association differed based on the origin of the migration event.

A landscape scale decision support tool for monitoring bird and bat migration across Wisconsin

USGS Publications Warehouse

Suarez, Manuel J.; Heglund, Patricia J.; Kratt, Robert; Kirsch, Eileen

2008-01-01

This project was initiated to begin addressing the question, “Are there patterns in timing, location, and direction among migrating landbirds?” that have been at the forefront of discussion with our Federal, State, and County partners with regard to siting wind energy projects. Our goal was to explore the use of Nexrad weather data to see if examining 5 or more years’ worth of data would provide us with a sense of the general timing, movement patterns and habitat use by migrating landbirds.

Biology of Myliobatis goodei (Springer, 1939), a widely distributed eagle ray, caught in northern Patagonia

NASA Astrophysics Data System (ADS)

Molina, Juan Manuel; Lopez Cazorla, Andrea

2015-01-01

Chondrichthyans play an important role in structuring marine communities. Myliobatis goodie is an eagle ray reported from South Carolina in the USA (35°N) to Santa Cuz, Argentina (44°S), however little is known about this species, which is considered data deficient by the IUCN. In order to create adequate management strategies for this species, biological information is sorely needed. The objective of this study was to describe the biology of the population of M. goodei and its relationships with season, sex and the geographic features of Anegada Bay, Argentina (from 39.96°S to 40.60°S and from 62.10°W to 62.46°W) in 2008. Specifically, the population structure of M. goodie was studied by sex, seasons and sites, its food habits by seasons and sites, and the reproductive biology by seasons and sex. The results show that M. goodei exhibits seasonal migrations. Young-of-the-year remain in the bay all year long, while adults enter during spring and summer. Juveniles in spring are likely to become first-time mating individuals that migrate into open sea at the end of summer. These individuals would return to give birth for the first time and mate for the second time during the next year at summer. Anegada Bay would then be a mating and nursery area for the species. M. goodei behave as a generalist feeder with a uniform diet composed mainly of bivalves. Seasonal differences in the diet found arise from differences in prey diversity between summer and spring. Spatial differences, however, arise from the different abundances of caprellids and bivalves. Trophic level was 3.2 and it constitutes the first reference for this species, characterizing it as a secondary consumer.

Organochlorine pollutants and stable isotopes in resident and migrant passerine birds from northwest Michoacán, Mexico.

PubMed

Mora, Miguel A

2008-10-01

Although concentrations of organochlorine compounds (OCs) in birds from most of the United States and Canada have decreased over the last 30 years, there is still concern that migrant birds might be exposed to elevated concentrations of OCs during migration in Latin America. The Lerma-Chapala Basin in west-central Mexico is an important migration corridor and wintering area for many species. The objectives of this study were to assess if resident and migrant birds wintering in western Michoacán, Mexico accumulated elevated concentrations of OCs during fall and spring and to determine if the stable isotopes delta(15)N, delta(13)C, and deltaD could be used to predict burdens and origins of DDE accumulation. Resident and migrant passerine insectivorous birds were collected during fall and spring (2001-2002) in northwest Michoacán, near Chapala Lake, Mexico. The carcasses were analyzed for OCs and tail feathers were analyzed for stable isotopes delta(15)N, delta(13)C, and deltaD. The OCs detected in more than 50% of the samples were: oxychlordane (79%), p,p'-DDE (100%), p,p'-DDT (57%), and total PCBs (100%). p,p'-DDE was the OC detected at the highest concentrations, whereas residues of other OCs were near or below detection limits. Overall, there were no significant differences in concentrations of OCs between seasons or between resident and migrant birds. Concentrations of DDE and oxychlordane were somewhat higher in migrant and resident birds during spring than in fall; however, concentrations were significantly different only for oxychlordane. Two resident birds collected in fall and spring had DDE residues >10 microg/g wet weight in carcass. There were no significant differences in delta(13)C and delta(15)N values among species, between seasons, or between migrant and resident birds. However, deltaD values were clearly different between species and helped differentiate migrant from resident birds. deltaD values also were negatively and significantly correlated with DDE concentrations in carcass. Birds with more depleted deltaD values in feathers tended to have higher DDE concentrations than those with less depleted deltaD values, suggesting a potential latitudinal accumulation of DDE. Overall, our results suggest that during fall and spring, there is not a significant buildup of persistent OCs in migrant and resident passerine insectivorous birds in northwest Michoacán, Mexico.

Molluscs of an intertidal soft-sediment area in China: Does overfishing explain a high density but low diversity community that benefits staging shorebirds?

NASA Astrophysics Data System (ADS)

Yang, Hong-Yan; Chen, Bing; Piersma, Theunis; Zhang, Zhengwang; Ding, Changqing

2016-03-01

The Yellow Sea is a key staging ground for shorebirds that migrate from Australasia to the Arctic each spring. A lot of attention has been paid to the impact of habitat loss due to land reclamation on shorebird survival, but any effects of overfishing of coastal resources are unclear. In this study, the abundance of molluscs in the intertidal mudflats of northern Bohai Bay on the Chinese Yellow Sea was investigated in 2008-2014 from the perspective of their importance as food for northward migrating shorebirds, especially Red Knots Calidris canutus. Numerically contributing 96% to the numbers of 17 species found in spring 2008, the bivalve Potamocorbula laevis (the staple food of Red Knots and other shorebirds) dominated the intertidal mollusc community. In the spring of 2008-2014, the densities of P. laevis were surprisingly high, varying between 3900 and 41,000 individuals/m2 at distinctly small sizes (average shell lengths of 1.1 to 4.8 mm), and thus reaching some of the highest densities of marine bivalves recorded worldwide and providing good food for shorebirds. The distribution of P. laevis was associated with relatively soft sediments in close proximity to the recently built seawalls. A monthly sampling programme showed steep seasonal changes in abundance and size. P. laevis were nearly absent in winter, each year settling on the intertidal mudflats anew. Peak densities were reached in spring, when 0-age P. laevis were 1-3 mm long. The findings point to a highly unusual demographic structure of the species, suggesting that some interfering factors are at play. We hypothesise that the current dominance of young P. laevis in Bohai Bay reflects the combined pressures of a nearly complete active removal of adult populations from mid-summer to autumn for shrimp farming (this clearing of adults may offer space for recruitment during the next spring) and low numbers of epibenthic predators of bivalves, such as shrimps and crabs, due to persistent overfishing in recent decades (allowing freshly settled juveniles to reach high densities). To the best of our knowledge, the idea that overfishing of competing marine mesopredators benefits staging shorebirds, at least in the short term, is novel; it now needs further experimental and comparative scrutiny. The long-term effects of overfishing on benthic communities of the mudflats need further investigation.

Migration of rice planthoppers and their vectored re-emerging and novel rice viruses in East Asia

PubMed Central

Otuka, Akira

2013-01-01

This review examines recent studies of the migration of three rice planthoppers, Laodelphax striatellus, Sogatella furcifera, and Nilaparvata lugens, in East Asia. Laodelphax striatellus has recently broken out in Jiangsu province, eastern China. The population density in the province started to increase in the early 2000s and peaked in 2004. In 2005, Rice stripe virus (RSV) viruliferous rate of L. striatellus peaked at 31.3%. Since then, rice stripe disease spread severely across the whole province. Due to the migration of the RSV vectors, the rice stripe disease spread to neighboring countries Japan and Korea. An overseas migration of L. striatellus that occurred in 2008 was analyzed, when a slow-moving cold vortex, a type of low pressure system, reached western Japan from Jiangsu, carrying the insects into Japan. Subsequently the rice stripe diseases struck these areas in Japan severely. In Korea, similar situations occurred in 2009, 2011, and 2012. Their migration sources were also estimated to be in Jiangsu by backward trajectory analysis. Rice black-streaked dwarf virus, whose vector is L. striatellus, has recently re-emerged in eastern China, and the evidence for overseas migrations of the virus, just like the RSV’s migrations, has been given. A method of predicting the overseas migration of L. striatellus has been developed by Japanese, Chinese, and Korean institutes. An evaluation of the prediction showed that this method properly predicted migration events that occurred in East Asia from 2008 to 2011. Southern rice black-streaked dwarf virus (SRBSDV) was first found in Guangdong province. Its vector is S. furcifera. An outbreak of SRBSDV occurred in southern China in 2009 and spread to Vietnam the same year. This disease and virus were also found in Japan in 2010. The epidemic triggered many migration studies to investigate concrete spring-summer migration routes in China, and the addition of migration sources for early arrivals in Guangdong and Guangxi have been proposed. Nilaparvata lugens is also an important insect pest of rice. Its migration situations on the Indochina peninsula and return migrations in China are discussed. PMID:24312081

Migration of health workers: a challenge for health care system.

PubMed

Afzal, Shaista; Masroor, Imrana; Shafqat, Gulnaz

2012-09-01

The migration of health workers has resulted in a growing apprehension universally because of its impact on health system of the developing countries. Although the choice to migrate is basically a personal one, however, the overall social and economic circumstances have important impact on the decision to migrate. The "push and pull" factors for migration are disparity in working conditions, pay, lack of promotion opportunities, poor living conditions, desire to gain experience, professional development, family background and family wealth. A strategic approach by the government and other agencies is mandatory for regulating the flow of health workers between countries. A range of policies and interventions are needed to deal with the broader health system issue and problems of health workers that influence their recruitment, retention, deployment and progress.

Deweyan integration: moving beyond place attachment in elderly migration theory.

PubMed

Cutchin, M P

2001-01-01

The fact that aging-in-place and elderly migration are intricately linked has been overlooked by behavioral approaches to elderly migration. "Humanistic" inquiry has provided important insights into aging-in-place and elderly migration as well as the connection between the two. Humanistic approaches, however, do not encapsulate the full range of experience involved in elders' lives. To move beyond humanistic research and key concepts such as place attachment, the philosophy of John Dewey is introduced. Dewey's viewpoint is merged with the geographical concept of place into what is termed "place integration." This perspective is subsequently compared with humanistic perspectives on aging-in-place and elderly migration decision-making. Fundamental differences such as temporal orientation and substantive focus are illustrated and discussed. Conclusions address the utility of such a perspective.

You can go home again: evidence from longitudinal data.

PubMed

Reagan, P B; Olsen, R J

2000-08-01

In this paper we analyze the economic and demographic factors that influence return migration, focusing on generation 1.5 immigrants. Using longitudinal data from the 1979 youth cohort of the National Longitudinal Surveys (NLSY79), we track residential histories of young immigrants to the United States and analyze the covariates associated with return migration to their home country. Overall, return migration appears to respond to economic incentives, as well as to cultural and linguistic ties to the United States and the home country. We find no role for welfare magnets in the decision to return, but we learn that welfare participation leads to lower probability of return migration. Finally, we see no evidence of a skill bias in return migration, where skill is measured by performance on the Armed Forces Qualifying Test.

Body fat influences departure from stopover sites in migratory birds: evidence from whole-island telemetry

PubMed Central

Goymann, Wolfgang; Spina, Fernando; Ferri, Andrea; Fusani, Leonida

2010-01-01

Migration remains one of the great mysteries of animal life. Small migratory birds rely on refuelling stopovers after crossing ecological barriers such as deserts or seas. Previous studies have suggested that fuel reserves may determine stopover duration but this hypothesis could not be tested because of methodological limitations. Here, we provide evidence that subcutaneous fat stores determine stopover duration by measuring the permanence of migratory garden warblers (Sylvia borin) on a small Mediterranean island during spring migration with telemetry methods. Garden warblers with large amounts of fat stores departed the island significantly sooner than lean birds. All except one fat bird left the island on the same evening after capture, with a mean total stopover estimate of 8.8 hours. In contrast, the mean estimated total stopover duration of lean birds was 41.3 hours. To our knowledge, this is the first study that measures the true minimum stopover duration of a songbird during migration. PMID:20164077

Survival and migration behavior of juvenile salmonids at McNary Dam, 2005: Final report of research

USGS Publications Warehouse

Perry, Russell W.; Braatz, Amy C.; Novick, Marc S.; Lucchesi, Joel N.; Rutz, Gary L.; Koch, Ryan C.; Schei, Jacquelyn L.; Adams, Noah S.; Rondorf, Dennis W.

2007-01-01

During 2005, we used radio-telemetry at McNary Dam to estimate passage and survival parameters of juvenile salmonids. During the spring migration period, two treatments were implemented: 1) 12-h spill operations with spill occurring between 1800 hours and 0600 hours, and 2) 24-h spill with spill occurring 24 hours per day. Treatments were not implemented during the summer migration period. However, a court-order was issued by Judge James Redden, U.S. 9th District Court, mandating a maximum powerhouse discharge of 50 kcfs with the remaining discharge to be spilled over the 24-h diel cycle between 1 July and 31 August 2005. Consequently, our study was conducted during two distinct periods: 1) a short period of involuntary spill for 24-h per day that occurred between 22 June and 30 June 2005, and 2) the period of court-ordered spill that was implemented after 1 July 2005.

Juvenile salmonid migratory behavior at the mouth of the Columbia River and within the plume

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMichael, Geoffrey A.; O'Toole, Amanda C.; Harnish, Ryan A.

A total of 8,159 acoustic-tagged salmonid smolts were detected at the mouth of the Columbia River. Of the fish detected at the mouth, 14% of yearling Chinook salmon, 9% of steelhead, and 22% of subyearling Chinook salmon were detected on a sparse array deployed in the Columbia River plume. Chinook salmon smolts decreased travel rate as they left the river and entered the plume, while steelhead increased travel rate. Chinook salmon also spent more time in the transitional area between the river mouth and plume as compared to steelhead. In early spring, yearling Chinook salmon and steelhead predominately migrated pastmore » the plume array towards the edge of the shelf and to the south. Later in the season, yearling Chinook salmon and steelhead smolts tended to migrate out of the river mouth in a northerly direction. Subyearling Chinook salmon migrated predominately past the portion of the plume array to the north of the river mouth.« less

Blood flow and blood cell interactions and migration in microvessels

NASA Astrophysics Data System (ADS)

Fedosov, Dmitry; Fornleitner, Julia; Gompper, Gerhard

2011-11-01

Blood flow in microcirculation plays a fundamental role in a wide range of physiological processes and pathologies in the organism. To understand and, if necessary, manipulate the course of these processes it is essential to investigate blood flow under realistic conditions including deformability of blood cells, their interactions, and behavior in the complex microvascular network which is characteristic for the microcirculation. We employ the Dissipative Particle Dynamics method to model blood as a suspension of deformable cells represented by a viscoelastic spring-network which incorporates appropriate mechanical and rheological cell-membrane properties. Blood flow is investigated in idealized geometries. In particular, migration of blood cells and their distribution in blood flow are studied with respect to various conditions such as hematocrit, flow rate, red blood cell aggregation. Physical mechanisms which govern cell migration in microcirculation and, in particular, margination of white blood cells towards the vessel wall, will be discussed. In addition, we characterize blood flow dynamics and quantify hemodynamic resistance. D.F. acknowledges the Humboldt Foundation for financial support.

The role of ethnic relations and education systems in migration from Southeast Asia to Australia.

PubMed

Sullivan, G; Gunasekaran, S

1993-08-01

"After a brief discussion of the geographical, cultural, and historical characteristics of Southeast Asia [and Hong Kong], a review is provided of the evolution of Australian immigration policy which, in our view, is a strong pull factor. This is followed by stock and flow analyses of Asian-born residents in Australia. The motivations for emigration in countries which exhibit substantial emigration rates are considered next and the article ends with the conclusion that demand factors and social networks play a decisive role in the decision to emigrate." Factors affecting migration significantly include political conditions and ethnic relations in countries of origin, and educational and career opportunities in the country of destination. excerpt

Comments in reply: new directions in migration research.

PubMed

Shaw, R P

1986-01-01

The author comments on a review of his recent book NEW DIRECTIONS IN MIGRATION RESEARCH and reflects on theory and model specification, problems of estimation and statistical inference, realities of temporal and spatial heterogeneity, choices of explanatory variables, and the importance of broader political issues in migration studies. A core hypothesis is that market forces have declined as influences on internal migration in Canada over the last 30 years. Theoretical underpinnings include declining relevance of wage considerations in the decision to migrate on the assumption that marginal utility of money diminishes and marginal utility of leisure increases as society becomes wealthier. The author perceives the human capital model to have limitations and is especially troubled by the "as if" clause--that all migrants behave "as if" they calculate benefits and risks with equal rigor. The author has "shadowed" and not quantified the costs involved. He implies that normative frameworks for future migration research and planning should be established.

Migration of South African health workers: the extent to which financial considerations influence internal flows and external movements

PubMed Central

2013-01-01

Background The loss of human resource capacity has had a severe impact on the health system in South Africa. This study investigates the causes of migration focussing on the role of salaries and benefits. Health professionals from public, private and non-governmental (NGO) health facilities located in selected peri–urban and urban areas in KwaZulu-Natal, South Africa were surveyed about their current positions and attitudes toward migration. Methods The study uses cross-sectional data collected in 2009. A total of 694 health professionals (430 in the public sector, 133 in the NGO sector and 131 in the private sector) were surveyed. An additional 11 health professionals were purposively selected for in-depth interviews. Odds ratios with 95% confidence intervals were calculated to determine whether salaries influenced HWs decisions to migrate. Results HWs decision to move was not positively associated with lower salaries. It was found, instead, that the consideration to move was determined by other factors including age, levels of stress experienced and the extent to which they were satisfied at their current place of work. Conclusions The OSD appears to have lowered the risk of HWs migrating due to low salaries. However, the results also indicate that the South African Department of Health needs to improve working conditions for HWs within the public health sector to assist in retention. PMID:23919539

Migration of South African health workers: the extent to which financial considerations influence internal flows and external movements.

PubMed

George, Gavin; Atujuna, Millicent; Gow, Jeff

2013-08-06

The loss of human resource capacity has had a severe impact on the health system in South Africa. This study investigates the causes of migration focussing on the role of salaries and benefits. Health professionals from public, private and non-governmental (NGO) health facilities located in selected peri-urban and urban areas in KwaZulu-Natal, South Africa were surveyed about their current positions and attitudes toward migration. The study uses cross-sectional data collected in 2009. A total of 694 health professionals (430 in the public sector, 133 in the NGO sector and 131 in the private sector) were surveyed. An additional 11 health professionals were purposively selected for in-depth interviews. Odds ratios with 95% confidence intervals were calculated to determine whether salaries influenced HWs decisions to migrate. HWs decision to move was not positively associated with lower salaries. It was found, instead, that the consideration to move was determined by other factors including age, levels of stress experienced and the extent to which they were satisfied at their current place of work. The OSD appears to have lowered the risk of HWs migrating due to low salaries. However, the results also indicate that the South African Department of Health needs to improve working conditions for HWs within the public health sector to assist in retention.

High-Resolution Aeromagnetic Survey To Image Shallow Faults, Poncha Springs and Vicinity, Chaffee County, Colorado

USGS Publications Warehouse

Grauch, V.J.S.; Drenth, Benjamin J.

2009-01-01

High-resolution aeromagnetic data were acquired over the town of Poncha Springs and areas to the northwest to image faults, especially where they are concealed. Because this area has known hot springs, faults or fault intersections at depth can provide pathways for upward migration of geothermal fluids or concentrate fracturing that enhances permeability. Thus, mapping concealed faults provides a focus for follow-up geothermal studies. Fault interpretation was accomplished by synthesizing interpretative maps derived from several different analytical methods, along with preliminary depth estimates. Faults were interpreted along linear aeromagnetic anomalies and breaks in anomaly patterns. Many linear features correspond to topographic features, such as drainages. A few of these are inferred to be fault-related. The interpreted faults show an overall pattern of criss-crossing fault zones, some of which appear to step over where they cross. Faults mapped by geologists suggest similar crossing patterns in exposed rocks along the mountain front. In low-lying areas, interpreted faults show zones of west-northwest-, north-, and northwest-striking faults that cross ~3 km (~2 mi) west-northwest of the town of Poncha Springs. More easterly striking faults extend east from this juncture. The associated aeromagnetic anomalies are likely caused by magnetic contrasts associated with faulted sediments that are concealed less than 200 m (656 ft) below the valley floor. The faults may involve basement rocks at greater depth as well. A relatively shallow (<300 m or <984 ft), faulted basement block is indicated under basin-fill sediments just north of the hot springs and south of the town of Poncha Springs.

A Comparison of Common and Novel Curriculum-Based Measurement of Reading Decision Rules to Predict Spring Performance for Students Receiving Supplemental Interventions

ERIC Educational Resources Information Center

Van Norman, Ethan R.; Parker, David C.

2018-01-01

Recent simulations suggest that trend line decision rules applied to curriculum-based measurement of reading progress monitoring data may lead to inaccurate interpretations unless data are collected for upward of 3 months. The authors of those studies did not manipulate goal line slope or account for a student's level of initial performance when…

Honey buzzards don't always make a beeline.

PubMed

Chapman, Jason W

2017-03-01

(a) European honey buzzards breeding in Western Europe primarily use soaring flight to make annual long-range migrations via the Strait of Gibraltar to winter in West Africa; this adult male was photographed on migration near Gibraltar. Photo: Javier Elloriaga. (b) Autumn migration routes of 12 satellite tagged adult European honey buzzards (colour-coded lines); compared with the shortest possible straight-line routes (dashed lines), most routes involved substantial westerly detours in Africa. Adapted from Vansteelant et al. (2016). (c) In contrast, Montagu's harriers predominantly use flapping flight during their migrations; this adult male is carrying a satellite transmitter. Photo: Theo van Kooten. (d) Autumn migration routes of 34 satellite tagged adult Montagu's harriers; migratory tracks more closely approached straight-line routes, and typically involved longer sea crossings, than seen in European honey buzzards. Adapted from Trierweiler et al. (). In Focus: Vansteelant, W.M.G., Shamoun-Baranes, J., van Manen, W., van Diermen, J. & Bouten, W. (2017) Seasonal detours by soaring migrants shaped by wind regimes along the East Atlantic Flyway. Journal of Animal Ecology, 86, 179-191. Migratory birds often make substantial detours from the shortest possible route during their annual migrations, which may potentially increase the duration and energetic cost of their journeys. Vansteelant et al. () investigate repeated migrations of adult European honey buzzards between the Netherlands and sub-Saharan Africa, and find that they make large westerly detours in Africa on both the spring and autumn routes. These detours allow migrants to capitalise on more favourable winds further along the route, thus reducing energy expenditure. Lifelong tracking studies will allow researchers to identify how migration routes have evolved to exploit predictable atmospheric and oceanic circulation patterns. © 2017 The Author. Journal of Animal Ecology © 2017 British Ecological Society.

Modeling Caribou Movements: Seasonal Ranges and Migration Routes of the Central Arctic Herd

PubMed Central

Nicholson, Kerry L.; Arthur, Stephen M.; Horne, Jon S.; Garton, Edward O.; Del Vecchio, Patricia A.

2016-01-01

Migration is an important component of the life history of many animals, but persistence of large-scale terrestrial migrations is being challenged by environmental changes that fragment habitats and create obstacles to animal movements. In northern Alaska, the Central Arctic herd (CAH) of barren-ground caribou (Rangifer tarandus granti) is known to migrate over large distances, but the herd’s seasonal distributions and migratory movements are not well documented. From 2003–2007, we used GPS radio-collars to determine seasonal ranges and migration routes of 54 female caribou from the CAH. We calculated Brownian bridges to model fall and spring migrations for each year and used the mean of these over all 4 years to identify areas that were used repeatedly. Annual estimates of sizes of seasonal ranges determined by 90% fixed kernel utilization distributions were similar between summer and winter (X̅ = 27,929 SE = 1,064 and X̅ = 26,585 SE = 4912 km2, respectively). Overlap between consecutive summer and winter ranges varied from 3.3–18.3%. Percent overlap between summer ranges used during consecutive years (X̅ = 62.4% SE = 3.7%) was higher than for winter ranges (X̅ = 42.8% SE = 5.9%). Caribou used multiple migration routes each year, but some areas were used by caribou during all years, suggesting that these areas should be managed to allow for continued utilization by caribou. Restoring migration routes after they have been disturbed or fragmented is challenging. However, prior knowledge of movements and threats may facilitate maintenance of migratory paths and seasonal ranges necessary for long-term persistence of migratory species. PMID:27045587

Seasonally dynamic diel vertical migrations of Mysis diluviana, coregonine fishes, and siscowet lake trout in the pelagia of western Lake Superior

USGS Publications Warehouse

Ahrenstorff, Tyler D.; Hrabik, Thomas R.; Stockwell, Jason D.; Yule, Daniel L.; Sass, Greg G.

2011-01-01

Diel vertical migrations are common among many aquatic species and are often associated with changing light levels. The underlying mechanisms are generally attributed to optimizing foraging efficiency or growth rates and avoiding predation risk (μ). The objectives of this study were to (1) assess seasonal and interannual changes in vertical migration patterns of three trophic levels in the Lake Superior pelagic food web and (2) examine the mechanisms underlying the observed variability by using models of foraging, growth, and μ. Our results suggest that the opossum shrimp Mysis diluviana, kiyi Coregonus kiyi, and siscowet lake trout Salvelinus namaycush migrate concurrently during each season, but spring migrations are less extensive than summer and fall migrations. In comparison with M. diluviana, kiyis, and siscowets, the migrations by ciscoes C. artedi were not as deep in the water column during the day, regardless of season. Foraging potential and μ probably drive the movement patterns of M. diluviana, while our modeling results indicate that movements by kiyis and ciscoes are related to foraging opportunity and growth potential and receive a lesser influence from μ. The siscowet is an abundant apex predator in the pelagia of Lake Superior and probably undertakes vertical migrations in the water column to optimize foraging efficiency and growth. The concurrent vertical movement patterns of most species are likely to facilitate nutrient transport in this exceedingly oligotrophic ecosystem, and they demonstrate strong linkages between predators and prey. Fishery management strategies should use an ecosystem approach and should consider how altering the densities of long-lived top predators produces cascading effects on the nutrient cycling and energy flow in lower trophic levels.

The morphodynamics and internal structure of intertidal fine-gravel dunes: Hills Flats, Severn Estuary, UK

NASA Astrophysics Data System (ADS)

Carling, P. A.; Radecki-Pawlik, A.; Williams, J. J.; Rumble, B.; Meshkova, L.; Bell, P.; Breakspear, R.

2006-01-01

In the macrotidal Severn estuary, UK, the dynamics of intertidal fine-gravel dunes were investigated. These dunes are migrating across a bedrock platform. Systematic observations were made of hydraulic climate, geometry, migration rates and internal sedimentary structures of the dunes. During spring tides, the ebb flow is dominant, dunes grow in height and have ebb orientated geometry with bedrock floors in the troughs. During neap tides, a weak flood flow may dominate. Dunes then are flood orientated or symmetrical. Neap dune heights decrease and the eroded sediment is stored in the dune troughs where the bedrock becomes blanketed by muddy gravel. During spring tides, instantaneous bed shear stresses reach 8 N m - 2 , sufficient to disrupt a 9 mm-gravel armour layer. However, a sustained bed shear stress of 4 N m - 2 is required to initiate dune migration at which time the critical depth-mean velocity is 1 m s - 1 . Ebb and flood inequalities in the bed shear stress explain the changes in dune asymmetry and internal structures. During flood tides, the crests of the dunes reverse such that very mobile sedimentary 'caps' overlie a more stable dune 'core'. Because ebb tides dominate, internal structures of the caps often are characterised by ebb orientated steep open-work foresets developed by strong tidal currents and some lower angle crossbeds deposited as weaker currents degrade foresets. The foresets forming the caps may be grouped into cosets (tidal bundles) and are separated from mud-infused cores of crossbeds that lie below, by reactivation and erosion surfaces blanketed by discontinuous mud drapes. The cores often exhibit distinctive muddy toe sets that define the spacing of tidal cosets.

Recent Salmon Declines: A Result of Lost Feeding Opportunities Due to Bad Timing?

PubMed Central

Chittenden, Cedar M.; Jensen, Jenny L. A.; Ewart, David; Anderson, Shannon; Balfry, Shannon; Downey, Elan; Eaves, Alexandra; Saksida, Sonja; Smith, Brian; Vincent, Stephen; Welch, David; McKinley, R. Scott

2010-01-01

As the timing of spring productivity blooms in near-shore areas advances due to warming trends in global climate, the selection pressures on out-migrating salmon smolts are shifting. Species and stocks that leave natal streams earlier may be favoured over later-migrating fish. The low post-release survival of hatchery fish during recent years may be in part due to static release times that do not take the timing of plankton blooms into account. This study examined the effects of release time on the migratory behaviour and survival of wild and hatchery-reared coho salmon (Oncorhynchus kisutch) using acoustic and coded-wire telemetry. Plankton monitoring and near-shore seining were also conducted to determine which habitat and food sources were favoured. Acoustic tags (n = 140) and coded-wire tags (n = 266,692) were implanted into coho salmon smolts at the Seymour and Quinsam Rivers, in British Columbia, Canada. Differences between wild and hatchery fish, and early and late releases were examined during the entire lifecycle. Physiological sampling was also carried out on 30 fish from each release group. The smolt-to-adult survival of coho salmon released during periods of high marine productivity was 1.5- to 3-fold greater than those released both before and after, and the fish's degree of smoltification affected their downstream migration time and duration of stay in the estuary. Therefore, hatchery managers should consider having smolts fully developed and ready for release during the peak of the near-shore plankton blooms. Monitoring chlorophyll a levels and water temperature early in the spring could provide a forecast of the timing of these blooms, giving hatcheries time to adjust their release schedule. PMID:20805978

Natural flows of H2-rich fluids in the ophiolites of Oman and the Philippines: Tectonic control of migration pathways and associated diagenetic processes

NASA Astrophysics Data System (ADS)

Deville, E. P.; Prinzhofer, A.; Vacquand, C.; Chavagnac, V.; Monnin, C.; Ceuleneer, G.; Arcilla, C. A.

2009-12-01

We compare the geological environments of sites of emission of natural hydrogen in the Oman ophiolite and the Zambales ophiolite (Luzon, Philippines). The genesis of natural H2 results from the interaction between ultrabasic rocks and aqueous solutions circulating in deep fracture networks, by oxidation of metals (Fe2+, Mn2+) and reduction of water, probably under high temperature conditions. This process generates very reducing conditions capable of destabilizing other molecules (notably reduction of deep CO2 being transformed into CH4 by Fisher-Tropsch type reactions). Nitrogen is also commonly associated to the H2-rich fluids. H2 flows are associated with the expulsion of hyperalkaline waters rich in ions OH- and Ca2+ and characterized by high pH (between 11 and 12). Most alkaline springs are found in the vicinity of major faults and/or lithological discontinuities like the basal thrust plane of the ophiolites and the peridotite-gabbro contact (Moho). Within the fracture networks, gas and water separate probably at shallow depth, i.e. close to the top of the upper aquifer level. Locally high flows of gas migrate vertically through fracture pathways and they are able to inflame spontaneously on the surface. Aqueous fluids tends to migrate laterally in the fracture network toward the creeks where most of the hyperalkaline springs are found. This water circulation induces a chain of diagenetic reactions starting in the fracture systems and continuing at the surface where it leads to the precipitation of calcite, aragonite, brucite and more rarely portlandite. This chain of diagenetic reactions is associated with the capture of the atmospheric CO2 during the precipitation of carbonates.

Physiological and endocrine changes in Atlantic salmon smolts during hatchery rearing, downstream migration and ocean entry

USGS Publications Warehouse

McCormick, Stephen D.; Sheehan, Timothy F.; Björnsson, Björn Thrandur; Lipsky, Christine; Kocik, John F.; Regish, Amy M.; O'Dea, Michael F.

2013-01-01

Billions of hatchery salmon smolts are released annually in an attempt to mitigate anthropogenic impacts on freshwater habitats, often with limited success. Mortality of wild and hatchery fish is high during downstream and early ocean migration. To understand changes that occur during migration, we examined physiological and endocrine changes in Atlantic salmon (Salmo salar) smolts during hatchery rearing, downstream migration, and early ocean entry in two successive years. Gill Na+/K+-ATPase activity increased in the hatchery during spring, increased further after river release, and was slightly lower after recapture in the ocean. Plasma growth hormone levels increased in the hatchery, were higher in the river, and increased further in the ocean. Plasma IGF-I remained relatively constant in the hatchery, increased in the river, then decreased in the ocean. Plasma thyroid hormones were variable in the hatchery, but increased in both river- and ocean-captured smolts. Naturally reared fish had lower condition factor, gill NKA activity, and plasma thyroxine than hatchery fish in the river but were similar in the ocean. This novel data set provides a vital first step in understanding the role and norms of endocrine function in smolts and the metrics of successful marine entry.

Reconsidering residency: Characterization and conservation implications of complex migratory patterns of shortnose sturgeon (Acispenser brevirostrum)

USGS Publications Warehouse

Dionne, Phillip E.; Zydlewski, Gayle B.; Kinnison, Michael T.; Zydlewski, Joseph D.; Wippelhauser, Gail S.

2013-01-01

Efforts to conserve endangered species usually involve attempts to define and manage threats at the appropriate scale of population processes. In some species that scale is localized; in others, dispersal and migration link demic units within larger metapopulations. Current conservation strategies for endangered shortnose sturgeon (Acipenser brevirostrum) assume the species is river resident, with little to no movement between rivers. However we have found that shortnose sturgeon travel more than 130 km through coastal waters between the largest rivers in Maine. Indeed, acoustic telemetry shows that shortnose sturgeon enter six out of the seven acoustically monitored rivers we have monitored, with over 70% of tagged individuals undertaking coastal migrations between river systems. Four migration patterns were identified for shortnose sturgeon inhabiting the Penobscot River, Maine: river resident (28%), spring coastal emigrant (24%), fall coastal emigrant (33%), and summer coastal emigrant (15%). No shortnose sturgeon classified as maturing female exhibited a resident pattern, indicating differential migration. Traditional river-specific assessment and management of shortnose sturgeon could be better characterized using a broader metapopulation scale, at least in the Gulf of Maine, that accounts for diverse migratory strategies and the importance of migratory corridors as critical habitat.

Migration And wintering areas Of Glaucous-winged Gulls From south-central Alaska

USGS Publications Warehouse

Hatch, Scott A.; Gill, V.A.; Mulcahy, Daniel M.

2011-01-01

We used satellite telemetry to investigate the migration patterns and wintering areas of Glaucous-winged Gulls (Larus glaucescens) from Middleton Island, Alaska, where this species' population increased tenfold from the 1970s to the 1990s. Fall migration spanned 11 weeks, including numerous stopovers en route, apparently for feeding. Spring migration from wintering sites to Middleton Island was shorter (4 weeks) and more direct. One juvenile spent several months in southern Prince William Sound. An adult spent several months near Craig, southeast Alaska, while three others overwintered in southern British Columbia. For all four wintering adults use of refuse-disposal sites was evident or strongly suggested. Commensalism with humans may have contributed to the increase on Middleton, but a strong case can also be made for a competing explanation-regional recruitment of gulls to high-quality nesting habitat in Alaska created after the earthquake of 1964. An analysis of band returns reveals broad overlap in the wintering grounds of gulls from different Alaska colonies and of gulls banded on the west coast from British Columbia to California. The seasonal movement of many gulls from Alaska is decidedly migratory, whereas gulls from British Columbia, Washington, and Oregon disperse locally in winter.

Acoustic insights into the zooplankton dynamics of the eastern Weddell Sea

NASA Astrophysics Data System (ADS)

Cisewski, Boris; Strass, Volker H.

2016-05-01

The success of any efforts to determine the effects of climate change on marine ecosystems depends on understanding in the first instance the natural variations, which contemporarily occur on the interannual and shorter time scales. Here we present results on the environmental controls of zooplankton distribution patterns and behaviour in the eastern Weddell Sea, Southern Ocean. Zooplankton abundance and vertical migration are derived from the mean volume backscattering strength (MVBS) and the vertical velocity measured by moored acoustic Doppler current profilers (ADCPs), which were deployed simultaneously at 64°S, 66.5°S and 69°S along the Greenwich Meridian from February, 2005, until March, 2008. While these time series span a period of full three years they resolve hourly changes. A highly persistent behavioural pattern found at all three mooring locations is the synchronous diel vertical migration (DVM) of two distinct groups of zooplankton that migrate between a deep residence depth during daytime and a shallow depth during nighttime. The DVM was closely coupled to the astronomical daylight cycles. However, while the DVM was symmetric around local noon, the annual modulation of the DVM was clearly asymmetric around winter solstice or summer solstice, respectively, at all three mooring sites. DVM at our observation sites persisted throughout winter, even at the highest latitude exposed to the polar night. Since the magnitude as well as the relative rate of change of illumination is minimal at this time, we propose that the ultimate causes of DVM separated from the light-mediated proximal cue that coordinates it. In all three years, a marked change in the migration behaviour occurred in late spring (late October/early November), when DVM ceased. The complete suspension of DVM after early November is possibly caused by the combination of two factors: (1) increased availability of food in the surface mixed layer provided by the phytoplankton spring bloom, and (2) vanishing diurnal enhancement of the threat from visually oriented predators when the illumination is quasi-continuous during the polar and subpolar summer. Zooplankton abundance in the water column, estimated as the mean MVBS in the depth range 50-300 m, was highest end of summer and lowest mid to end winter on the average annual cycle. However, zooplankton abundance varied several-fold between years and between locations. Based on satellite and in situ data of chlorophyll and sea ice as well as on hydrographic measurements, the interannual and spatial variations of zooplankton mean abundance can be explained by differences in the magnitude of the phytoplankton spring bloom, which develops during the seasonal sea ice retreat. Whereas the vernal ice melt appears necessary to stimulate the blooming of phytoplankton, it is not the determinator of the blooms magnitude, its areal extent and duration. A possible explanation for the limitation of the phytoplankton bloom in some years is top-down control. We hypothesise that the phytoplankton spring development can be curbed by grazing when the zooplankton had attained high abundance by growth during the preceding summer.

Fish Passage Center; Columbia Basin Fish and Wildlife Authority, 2000 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeHart, Michele

2001-06-01

The year 2000 hydrosystem operations illustrated two main points: (1) that the NMFS Biological Opinion on the operations of the Federal Columbia River Power System (FCRPS) fish migration measures could not be met in a slightly below average water year, and; (2) the impacts and relationships of energy deregulation and volatile wholesale energy prices on the ability of the FCRPS to provide the Biological Opinion fish migration measures. In 2000, a slightly below average water year, the flow targets were not met and, when energy ''emergencies'' were declared, salmon protection measures were reduced. The 2000 migration year was a belowmore » average runoff volume year with an actual run off volume of 61.1 MAF or 96% of average. This year illustrated the ability of the hydro system to meet the migration protection measures established by the NMFS Biological Opinion. The winter operation of storage reservoirs was based upon inaccurate runoff volume forecasts which predicted a January-July runoff volume forecast at The Dalles of 102 to 105% of average, from January through June. Reservoir flood control drafts during the winter months occurred according to these forecasts. This caused an over-draft of reservoirs that resulted in less volume of water available for fish flow augmentation in the spring and the summer. The season Biological Opinion flow targets for spring and summer migrants at Lower Granite and McNary dams were not met. Several power emergencies were declared by BPA in the summer of 2000. The first in June was caused by loss of resources (WNP2 went off-line). The second and third emergencies were declared in August as a result of power emergencies in California and in the Northwest. The unanticipated effects of energy deregulation, power market volatility and rising wholesale electricity prices, and Californian energy deregulation reduced the ability of the FCRPS to implement fish protection measures. A Spill Plan Agreement was implemented in the FCRPS. Under this plan, spill hours were increased at Lower Monumental Dam. Spill volume at The Dalles was reduced and daytime spill tests were conducted at John Day and Bonneville Dams. Although provided for fish, most spill that occurred in 2000 was either in excess of project hydraulic capacity or excess generation. This effectively reduced the actual cost of the spill program. For the most part, spill in 2000 was managed to the waiver limits for total dissolved gas levels and the NMFS action criteria for dissolved gas signs were not exceeded. Hatchery spring chinook returns comprised an estimated 81.4% of the total spring chinook adult return to Lower Granite Dam. Smolt travel time and survival were similar to past years for most Smolt Monitoring Program groups. The notable exceptions were Snake River hatchery steelhead groups and mid-Columbia hatchery sub-yearling groups from Wells and Ringold hatcheries, which had significantly lower survival than previous years. Yearling chinook travel time showed variation from past years, reflecting the atypical flow shape in 2000 which had high flows in April, declining through May.« less

Why are you draining your brain? Factors underlying decisions of graduating Lebanese medical students to migrate.

PubMed

Akl, Elie A; Maroun, Nancy; Major, Stella; Afif, Claude; Chahoud, Bechara; Choucair, Jacques; Sakr, Mazen; Schünemann, Holger J

2007-03-01

In the context of a worldwide physician brain drain phenomenon, Lebanon has the highest emigration factor in the Middle East and North Africa. In this manuscript we aim to identify and develop a conceptual framework for the factors underlying the decisions of graduating Lebanese medical students to train abroad. We conducted two focus groups and seven semi-structured individual interviews with 23 students. In the deductive analysis (based on the push-pull theory), students reported push factors in Lebanon and pull factors abroad related to five dimensions. They focused predominantly on how training abroad provides them with a competitive advantage in an oversaturated Lebanese job market. An inductive analysis revealed the following emerging concepts: repel factors abroad and retain factors locally; societal expectations that students should train abroad; marketing of abroad training; and an established culture of migration. The marketing of abroad training and the culture of migration are prevalent in the academic institutions.

Does Specification Matter? Experiments with Simple Multiregional Probabilistic Population Projections

PubMed Central

Raymer, James; Abel, Guy J.; Rogers, Andrei

2012-01-01

Population projection models that introduce uncertainty are a growing subset of projection models in general. In this paper, we focus on the importance of decisions made with regard to the model specifications adopted. We compare the forecasts and prediction intervals associated with four simple regional population projection models: an overall growth rate model, a component model with net migration, a component model with in-migration and out-migration rates, and a multiregional model with destination-specific out-migration rates. Vector autoregressive models are used to forecast future rates of growth, birth, death, net migration, in-migration and out-migration, and destination-specific out-migration for the North, Midlands and South regions in England. They are also used to forecast different international migration measures. The base data represent a time series of annual data provided by the Office for National Statistics from 1976 to 2008. The results illustrate how both the forecasted subpopulation totals and the corresponding prediction intervals differ for the multiregional model in comparison to other simpler models, as well as for different assumptions about international migration. The paper ends end with a discussion of our results and possible directions for future research. PMID:23236221

Practical (?) considerations for implementing assisted migration strategies for trees in North America

NASA Astrophysics Data System (ADS)

McKenney, D.; Pedlar, J.

2011-12-01

Climate is one of the major influences on forests and much effort has gone into projecting the impacts of rapid climate change on forest distribution and productivity. Such efforts are premised on the notion that the current generation of Global Climate Models (GCMs) provide reasonably accurate representations of future climate. But what is the appropriate level of faith to put in these projections when making relatively fine-scale resource management decisions such as the movement of plant genetic material? In this talk we review recent outcomes of climate envelope models for North American tree species that suggest optimal climate regimes could move on average ~700km within the next 100 years. Newer generation GCMs seem to confirm these results but much uncertainty remains for practical decision-making. Despite these uncertainties, assisted migration has been suggested as a climate change adaptation tool wherein populations of trees are moved up to a few hundred kilometers north (or a few hundred meters upslope) to keep pace with the anticipated changes in optimal climate regimes. A continent-wide web based tool (SEEDWHERE) is presented, which assists in identifying appropriate translocation distances for assisted migration initiatives. We finish with some suggestions for future work on the topic of forest regeneration decisions under an evolving and uncertain future climate.

Identification of pests and diseases of Dalbergia hainanensis based on EVI time series and classification of decision tree

NASA Astrophysics Data System (ADS)

Luo, Qiu; Xin, Wu; Qiming, Xiong

2017-06-01

In the process of vegetation remote sensing information extraction, the problem of phenological features and low performance of remote sensing analysis algorithm is not considered. To solve this problem, the method of remote sensing vegetation information based on EVI time-series and the classification of decision-tree of multi-source branch similarity is promoted. Firstly, to improve the time-series stability of recognition accuracy, the seasonal feature of vegetation is extracted based on the fitting span range of time-series. Secondly, the decision-tree similarity is distinguished by adaptive selection path or probability parameter of component prediction. As an index, it is to evaluate the degree of task association, decide whether to perform migration of multi-source decision tree, and ensure the speed of migration. Finally, the accuracy of classification and recognition of pests and diseases can reach 87%--98% of commercial forest in Dalbergia hainanensis, which is significantly better than that of MODIS coverage accuracy of 80%--96% in this area. Therefore, the validity of the proposed method can be verified.

Migration stopovers and the conservation of arctic-breeding Calidrine sandpipers

USGS Publications Warehouse

Skagen, Susan K.

2006-01-01

Long-distance migration, one of the most physically demanding events in the animal kingdom, is well developed in many species of Charadriidae and Scolopacidae. Some shorebirds renowned for their extraordinary long-distance migrations, notably American Golden-Plover (Pluvialis dominica), Red Knot (Calidris canutus rufa), and White-rumped Sandpiper (C. fuscicollis), travel as many as 15,000 km between southern South American wintering grounds and Canadian Arctic breeding areas. Migration strategies of shorebirds vary in many aspects. There are remarkable accounts of shorebirds, such as northbound Red Knots, that stage in a few key sites for 2–3 weeks and lay on extensive body stores, then fly nonstop for distances of ≤2,500 km (Harrington 2001, Piersma et al. 2005). Less well known are the examples of populations that refuel only briefly at stopover sites, disperse broadly on the landscape, and fly shorter distances between sites (Skagen 1997, Haig et al. 1998, Warnock et al. 1998). This latter pattern applies to many long-distance migrant shorebirds that cross the interior plains of North America during spring and fall migrations. For them, interior wetland complexes provide critical refueling resources along the direct routes between summering and wintering grounds (Skagen et al. 1999). In this issue of The Auk, Krapu et al. (2006) describe patterns and implications of fat deposition by Semipalmated Sandpipers (C. pusilla), White-rumped Sandpipers, and Baird's Sandpipers (C. bairdii) refueling during northward migration across the prairies of mid-continental North America.

Hydrogeologic setting and conceptual hydrologic model of the Spring Creek basin, Centre County, Pennsylvania

USGS Publications Warehouse

Fulton, John W.; Koerkle, Edward H.; McAuley, Steven D.; Hoffman, Scott A.; Zarr, Linda F.

2005-01-01

The Spring Creek Basin, Centre County, Pa., is experiencing some of the most rapid growth and development within the Commonwealth. This trend has resulted in land-use changes and increased water use, which will affect the quantity and quality of stormwater runoff, surface water, ground water, and aquatic resources within the basin. The U.S. Geological Survey (USGS), in cooperation with the ClearWater Conservancy (CWC), Spring Creek Watershed Community (SCWC), and Spring Creek Watershed Commission (SCWCm), has developed a Watershed Plan (Plan) to assist decision makers in water-resources planning. One element of the Plan is to provide a summary of the basin characteristics and a conceptual model that incorporates the hydrogeologic characteristics of the basin. The report presents hydrogeologic data for the basin and presents a conceptual model that can be used as the basis for simulating surface-water and ground-water flow within the basin. Basin characteristics; sources of data referenced in this text; physical characteristics such as climate, physiography, topography, and land use; hydrogeologic characteristics; and water-quality characteristics are discussed. A conceptual model is a simplified description of the physical components and interaction of the surface- and ground-water systems. The purpose for constructing a conceptual model is to simplify the problem and to organize the available data so that the system can be analyzed accurately. Simplification is necessary, because a complete accounting of a system, such as Spring Creek, is not possible. The data and the conceptual model could be used in development of a fully coupled numerical model that dynamically links surface water, ground water, and land-use changes. The model could be used by decision makers to manage water resources within the basin and as a prototype that is transferable to other watersheds.

Migration of northern yellowstone elk: Implications of spatial structuring

USGS Publications Warehouse

White, P.J.; Proffitt, K.M.; Mech, L.D.; Evans, S.B.; Cunningham, J.A.; Hamlin, K.L.

2010-01-01

Migration can enhance survival and recruitment of mammals by increasing access to higher-quality forage or reducing predation risk, or both. We used telemetry locations collected from 140 adult female elk during 20002003 and 20072008 to identify factors influencing the migration of northern Yellowstone elk. Elk wintered in 2 semidistinct herd segments and migrated 10140 km to at least 12 summer areas in Yellowstone National Park (YNP) and nearby areas of Montana. Spring migrations were delayed after winters with increased snow pack, with earlier migration in years with earlier vegetation green-up. Elk wintering at lower elevations outside YNP migrated an average of 13 days earlier than elk at higher elevations. The timing of autumn migrations varied annually, but elk left their summer ranges at about the same time regardless of elevation, wolf numbers, or distance to their wintering areas. Elk monitored for multiple years typically returned to the same summer (96 fidelity, n 52) and winter (61 fidelity, n 41) ranges. Elk that wintered at lower elevations in or near the northwestern portion of the park tended to summer in the western part of YNP (56), and elk that wintered at higher elevations spent summer primarily in the eastern and northern parts of the park (82). Elk did not grossly modify their migration timing, routes, or use areas after wolf restoration. Elk mortality was low during summer and migration (8 of 225 elk-summers). However, spatial segregation and differential mortality and recruitment between herd segments on the northern winter range apparently contributed to a higher proportion of the elk population wintering outside the northwestern portion of YNP and summering in the western portion of the park. This change could shift wolf spatial dynamics more outside YNP and increase the risk of transmission of brucellosis from elk to cattle north of the park. ?? 2010 American Society of Mammalogists.

Alternative foraging strategies enable a mountain ungulate to persist after migration loss

USGS Publications Warehouse

Courtemanch, Alyson B.; Kauffman, Matthew J.; Kilpatrick, Steve; Dewey, Sarah R.

2017-01-01

The persistence of many migratory ungulate populations worldwide is threatened due to anthropogenic impacts to seasonal ranges and migration routes. While many studies have linked migratory ungulate declines to migration disruption or loss, very few have explored the underlying factors that determine whether a population perishes or persists. In some cases, populations undergo severe declines and extirpation after migration loss; however, others appear able to persist as residents. We predict that to persist, populations must replace the traditional benefits of migration by altering the foraging strategies they employ as residents within one seasonal range. We propose the alternative foraging strategies (AFS) hypothesis as a framework for identifying various behavioral strategies that populations may use to cope with migration loss. We tested the hypothesis using the formerly migratory Teton bighorn sheep population in northwest Wyoming, which ceased migrating over 60 yr ago, but has persisted as a resident population. We used global positioning system data to evaluate winter and summer habitat selection and seasonal elevational movements for 28 adult female bighorn sheep (Ovis canadensis) from 2008 to 2010. Resource selection functions revealed that bighorn sheep employ winter foraging strategies to survive as residents by seeking out rugged, high-elevation, windswept ridgelines. Seasonal movement analyses indicated that bighorn sheep undergo a newly documented “abbreviated migration” strategy that is closely synchronized with vegetation green-up patterns within their one range. Bighorn sheep descend 500 m in elevation and travel up to 10 km in spring, gaining access to newly emergent forage approximately 30 d before it appears on their high-elevation winter and summer ranges. Our findings indicate that the Teton bighorn sheep population has persisted due to its habitat selection, AFS, and unique movement patterns, which allow migration loss to be mediated to some extent. The identification of AFS and the habitats that support them can help reveal the underlying benefits of migration and conserve populations in the face of future migration loss.

Migrating to 9.1 -- Why Not...How Hard Could It Be?

NASA Technical Reports Server (NTRS)

Little, Keith; Miller, Carole; Schwindt, Paul; Zimmerman, Cheryl

2011-01-01

With 19+ Million documents in the 8.0 Vault. the decision was to migrate only selected top-level Documents, Drawings, Models and Assemblies to Kennedy Space Center's Brand-Spankin-New 9.1 Windchill system. Come with us as we detail our journey. We'll share our triumphs. tools, and approaches, as well as our challenges (and a surprise or two) discovered on the trip.

Adding Bite to the Bark: Using LibGuides2 Migration as Impetus to Introduce Strong Content Standards

ERIC Educational Resources Information Center

Fritch, Melia; Pitts, Joelle E.

2016-01-01

The authors discuss the long-term accumulation of unstandardized and inaccessible content within the Libguides system and the decision-making process to create and implement a set of standards using the migration to the LibGuides2 platform as a vehicle for change. Included in the discussion are strategies for the creation of standards and…

Warmer springs lead to mistimed reproduction in great tits (Parus major)

PubMed Central

Visser, M. E.; Noordwijk, A. J. van; Tinbergen, J. M.; Lessells, C. M.

1998-01-01

In seasonal environments, the main selection pressure on the timing of reproduction (the ultimate factor) is synchrony between offspring requirements and food availability. However, reproduction is initiated much earlier than the time of maximum food requirement of the offspring. Individuals should therefore start reproduction in response to cues (the proximate factors), available in the environment of reproductive decision making, which predict the later environment of selection. With increasing spring temperatures over the past decades, vegetation phenology has advanced, with a concomitant advancement in the reproduction of some species at higher trophic levels. However, a mismatch between food abundance and offspring needs may occur if changes in the environment of decision making do not match those in the environment of selection. Date of egg laying in a great tit (Parus major) population has not advanced over a 23-year period, but selection for early laying has intensified. We believe that this is the first documented case of an adaptive response being hampered because a changing abiotic factor affects the environment in which a reproductive decision is made differently from the environment in which selection occurs.

Physiological status of naturally reared juvenile spring chinook salmon in the Yakima River: Seasonal dynamics and changes associated with smolting

USGS Publications Warehouse

Beckman, B.R.; Larsen, D.A.; Sharpe, C.; Lee-Pawlak, B.; Schreck, C.B.; Dickhoff, Walton W.

2000-01-01

Two year-classes of juvenile spring chinook salmon Oncorhynchus tshawytscha from the Yakima River, Washington, were sampled from July (3-4 months postemergence) through May (yearling smolt out-migration). Physiological characters measured included liver glycogen, body lipid, gill Na+-K+ ATPase, plasma thyroxine (T4), and plasma insulin-like growth factor-I (IGF-I). Distinct physiological changes were found that corresponded to season. Summer and fall were characterized by relatively high body lipid and condition factor. Winter was characterized by decreases in body lipid, condition factor, and plasma hormones. An increase in condition factor and body lipid was found in February and March. Finally, April and May were characterized by dramatic changes characteristic of smolting, including increased gill Na+-K+ ATPase activity, plasma T4, and IGF-I and decreased condition factor, body lipid, and liver glycogen. These results create a physiological template for juvenile spring chinook salmon in the drainage that provides a baseline for comparison with other years, populations, and life history types. In addition, this baseline provides a standard for controlled laboratory experiments and a target for fish culturists who rear juvenile spring chinook salmon for release from conservation hatcheries. The implications of these results for juvenile chinook salmon ecology and life history are discussed.