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Sample records for bird migration links

  1. Radar studies of bird migration

    NASA Technical Reports Server (NTRS)

    Williams, T. C.; Williams, J. M.

    1974-01-01

    Observations of bird migration with NASA radars were made at Wallops Island, Va. Simultaneous observations were made at a number of radar sites in the North Atlantic Ocean in an effort to discover what happened to those birds that were observed leaving the coast of North America headed toward Bermuda, the Caribbean and South America. Transatlantic migration, utilizing observations from a large number of radars is discussed. Detailed studies of bird movements at Wallops Island are presented.

  2. Bird Migration Echoes Observed by Polarimetric Radar

    NASA Astrophysics Data System (ADS)

    Minda, Haruya; Furuzawa, Fumie A.; Satoh, Shinsuke; Nakamura, Kenji

    A C-band polarimetric radar on Okinawa Island successfully observed large-scale bird migrations over the western Pacific Ocean. The birds generated interesting polarimetric signatures. This paper describes the signatures and speculates bird behavior.

  3. Migrating Birds and Tickborne Encephalitis Virus

    PubMed Central

    Lundkvist, Åke; Falk, Kerstin I.; Garpmo, Ulf; Bergström, Sven; Lindegren, Gunnel; Sjöstedt, Anders; Mejlon, Hans; Fransson, Thord; Haemig, Paul D.; Olsen, Björn

    2007-01-01

    During spring and autumn 2001, we screened 13,260 migrating birds at Ottenby Bird Observatory, Sweden, and found 3.4% were infested with ticks. Four birds, each a different passerine species, carried tickborne encephalitis virus (TBEV)–infected ticks (Ixodes ricinus). Migrating birds may play a role in the geographic dispersal of TBEV-infected ticks. PMID:17953095

  4. Endogenous timing factors in bird migration

    NASA Technical Reports Server (NTRS)

    Gwinner, E. G.

    1972-01-01

    Several species of warbler birds were observed in an effort to determine what initiates and terminates migration. Environmental and endogenous timing mechanisms were analyzed. The results indicate that endogenous stimuli are dominant factors for bird migration especially for long distances. It was concluded that environmental factors act as an assist mechanism.

  5. Factors influencing phototaxis in nocturnal migrating birds.

    PubMed

    Zhao, Xuebing; Chen, Mingyan; Wu, Zhaolu; Wang, Zijiang

    2014-12-01

    Many migratory bird species fly during the night (nocturnal migrants) and have been shown to display some phototaxis to artificial light. During 2006 to 2009, we investigated phototaxis in nocturnal migrants at Jinshan Yakou in Xinping County (N23°56', E101°30'; 2400 m above sea-level), and at the Niaowang Mountain in Funing County (N23°30', E105°35'; 1400 m above sea-level), both in the Yunnan Province of Southwest China. A total of 5069 birds, representing 129 species, were captured by mist-netting and artificial light. The extent of phototaxis effect on bird migration was examined during all four seasons, three phases of the moon, and under two weather conditions (mist and wind). Data were statistically analyzed to determine the extent to which these factors may impact phototaxis of nocturnal migrants. The results point to phototaxis in birds migrating in the spring and autumn, especially in the autumn. Furthermore, migrating birds were more readily attracted to artificial lights during nights with little moonlight, mist, and a headwind. Regardless of the initial orientation in which birds flew, either following the wind or against the wind, birds would always fly against the wind when flying towards the light. This study broadens our understanding of the nocturnal bird migration, potentially resulting in improved bird ringing practices, increased awareness, and better policies regarding bird protection. PMID:25483789

  6. A polar system of intercontinental bird migration.

    PubMed

    Alerstam, Thomas; Bäckman, Johan; Gudmundsson, Gudmundur A; Hedenström, Anders; Henningsson, Sara S; Karlsson, Håkan; Rosén, Mikael; Strandberg, Roine

    2007-10-22

    Studies of bird migration in the Beringia region of Alaska and eastern Siberia are of special interest for revealing the importance of bird migration between Eurasia and North America, for evaluating orientation principles used by the birds at polar latitudes and for understanding the evolutionary implications of intercontinental migratory connectivity among birds as well as their parasites. We used tracking radar placed onboard the ice-breaker Oden to register bird migratory flights from 30 July to 19 August 2005 and we encountered extensive bird migration in the whole Beringia range from latitude 64 degrees N in Bering Strait up to latitude 75 degrees N far north of Wrangel Island, with eastward flights making up 79% of all track directions. The results from Beringia were used in combination with radar studies from the Arctic Ocean north of Siberia and in the Beaufort Sea to make a reconstruction of a major Siberian-American bird migration system in a wide Arctic sector between longitudes 110 degrees E and 130 degrees W, spanning one-third of the entire circumpolar circle. This system was estimated to involve more than 2 million birds, mainly shorebirds, terns and skuas, flying across the Arctic Ocean at mean altitudes exceeding 1 km (maximum altitudes 3-5 km). Great circle orientation provided a significantly better fit with observed flight directions at 20 different sites and areas than constant geographical compass orientation. The long flights over the sea spanned 40-80 degrees of longitude, corresponding to distances and durations of 1400-2600 km and 26-48 hours, respectively. The birds continued from this eastward migration system over the Arctic Ocean into several different flyway systems at the American continents and the Pacific Ocean. Minimization of distances between tundra breeding sectors and northerly stopover sites, in combination with the Beringia glacial refugium and colonization history, seemed to be important for the evolution of this major

  7. Nocturnal bird migration in opaque clouds

    NASA Technical Reports Server (NTRS)

    Griffin, D. R.

    1972-01-01

    The use of a tracking radar to measure the flight paths of migrating birds on nights with opaque clouds is discussed. The effects of wind and lack of visual references are examined. The limitations of the radar observations are described, and samples of tracks obtained during radar observations are included. It is concluded that nonvisual mechanisms of orientation make it possible for birds to migrate in opaque clouds, but the exact nature of the sensory information cannot be determined by radar observations.

  8. Migration along orthodromic sun compass routes by arctic birds.

    PubMed

    Alerstam, T; Gudmundsson, G A; Green, M; Hedenstrom, A

    2001-01-12

    Flight directions of birds migrating at high geographic and magnetic latitudes can be used to test bird orientation by celestial or geomagnetic compass systems under polar conditions. Migration patterns of arctic shorebirds, revealed by tracking radar studies during an icebreaker expedition along the Northwest Passage in 1999, support predicted sun compass trajectories but cannot be reconciled with orientation along either geographic or magnetic loxodromes (rhumb lines). Sun compass routes are similar to orthodromes (great circle routes) at high latitudes, showing changing geographic courses as the birds traverse longitudes and their internal clock gets out of phase with local time. These routes bring the shorebirds from high arctic Canada to the east coast of North America, from which they make transoceanic flights to South America. The observations are also consistent with a migration link between Siberia and the Beaufort Sea region by way of sun compass routes across the Arctic Ocean. PMID:11209079

  9. Individuality in bird migration: routes and timing.

    PubMed

    Vardanis, Yannis; Klaassen, Raymond H G; Strandberg, Roine; Alerstam, Thomas

    2011-08-23

    The exploration of animal migration has entered a new era with individual-based tracking during multiple years. Here, we investigated repeated migratory journeys of a long-distance migrating bird, the marsh harrier Circus aeruginosus, in order to analyse the variation within and between individuals with respect to routes and timing. We found that there was a stronger individual repeatability in time than in space. Thus, the annual timing of migration varied much less between repeated journeys of the same individual than between different individuals, while there was considerable variation in the routes of the same individual on repeated journeys. The overall contrast in repeatability between time and space was unexpected and may be owing to strong endogenous control of timing, while short-term variation in environmental conditions (weather and habitat) might promote route flexibility. The individual variation in migration routes indicates that the birds navigate mainly by other means than detailed route recapitulation based on landmark recognition. PMID:21307045

  10. Analysis of Winds in Extreme Bird Migrations

    NASA Astrophysics Data System (ADS)

    Chapman, W.; Mills, C. M.; Gill, R. E.; Douglas, D.; Walsh, J. E.

    2013-12-01

    Bar-tailed Godwits feed in the nutrient-rich mud flats of western Alaska during the summer prior to attempting an extreme, non-stop migration of ~10,000 km lasting up to ten days and nights between late August and October to the Southern Hemisphere. In-situ measurements indicate that the birds make use of episodic near-surface tailwinds (north/northeast winds) on the backsides of low-pressure systems passing through the Gulf of Alaska to facilitate their trip. Projections of future climate from GCMs indicate northward shifts in these low-pressure systems, likely making a trip that already pushes the physical limits of these birds (in the present climate) more arduous. A generalized tailwind index is created in order to quantify the near-surface winds experienced during a typical migration season, providing clarity on the frequency and duration of beneficial tailwind episodes and facilitating comparison between present climate and paleoclimate scenarios. A comparison of our tailwind index to in-situ measurements verifies that the birds generally depart Alaska at advantageous times. Examination of past climate for possible alternate migration pathways provides useful information concerning the future of these birds. Spatial patterns of future wind and storm track shifts are consistent with more difficult migrations during the next century.

  11. Lekking birds in a tropical forest forego sex for migration

    PubMed Central

    Boyle, W. Alice; Guglielmo, Christopher G.; Hobson, Keith A.; Norris, D. Ryan

    2011-01-01

    Facultative, partially migratory animals provide a contemporary window into the evolution of migration, offering rare opportunities to examine the life-history trade-offs associated with migration. For the first time, to our knowledge, we describe the nature of these trade-offs, using a lek-breeding tropical bird, the white-ruffed manakin (Corapipo altera). Previous evidence indicated that weather drives post-breeding migration to lower elevations bringing condition-related benefits. Using elevation-sensitive stable isotope measurements and more than 1200 h of behavioural observations, we show that male manakins which migrate incur costs of diminished social status and matings with females the following breeding season. Because migratory tendency depends on inter-annual variation in weather, physical costs of displays and breeding prospects the following year, migratory decisions are subject to both natural and sexual selection, with the outcome of such decisions linked to changing climatic regimes. PMID:21471048

  12. Flight mode affects allometry of migration range in birds.

    PubMed

    Watanabe, Yuuki Y

    2016-08-01

    Billions of birds migrate to exploit seasonally available resources. The ranges of migration vary greatly among species, but the underlying mechanisms are poorly understood. I hypothesise that flight mode (flapping or soaring) and body mass affect migration range through their influence on flight energetics. Here, I compiled the tracks of migratory birds (196 species, weighing 12-10 350 g) recorded by electronic tags in the last few decades. In flapping birds, migration ranges decreased with body mass, as predicted from rapidly increasing flight cost with increasing body mass. The species with higher aspect ratio and lower wing loading had larger migration ranges. In soaring birds, migration ranges were mass-independent and larger than those of flapping birds, reflecting their low flight costs irrespective of body mass. This study demonstrates that many animal-tracking studies are now available to explore the general patterns and the underlying mechanisms of animal migration. PMID:27305867

  13. Modeling Bird Migration under Climate Change: A Mechanistic Approach

    NASA Technical Reports Server (NTRS)

    Smith, James A.

    2009-01-01

    How will migrating birds respond to changes in the environment under climate change? What are the implications for migratory success under the various accelerated climate change scenarios as forecast by the Intergovernmental Panel on Climate Change? How will reductions or increased variability in the number or quality of wetland stop-over sites affect migratory bird species? The answers to these questions have important ramifications for conservation biology and wildlife management. Here, we describe the use of continental scale simulation modeling to explore how spatio-temporal changes along migratory flyways affect en-route migration success. We use an individually based, biophysical, mechanistic, bird migration model to simulate the movement of shorebirds in North America as a tool to study how such factors as drought and wetland loss may impact migratory success and modify migration patterns. Our model is driven by remote sensing and climate data and incorporates important landscape variables. The energy budget components of the model include resting, foraging, and flight, but presently predation is ignored. Results/Conclusions We illustrate our model by studying the spring migration of sandpipers through the Great Plains to their Arctic breeding grounds. Why many species of shorebirds have shown significant declines remains a puzzle. Shorebirds are sensitive to stop-over quality and spacing because of their need for frequent refueling stops and their opportunistic feeding patterns. We predict bird "hydrographs that is, stop-over frequency with latitude, that are in agreement with the literature. Mean stop-over durations predicted from our model for nominal cases also are consistent with the limited, but available data. For the shorebird species simulated, our model predicts that shorebirds exhibit significant plasticity and are able to shift their migration patterns in response to changing drought conditions. However, the question remains as to whether this

  14. From a Bird's Eye View: An Interdisciplinary Approach to Migration

    ERIC Educational Resources Information Center

    Benson, Juliann

    2007-01-01

    Inspiring students to learn about birds can be a daunting task--students see birds just about every day and often don't think twice about them. The activity described here is designed to excite students to "become" birds. Students are asked to create a model and tell the life story of a bird by mapping its migration pattern. (Contains 6 figures, 6…

  15. 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.

  16. 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.

  17. MITES (FAMILY TROMBICULIDAE) PARASITIZING BIRDS MIGRATING FROM AFRICA TO EUROPE.

    PubMed

    VARMA, M G

    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

  18. The use of low-level jets by migrating birds.

    PubMed

    Liechti, F; Schaller, E

    1999-11-01

    Birds flying at high altitudes have occasionally been observed above mountain areas and the open sea. For the first time the regular occurrence of migrating birds flying within a low-level jet at heights of 5000 to almost 9000 m asl. have now been verified by radar above the Negev desert in southern Israel. Tracks of rather large birds with wing-beat frequencies of 5-6 Hz were measured to have horizontal flight speeds up to 50 m/s. Visual observations, seasonal occurrence, and wing-beat frequencies allowed to associate them with small species of the order Ciconiiformes (mainly Ardeidae) and possibly with members of the Laro-Limicolae group. These wading birds seem prone to continuing nocturnal migration into daytime under favorable conditions and to make use of high wind speeds at sometimes extreme altitudes. PMID:10551952

  19. 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. PMID:26791618

  20. Helminths in migrating and wintering birds recorded in Poland.

    PubMed

    Okulewicz, Anna

    2014-01-01

    Among 544 species of helminths recorded in birds on the territory of Poland, probably some (17 species of Digenea, 21 Cestoda, 13 Nematoda and 5 Acanthocephala) do not belong to the native fauna. These are helminths obtained in mature stage from birds shortly after their arrival from wintering grounds, or from foreign populations wintering with us, or being in the course of spring or autumn migration through the area of our country. In general, these helminth species have been recorded sporadically in the examined birds. PMID:24930242

  1. Tracking radar studies of bird migration

    NASA Technical Reports Server (NTRS)

    Williams, T. C.; Williams, J. M.; Teal, J. M.; Kanwisher, J. W.

    1972-01-01

    The application of tracking radar for determining the flight paths of migratory birds is discussed. The effects produced by various meteorological parameters are described. Samples of radar scope presentations obtained during tracking studies are presented. The characteristics of the radars and their limitations are examined.

  2. Modeling Bird Migration in Changing Habitats: Space-based Ornithology using Satellites and GIS

    NASA Technical Reports Server (NTRS)

    Smith, James A.; Deppe, Jill L.

    2008-01-01

    Understanding bird migration and avian biodiversity is one of the most compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties presenting challenges in both geographic space and time. Space based technology, coupled with geographic information systems, 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 NASA, 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. In our work, we use individual organism biophysical models and drive these models with satellite observations and numerical weather predictions of the spatio-temporal gradients in climate and habitat. Geographic information system technology comprises one component of our overall simulation framework, especially for characterizing the changing habitats and conditions encountered by en-route migratory birds. Simulation provides a tool for studying bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. Such models yield an understanding of how a migratory flyway and its component habitats function as a whole and link stop-over ecology with biological conservation and management. We present examples of our simulation of shorebirds, principally, pectoral sandpipers, along the central flyways of the United States and Canada from the Gulf of Mexico to Alaska.

  3. Postexercise ketosis in night-migrating passerine birds.

    PubMed

    Jenni-Eiermann, S; Jenni, L

    2001-01-01

    This study investigated the postexercise metabolism of six species of free-living, night-migrating passerine birds (European robin, pied flycatcher, wheatear, redstart, blackcap, and garden warbler). The birds were caught during autumn migration out of their nocturnal flight, and their metabolism changed from a fasting, highly active state to a fasting, resting state. Concentrations of six plasma metabolites of the fat, carbohydrate, and protein metabolism were measured during up to 10 h of recovery time. The metabolic changes indicated a biphasic pattern: (a) a quick first response to the reduced energy demands during the first 20 min of recovery, suggested by an increase and subsequent decrease of free fatty acid levels, and (b) subsequently, a postexercise ketosis and a reduction of lipolysis and proteolysis, suggested by high beta-hydroxy-butyrate and low free fatty acid, glycerol, triglyceride, and uric acid levels. This metabolic pattern differs from that of humans and rats, in which ketosis starts immediately postexercise or is absent in trained subjects. Since migrating birds are naturally adapted to endurance exercise, it is hypothesized that the high and long-lasting postexercise ketosis does not evoke physiological problems (such as hypoglycemia) but, by contrast, increases the ability of birds to rely on lipids, to a very high extent, during and after flight and decreases the dependence on glucose and glucogenic amino acids. Differences between species in fat stores and metabolic pattern support this hypothesis. PMID:11226017

  4. Theoretical approaches to bird migration. The white stork as a case study

    NASA Astrophysics Data System (ADS)

    Kölzsch, A.; Blasius, B.

    2008-04-01

    Birds are often considered to be one of the best studied groups of organisms. However, only a few investigations have been devoted to a theoretical analysis of avian migration patterns in time and space. This paper is meant to be a first step into this direction. We start by presenting different types of observational data sets that are available and discuss their advantages and disadvantages for use in quantitative analysis of bird movement and migration. Based on ring recovery and satellite telemetry data we perform a statistical analysis of the migratory patterns of the white stork Ciconia ciconia. We find that standard methods from random walk theory can be applied, but have to be carefully interpreted and possibly modified to analyse migration movement data which are dominated by seasonal drift. Our analysis reveals two different modes of movement fast, directed migration and slow, undirected resting. Furthermore, we present a conceptional network model of avian migration. In our model a number of discrete breeding, resting and wintering habitats are linked by migration in the form of seasonally driven transition probabilities that are described by a unimodal circular function of time. Our study emphasises the need for more rigorous quantitative data analysis and mathematical modelling to gain a better understanding of the dynamic processes of avian migration.

  5. Population decline is linked to migration route in the Common Cuckoo

    PubMed Central

    Hewson, Chris M.; Thorup, Kasper; Pearce-Higgins, James W.; Atkinson, Philip W.

    2016-01-01

    Migratory species are in rapid decline globally. Although most mortality in long-distance migrant birds is thought to occur during migration, evidence of conditions on migration affecting breeding population sizes has been completely lacking. We addressed this by tracking 42 male Common Cuckoos from the rapidly declining UK population during 56 autumn migrations in 2011–14. Uniquely, the birds use two distinct routes to reach the same wintering grounds, allowing assessment of survival during migration independently of origin and destination. Mortality up to completion of the Sahara crossing (the major ecological barrier encountered in both routes) is higher for birds using the shorter route. The proportion of birds using this route strongly correlates with population decline across nine local breeding populations. Knowledge of variability in migratory behaviour and performance linked to robust population change data may therefore be necessary to understand population declines of migratory species and efficiently target conservation resources. PMID:27433888

  6. Population decline is linked to migration route in the Common Cuckoo.

    PubMed

    Hewson, Chris M; Thorup, Kasper; Pearce-Higgins, James W; Atkinson, Philip W

    2016-01-01

    Migratory species are in rapid decline globally. Although most mortality in long-distance migrant birds is thought to occur during migration, evidence of conditions on migration affecting breeding population sizes has been completely lacking. We addressed this by tracking 42 male Common Cuckoos from the rapidly declining UK population during 56 autumn migrations in 2011-14. Uniquely, the birds use two distinct routes to reach the same wintering grounds, allowing assessment of survival during migration independently of origin and destination. Mortality up to completion of the Sahara crossing (the major ecological barrier encountered in both routes) is higher for birds using the shorter route. The proportion of birds using this route strongly correlates with population decline across nine local breeding populations. Knowledge of variability in migratory behaviour and performance linked to robust population change data may therefore be necessary to understand population declines of migratory species and efficiently target conservation resources. PMID:27433888

  7. Migration timing and its determinants for nocturnal migratory birds during autumn migration.

    PubMed

    La Sorte, Frank A; Hochachka, Wesley M; Farnsworth, Andrew; Sheldon, Daniel; Fink, Daniel; Geevarghese, Jeffrey; Winner, Kevin; Van Doren, Benjamin M; Kelling, Steve

    2015-09-01

    1. Migration is a common strategy used by birds that breed in seasonal environments, and multiple environmental and biological factors determine the timing of migration. How these factors operate in combination during autumn migration, which is considered to be under weaker time constraints relative to spring migration, is not clear. 2. Here, we examine the patterns and determinants of migration timing for nocturnal migrants during autumn migration in the north-eastern USA using nocturnal reflectivity data from 12 weather surveillance radar stations and modelled diurnal probability of occurrence for 142 species of nocturnal migrants. We first model the capacity of seasonal atmospheric conditions (wind and precipitation) and ecological productivity (vegetation greenness) to predict autumn migration intensity. We then test predictions, formulated under optimal migration theory, on how migration timing should be related to assemblage-level estimates of body size and total migration distance within the context of dietary guild (insectivore and omnivore) and level of dietary plasticity during autumn migration. 3. Our results indicate seasonal declines in ecological productivity delineate the beginning and end of peak migration, whose intensity is best predicted by the velocity of winds at migration altitudes. Insectivorous migrants departed earlier in the season and, consistent with our predictions, large-bodied and long-distance insectivorous migrants departed the earliest. Contrary to our predictions, large-bodied and some long-distance omnivorous migrants departed later in the season, patterns that were replicated in part by insectivorous migrants that displayed dietary plasticity during autumn migration. 4. Our findings indicate migration timing in the region is dictated by optimality strategies, modified based on the breadth and flexibility of migrant's foraging diets, with declining ecological productivity defining possible resource thresholds during which

  8. Methods of quantitative and qualitative analysis of bird migration with a tracking radar

    NASA Technical Reports Server (NTRS)

    Bruderer, B.; Steidinger, P.

    1972-01-01

    Methods of analyzing bird migration by using tracking radar are discussed. The procedure for assessing the rate of bird passage is described. Three topics are presented concerning the grouping of nocturnal migrants, the velocity of migratory flight, and identification of species by radar echoes. The height and volume of migration under different weather conditions are examined. The methods for studying the directions of migration and the correlation between winds and the height and direction of migrating birds are presented.

  9. Seasonal changes in the altitudinal distribution of nocturnally migrating birds during autumn migration.

    PubMed

    La Sorte, Frank A; Hochachka, Wesley M; Farnsworth, Andrew; Sheldon, Daniel; Van Doren, Benjamin M; Fink, Daniel; Kelling, Steve

    2015-12-01

    Wind plays a significant role in the flight altitudes selected by nocturnally migrating birds. At mid-latitudes in the Northern Hemisphere, atmospheric conditions are dictated by the polar-front jet stream, whose amplitude increases in the autumn. One consequence for migratory birds is that the region's prevailing westerly winds become progressively stronger at higher migration altitudes. We expect this seasonality in wind speed to result in migrants occupying progressively lower flight altitudes, which we test using density estimates of nocturnal migrants at 100 m altitudinal intervals from 12 weather surveillance radar stations located in the northeastern USA. Contrary to our expectations, median migration altitudes deviated little across the season, and the variance was lower during the middle of the season and higher during the beginning and especially the end of the season. Early-season migrants included small- to intermediate-sized long-distance migrants in the orders Charadriiformes and Passeriformes, and late-season migrants included large-bodied and intermediate-distance migrants in the order Anseriformes. Therefore, seasonality in the composition of migratory species, and related variation in migration strategies and behaviours, resulted in a convex-concave bounded distribution of migration altitudes. Our results provide a basis for assessing the implications for migratory bird populations of changes in mid-latitude atmospheric conditions probably occurring under global climate change. PMID:27019724

  10. Seasonal changes in the altitudinal distribution of nocturnally migrating birds during autumn migration

    PubMed Central

    La Sorte, Frank A.; Hochachka, Wesley M.; Farnsworth, Andrew; Sheldon, Daniel; Van Doren, Benjamin M.; Fink, Daniel; Kelling, Steve

    2015-01-01

    Wind plays a significant role in the flight altitudes selected by nocturnally migrating birds. At mid-latitudes in the Northern Hemisphere, atmospheric conditions are dictated by the polar-front jet stream, whose amplitude increases in the autumn. One consequence for migratory birds is that the region’s prevailing westerly winds become progressively stronger at higher migration altitudes. We expect this seasonality in wind speed to result in migrants occupying progressively lower flight altitudes, which we test using density estimates of nocturnal migrants at 100 m altitudinal intervals from 12 weather surveillance radar stations located in the northeastern USA. Contrary to our expectations, median migration altitudes deviated little across the season, and the variance was lower during the middle of the season and higher during the beginning and especially the end of the season. Early-season migrants included small- to intermediate-sized long-distance migrants in the orders Charadriiformes and Passeriformes, and late-season migrants included large-bodied and intermediate-distance migrants in the order Anseriformes. Therefore, seasonality in the composition of migratory species, and related variation in migration strategies and behaviours, resulted in a convex–concave bounded distribution of migration altitudes. Our results provide a basis for assessing the implications for migratory bird populations of changes in mid-latitude atmospheric conditions probably occurring under global climate change. PMID:27019724

  11. 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

  12. The conservation value of residential yards: linking birds and people.

    PubMed

    Lerman, Susannah B; Warren, Paige S

    2011-06-01

    Urbanization is recognized as one of the greatest threats to biodiversity throughout the world. However, the vegetation within an urbanized landscape is diverse and includes a variety of native and exotic plant species. This variation allows for testing whether certain landscape designs outperform others in the support of native biodiversity. Residential yards represent a large component of an urban landscape and, if managed collectively for birds and other wildlife, could offset some of the negative effects of urbanization. In addition, many urbanites have their primary interaction with the natural world in their front and back yards. Therefore, ensuring positive wildlife experiences for them is essential in promoting urban biodiversity. At the Central Arizona-Phoenix Long-Term Ecological Research site we tested the efficacy of native landscaping in residential yards in attracting native birds. We also explored the links between socioeconomic factors, landscape designs, and urban gradient measurements with the urban bird communities. A redundancy analysis suggested that native desert bird species increased in abundance in neighborhoods with desert landscaping designs, neighborhoods closer to large desert tracts, and higher-income neighborhoods. Variance partitioning showed that collectively these three sets of environmental variables explained almost 50% of the variation in the urban bird community. Results suggested racial and economic inequities in access to biodiversity, whereby predominantly Hispanic and lower-income neighborhoods had fewer native birds. We also found that residents' satisfaction with bird diversity was positively correlated with actual bird diversity. Our study provides new insights into the relative importance of socioeconomic variables and common urban ecological measurements in explaining urban bird communities. Urban planners can use this information to develop residential landscapes that support the well-being of both birds and people

  13. The effects of urbanization on migrating birds on the western shore of Lake Michigan

    EPA Science Inventory

    Urbanization continues to transform the global landscape at an alarming rate, yet most ecological studies focus on more natural ecosystems. Many cities lie within major flyways for migrating birds, and our knowledge of how urbanization affects migrating birds is severely lacking....

  14. Bird migration flight altitudes studied by a network of operational weather radars.

    PubMed

    Dokter, Adriaan M; Liechti, Felix; Stark, Herbert; Delobbe, Laurent; Tabary, Pierre; Holleman, Iwan

    2011-01-01

    A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume of weather radar sites in The Netherlands, Belgium and France for a full migration season during autumn 2007 and spring 2008. We show that weather radar can extract near real-time bird density altitude profiles that closely correspond to the density profiles measured by dedicated bird radar. Doppler weather radar can thus be used as a reliable sensor for quantifying bird densities aloft in an operational setting, which--when extended to multiple radars--enables the mapping and continuous monitoring of bird migration flyways. By applying the automated method to a network of weather radars, we observed how mesoscale variability in weather conditions structured the timing and altitude profile of bird migration within single nights. Bird density altitude profiles were observed that consisted of multiple layers, which could be explained from the distinct wind conditions at different take-off sites. Consistently lower bird densities are recorded in The Netherlands compared with sites in France and eastern Belgium, which reveals some of the spatial extent of the dominant Scandinavian flyway over continental Europe. PMID:20519212

  15. Bird migration flight altitudes studied by a network of operational weather radars

    PubMed Central

    Dokter, Adriaan M.; Liechti, Felix; Stark, Herbert; Delobbe, Laurent; Tabary, Pierre; Holleman, Iwan

    2011-01-01

    A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume of weather radar sites in The Netherlands, Belgium and France for a full migration season during autumn 2007 and spring 2008. We show that weather radar can extract near real-time bird density altitude profiles that closely correspond to the density profiles measured by dedicated bird radar. Doppler weather radar can thus be used as a reliable sensor for quantifying bird densities aloft in an operational setting, which—when extended to multiple radars—enables the mapping and continuous monitoring of bird migration flyways. By applying the automated method to a network of weather radars, we observed how mesoscale variability in weather conditions structured the timing and altitude profile of bird migration within single nights. Bird density altitude profiles were observed that consisted of multiple layers, which could be explained from the distinct wind conditions at different take-off sites. Consistently lower bird densities are recorded in The Netherlands compared with sites in France and eastern Belgium, which reveals some of the spatial extent of the dominant Scandinavian flyway over continental Europe. PMID:20519212

  16. Phenological synchrony of bird migration with tree flowering at desert riparian stopover sites

    USGS Publications Warehouse

    Kellermann, Jherime L.; Van Riper, Charles, III

    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.

  17. Characteristics of important stopover locations for migrating birds: remote sensing with radar in the Great Lakes basin.

    PubMed

    Bonter, David N; Gauthreaux, Sidney A; Donovan, Therese M

    2009-04-01

    A preliminary stage in developing comprehensive conservation plans involves identifying areas used by the organisms of interest. The areas used by migratory land birds during temporal breaks in migration (stopover periods) have received relatively little research and conservation attention. Methodologies for identifying stopover sites across large geographic areas have been, until recently, unavailable. Advances in weather-radar technology now allow for evaluation of bird migration patterns at large spatial scales. We analyzed radar data (WSR-88D) recorded during spring migration in 2000 and 2001 at 6 sites in the Great Lakes basin (U.S.A.). Our goal was to link areas of high migrant activity with the land-cover types and landscape contexts corresponding to those areas. To characterize the landscapes surrounding stopover locations, we integrated radar and land-cover data within a geographic information system. We compared landscape metrics within 5 km of areas that consistently hosted large numbers of migrants with landscapes surrounding randomly selected areas that were used by relatively few birds during migration. Concentration areas were characterized by 1.2 times more forest cover and 9.3 times more water cover than areas with little migrant activity. We detected a strong negative relationship between activity of migratory birds and agricultural land uses. Examination of individual migration events confirmed the importance of fragments of forested habitat in highly altered landscapes and highlighted large concentrations of birds departing from near-shore terrestrial areas in the Great Lakes basin. We conclude that conservation efforts can be more effectively targeted through intensive analysis of radar imagery. PMID:18983598

  18. Bird species migration ratio in East Asia, Australia, and surrounding islands

    NASA Astrophysics Data System (ADS)

    Kuo, Yiliang; Lin, Da-Li; Chuang, Fu-Man; Lee, Pei-Fen; Ding, Tzung-Su

    2013-08-01

    Bird migration and its relationship with the contemporary environment have attracted long-term discussion. We calculated the avian migration ratio (the proportion of breeding species that migrate) in the areas from 70°E to 180°E and examined its relationship with the annual ranges of ambient temperature, primary productivity (estimated by the Enhanced Vegetation Index), and precipitation, along with island isolation and elevational range. The avian migration ratio increased with increasing latitude in general but varied greatly between the two hemispheres. Additionally, it showed minimal differences between continents and islands. Our analyses revealed that the seasonality of ambient temperature, which represents the energy expenditure of birds, is the dominant factor in determining bird species migration. Seasonality in primary productivity and other environmental factors play an indirect or limited role in bird species migration. The lower avian migration ratio in the Southern Hemisphere can be attributed to its paleogeographical isolation, stable paleoclimate, and warm contemporary environment. Under current trends of global warming, our findings should lead to further studies of the impact of warming on bird migration.

  19. Brain regions associated with visual cues are important for bird migration.

    PubMed

    Vincze, Orsolya; Vágási, Csongor I; Pap, Péter L; Osváth, Gergely; Møller, Anders Pape

    2015-11-01

    Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration. PMID:26538538

  20. Understanding soaring bird migration through interactions and decisions at the individual level.

    PubMed

    van Loon, E E; Shamoun-Baranes, J; Bouten, W; Davis, S L

    2011-02-01

    Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel networks is still very limited. To start investigating these aspects we developed an individual-based simulation model that describes the local interactions between birds and their environment during their migratory flight, leading to emergent patterns at larger scales. The aim of our model is to identify likely decision rules with respect to thermal selection and navigation. After explaining the model, it is applied to analyse the migration of white storks (Ciconia ciconia) over part of its migration domain. A model base-run is accompanied by a sensitivity analysis. It appears that social interactions lead to the use of fewer thermals and slight increases in distance travelled. Possibilities for different model extensions and further model application are discussed. PMID:21075120

  1. Strategic Grassland Bird Conservation throughout the annual cycle: Linking policy alternatives, landowner decisions, and biological population outcomes

    USGS Publications Warehouse

    Drum, Ryan G.; Ribic, Christine; Koch, Katie; Lonsdorf, Eric V.; Grant, Edward C.; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, D.C., Jr.; Rideout, Catherine; Sample, David W.

    2015-01-01

    Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds.

  2. Strategic Grassland Bird Conservation throughout the Annual Cycle: Linking Policy Alternatives, Landowner Decisions, and Biological Population Outcomes.

    PubMed

    Drum, Ryan G; Ribic, Christine A; Koch, Katie; Lonsdorf, Eric; Grant, Evan; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, David C; Rideout, Catherine; Sample, David

    2015-01-01

    Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds. PMID:26569108

  3. Strategic Grassland Bird Conservation throughout the Annual Cycle: Linking Policy Alternatives, Landowner Decisions, and Biological Population Outcomes

    PubMed Central

    Drum, Ryan G.; Ribic, Christine A.; Koch, Katie; Lonsdorf, Eric; Grant, Evan; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, David C.; Rideout, Catherine; Sample, David

    2015-01-01

    Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds. PMID:26569108

  4. Impact of Spring Bird Migration on the Range Expansion of Ixodes scapularis Tick Population.

    PubMed

    Wu, Xiaotian; Röst, Gergely; Zou, Xingfu

    2016-01-01

    Many observational studies suggest that seasonal migratory birds play an important role in spreading Ixodes scapularis, a vector of Lyme disease, along their migratory flyways, and they are believed to be responsible for geographic range expansion of I. scapularis in Canada. However, the interplay between the dynamics of I. scapularis on land and migratory birds in the air is not well understood. In this study, we develop a periodic delay meta-population model which takes into consideration the local landscape for tick reproduction within patches and the times needed for ticks to be transported by birds between patches. Assuming that the tick population is endemic in the source region, we find that bird migration may boost an already established tick population at the subsequent region and thus increase the risk to humans, or bird migration may help ticks to establish in a region where the local landscape is not appropriate for ticks to survive in the absence of bird migration, imposing risks to public health. This theoretical study reveals that bird migration plays an important role in the geographic range expansion of I. scapularis, and therefore our findings may suggest some strategies for Lyme disease prevention and control. PMID:26688012

  5. Ticks (Ixodidae) on birds migrating from Europe and Asia to Africa, 1959-61*

    PubMed Central

    Hoogstraal, Harry; Kaiser, Makram N.; Traylor, Melvin A.; Guindy, Ezzat; Gaber, Sobhy

    1963-01-01

    The need for imaginative thinking and research in the epidemiology of diseases transmitted by arthropods is made manifest by new views of the longevity and host ranges of arthropod-borne viruses, as well as by other biological and medical phenomena. Among these is the intercontinental transport of ticks by migrating birds. During the fall migration periods of 1959, 1960 and 1961, 32 086 birds (comprising 72 forms) were examined for ticks in Egypt while en route from Asia and eastern Europe to tropical Africa. Of these, 40 forms, represented by 31 434 birds, were tick-infested. The bird hosts, numbering 1040 (3.31% of the tick-infested bird forms examined), bore 1761 ticks, or 1.69 ticks per host. Common ticks taken were Hyalomma m. marginatum, Haemaphysalis punctata, and Ixodes ricinus. Ixodes frontalis and Hyalomma aegyptium were less common and Haemaphysalis sulcata, H. otophila, and H. pavlovskyi were rare. The common tick species are known to be reservoirs and vectors of pathogens causing a number of human and animal diseases in Europe and Asia. Several of the bird hosts have also been incriminated as reservoirs in their summer ranges. Over 20 strains of pathogenic viruses were isolated from these birds and their ticks in Egypt in the 1961 fall migration period. The most difficult problems in investigations such as this in many parts of the world are taxonomic ones: the correct identification of bird hosts, of immature stages of ticks and of viruses. PMID:13961632

  6. Temporal changes in the structure of a plant-frugivore network are influenced by bird migration and fruit availability

    PubMed Central

    Andresen, Ellen; Díaz-Castelazo, Cecilia

    2016-01-01

    results revealed that migration and fruit richness explain the temporal variations in network size, connectance, nestedness and interaction strength asymmetry. On the other hand, fruit abundance only explained connectance and nestedness. Discussion. By means of a fine-resolution temporal analysis, we evidenced for the first time how temporal changes in the interaction network structure respond to the arrival of migratory species into the system and to fruit availability. Additionally, few migratory bird species are important links for structuring networks, while most of them were peripheral species. We showed the relevance of studying bird–plant interactions at fine temporal scales, considering changing scenarios of species composition with a quantitative network approach. PMID:27330852

  7. On a probabilistic model for the numerical estimation of nocturnal migration of birds.

    PubMed

    Baushev, Alexey Nickolayevich; Sinelschikova, Alexandra

    2007-01-01

    The study of nocturnal bird migration by cone methods of observation has a century-long history but has continued to be used up to the present. To describe the flux and estimate the number of passing birds a probabilistic model is proposed. This model is based on the concept of dynamic Poisson ensemble of points in appropriate phase space and has two parameters. One is scalar and the other one is functional. We constructed consistent estimations of these parameters and discuss their use for the numerical estimation of the flux of birds observed in a narrow light cone generated by the bright lunar disk and formed by an open angle of telescope. Selection on the same type of birds was suggested as the necessary condition for the model application. Ground speed of each bird was introduced into the model as a new but obligatory value determining the quantification of the flux of bird. PMID:16546224

  8. Comparative use of riparian corridors and oases by migrating birds in southeast Arizona

    USGS Publications Warehouse

    Skagen, S.K.; Melcher, C.P.; Howe, W.H.; Knopf, F.L.

    1998-01-01

    The relative importance of cottonwood-willow riparian corridors and isolated oases to land birds migrating across southeastern Arizona was evaluated during four spring migrations, 1989 to 1994, based on patterns of species richness, relative abundance, density, and body condition of birds. We surveyed birds in 13 study sites ranging in size and connectivity from small isolated patches to extensive riparian forest, sampled vegetation and insects, and captured birds in mistnets. The continuous band of riparian vegetation along the San Pedro River does not appear to be functioning as a corridor for many migrating species, although it may for a few, namely Yellow-breasted Chats (Icteria virens), Summer Tanagers (Piranga rubra), and Northern Rough-winged Swallows (Steldigopteryx serripennis), which account for fewer than 10% of the individuals migrating through the area. Small, isolated oases hosted more avian species than the corridor sites, and the relative abundances of most migrating birds did not differ between sites relative to size-connectivity. There were few differences in between-year variability in the relative abundances of migrating birds between corridor and oasis sites. Between-year variability decreased with overall abundance of species and was greater for species with breeding ranges that centered north of 50??N latitude. Body condition of birds did not differ relative to the size-connectivity of the capture site, but individuals of species with more northerly breeding ranges had more body fat than species that breed nearby. Peak migration densities of several bird species far exceeded breeding densities reported for the San Pedro River, suggesting that large components of these species were en route migrants. Peak densities of Yellow Warblers (Dendroica petechia) reached 48.0 birds/ha, of Wilson's Warblers (Wilsonia pusilla) 33.7 birds/ha, and of Yellow-rumped Warblers (D. coronata) 30.1 birds/ha. Riparian vegetation is limited in extent in the

  9. Modelling the progression of bird migration with conditional autoregressive models applied to ringing data.

    PubMed

    Ambrosini, Roberto; Borgoni, Riccardo; Rubolini, Diego; Sicurella, Beatrice; Fiedler, Wolfgang; Bairlein, Franz; Baillie, Stephen R; Robinson, Robert A; Clark, Jacquie A; Spina, Fernando; Saino, Nicola

    2014-01-01

    Migration is a fundamental stage in the life history of several taxa, including birds, and is under strong selective pressure. At present, the only data that may allow for both an assessment of patterns of bird migration and for retrospective analyses of changes in migration timing are the databases of ring recoveries. We used ring recoveries of the Barn Swallow Hirundo rustica collected from 1908-2008 in Europe to model the calendar date at which a given proportion of birds is expected to have reached a given geographical area ('progression of migration') and to investigate the change in timing of migration over the same areas between three time periods (1908-1969, 1970-1990, 1991-2008). The analyses were conducted using binomial conditional autoregressive (CAR) mixed models. We first concentrated on data from the British Isles and then expanded the models to western Europe and north Africa. We produced maps of the progression of migration that disclosed local patterns of migration consistent with those obtained from the analyses of the movements of ringed individuals. Timing of migration estimated from our model is consistent with data on migration phenology of the Barn Swallow available in the literature, but in some cases it is later than that estimated by data collected at ringing stations, which, however, may not be representative of migration phenology over large geographical areas. The comparison of median migration date estimated over the same geographical area among time periods showed no significant advancement of spring migration over the whole of Europe, but a significant advancement of autumn migration in southern Europe. Our modelling approach can be generalized to any records of ringing date and locality of individuals including those which have not been recovered subsequently, as well as to geo-referenced databases of sightings of migratory individuals. PMID:25047331

  10. Bird migration advances more strongly in urban environments.

    PubMed

    Tryjanowski, Piotr; Sparks, Tim H; Kuźniak, Stanisław; Czechowski, Paweł; Jerzak, Leszek

    2013-01-01

    Urbanization has a marked effect on the reproduction and other ecological and behavioural traits of many living organisms, including birds. In migrant birds, survival and reproductive output is influenced by the (mis)synchronization of arrival with the availability of resources. Many recent studies have shown that arrival timing is related to temperatures en-route and at destination. Because urban areas are "heat islands", with higher temperatures that influence earlier vegetation and invertebrate development, this should favour earlier arrival of migrant birds to cities rather than to rural areas. In this paper, we analysed differences between urban and rural habitats in mean dates and trends of first arrival dates of 18 species of migratory bird species in western Poland during 1983-2010. For many individual species, and overall, mean first arrival date was significantly earlier in rural areas than in urban areas (significant for 11 species). However, the trend towards earlier first arrival dates was stronger in urban areas for 15 of the 18 species (significantly stronger in four species). Consequently, arrival dates in urban areas are fast approaching, or have now matched or passed those in rural areas. These findings suggest that recent environmental changes may have more rapidly changed the migratory habits of birds occupying urban habitats than those occupying rural habitats. PMID:23667625

  11. Bird Migration Advances More Strongly in Urban Environments

    PubMed Central

    Tryjanowski, Piotr; Sparks, Tim H.; Kuźniak, Stanisław; Czechowski, Paweł; Jerzak, Leszek

    2013-01-01

    Urbanization has a marked effect on the reproduction and other ecological and behavioural traits of many living organisms, including birds. In migrant birds, survival and reproductive output is influenced by the (mis)synchronization of arrival with the availability of resources. Many recent studies have shown that arrival timing is related to temperatures en-route and at destination. Because urban areas are “heat islands”, with higher temperatures that influence earlier vegetation and invertebrate development, this should favour earlier arrival of migrant birds to cities rather than to rural areas. In this paper, we analysed differences between urban and rural habitats in mean dates and trends of first arrival dates of 18 species of migratory bird species in western Poland during 1983–2010. For many individual species, and overall, mean first arrival date was significantly earlier in rural areas than in urban areas (significant for 11 species). However, the trend towards earlier first arrival dates was stronger in urban areas for 15 of the 18 species (significantly stronger in four species). Consequently, arrival dates in urban areas are fast approaching, or have now matched or passed those in rural areas. These findings suggest that recent environmental changes may have more rapidly changed the migratory habits of birds occupying urban habitats than those occupying rural habitats. PMID:23667625

  12. Modelling the Progression of Bird Migration with Conditional Autoregressive Models Applied to Ringing Data

    PubMed Central

    Ambrosini, Roberto; Borgoni, Riccardo; Rubolini, Diego; Sicurella, Beatrice; Fiedler, Wolfgang; Bairlein, Franz; Baillie, Stephen R.; Robinson, Robert A.; Clark, Jacquie A.; Spina, Fernando; Saino, Nicola

    2014-01-01

    Migration is a fundamental stage in the life history of several taxa, including birds, and is under strong selective pressure. At present, the only data that may allow for both an assessment of patterns of bird migration and for retrospective analyses of changes in migration timing are the databases of ring recoveries. We used ring recoveries of the Barn Swallow Hirundo rustica collected from 1908–2008 in Europe to model the calendar date at which a given proportion of birds is expected to have reached a given geographical area (‘progression of migration’) and to investigate the change in timing of migration over the same areas between three time periods (1908–1969, 1970–1990, 1991–2008). The analyses were conducted using binomial conditional autoregressive (CAR) mixed models. We first concentrated on data from the British Isles and then expanded the models to western Europe and north Africa. We produced maps of the progression of migration that disclosed local patterns of migration consistent with those obtained from the analyses of the movements of ringed individuals. Timing of migration estimated from our model is consistent with data on migration phenology of the Barn Swallow available in the literature, but in some cases it is later than that estimated by data collected at ringing stations, which, however, may not be representative of migration phenology over large geographical areas. The comparison of median migration date estimated over the same geographical area among time periods showed no significant advancement of spring migration over the whole of Europe, but a significant advancement of autumn migration in southern Europe. Our modelling approach can be generalized to any records of ringing date and locality of individuals including those which have not been recovered subsequently, as well as to geo-referenced databases of sightings of migratory individuals. PMID:25047331

  13. A technique for removing the effect of migrating birds in 915-MHz wind profiler data.

    SciTech Connect

    Pekour, M. S.; Coulter, R. L.; Environmental Research

    1999-12-01

    A method is described and evaluated for decreasing artifacts in radar wind profiler data resulting from overflying, migrating birds. The method processes the prerecorded, averaged spectral data of a wind profiler to derive hourly wind profiles during conditions of frequent backscattering from birds. Comparison with in situ measurements revealed a significant improvement over the 'traditional,' online processing routine. When both the traditional method and the proposed new method are applied to an extended dataset, a practical procedure can be implemented to detect periods with significant bird-caused artifacts.

  14. Bird mortality during nocturnal migration over Lake Michigan: A case study

    USGS Publications Warehouse

    Diehl, Robert H.; Bates, John M.; Willard, David E.; Gnoske, Thomas P.

    2014-01-01

    Millions of birds die each year during migration. Most of this mortality goes unobserved and conditions surrounding the actual events are often not thoroughly documented. We present a case study of substantial migrant casualties along the shores of southwestern Lake Michigan during May 1996 when we found 2,981 dead birds of 114 species, mostly migrant passerines. An unusual sequence of events allowed us to document the circumstances surrounding this migratory bird kill. Bird carcasses appeared on the southwestern shores of Lake Michigan in the days following storm systems that produced high rain and in one case, hail. Encounters between birds and precipitation over open water were recorded by weather radar, and were followed by winds that drifted dead birds toward highly populated shorelines where the kill was observed and documented. Climatologically, May 1996 was exceptional for producing weather conditions that both killed birds en masse and allowed the mortality to be documented. As a result, this is one of the more thoroughly documented instances of a weather-related mass mortality event during migration.

  15. Bird Migration and Risk for H5N1 Transmission into Qinghai Lake, China

    PubMed Central

    Cui, Peng; Hou, Yuansheng; Xing, Zhi; He, Yubang; Guo, Shan; Luo, Ze; Yan, Baoping; Yin, Zuohua

    2011-01-01

    Abstract The highly pathogenic avian influenza H5N1 virus still cause devastating effects to humans, agricultural poultry flocks, and wild birds. Wild birds are also detected to carry H5N1 over long distances and are able to introduce it into new areas during migration. In this article, our objective is to provide lists of bird species potentially involved in the introduction of highly pathogenic avian influenza H5N1 in Qinghai Lake, which is an important breeding and stopover site for aquatic birds along the Central Asian Flyway. Bird species were classified according to the following behavioral and ecological factors: migratory status, abundance, degree of mixing species and gregariousness, and the prevalence rate of H5N1 virus. Most of the high-risk species were from the family Anatidae, order Anseriformes (9/14 in spring, 11/15 in fall). We also estimated the relative risk of bird species involved by using a semi-quantitative method; species from family Anatidae accounted for over 39% and over 91% of the total risk at spring and fall migration periods, respectively. Results also show the relative risk for each bird aggregating site in helping to identify high-risk areas. This work may also be instructive and meaningful to the avian influenza surveillance in the breeding, stopover, and wintering sites besides Qinghai Lake along the Central Asian Flyway. PMID:20925522

  16. Bird Migration and Avian Influenza: A Comparison of Hydrogen Stable Isotopes and Satellite Tracking Methods

    PubMed Central

    Kelly, Jeffrey F.; Xiao, Xiangming; Takekawa, John Y.; Hill, Nichola J.; Yamage, Mat; Haque, Enam Ul; Islam, Mohammad Anwarul; Mundkur, Taej; Yavuz, Kiraz Erciyas; Leader, Paul; Leung, Connie Y. H.; Smith, Bena; Spragens, Kyle A.; Vandegrift, Kurt; Hosseini, Parviez R.; Saif, Samia; Mohsanin, Samiul; Mikolon, Andrea; Islam, Ausrafal; George, Acty; Sivananinthaperumal, Balachandran; Daszak, Peter; Newman, Scott H.

    2014-01-01

    Satellite-based tracking of migratory waterfowl is an important tool for understanding the potential role of wild birds in the long-distance transmission of highly pathogenic avian influenza. However, employing this technique on a continental scale is prohibitively expensive. This study explores the utility of stable isotope ratios in feathers in examining both the distances traveled by migratory birds and variation in migration behavior. We compared the satellite-derived movement data of 22 ducks from 8 species captured at wintering areas in Bangladesh, Turkey, and Hong Kong with deuterium ratios (δD) of these and other individuals captured at the same locations. We derived likely molting locations from the satellite tracking data and generated expected isotope ratios based on an interpolated map of δD in rainwater. Although δD was correlated with the distance between wintering and molting locations, surprisingly, measured δD values were not correlated with either expected values or latitudes of molting sites. However, population-level parameters derived from the satellite-tracking data, such as mean distance between wintering and molting locations and variation in migration distance, were reflected by means and variation of the stable isotope values. Our findings call into question the relevance of the rainfall isotope map for Asia for linking feather isotopes to molting locations, and underscore the need for extensive ground truthing in the form of feather-based isoscapes. Nevertheless, stable isotopes from feathers could inform disease models by characterizing the degree to which regional breeding populations interact at common wintering locations. Feather isotopes also could aid in surveying wintering locations to determine where high-resolution tracking techniques (e.g. satellite tracking) could most effectively be employed. Moreover, intrinsic markers such as stable isotopes offer the only means of inferring movement information from birds that have died

  17. Bird migration and avian influenza: a comparison of hydrogen stable isotopes and satellite tracking methods

    USGS Publications Warehouse

    Bridge, Eli S.; Kelly, Jeffrey F.; Xiao, Xiangming; Takekawa, John Y.; Hill, Nichola J.; Yamage, Mat; Haque, Enam Ul; Islam, Mohammad Anwarul; Mundkur, Taej; Yavuz, Kiraz Erciyas; Leader, Paul; Leung, Connie Y.H.; Smith, Bena; Spragens, Kyle A.; Vandegrift, Kurt J.; Hosseini, Parviez R.; Saif, Samia; Mohsanin, Samiul; Mikolon, Andrea; Islam, Ausrafal; George, Acty; Sivananinthaperumal, Balachandran; Daszak, Peter; Newman, Scott H.

    2014-01-01

    Satellite-based tracking of migratory waterfowl is an important tool for understanding the potential role of wild birds in the long-distance transmission of highly pathogenic avian influenza. However, employing this technique on a continental scale is prohibitively expensive. This study explores the utility of stable isotope ratios in feathers in examining both the distances traveled by migratory birds and variation in migration behavior. We compared the satellite-derived movement data of 22 ducks from 8 species captured at wintering areas in Bangladesh, Turkey, and Hong Kong with deuterium ratios (δD) in the feathers of these and other individuals captured at the same locations. We derived likely molting locations from the satellite tracking data and generated expected isotope ratios based on an interpolated map of δD in rainwater. Although δD was correlated with the distance between wintering and molting locations, surprisingly, measured δD values were not correlated with either expected values or latitudes of molting sites. However, population-level parameters derived from the satellite-tracking data, such as mean distance between wintering and molting locations and variation in migration distance, were reflected by means and variation of the stable isotope values. Our findings call into question the relevance of the rainfall isotope map for Asia for linking feather isotopes to molting locations, and underscore the need for extensive ground truthing in the form of feather-based isoscapes. Nevertheless, stable isotopes from feathers could inform disease models by characterizing the degree to which regional breeding populations interact at common wintering locations. Feather isotopes also could aid in surveying wintering locations to determine where high-resolution tracking techniques (e.g. satellite tracking) could most effectively be employed. Moreover, intrinsic markers such as stable isotopes offer the only means of inferring movement information from

  18. Space-based Remote Sensing: A Tool for Studying Bird Migration Across Multiple Scales

    NASA Technical Reports Server (NTRS)

    Smith, James A.

    2005-01-01

    The study of bird migration on a global scale is one of the compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties. Space based technology offers new opportunities to shed understanding on the distribution and migration of organisms on the planet and their sensitivity to human disturbances and environmental changes. Our working hypothesis is that individual organism biophysical models of energy and water balance, driven by satellite measurements of spatio-temporal gradients in climate and habitat, will help us to explain the variability in avian species richness and distribution. Further, these models provide an ecological forecasting tool for science and application users to visualize the possible consequences of loss of wetlands, flooding, or other natural disasters such as hurricanes on avian biodiversity and bird migration.

  19. Lyme disease and migrating birds in the Saint Croix River Valley.

    PubMed Central

    Weisbrod, A R; Johnson, R C

    1989-01-01

    During a study of migrating land birds in 1987, we examined over 9,200 individual birds representing 99 species from the Saint Croix River Valley, a Lyme disease-endemic area of east central Minnesota and northwestern Wisconsin. We found that 250 deer tick (Ixodes dammini) larvae and nymphs infested 58 birds from 15 migrant species; 56 ticks (22.4%) were positive for the Lyme disease spirochete Borrelia burgdorferi. Five ground-foraging migrant bird species favoring mesic habitats, veery (Catharus fuscescens), ovenbird (Seiurus aurocapillus), northern waterthrush (S. novaboracensis), common yellowthroat (Geothlypis trichas), and swamp sparrow (Melospiza georgiana), accounted for nearly three-quarters of parasitized individuals. Nearly half of the spirochete-positive ticks were removed from migrating birds taken in a riparian floodplain forest. Recaptured migrants with infected ticks indicate that they transmit B. burgdorferi to hexapod larvae. We suggest that birds may be both an important local reservoir in the upper Mississippi Valley and long-distance dispersal agents for B. burgdorferi-infected ticks to other regions of the continent. PMID:2782872

  20. Emergence of long distance bird migrations: a new model integrating global climate changes

    NASA Astrophysics Data System (ADS)

    Louchart, Antoine

    2008-12-01

    During modern birds history, climatic and environmental conditions have evolved on wide scales. In a continuously changing world, landbirds annual migrations emerged and developed. However, models accounting for the origins of these avian migrations were formulated with static ecogeographic perspectives. Here I reviewed Cenozoic paleoclimatic and paleontological data relative to the palearctic paleotropical long distance (LD) migration system. This led to propose a new model for the origin of LD migrations, the ‘shifting home’ model (SHM). It is based on a dynamic perspective of climate evolution and may apply to the origins of most modern migrations. Non-migrant tropical African bird taxa were present at European latitudes during most of the Cenozoic. Their distribution limits shifted progressively toward modern tropical latitudes during periods of global cooling and increasing seasonality. In parallel, decreasing winter temperatures in the western Palearctic drove shifts of population winter ranges toward the equator. I propose that this induced the emergence of most short distance migrations, and in turn LD migrations. This model reconciliates ecologically tropical ancestry of most LD migrants with predominant winter range shifts, in accordance with requirements for heritable homing. In addition, it is more parsimonious than other non-exclusive models. Greater intrinsic plasticity of winter ranges implied by the SHM is supported by recently observed impacts of the present global warming on migrating birds. This may induce particular threats to some LD migrants. The ancestral, breeding homes of LD migrants were not ‘northern’ or ‘southern’ but shifted across high and middle latitudes while migrations emerged through winter range shifts themselves.

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

    USGS Publications Warehouse

    Dusek, R.J.; McLean, R.G.; Kramer, L.D.; Ubico, S.R.; Dupuis, A.P., II; 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.

  2. Experimental reduction of winter food decreases body condition and delays migration in a long-distance migratory bird.

    PubMed

    Cooper, Nathan W; Sherry, Thomas W; Marra, Peter P

    2015-07-01

    Many tropical habitats experience pronounced dry seasons, during which arthropod food availability declines, potentially limiting resident and migratory animal populations. In response to declines in food, individuals may attempt to alter their space use to enhance access to food resources, but may be socially constrained from doing so by con- and heterospecifics. If social constraints exist, food declines should result in decreased body condition. In migratory birds, correlational evidence suggests a link between body condition and migration timing. Poor body condition and delayed migration may, in turn, impact fitness in subsequent seasons via carry-over effects. To determine if winter food availability affects space use, inter- and intraspecific competition, body composition (i.e., mass, fat, and pectoral muscle), and migration timing, we experimentally decreased food availability on individual American Redstart (Setophaga ruticilla) territories in high-quality mangrove habitat. Redstarts on control territories experienced -40% loss of food due to the seasonal nature of the environment. Redstarts on experimental territories experienced -80% declines in food, which closely mimicked natural declines in nearby, low-quality, scrub habitat. Individuals on food-reduced territories did not expand their territories locally, but instead either became non-territorial "floaters" or remained on territory. Regardless of territorial status, food-reduced American Redstarts all deposited fat compared to control birds. Fat deposits provide insurance against the risk of starvation, but, for American Redstarts, came at the expense of maintaining pectoral muscle. Subsequently, food-reduced American Redstarts experienced, on average, a one-week delay in departure on spring migration, likely due to the loss of pectoral muscle. Thus, our results demonstrate experimentally, for the first time, that declines in winter food availability can result in a fat-muscle trade-off, which, in

  3. Leucocyte profiles of Arctic marine birds: correlates of migration and breeding phenology

    PubMed Central

    Mallory, Mark L.; Little, Catherine M.; Boyd, Ellen S.; Ballard, Jennifer; Elliott, Kyle H.; Gilchrist, H. Grant; Hipfner, J. Mark; Petersen, Aevar; Shutler, Dave

    2015-01-01

    Most Arctic marine birds are migratory, wintering south of the limit of annual pack ice and returning north each year for the physiologically stressful breeding season. The Arctic environment is changing rapidly due to global warming and anthropogenic activities, which may influence the timing of breeding in relation to arrival times following migration, as well as providing additional stressors (e.g. disturbance from ships) to which birds may respond. During stressful parts of their annual cycle, such as breeding, birds may reallocate resources so that they have increased heterophil-to-lymphocyte ratios in their white blood cell (leucocyte) profiles. We analysed leucocyte profiles of nine species of marine birds to establish reference ranges for these species in advance of future Arctic change. Leucocyte profiles tended to cluster among taxonomic groups across studies, suggesting that reference values for a particular group can be established, and within species there was evidence that birds from colonies that had to migrate farther had higher heterophil-to-lymphocyte ratios during incubation than those that did not have to travel as far, particularly for species with high wing loading. PMID:27293713

  4. 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.

  5. Birds, Plants, and Climate: Impacts of Climatic Change on the Phenology of Spring Bird Migration in the Great Lakes, USA

    NASA Astrophysics Data System (ADS)

    Macmynowski, D. P.; Root, T. L.

    2004-12-01

    Global climate change is likely to emerge as a significant, if not dominant force, in ecosystem change over the next several decades. While the potential impacts of discordant range shifts have received considerable attention, asynchronies in phenology have received less attention. Migrating birds are of particular concern given their need of multiple habitats, which often involve large spatial scales. Time is of the essence for migrating birds: it is critical for departures with favorable weather conditions, intersecting adequate resources to fuel further flight, and for spring migrants, arrival on the breeding grounds in concert with the flush of food to feed offspring. We assess changes in the spring phenology of migrant birds in the Great Lakes region using observations in Germfask, MI, USA (49° 17'N, 85° 57'W) from 1965-1994 and Fairfield Township, WI,USA (43° 30'N, 89° 30'W) from 1976-1999. We correlate the species temporal changes with abiotic and biotic variables to understand how migrants' behaviour is associated with spring green-up (plant phenology) and multi-scalar climate/weather variables, such as the North Atlantic Oscillation, and local and regional temperature. We assess the observed changes and correlations in light of migrant life history factors (wintering grounds, diet, residency) to understand which species, or groups of species, are particularly at risk from climatic-change-induced disruptions to the migratory and breeding schedule. The implications of potential ecosystem asynchronies between climate/weather, migratory schedules, and the arrival of spring are discussed.

  6. 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. PMID:23300969

  7. 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

  8. Influenza A Virus Migration and Persistence in North American Wild Birds

    PubMed Central

    Kühnert, Denise; Fourment, Mathieu; Raven, Garnet; Pryor, S. Paul; Niles, Lawrence J.; Danner, Angela; Walker, David; Mendenhall, Ian H.; Su, Yvonne C. F.; Dugan, Vivien G.; Halpin, Rebecca A.; Stockwell, Timothy B.; Webby, Richard J.; Wentworth, David E.; Drummond, Alexei J.; Smith, Gavin J. D.; Webster, Robert G.

    2013-01-01

    Wild birds have been implicated in the emergence of human and livestock influenza. The successful prediction of viral spread and disease emergence, as well as formulation of preparedness plans have been hampered by a critical lack of knowledge of viral movements between different host populations. The patterns of viral spread and subsequent risk posed by wild bird viruses therefore remain unpredictable. Here we analyze genomic data, including 287 newly sequenced avian influenza A virus (AIV) samples isolated over a 34-year period of continuous systematic surveillance of North American migratory birds. We use a Bayesian statistical framework to test hypotheses of viral migration, population structure and patterns of genetic reassortment. Our results reveal that despite the high prevalence of Charadriiformes infected in Delaware Bay this host population does not appear to significantly contribute to the North American AIV diversity sampled in Anseriformes. In contrast, influenza viruses sampled from Anseriformes in Alberta are representative of the AIV diversity circulating in North American Anseriformes. While AIV may be restricted to specific migratory flyways over short time frames, our large-scale analysis showed that the long-term persistence of AIV was independent of bird flyways with migration between populations throughout North America. Analysis of long-term surveillance data provides vital insights to develop appropriately informed predictive models critical for pandemic preparedness and livestock protection. PMID:24009503

  9. Oxidative Stress in Endurance Flight: An Unconsidered Factor in Bird Migration

    PubMed Central

    Jenni-Eiermann, Susanne; Jenni, Lukas; Smith, Shona; Costantini, David

    2014-01-01

    Migrating birds perform extraordinary endurance flights, up to 200 h non-stop, at a very high metabolic rate and while fasting. Such an intense and prolonged physical activity is normally associated with an increased production of reactive oxygen and nitrogen species (RONS) and thus increased risk of oxidative stress. However, up to now it was unknown whether endurance flight evokes oxidative stress. We measured a marker of oxidative damage (protein carbonyls, PCs) and a marker of enzymatic antioxidant capacity (glutathione peroxidase, GPx) in the European robin (Erithacus rubecula), a nocturnal migrant, on its way to the non-breeding grounds. Both markers were significantly higher in European robins caught out of their nocturnal flight than in conspecifics caught during the day while resting. Independently of time of day, both markers showed higher concentrations in individuals with reduced flight muscles. Adults had higher GPx concentrations than first-year birds on their first migration. These results show for the first time that free-flying migrants experience oxidative stress during endurance flight and up-regulate one component of antioxidant capacity. We discuss that avoiding oxidative stress may be an overlooked factor shaping bird migration strategies, e.g. by disfavouring long non-stop flights and an extensive catabolism of the flight muscles. PMID:24830743

  10. A fall land bird migration across the South China Sea from Indo-China to the Greater Sunda Islands

    USGS Publications Warehouse

    Ellis, D.H.; Kepler, A.K.; Kepler, C.B.

    1994-01-01

    We encountered 150 land birds representing 14 families along the cruise track of the Soviet Oceanographic Research Vessel AKADEMlK KOROLEV in the South China Sea. We saw most of these birds during a 3 -day period in a small area c. 350 km southeast of the southern tip of the Indo-China peninsula. These observations suggest that a significant land bird migration corridor crosses the South China Sea from Viet Nam to Borneo.

  11. DEVELOPING AND IMPLEMENTING A BIRD MIGRATION MONITORING, ASSESSMENT AND PUBLIC OUTREACH PROGRAM FOR YOUR COMMUNITY - THE BIRDCAST PROJECT

    EPA Science Inventory

    The USEPA has developed a technology transfer handbook for the EMPACt BirdCast bird migration monitoring project. The document is essentially a "How-To" Handbook that addresses the planning and implementation steps that were needed to develop, operate and maintain a program simil...

  12. Convergent patterns of long-distance nocturnal migration in noctuid moths and passerine birds.

    PubMed

    Alerstam, Thomas; Chapman, Jason W; Bäckman, Johan; Smith, Alan D; Karlsson, Håkan; Nilsson, Cecilia; Reynolds, Don R; Klaassen, Raymond H G; Hill, Jane K

    2011-10-22

    Vast numbers of insects and passerines achieve long-distance migrations between summer and winter locations by undertaking high-altitude nocturnal flights. Insects such as noctuid moths fly relatively slowly in relation to the surrounding air, with airspeeds approximately one-third of that of passerines. Thus, it has been widely assumed that windborne insect migrants will have comparatively little control over their migration speed and direction compared with migrant birds. We used radar to carry out the first comparative analyses of the flight behaviour and migratory strategies of insects and birds under nearly equivalent natural conditions. Contrary to expectations, noctuid moths attained almost identical ground speeds and travel directions compared with passerines, despite their very different flight powers and sensory capacities. Moths achieved fast travel speeds in seasonally appropriate migration directions by exploiting favourably directed winds and selecting flight altitudes that coincided with the fastest air streams. By contrast, passerines were less selective of wind conditions, relying on self-powered flight in their seasonally preferred direction, often with little or no tailwind assistance. Our results demonstrate that noctuid moths and passerines show contrasting risk-prone and risk-averse migratory strategies in relation to wind. Comparative studies of the flight behaviours of distantly related taxa are critically important for understanding the evolution of animal migration strategies. PMID:21389024

  13. Avian influenza H5N1 viral and bird migration networks in Asia

    PubMed Central

    Tian, Huaiyu; Zhou, Sen; Dong, Lu; Van Boeckel, Thomas P.; Cui, Yujun; Newman, Scott H.; Takekawa, John Y.; Prosser, Diann J.; Xiao, Xiangming; Wu, Yarong; Cazelles, Bernard; Huang, Shanqian; Yang, Ruifu; Grenfell, Bryan T.; Xu, Bing

    2015-01-01

    The spatial spread of the highly pathogenic avian influenza virus H5N1 and its long-term persistence in Asia have resulted in avian influenza panzootics and enormous economic losses in the poultry sector. However, an understanding of the regional long-distance transmission and seasonal patterns of the virus is still lacking. In this study, we present a phylogeographic approach to reconstruct the viral migration network. We show that within each wild fowl migratory flyway, the timing of H5N1 outbreaks and viral migrations are closely associated, but little viral transmission was observed between the flyways. The bird migration network is shown to better reflect the observed viral gene sequence data than other networks and contributes to seasonal H5N1 epidemics in local regions and its large-scale transmission along flyways. These findings have potentially far-reaching consequences, improving our understanding of how bird migration drives the periodic reemergence of H5N1 in Asia. PMID:25535385

  14. Avian influenza H5N1 viral and bird migration networks in Asia

    USGS Publications Warehouse

    Tian, Huaivu; Zhou, Sen; Dong, Lu; Van Boeckel, Thomas P.; Cui, Yujun; Newman, Scott H.; Takekawa, John Y.; Prosser, Diann J.; Xiao, Xiangming; Wu, Yarong; Cazelles, Bernard; Huang, Shanqian; Yang, Ruifu; Grenfell, Bryan T.; Xu, Bing

    2015-01-01

    The spatial spread of the highly pathogenic avian influenza virus H5N1 and its long-term persistence in Asia have resulted in avian influenza panzootics and enormous economic losses in the poultry sector. However, an understanding of the regional long-distance transmission and seasonal patterns of the virus is still lacking. In this study, we present a phylogeographic approach to reconstruct the viral migration network. We show that within each wild fowl migratory flyway, the timing of H5N1 outbreaks and viral migrations are closely associated, but little viral transmission was observed between the flyways. The bird migration network is shown to better reflect the observed viral gene sequence data than other networks and contributes to seasonal H5N1 epidemics in local regions and its large-scale transmission along flyways. These findings have potentially far-reaching consequences, improving our understanding of how bird migration drives the periodic reemergence of H5N1 in Asia.

  15. Speeds and wingbeat frequencies of migrating birds compared with calculated benchmarks.

    PubMed

    Pennycuick, C J

    2001-10-01

    Sixteen species of birds passing Falsterbo in southwest Sweden during the autumn migration season were observed using short-range optical methods. Air speeds and wingbeat frequencies were measured, reduced to sea level, and compared with benchmark values computed by Flight.bas, a published flight performance program based on flight mechanics. The benchmark for air speed was the calculated sea-level value of the minimum power speed (V(mp)). The mean speeds of three raptor species that flew by flap-gliding were below V(mp), apparently because the flap-glide cycle involved slowing down below V(mp) when gliding and accelerating back up to V(mp) when flapping. The mean speeds of 11 species that flew by continuous flapping were between 0.82V(mp) and 1.27V(mp). Two passerine species that flew by bounding had mean speeds of 1.70V(mp) and 1.96V(mp), but these high mean speeds reflected their ability to fly faster against head winds. These results do not support predictions from optimal migration theory, which suggest that migrating birds 'should' fly faster, relative to V(mp). However, observations were restricted for technical reasons to birds flying below 200 m and may not represent birds that were seriously committed to long-distance migration. The benchmark wingbeat frequency (f(ref)) was derived from dimensional reasoning, not from statistical analysis of observations. Observed wingbeat frequencies ranged from 0.81f(ref) to 1.05f(ref), except in the two bounding species, whose wingbeat frequencies appeared anomalously high. However, the mechanics of bounding with a power fraction q imply that gravity during the flapping phase is increased by a factor 1/q, and when the value of gravity was so adjusted in the expression for f(ref), the wingbeat frequencies of the two bounding species were predicted correctly as a function of the power fraction. In small birds with more muscle power than is required to fly at speeds near V(mp), bounding is an effective method of adjusting

  16. Air speeds of migrating birds observed by ornithodolite and compared with predictions from flight theory.

    PubMed

    Pennycuick, C J; Åkesson, Susanne; Hedenström, Anders

    2013-09-01

    We measured the air speeds of 31 bird species, for which we had body mass and wing measurements, migrating along the east coast of Sweden in autumn, using a Vectronix Vector 21 ornithodolite and a Gill WindSonic anemometer. We expected each species' average air speed to exceed its calculated minimum-power speed (Vmp), and to fall below its maximum-range speed (Vmr), but found some exceptions to both limits. To resolve these discrepancies, we first reduced the assumed induced power factor for all species from 1.2 to 0.9, attributing this to splayed and up-turned primary feathers, and then assigned body drag coefficients for different species down to 0.060 for small waders, and up to 0.12 for the mute swan, in the Reynolds number range 25 000-250 000. These results will be used to amend the default values in existing software that estimates fuel consumption in migration, energy heights on arrival and other aspects of flight performance, using classical aeronautical theory. The body drag coefficients are central to range calculations. Although they cannot be measured on dead bird bodies, they could be checked against wind tunnel measurements on living birds, using existing methods. PMID:23804440

  17. Evidence of spread of the emerging infectious disease, finch trichomonosis, by migrating birds.

    PubMed

    Lawson, Becki; Robinson, Robert A; Neimanis, Aleksija; Handeland, Kjell; Isomursu, Marja; Agren, Erik O; Hamnes, Inger S; Tyler, Kevin M; Chantrey, Julian; Hughes, Laura A; Pennycott, Tom W; Simpson, Vic R; John, Shinto K; Peck, Kirsi M; Toms, Mike P; Bennett, Malcolm; Kirkwood, James K; Cunningham, Andrew A

    2011-06-01

    Finch trichomonosis emerged in Great Britain in 2005 and led to epidemic mortality and a significant population decline of greenfinches, Carduelis chloris and chaffinches, Fringilla coelebs, in the central and western counties of England and Wales in the autumn of 2006. In this article, we show continued epidemic spread of the disease with a pronounced shift in geographical distribution towards eastern England in 2007. This was followed by international spread to southern Fennoscandia where cases were confirmed at multiple sites in the summer of 2008. Sequence data of the ITS1/5.8S/ITS2 ribosomal region and part of the small subunit (SSU) rRNA gene showed no variation between the British and Fennoscandian parasite strains of Trichomonas gallinae. Epidemiological and historical ring return data support bird migration as a plausible mechanism for the observed pattern of disease spread, and suggest the chaffinch as the most likely primary vector. This finding is novel since, although intuitive, confirmed disease spread by migratory birds is very rare and, when it has been recognised, this has generally been for diseases caused by viral pathogens. We believe this to be the first documented case of the spread of a protozoal emerging infectious disease by migrating birds. PMID:21935745

  18. Air speeds of migrating birds observed by ornithodolite and compared with predictions from flight theory

    PubMed Central

    Pennycuick, C. J.; Åkesson, Susanne; Hedenström, Anders

    2013-01-01

    We measured the air speeds of 31 bird species, for which we had body mass and wing measurements, migrating along the east coast of Sweden in autumn, using a Vectronix Vector 21 ornithodolite and a Gill WindSonic anemometer. We expected each species’ average air speed to exceed its calculated minimum-power speed (Vmp), and to fall below its maximum-range speed (Vmr), but found some exceptions to both limits. To resolve these discrepancies, we first reduced the assumed induced power factor for all species from 1.2 to 0.9, attributing this to splayed and up-turned primary feathers, and then assigned body drag coefficients for different species down to 0.060 for small waders, and up to 0.12 for the mute swan, in the Reynolds number range 25 000–250 000. These results will be used to amend the default values in existing software that estimates fuel consumption in migration, energy heights on arrival and other aspects of flight performance, using classical aeronautical theory. The body drag coefficients are central to range calculations. Although they cannot be measured on dead bird bodies, they could be checked against wind tunnel measurements on living birds, using existing methods. PMID:23804440

  19. Arthropods and associated arthropod-borne diseases transmitted by migrating birds. The case of ticks and tick-borne pathogens.

    PubMed

    Sparagano, Olivier; George, David; Giangaspero, Annunziata; Špitalská, Eva

    2015-09-30

    Geographic spread of parasites and pathogens poses a constant risk to animal health and welfare, particularly given that climate change is expected to potentially expand appropriate ranges for many key species. The spread of deleterious organisms via trade routes and human travelling is relatively closely controlled, though represents only one possible means of parasite/pathogen distribution. The transmission via natural parasite/pathogen movement between geographic locales, is far harder to manage. Though the extent of such movement may be limited by the relative inability of many parasites and pathogens to actively migrate, passive movement over long distances may still occur via migratory hosts. This paper reviews the potential role of migrating birds in the transfer of ectoparasites and pathogens between geographic locales, focusing primarily on ticks. Bird-tick-pathogen relationships are considered, and evidence provided of long-range parasite/pathogen transfer from one location to another during bird migration events. As shown in this paper not only many different arthropod species are carried by migrating birds but consequently these pests carry many different pathogens species which can be transmitted to the migrating birds or to other animal species when those arthropods are dropping during these migrations. Data available from the literature are provided highlighting the need to understand better dissemination paths and disease epidemiology. PMID:26343302

  20. From warm to cold: migration of Adélie penguins within Cape Bird, Ross Island

    PubMed Central

    Nie, Yaguang; Sun, Liguang; Liu, Xiaodong; Emslie, Steven D.

    2015-01-01

    Due to their sensitivity to environmental change, penguins in Antarctica are widely used as bio-indicators in paleoclimatic research. On the basis of bio-element assemblages identified in four ornithogenic sediment profiles, we reconstructed the historical penguin population change at Cape Bird, Ross Island, for the past 1600 years. Clear succession of penguin population peaks were observed in different profiles at about 1400 AD, which suggested a high probability of migration within this region. The succession was most obviously marked by a sand layer lasting from 1400 to 1900 AD in one of the analyzed profiles. Multiple physical/chemical parameters indicated this sand layer was not formed in a lacustrine environment, but was marine-derived. Both isostatic subsidence and frequent storms under the colder climatic condition of the Little Ice Age were presumed to have caused the abandonment of the colonies, and we believe the penguins migrated from the coastal area of mid Cape Bird northward and to higher ground as recorded in the other sediment profiles. This migration was an ecological response to global climate change and possible subsequent geological effects in Antarctica. PMID:26113152

  1. Ecological Causes and Consequences of Intratropical Migration in Temperate-Breeding Migratory Birds.

    PubMed

    Stutchbury, Bridget J M; Siddiqui, Raafia; Applegate, Kelly; Hvenegaard, Glen T; Mammenga, Paul; Mickle, Nanette; Pearman, Myrna; Ray, James D; Savage, Anne; Shaheen, Tim; Fraser, Kevin C

    2016-09-01

    New discoveries from direct tracking of temperate-breeding passerines show that intratropical migration (ITM) occurs in a growing number of species, which has important implications for understanding their evolution of migration, population dynamics, and conservation needs. Our large sample size ([Formula: see text]) for purple martins (Progne subis subis) tracked with geolocators to winter sites in Brazil, combined with geolocator deployments at breeding colonies across North America, allowed us to test hypotheses for ITM, something which has not yet been possible to do for other species. ITM in purple martins was not obligate; only 44% of individuals exhibited ITM, and movements were not coordinated in time or space. We found no evidence to support the resource hypothesis; rainfall and temperature experienced by individual birds during their last 2 weeks at their first roost site were similar to conditions at their second roost site after ITM. Birds generally migrated away from the heavily forested northwestern Amazon to less forested regions to the south and east. ITM in this aerial insectivore appears to support the competition-avoidance hypothesis and may be triggered by increasing local density in the core wintering region. Full life cycle models and migratory networks will need to incorporate ITM to properly address seasonal carryover effects and identify which wintering regions are most important for conservation. PMID:27513909

  2. From warm to cold: migration of Adélie penguins within Cape Bird, Ross Island

    NASA Astrophysics Data System (ADS)

    Nie, Yaguang; Sun, Liguang; Liu, Xiaodong; Emslie, Steven D.

    2015-06-01

    Due to their sensitivity to environmental change, penguins in Antarctica are widely used as bio-indicators in paleoclimatic research. On the basis of bio-element assemblages identified in four ornithogenic sediment profiles, we reconstructed the historical penguin population change at Cape Bird, Ross Island, for the past 1600 years. Clear succession of penguin population peaks were observed in different profiles at about 1400 AD, which suggested a high probability of migration within this region. The succession was most obviously marked by a sand layer lasting from 1400 to 1900 AD in one of the analyzed profiles. Multiple physical/chemical parameters indicated this sand layer was not formed in a lacustrine environment, but was marine-derived. Both isostatic subsidence and frequent storms under the colder climatic condition of the Little Ice Age were presumed to have caused the abandonment of the colonies, and we believe the penguins migrated from the coastal area of mid Cape Bird northward and to higher ground as recorded in the other sediment profiles. This migration was an ecological response to global climate change and possible subsequent geological effects in Antarctica.

  3. From warm to cold: migration of Adélie penguins within Cape Bird, Ross Island.

    PubMed

    Nie, Yaguang; Sun, Liguang; Liu, Xiaodong; Emslie, Steven D

    2015-01-01

    Due to their sensitivity to environmental change, penguins in Antarctica are widely used as bio-indicators in paleoclimatic research. On the basis of bio-element assemblages identified in four ornithogenic sediment profiles, we reconstructed the historical penguin population change at Cape Bird, Ross Island, for the past 1600 years. Clear succession of penguin population peaks were observed in different profiles at about 1400 AD, which suggested a high probability of migration within this region. The succession was most obviously marked by a sand layer lasting from 1400 to 1900 AD in one of the analyzed profiles. Multiple physical/chemical parameters indicated this sand layer was not formed in a lacustrine environment, but was marine-derived. Both isostatic subsidence and frequent storms under the colder climatic condition of the Little Ice Age were presumed to have caused the abandonment of the colonies, and we believe the penguins migrated from the coastal area of mid Cape Bird northward and to higher ground as recorded in the other sediment profiles. This migration was an ecological response to global climate change and possible subsequent geological effects in Antarctica. PMID:26113152

  4. On the potential roles of ticks and migrating birds in the ecology of West Nile virus

    PubMed Central

    Hagman, Karl; Barboutis, Christos; Ehrenborg, Christian; Fransson, Thord; Jaenson, Thomas G. T.; Lindgren, Per-Eric; Lundkvist, Åke; Nyström, Fredrik; Waldenström, Jonas; Salaneck, Erik

    2014-01-01

    Background Mosquitoes are the primary vectors of West Nile virus (WNV). Ticks have, however, been suggested to be potential reservoirs of WNV. In order to investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northwards from Africa to Europe, were analyzed for the potential presence of WNV-RNA. Methods On the Mediterranean islands Capri and Antikythira a total of 14,824 birds were captured and investigated from which 747 ticks were collected. Results and conclusion Most of the identified ticks (93%) were nymphs and larvae of Hyalomma marginatum sensu lato, most of which were or appear to be Hyalomma rufipes. Of these ticks 729 were individually screened for WNV-RNA. None of the ticks was found to be WNV positive. Thus, there was no evidence that Hyalomma marginatum s.l. ticks play a role in the spread of WNV from Africa to Europe. PMID:24455105

  5. A role for migration-linked genes and genomic islands in divergence of a songbird.

    PubMed

    Ruegg, Kristen; Anderson, Eric C; Boone, Jason; Pouls, Jazz; Smith, Thomas B

    2014-10-01

    Next-generation sequencing has made it possible to begin asking questions about the process of divergence at the level of the genome. For example, recently, there has been a debate around the role of 'genomic islands of divergence' (i.e. blocks of outlier loci) in facilitating the process of speciation-with-gene-flow. The Swainson's thrush, Catharus ustulatus, is a migratory songbird with two genetically distinct subspecies that differ in a number of traits known to be involved in reproductive isolation in birds (plumage coloration, song and migratory behaviour), despite contemporary gene flow along a secondary contact zone. Here, we use RAD-PE sequencing to test emerging hypotheses about the process of divergence at the level of the genome and identify genes and gene regions involved in differentiation in this migratory songbird. Our analyses revealed distinct genomic islands on 15 of the 23 chromosomes and an accelerated rate of divergence on the Z chromosome, one of the avian sex chromosomes. Further, an analysis of loci linked to traits known to be involved in reproductive isolation in songbirds showed that genes linked to migration are significantly more differentiated than expected by chance, but that these genes lie primarily outside the genomic islands. Overall, our analysis supports the idea that genes linked to migration play an important role in divergence in migratory songbirds, but we find no compelling evidence that the observed genomic islands are facilitating adaptive divergence in migratory behaviour. PMID:24954641

  6. Stable Isotopes in Ecological Sceinces: Bird and Fish Diet and Migration in Virginia

    NASA Astrophysics Data System (ADS)

    Schmidt, S.; Dias, R. F.; Ake, R.; Jones, C. M.

    2002-12-01

    The preservation of ecologically sensitive habitats for birds and fishes in Virginia requires a detailed understanding of the important changes in diet and migration over the life span of the animal. Stable isotope analysis offers the potential to assess migration and trophic level variability in birds and fishes from southeastern Virginia and the greater Chesapeake Bay. Fish of various species and ages from different locations throughout the Chesapeake Bay were analyzed for carbon-13 and nitrogen-15 bulk natural abundance. Of particular note, blue fish were found to have significantly higher d15N values than striped bass which are believed to be trophic competitors. Observations are discussed relative to the maturity of the different fish, variation in water-mass chemistry (N-inputs), local environmental habitats, trophic relationships and migratory habits. In conjunction with banding studies being conducted by Virginia Department of Game and Inland Fisheries in the Great Dismal Swamp (VA), breast feathers from Carolina Wren, Common Yellowthroat, Northern Cardinal, Ovenbird, and Prothonotary Warbler were analyzed for carbon-13 and nitrogen-15 bulk natural abundance. Given the preliminary nature of this work our ability to identify trends between species was less than satisfying, thus highlighting the need for larger sample populations over more than one breeding season. However, within a given species (most notably the Prothonotary Warbler) we are able to discern a change in diet. The hatching year Prothonotary warbler were more enriched in both carbon-13 and nitrogen-15 than the after-hatching-year (AHY) birds, indicating a change in food sources between the two age groups. By sampling over time and at various sample sites, isotopic analyses allow a more detailed investigation of the spatial and temporal variation in the diets and migratory habits of fishes and birds in Virginia and the Chesapeake Bay.

  7. Bird Migration Under Climate Change - A Mechanistic Approach Using Remote Sensing

    NASA Technical Reports Server (NTRS)

    Smith, James A.; Blattner, Tim; Messmer, Peter

    2010-01-01

    The broad-scale reductions and shifts that may be expected under climate change in the availability and quality of stopover habitat for long-distance migrants is an area of increasing concern for conservation biologists. Researchers generally have taken two broad approaches to the modeling of migration behaviour to understand the impact of these changes on migratory bird populations. These include models based on causal processes and their response to environmental stimulation, "mechanistic models", or models that primarily are based on observed animal distribution patterns and the correlation of these patterns with environmental variables, i.e. "data driven" models. Investigators have applied the latter technique to forecast changes in migration patterns with changes in the environment, for example, as might be expected under climate change, by forecasting how the underlying environmental data layers upon which the relationships are built will change over time. The learned geostatstical correlations are then applied to the modified data layers.. However, this is problematic. Even if the projections of how the underlying data layers will change are correct, it is not evident that the statistical relationships will remain the same, i.e. that the animal organism may not adapt its' behaviour to the changing conditions. Mechanistic models that explicitly take into account the physical, biological, and behaviour responses of an organism as well as the underlying changes in the landscape offer an alternative to address these shortcomings. The availability of satellite remote sensing observations at multiple spatial and temporal scales, coupled with advances in climate modeling and information technologies enable the application of the mechanistic models to predict how continental bird migration patterns may change in response to environmental change. In earlier work, we simulated the impact of effects of wetland loss and inter-annual variability on the fitness of

  8. Spring phenology of ecological productivity contributes to the use of looped migration strategies by birds

    PubMed Central

    La Sorte, Frank A.; Fink, Daniel; Hochachka, Wesley M.; DeLong, John P.; Kelling, Steve

    2014-01-01

    Migration is a common strategy used by birds that breed in seasonal environments. The patterns and determinants of migration routes, however, remain poorly understood. Recent empirical analyses have demonstrated that the locations of two North America migration flyways (eastern and western) shift seasonally, reflecting the influence of looped migration strategies. For the eastern but not western flyway, seasonal variation in atmospheric circulation has been identified as an explanation. Here, we test an alternative explanation based on the phenology of ecological productivity, which may be of greater relevance in western North America, where phenology is more broadly dictated by elevation. Migrants in the western flyway selected lower-elevation spring routes that were wetter, greener and more productive, and higher-elevation autumn routes that were less green and less productive, but probably more direct. Migrants in the eastern flyway showed little season variation but maintained associations with maximum regional greenness. Our findings suggest the annual phenology of ecological productivity is associated with en route timing in both flyways, and the spring phenology of ecological productivity contributes to the use of looped strategies in the western flyway. This fine-tuned spatial synchronization may be disrupted when changing climate induces a mismatch between food availability and needs. PMID:25209934

  9. Detecting mismatches of bird migration stopover and tree phenology in response to changing climate

    USGS Publications Warehouse

    Kellermann, Jherime L.; Van Riper, Charles, III

    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.

  10. Detection by Enzyme-Linked Immunosorbent Assay of Antibodies to West Nile virus in Birds

    PubMed Central

    Dupuis, Alan P.; Nicholas, David; Young, Donna; Maffei, Joseph; Kramer, Laura D.

    2002-01-01

    We adapted an indirect immunoglobulin G enzyme-linked immunosorbent assay to facilitate studies of West Nile virus (WNV) and evaluated its application to taxonomically diverse avian species. Anti-WNV antibodies were detected in 23 bird species, including many exotic species, demonstrating its value in studies of WNV epizootiology. PMID:12194778

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

    USGS Publications Warehouse

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

  12. A strong magnetic pulse affects the precision of departure direction of naturally migrating adult but not juvenile birds

    PubMed Central

    Holland, Richard A.; Helm, Barbara

    2013-01-01

    The mechanisms by which migratory birds achieve their often spectacular navigational performance are still largely unclear, but perception of cues from the Earth's magnetic field is thought to play a role. Birds that possess migratory experience can use map-based navigation, which may involve a receptor that uses ferrimagnetic material for detecting gradients in the magnetic field. Such a mechanism can be experimentally disrupted by applying a strong magnetic pulse that re-magnetizes ferrimagnetic materials. In captivity, this treatment indeed affected bearings of adult but not of naive juvenile birds. However, field studies, which expose birds to various navigational cues, yielded mixed results. Supportive studies were difficult to interpret because they were conducted in spring when all age groups navigate back to breeding areas. The present study, therefore, applied a magnetic pulse treatment in autumn to naturally migrating, radio-tagged European robins. We found that, although overall bearings were seasonally correct, orientation of adult but not juvenile robins was compromised by a pulse. Pulsed adults that departed within 10 days of treatment failed to show significant orientation and deviated more from mean migration direction than adult controls and juveniles. Thus, our data give field-based support for a possible ferrimagnetic map-sense during bird migration. PMID:23389901

  13. Seasonally Changing Cryptochrome 1b Expression in the Retinal Ganglion Cells of a Migrating Passerine Bird.

    PubMed

    Nießner, Christine; Gross, Julia Christina; Denzau, Susanne; Peichl, Leo; Fleissner, Gerta; Wiltschko, Wolfgang; Wiltschko, Roswitha

    2016-01-01

    Cryptochromes, blue-light absorbing proteins involved in the circadian clock, have been proposed to be the receptor molecules of the avian magnetic compass. In birds, several cryptochromes occur: Cryptochrome 2, Cryptochrome 4 and two splice products of Cryptochrome 1, Cry1a and Cry1b. With an antibody not distinguishing between the two splice products, Cryptochrome 1 had been detected in the retinal ganglion cells of garden warblers during migration. A recent study located Cry1a in the outer segments of UV/V-cones in the retina of domestic chickens and European robins, another migratory species. Here we report the presence of cryptochrome 1b (eCry1b) in retinal ganglion cells and displaced ganglion cells of European Robins, Erithacus rubecula. Immuno-histochemistry at the light microscopic and electron microscopic level showed eCry1b in the cell plasma, free in the cytosol as well as bound to membranes. This is supported by immuno-blotting. However, this applies only to robins in the migratory state. After the end of the migratory phase, the amount of eCry1b was markedly reduced and hardly detectable. In robins, the amount of eCry1b in the retinal ganglion cells varies with season: it appears to be strongly expressed only during the migratory period when the birds show nocturnal migratory restlessness. Since the avian magnetic compass does not seem to be restricted to the migratory phase, this seasonal variation makes a role of eCry1b in magnetoreception rather unlikely. Rather, it could be involved in physiological processes controlling migratory restlessness and thus enabling birds to perform their nocturnal flights. PMID:26953690

  14. Seasonally Changing Cryptochrome 1b Expression in the Retinal Ganglion Cells of a Migrating Passerine Bird

    PubMed Central

    Nießner, Christine; Gross, Julia Christina; Denzau, Susanne; Peichl, Leo; Fleissner, Gerta; Wiltschko, Wolfgang; Wiltschko, Roswitha

    2016-01-01

    Cryptochromes, blue-light absorbing proteins involved in the circadian clock, have been proposed to be the receptor molecules of the avian magnetic compass. In birds, several cryptochromes occur: Cryptochrome 2, Cryptochrome 4 and two splice products of Cryptochrome 1, Cry1a and Cry1b. With an antibody not distinguishing between the two splice products, Cryptochrome 1 had been detected in the retinal ganglion cells of garden warblers during migration. A recent study located Cry1a in the outer segments of UV/V-cones in the retina of domestic chickens and European robins, another migratory species. Here we report the presence of cryptochrome 1b (eCry1b) in retinal ganglion cells and displaced ganglion cells of European Robins, Erithacus rubecula. Immuno-histochemistry at the light microscopic and electron microscopic level showed eCry1b in the cell plasma, free in the cytosol as well as bound to membranes. This is supported by immuno-blotting. However, this applies only to robins in the migratory state. After the end of the migratory phase, the amount of eCry1b was markedly reduced and hardly detectable. In robins, the amount of eCry1b in the retinal ganglion cells varies with season: it appears to be strongly expressed only during the migratory period when the birds show nocturnal migratory restlessness. Since the avian magnetic compass does not seem to be restricted to the migratory phase, this seasonal variation makes a role of eCry1b in magnetoreception rather unlikely. Rather, it could be involved in physiological processes controlling migratory restlessness and thus enabling birds to perform their nocturnal flights. PMID:26953690

  15. Patterns of bird migration phenology in South Africa suggest northern hemisphere climate as the most consistent driver of change.

    PubMed

    Bussière, Elsa M S; Underhill, Les G; Altwegg, Res

    2015-06-01

    Current knowledge of phenological shifts in Palearctic bird migration is largely based on data collected on migrants at their breeding grounds; little is known about the phenology of these birds at their nonbreeding grounds, and even less about that of intra-African migrants. Because climate change patterns are not uniform across the globe, we can expect regional disparities in bird phenological responses. It is also likely that they vary across species, as species show differences in the strength of affinities they have with particular habitats and environments. Here, we examine the arrival and departure of nine Palearctic and seven intra-African migratory species in the central Highveld of South Africa, where the former spend their nonbreeding season and the latter their breeding season. Using novel analytical methods based on bird atlas data, we show phenological shifts in migration of five species - red-backed shrike, spotted flycatcher, common sandpiper, white-winged tern (Palearctic migrants), and diederik cuckoo (intra-African migrant) - between two atlas periods: 1987-1991 and 2007-2012. During this time period, Palearctic migrants advanced their departure from their South African nonbreeding grounds. This trend was mainly driven by waterbirds. No consistent changes were observed for intra-African migrants. Our results suggest that the most consistent drivers of migration phenological shifts act in the northern hemisphere, probably at the breeding grounds. PMID:25640890

  16. Pre-migration Trauma Exposure and Psychological Distress for Asian American Immigrants: Linking the Pre- and Post-migration Contexts.

    PubMed

    Li, Miao; Anderson, James G

    2016-08-01

    Drawing on the life course perspective and the assumptive world theory, this paper examines whether pre-migration trauma exposure is associated with psychological distress through post-migration perceived discrimination for Asian American immigrants. The study is based on cross-sectional data from the National Latino and Asian American Study (N = 1639). Structural equation model is used to estimate the relationship between pre-migration trauma, post-migration perceived discrimination, and psychological distress. Additional models are estimated to explore possible variations across ethnic groups as well as across different types of pre-migration trauma experience. Pre-migration trauma exposure is associated with higher levels of psychological distress, both directly and indirectly through higher level of perceived discrimination, even after controlling for demographic/acculturative factors and post-migration trauma exposure. This pattern holds for the following sub-types of pre-migration trauma: political trauma, crime victimization, physical violence, accidental trauma, and relational trauma. Multi-group analyses show that this pattern holds for all Asian immigrant subgroups except the Vietnamese. Studies of immigrant mental health primarily focus on post-migration stressors. Few studies have considered the link between pre- and post-migration contexts in assessing mental health outcomes. The study illustrates the usefulness of bridging the pre- and post-migration context in identifying the mental health risks along the immigrant life course. PMID:26319042

  17. Why do some, but not all, tropical birds migrate? A comparative study of diet breadth and fruit preference

    USGS Publications Warehouse

    Boyle, W.A.; Conway, C.J.; Bronstein, Judith L.

    2011-01-01

    Annual migrations of birds profoundly influence terrestrial communities. However, few empirical studies examine why birds migrate, in part due to the difficulty of testing causal hypotheses in long-distance migration systems. Short-distance altitudinal migrations provide relatively tractable systems in which to test explanations for migration. Many past studies explain tropical altitudinal migration as a response to spatial and temporal variation in fruit availability. Yet this hypothesis fails to explain why some coexisting, closely-related frugivorous birds remain resident year-round. We take a mechanistic approach by proposing and evaluating two hypotheses (one based on competitive exclusion and the other based on differences in dietary specialization) to explain why some, but not all, tropical frugivores migrate. We tested predictions of these hypotheses by comparing diets, fruit preferences, and the relationships between diet and preference in closely-related pairs of migrant and resident species. Fecal samples and experimental choice trials revealed that sympatric migrants and residents differed in both their diets and fruit preferences. Migrants consumed a greater diversity of fruits and fewer arthropods than did their resident counterparts. Migrants also tended to have slightly stronger fruit preferences than residents. Most critically, diets of migrants more closely matched their preferences than did the diets of residents. These results suggest that migrants may be competitively superior foragers for fruit compared to residents (rather than vice versa), implying that current competitive interactions are unlikely to explain variation in migratory behavior among coexisting frugivores. We found some support for the dietary specialization hypothesis, propose refinements to the mechanism underlying this hypothesis, and discuss how dietary specialization might ultimately reflect past interspecific competition. We recommend that future studies quantify variation

  18. Rapid loss of antipredatory behaviour in captive-bred birds is linked to current avian invasions.

    PubMed

    Carrete, Martina; Tella, José L

    2015-01-01

    Despite the importance of behaviour in conservation biology, there have been few studies that address behaviour in areas such as invasion ecology. There is an urgent need to identify specific traits that facilitate the establishment and spread of alien species to prevent biological invasions and their impact on biodiversity. Changes in antipredatory behaviour in captivity have been proposed to explain the higher invasiveness of wild-caught exotic species. We experimentally tested this hypothesis by assessing the response of wild-caught and captive-bred cage birds facing an approaching predator and their ability to escape from human capture, using species available in the Spanish pet market. Results showed the loss of antipredatory responses and escape abilities in captive-bred birds compared with wild-caught ones. An intraspecific comparison between wild-caught and the first generation of captive-bred birds pointed to a rapid behavioural loss in captivity (individual lifetime) rather than to differences among species (evolutionary exposure). In the context of current avian invasions, the proportion of individuals showing antipredatory responses within a species was positively related to the likelihood of the species being found escaped and breeding in the wild. These results offer a link between behaviour, fitness, and the invasion syndrome in birds. PMID:26667185

  19. Rapid loss of antipredatory behaviour in captive-bred birds is linked to current avian invasions

    PubMed Central

    Carrete, Martina; Tella, José L.

    2015-01-01

    Despite the importance of behaviour in conservation biology, there have been few studies that address behaviour in areas such as invasion ecology. There is an urgent need to identify specific traits that facilitate the establishment and spread of alien species to prevent biological invasions and their impact on biodiversity. Changes in antipredatory behaviour in captivity have been proposed to explain the higher invasiveness of wild-caught exotic species. We experimentally tested this hypothesis by assessing the response of wild-caught and captive-bred cage birds facing an approaching predator and their ability to escape from human capture, using species available in the Spanish pet market. Results showed the loss of antipredatory responses and escape abilities in captive-bred birds compared with wild-caught ones. An intraspecific comparison between wild-caught and the first generation of captive-bred birds pointed to a rapid behavioural loss in captivity (individual lifetime) rather than to differences among species (evolutionary exposure). In the context of current avian invasions, the proportion of individuals showing antipredatory responses within a species was positively related to the likelihood of the species being found escaped and breeding in the wild. These results offer a link between behaviour, fitness, and the invasion syndrome in birds. PMID:26667185

  20. Birds of Two Oceans? Trans-Andean and Divergent Migration of Black Skimmers (Rynchops niger cinerascens) from the Peruvian Amazon

    PubMed Central

    Davenport, Lisa C.

    2016-01-01

    Seasonal flooding compels some birds that breed in aquatic habitats in Amazonia to undertake annual migrations, yet we know little about how the complex landscape of the Amazon region is used seasonally by these species. The possibility of trans-Andes migration for Amazonian breeding birds has largely been discounted given the high geographic barrier posed by the Andean Cordillera and the desert habitat along much of the Pacific Coast. Here we demonstrate a trans-Andes route for Black Skimmers (Rynchops niger cinerascens) breeding on the Manu River (in the lowlands of Manu National Park, Perú), as well as divergent movement patterns both regionally and across the continent. Of eight skimmers tracked with satellite telemetry, three provided data on their outbound migrations, with two crossing the high Peruvian Andes to the Pacific. A third traveled over 1800 km to the southeast before transmissions ended in eastern Paraguay. One of the two trans-Andean migrants demonstrated a full round-trip migration back to its tagging location after traveling down the Pacific Coast from latitude 9° South to latitude 37° S, spending the austral summer in the Gulf of Arauco, Chile. This is the first documentation of a trans-Andes migration observed for any bird breeding in lowland Amazonia. To our knowledge, this research also documents the first example of a tropical-breeding waterbird migrating out of the tropics to spend the non-breeding season in the temperate summer, this being the reverse pattern with respect to seasonality for austral migrants in general. PMID:26760301

  1. Birds of Two Oceans? Trans-Andean and Divergent Migration of Black Skimmers (Rynchops niger cinerascens) from the Peruvian Amazon.

    PubMed

    Davenport, Lisa C; Goodenough, Katharine S; Haugaasen, Torbjørn

    2016-01-01

    Seasonal flooding compels some birds that breed in aquatic habitats in Amazonia to undertake annual migrations, yet we know little about how the complex landscape of the Amazon region is used seasonally by these species. The possibility of trans-Andes migration for Amazonian breeding birds has largely been discounted given the high geographic barrier posed by the Andean Cordillera and the desert habitat along much of the Pacific Coast. Here we demonstrate a trans-Andes route for Black Skimmers (Rynchops niger cinerascens) breeding on the Manu River (in the lowlands of Manu National Park, Perú), as well as divergent movement patterns both regionally and across the continent. Of eight skimmers tracked with satellite telemetry, three provided data on their outbound migrations, with two crossing the high Peruvian Andes to the Pacific. A third traveled over 1800 km to the southeast before transmissions ended in eastern Paraguay. One of the two trans-Andean migrants demonstrated a full round-trip migration back to its tagging location after traveling down the Pacific Coast from latitude 9° South to latitude 37° S, spending the austral summer in the Gulf of Arauco, Chile. This is the first documentation of a trans-Andes migration observed for any bird breeding in lowland Amazonia. To our knowledge, this research also documents the first example of a tropical-breeding waterbird migrating out of the tropics to spend the non-breeding season in the temperate summer, this being the reverse pattern with respect to seasonality for austral migrants in general. PMID:26760301

  2. Linking the evolution of body shape and locomotor biomechanics in bird-line archosaurs.

    PubMed

    Allen, Vivian; Bates, Karl T; Li, Zhiheng; Hutchinson, John R

    2013-05-01

    Locomotion in living birds (Neornithes) has two remarkable features: feather-assisted flight, and the use of unusually crouched hindlimbs for bipedal support and movement. When and how these defining functional traits evolved remains controversial. However, the advent of computer modelling approaches and the discoveries of exceptionally preserved key specimens now make it possible to use quantitative data on whole-body morphology to address the biomechanics underlying this issue. Here we use digital body reconstructions to quantify evolutionary trends in locomotor biomechanics (whole-body proportions and centre-of-mass position) across the clade Archosauria. We use three-dimensional digital reconstruction to estimate body shape from skeletal dimensions for 17 archosaurs along the ancestral bird line, including the exceptionally preserved, feathered taxa Microraptor, Archaeopteryx, Pengornis and Yixianornis, which represent key stages in the evolution of the avian body plan. Rather than a discrete transition from more-upright postures in the basal-most birds (Avialae) and their immediate outgroup deinonychosauria, our results support hypotheses of a gradual, stepwise acquisition of more-crouched limb postures across much of theropod evolution, although we find evidence of an accelerated change within the clade Maniraptora (birds and their closest relatives, such as deinonychosaurs). In addition, whereas reduction of the tail is widely accepted to be the primary morphological factor correlated with centre-of-mass position and, hence, evolution of hindlimb posture, we instead find that enlargement of the pectoral limb and several associated trends have a much stronger influence. Intriguingly, our support for the onset of accelerated morpho-functional trends within Maniraptora is closely correlated with the evolution of flight. Because we find that the evolution of enlarged forelimbs is strongly linked, via whole-body centre of mass, to hindlimb function during

  3. 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.

  4. 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, III

    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

  5. Making connections for bird conservation: linking states, provinces & territories to important wintering and breeding grounds

    USGS Publications Warehouse

    Blancher, P.J.; Jacobs, B.; Couturier, A.; Beardmore, C.J.; Dettmers, R.; Dunn, E.H.; Easton, W.; Iñigo-Elias, E.E.; Rich, T.D.; Rosenberg, K.V.; Ruth, J.M.

    2006-01-01

    To effectively conserve migratory landbirds, we need to be involved in conservation beyond our political borders. This has been a central tenet of Partners in Flight (PIF) since the initiative began in 1990 with a focus on Nearctic-Neotropical migrants. Implementation of this concept has also been fundamental to the success of the North American Waterfowl Management Plan (e.g., NAWMP 2004). Actions by individual states, provinces and territories are key to the success of PIF efforts at the continental scale, and great progress has been made in recent years though various initiatives. Currently, U.S. state Wildlife Action Plans are outlining a vast array of actions to benefit priority species. However, it is also very important to take action in regions that support these same species at the other end of their migratory movements, to ensure effective protection year-round (Rappole et al. 1983, Webster and Marra 2005, Elliott et al. 2005). For instance, conservation action is needed on the wintering grounds for many birds that breed in Canada and the U.S. but spend a large portion of their annual cycle in Mexico, the West Indies, Central and/or South America. In this document we use maps to summarize migratory connections between individual U.S. states, Canadian provinces & territories and the regions that support the same birds at the other end of migration. The maps give a general picture of where birds go, providing a starting point for targeting action. With this information in hand, decision-makers can explore partnerships and mechanism that would help further conservation action outside their bordersa?|

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

    PubMed

    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

    2015-11-01

    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 ([Formula: see text], 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

  7. Linking morphodynamics and directional persistence of T lymphocyte migration.

    PubMed

    Liu, Xiaji; Welf, Erik S; Haugh, Jason M

    2015-05-01

    T cells play a central role in the adaptive immune response, and their directed migration is essential for homing to sites of antigen presentation. Like neutrophils, T lymphocytes are rapidly moving cells that exhibit amoeboid movement, characterized by a definitive polarity with F-actin concentrated at the front and myosin II elsewhere. In this study, we used total internal reflection fluorescence (TIRF) microscopy to monitor the cells' areas of contact with a surface presenting adhesive ICAM-1 and the chemokine, CXCL12/SDF-1. Our analysis reveals that T-cell migration and reorientation are achieved by bifurcation and lateral separation of protrusions along the leading membrane edge, followed by cessation of one of the protrusions, which acts as a pivot for cell turning. We show that the distribution of bifurcation frequencies exhibits characteristics of a random, spontaneous process; yet, the waiting time between bifurcation events depends on whether or not the pivot point remains on the same side of the migration axis. Our analysis further suggests that switching of the dominant protrusion between the two sides of the migration axis is associated with persistent migration, whereas the opposite is true of cell turning. To help explain the bifurcation phenomenon and how distinct migration behaviours might arise, a spatio-temporal, stochastic model describing F-actin dynamics is offered. PMID:25904526

  8. Linking Dynamic Habitat Selection with Wading Bird Foraging Distributions across Resource Gradients

    PubMed Central

    Beerens, James M.; Noonburg, Erik G.; Gawlik, Dale E.

    2015-01-01

    Species distribution models (SDM) link species occurrence with a suite of environmental predictors and provide an estimate of habitat quality when the variable set captures the biological requirements of the species. SDMs are inherently more complex when they include components of a species’ ecology such as conspecific attraction and behavioral flexibility to exploit resources that vary across time and space. Wading birds are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality; thus serving as important indicator species for wetland systems. We developed a spatio-temporal, multi-SDM framework using Great Egret (Ardea alba), White Ibis (Eudocimus albus), and Wood Stork (Mycteria Americana) distributions over a decadal gradient of environmental conditions to predict species-specific abundance across space and locations used on the landscape over time. In models of temporal dynamics, species demonstrated conditional preferences for resources based on resource levels linked to differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of inundation was concentrated in shallow depths. Similar responses were observed in models predicting locations used over time, accounting for spatial autocorrelation. Species clustered in response to differing habitat conditions, indicating that social attraction can co-vary with foraging strategy, water-level changes, and habitat quality. This modeling framework can be applied to evaluate the multi-annual resource pulses occurring in real-time, climate change scenarios, or restorative hydrological regimes by tracking changing seasonal and annual distribution and abundance of high quality foraging patches. PMID:26107386

  9. Linking Dynamic Habitat Selection with Wading Bird Foraging Distributions across Resource Gradients.

    PubMed

    Beerens, James M; Noonburg, Erik G; Gawlik, Dale E

    2015-01-01

    Species distribution models (SDM) link species occurrence with a suite of environmental predictors and provide an estimate of habitat quality when the variable set captures the biological requirements of the species. SDMs are inherently more complex when they include components of a species' ecology such as conspecific attraction and behavioral flexibility to exploit resources that vary across time and space. Wading birds are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality; thus serving as important indicator species for wetland systems. We developed a spatio-temporal, multi-SDM framework using Great Egret (Ardea alba), White Ibis (Eudocimus albus), and Wood Stork (Mycteria Americana) distributions over a decadal gradient of environmental conditions to predict species-specific abundance across space and locations used on the landscape over time. In models of temporal dynamics, species demonstrated conditional preferences for resources based on resource levels linked to differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of inundation was concentrated in shallow depths. Similar responses were observed in models predicting locations used over time, accounting for spatial autocorrelation. Species clustered in response to differing habitat conditions, indicating that social attraction can co-vary with foraging strategy, water-level changes, and habitat quality. This modeling framework can be applied to evaluate the multi-annual resource pulses occurring in real-time, climate change scenarios, or restorative hydrological regimes by tracking changing seasonal and annual distribution and abundance of high quality foraging patches. PMID:26107386

  10. Linking dynamic habitat selection with wading bird foraging distributions across resource gradients

    USGS Publications Warehouse

    Beerens, James; Noonberg, Erik G.; Gawlik, Dale E.

    2015-01-01

    Species distribution models (SDM) link species occurrence with a suite of environmental predictors and provide an estimate of habitat quality when the variable set captures the biological requirements of the species. SDMs are inherently more complex when they include components of a species' ecology such as conspecific attraction and behavioral flexibility to exploit resources that vary across time and space. Wading birds are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality; thus serving as important indicator species for wetland systems. We developed a spatio-temporal, multi-SDM framework using Great Egret (Ardea alba), White Ibis (Eudocimus albus), and Wood Stork (Mycteria Americana) distributions over a decadal gradient of environmental conditions to predict species-specific abundance across space and locations used on the landscape over time. In models of temporal dynamics, species demonstrated conditional preferences for resources based on resource levels linked to differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of inundation was concentrated in shallow depths. Similar responses were observed in models predicting locations used over time, accounting for spatial autocorrelation. Species clustered in response to differing habitat conditions, indicating that social attraction can co-vary with foraging strategy, water-level changes, and habitat quality. This modeling framework can be applied to evaluate the multi-annual resource pulses occurring in real-time, climate change scenarios, or restorative hydrological regimes by tracking changing seasonal and annual distribution and abundance of high quality foraging patches.

  11. Assessment of the Impacts of Green Mountain Power Corporation's Wind Power Facility on Breeding and Migrating Birds in Searsburg, Vermont: July 1996--July 1998

    SciTech Connect

    Kerlinger, P.

    2002-03-01

    A 6-megawatt, 11 turbine wind power development was constructed by Green Mountain Power Corporation in Searsburg, southern Vermont, in 1996. To determine whether birds were impacted, a series of modified BA (Before, After) studies was conducted before construction (1993-1996), during (1996), and after (1997) construction on the project site. The studies were designed to monitor changes in breeding bird community (species composition and abundance) on the site, examine the behavior and numbers of songbirds migrating at night over the site and hawks migrating over the site in daylight, and search for carcasses of birds that might have collided with the turbines.

  12. The gliding speed of migrating birds: slow and safe or fast and risky?

    PubMed

    Horvitz, Nir; Sapir, Nir; Liechti, Felix; Avissar, Roni; Mahrer, Isaac; Nathan, Ran

    2014-06-01

    Aerodynamic theory postulates that gliding airspeed, a major flight performance component for soaring avian migrants, scales with bird size and wing morphology. We tested this prediction, and the role of gliding altitude and soaring conditions, using atmospheric simulations and radar tracks of 1346 birds from 12 species. Gliding airspeed did not scale with bird size and wing morphology, and unexpectedly converged to a narrow range. To explain this discrepancy, we propose that soaring-gliding birds adjust their gliding airspeed according to the risk of grounding or switching to costly flapping flight. Introducing the Risk Aversion Flight Index (RAFI, the ratio of actual to theoretical risk-averse gliding airspeed), we found that inter- and intraspecific variation in RAFI positively correlated with wing loading, and negatively correlated with convective thermal conditions and gliding altitude, respectively. We propose that risk-sensitive behaviour modulates the evolution (morphology) and ecology (response to environmental conditions) of bird soaring flight. PMID:24641086

  13. Linking North Slope Climate, Hydrology, and Fish Migration

    NASA Astrophysics Data System (ADS)

    Betts, E.; Kane, D. L.

    2010-12-01

    Fish and wildlife species in the Arctic have developed life history strategies to deal with the extreme climate of the North. In the case of Arctic grayling, these strategies include long life, yearly spawning, and migration. In order to understand how such a species will be affected by a changing climate, we must determine how these adaptive strategies may be at odds with the changing Arctic landscape. Arctic grayling migrate in the spring and early summer to spawning and feeding sites and then in the fall migrate back to overwintering sites. Migration to spawning sites occurs just after break up when rivers are quite swollen from the melting of an entire winter’s worth of snow. Low precipitation and high evapotranspiration rates early in the summer can lead to low water levels and a fragmentation of the hydrologic landscape. This fragmentation creates a barrier to fish migration. As the summer progresses, precipitation tends to increase and evapotranspiration decreases. Hydrologic connectivity is generally restored by the end of summer and soils are wet prior to freeze-up. Increased temperatures associated with climate change lead to greater evapotranspiration. This may lead to increased drying in the summer in the Arctic. Although annual precipitation rates are expected to increase, the direction and magnitude of the change in summer precipitation is less clear. Another possible change in precipitation may be in the form of increased variability or in the probability of extreme events. The research to be presented here details an attempt to recreate the occurrence of hydrologic barriers to fish migration in the Upper Kuparuk River on the North Slope of Alaska. Locations along the Upper Kuparuk which become barriers to migration during low flows were identified and monitored during the summer of 2010. These locations were chosen because during previous low flow events, these stretches run dry even though water is seen flowing both up and downstream of these

  14. Fast-X on the Z: Rapid evolution of sex-linked genes in birds

    PubMed Central

    Mank, Judith E.; Axelsson, Erik; Ellegren, Hans

    2007-01-01

    Theoretical work predicts natural selection to be more efficient in the fixation of beneficial mutations in X-linked genes than in autosomal genes. This “fast-X effect” should be evident by an increased ratio of nonsynonymous to synonymous substitutions (dN/dS) for sex-linked genes; however, recent studies have produced mixed support for this expectation. To make an independent test of the idea of fast-X evolution, we focused on birds, which have female heterogamety (males ZZ, females ZW), where analogous arguments would predict a fast-Z effect. We aligned 2.8 Mb of orthologous protein-coding sequence of zebra finch and chicken from 172 Z-linked and 4848 autosomal genes. Zebra finch data were in the form of EST sequences from brain cDNA libraries, while chicken genes were from the draft genome sequence. The dN/dS ratio was significantly higher for Z-linked (0.110) than for all autosomal genes (0.085; P = 0.002), as well as for genes linked to similarly sized autosomes 1–10 (0.0948; P = 0.04). This pattern of fast-Z was evident even after we accounted for the nonrandom distribution of male-biased genes. We also examined the nature of standing variation in the chicken protein-coding regions. The ratio of nonsynonymous to synonymous polymorphism (pN/pS) did not differ significantly between genes on the Z chromosome (0.104) and on the autosomes (0.0908). In conjunction, these results suggest that evolution proceeds more quickly on the Z chromosome, where hemizygous exposure of beneficial nondominant mutations increases the rate of fixation. PMID:17416747

  15. Ecosystem connectivity: anadromous fish migration linked to freshwater amphipods

    NASA Astrophysics Data System (ADS)

    Macavoy, S. E.; Fogel, M. L.; Fong, D.; Hanson, N.

    2009-12-01

    Anadromous fish migrate to coastal streams to spawn each spring and may transfer marine derived nutrients to oligotrophic tidal freshwater. River herring (Alosa sp) are the dominant anadromous genus in Virginia, USA. This study investigates whether marine nutrients derived by the spawning Alosa were incorporated into benthic invertebrates by using the stable isotopes of carbon and nitrogen. Spawning Alosa had higher δ13C and δ15N than resident freshwater omnivorous fishes (-18.5 and 13.9‰ versus -25.7 and 11.8‰). In a tidal stream supporting abundant spawning Alosa, significant 13C and 15N enrichment was observed among stream invertebrates, particularly in the amphipod Gammarus fasciatus, coincident with the Alosa spawning migration. Among G. fasciatus, δ13C increased from -28.5 to -26.0‰ between early and late April then fell to -28.1‰ in early June. A similar trend was observed in mayflies (Heptageniidae). In an adjacent tidal stream that did not support spawning Alosa, enrichment among invertebrates was not observed. Particulate organic matter and sediments from both streams remained 13C and 15N depleted during the Alosa spawning run (between -29 and -28‰, 0.5 and 3.0‰ respectively), suggesting that marine material was not present. Although marine organic material may have been incorporated into stream invertebrates, it did not become a substantial component of other ecosystem components measured.

  16. It is time to move: linking flight and foraging behaviour in a diving bird.

    PubMed

    Pelletier, David; Guillemette, Magella; Grandbois, Jean-Marc; Butler, Patrick J

    2007-08-22

    Although the adaptive value of flight may seem obvious, it is the most difficult behaviour of birds to monitor. Here, we describe a technique to quantify the frequency and the duration of flights over several months by implanting a data logger that records heart rate (fH), hydrostatic pressure (diving depth) and the body angle of a large sea duck species, the common eider (Somateria mollissima). According to the mean fH recorded during flight and the parameters recorded to identify the fH flight signature, we were able to identify all flights performed by 13 individuals during eight months. We cumulated local flight time (outside migrations) and found that activity occurs primarily during dawn and morning and that flying activities are strongly related to diving activities (Pearson's r=0.88, permutation test p<0.001). This relationship was interpreted as a consequence of living in a dynamic environment where sea currents move the ducks away from the food patches. We believe that the technique described here will open new avenues of investigation in the adaptive value of flight. PMID:17504730

  17. Timing of autumn bird migration under climate change: advances in long-distance migrants, delays in short-distance migrants

    USGS Publications Warehouse

    Jenni, L.; Kery, M.

    2003-01-01

    As a response to increasing spring temperature in temperate regions in recent years, populations of many plant and animal species, including migratory birds, have advanced the seasonal start of their reproduction or growth. However, the effects of climate changes on subsequent events of the annual cycle remain poorly understood. We investigated long-term changes in the timing of autumn migration in birds, a key event in the annual cycle limiting the reproductive period. Using data spanning a 42-year period, we analysed long-term changes in the passage of 65 species of migratory birds through Western Europe. The autumn passage of migrants wintering south of the Sahara has advanced in recent years, presumably as a result of selection pressure to cross the Sahel before its seasonal dry period. In contrast, migrants wintering north of the Sahara have delayed autumn passage. In addition, species with a variable rather than a fixed number of broods per year have delayed passage, possibly because they are free to attempt more broods. Recent climate changes seem to have a simple unidirectional effect on the seasonal onset of reproduction, but complex and opposing effects on the timing of subsequent events in the annual cycle, depending on the ecology and life history of a species. This complicates predictions of overall effects of global warming on avian communities.

  18. Variation of Basal EROD Activities in Ten Passerine Bird Species – Relationships with Diet and Migration Status

    PubMed Central

    Rainio, Miia J.; Kanerva, Mirella; Wahlberg, Niklas; Nikinmaa, Mikko; Eeva, Tapio

    2012-01-01

    Inter-specific differences in animal defence mechanisms against toxic substances are currently poorly understood. The ethoxyresorufin-O-deethylase (EROD) enzyme plays an important role in defence against toxic chemicals in a wide variety of animals, and it is an important biomarker for environmental contamination. We compared basal hepatic EROD activity levels among ten passerine species to see if there is inter-specific variation in enzyme activity, especially in relation to their diet and migration status. Migratory insectivores showed higher EROD activity compared to granivores. We hypothesize that the variable invertebrate diet of migratory insectivores contains a wider range of natural toxins than the narrower diet of granivores. This may have affected the evolution of mixed function oxidases (MFO) system and enzyme activities. We further tested whether metabolic rates or relative liver size were associated with the variation in detoxification capacity. We found no association between EROD activity and relative (per mass unit) basal metabolic rate (BMR). Instead, EROD activity and relative liver mass (% of body mass) correlated positively, suggesting that a proportionally large liver also functions efficiently. Our results suggest that granivores and non-migratory birds may be more vulnerable to environmental contaminants than insectivores and migratory birds. The diet and migration status, however, are phylogenetically strongly connected to each other, and their roles cannot be fully separated in our analysis with only ten passerine species. PMID:22479477

  19. Findings from an Independent Evaluation of the AMNH's Online Seminars on Science Course: "The Link between Dinosaurs and Birds"

    ERIC Educational Resources Information Center

    Inverness Research, 2008

    2008-01-01

    Inverness Research studied the American Museum of Natural History's (AMNH) Seminars on Science program for eight years, from its inception in 1998 to 2006. This paper presents teacher survey ratings for "The Link between Dinosaurs and Birds", along with profiles of three teachers who took the course. Course takers report on the annual follow-up…

  20. Disease Dynamics and Bird Migration—Linking Mallards Anas platyrhynchos and Subtype Diversity of the Influenza A Virus in Time and Space

    PubMed Central

    Gunnarsson, Gunnar; Latorre-Margalef, Neus; Hobson, Keith A.; Van Wilgenburg, Steven L.; Elmberg, Johan; Olsen, Björn; Fouchier, Ron A. M.; Waldenström, Jonas

    2012-01-01

    The mallard Anas platyrhynchos is a reservoir species for influenza A virus in the northern hemisphere, with particularly high prevalence rates prior to as well as during its prolonged autumn migration. It has been proposed that the virus is brought from the breeding grounds and transmitted to conspecifics during subsequent staging during migration, and so a better understanding of the natal origin of staging ducks is vital to deciphering the dynamics of viral movement pathways. Ottenby is an important stopover site in southeast Sweden almost halfway downstream in the major Northwest European flyway, and is used by millions of waterfowl each year. Here, mallards were captured and sampled for influenza A virus infection, and positive samples were subtyped in order to study possible links to the natal area, which were determined by a novel approach combining banding recovery data and isotopic measurements (δ2H) of feathers grown on breeding grounds. Geographic assignments showed that the core natal areas of studied mallards were in Estonia, southern and central Finland, and northwestern Russia. This study demonstrates a clear temporal succession of latitudes of natal origin during the course of autumn migration. We also demonstrate a corresponding and concomitant shift in virus subtypes. Acknowledging that these two different patterns were based in part upon different data, a likely interpretation worth further testing is that the early arriving birds with more proximate origins have different influenza A subtypes than the more distantly originating late autumn birds. If true, this knowledge would allow novel insight into the origins and transmission of the influenza A virus among migratory hosts previously unavailable through conventional approaches. PMID:22536424

  1. Ecological conditions in wintering and passage areas as determinants of timing of spring migration in trans-Saharan migratory birds.

    PubMed

    Robson, David; Barriocanal, Carles

    2011-03-01

    1. Climate change has been associated with shifts in the timing of biological events, including the spring arrival of migratory birds. Early arrival at breeding sites is an important life-history trait, usually associated with higher breeding success and therefore, susceptible to selection and evolution in response to changing climatic conditions. 2. Here, we examine the effect of changes in the environmental conditions of wintering and passage areas on the mean passage time of 13 trans-Saharan passerines during their spring migration through the western Mediterranean over the 15 years from 1993 to 2007. 3. We found that most of the species studied have been advancing the timing of their passage in recent years. However, annual variation in the mean date of passage was positively correlated with vegetation growth (measured as the normalized difference vegetation index [NDVI]) both in the Sahel (the region of departure) and in northern Africa (the passage area). Thus, migration dates were delayed in years with high primary productivity in passage and wintering zones. All species seem to respond similarly to NDVI in the Sahel; however, late migrants were less affected by ecological conditions in northern Africa than those migrating earlier, suggesting differences based on species ecology. 4. Mean timing of passage was not related to the North Atlantic Oscillation (NAO), El Niño-Southern Oscillation (ENSO), temperature or NDVI in the species-specific wintering areas (the overwintering region) when analysed in combination with the other covariates. 5. Our findings show that ecological conditions in the winter quarters (specifically the Sahel) and en route are relevant factors influencing trends in the passage dates of trans-Saharan migratory birds on the southern fringe of Europe. Possible long-term consequences for late arriving spring migrants are discussed. PMID:21073454

  2. Maternal Condition but Not Corticosterone Is Linked to Offspring Sex Ratio in a Passerine Bird

    PubMed Central

    Henderson, Lindsay J.; Evans, Neil P.; Heidinger, Britt J.; Adams, Aileen; Arnold, Kathryn E.

    2014-01-01

    There is evidence of offspring sex ratio adjustment in a range of species, but the potential mechanisms remain largely unknown. Elevated maternal corticosterone (CORT) is associated with factors that can favour brood sex ratio adjustment, such as reduced maternal condition, food availability and partner attractiveness. Therefore, the steroid hormone has been suggested to play a key role in sex ratio manipulation. However, despite correlative and causal evidence CORT is linked to sex ratio manipulation in some avian species, the timing of adjustment varies between studies. Consequently, whether CORT is consistently involved in sex-ratio adjustment, and how the hormone acts as a mechanism for this adjustment remains unclear. Here we measured maternal baseline CORT and body condition in free-living blue tits (Cyanistes caeruleus) over three years and related these factors to brood sex ratio and nestling quality. In addition, a non-invasive technique was employed to experimentally elevate maternal CORT during egg laying, and its effects upon sex ratio and nestling quality were measured. We found that maternal CORT was not correlated with brood sex ratio, but mothers with elevated CORT fledged lighter offspring. Also, experimental elevation of maternal CORT did not influence brood sex ratio or nestling quality. In one year, mothers in superior body condition produced male biased broods, and maternal condition was positively correlated with both nestling mass and growth rate in all years. Unlike previous studies maternal condition was not correlated with maternal CORT. This study provides evidence that maternal condition is linked to brood sex ratio manipulation in blue tits. However, maternal baseline CORT may not be the mechanistic link between the maternal condition and sex ratio adjustment. Overall, this study serves to highlight the complexity of sex ratio adjustment in birds and the difficulties associated with identifying sex biasing mechanisms. PMID:25347532

  3. The Difference That Data Make: Examining Bird Migration Data to Build Scientific Skills

    ERIC Educational Resources Information Center

    Sturner, Kelly; Lucci, Karen

    2015-01-01

    This inquiry-based activity for high school students introduces concepts of ecology and the importance of data analysis to science. Using an investigative case, students generate independent questions about birds, access Cornell Lab of Ornithology online resources to collect data, organize and graph data using Excel, and make claims based on…

  4. Bird community composition linked to human West Nile virus cases along the Colorado front range.

    PubMed

    McKenzie, Valerie J; Goulet, Nicolas E

    2010-12-01

    In the present study, we examined whether bird community composition can predict the annual number of human West Nile virus (WNV) cases on a per county basis in the Colorado Front Range, a region that experienced high numbers of human cases during the early part of the North American epidemic. We analyzed data sets pertaining to birds and human WNV cases from multiple existing databases between the years 2002 and 2008. Based on previous studies that used amplification fractions to compare the relative competence of different bird species, ten bird species that are common in Colorado were selected and categorized as high amplification birds, such as the American Robin (Turdus migratorius), or low amplification birds, such as the American Crow (Corvus brachyrhynchos). A general linear modeling analysis was used with an information theoretic (AIC) model sorting approach to examine which of the models best predicted the number of human WNV cases per county. Candidate models included year as a covariate and one of several bird community descriptors (e.g., richness, diversity, total bird abundance, high amplification abundance, or low amplification abundance). Results demonstrated that high amplification birds were a significant predictor of human WNV cases between 2002 and 2008. Our results suggest that a small subset of the bird community with high amplification fractions may drive the dynamics of human disease risk for West Nile. This study has implications for surveillance of West Nile and may offer insight into disease risk associated with other vector-borne zoonotic diseases. PMID:21125307

  5. X-linked inheritance in neuronal migration disorders (NMD)

    SciTech Connect

    Andermann, E.; Dubeau, F.; Tampieri, D.

    1994-09-01

    With the advent of MRI imaging, an increasing number of NMD have been identified in patients with epilepsy. Although most cases have been sporadic, families with these disorders have now been reported in several types of NMD. Furthermore, subcortical bank heterotopia (SBH) or {open_quotes}double cortex syndrome{close_quotes} and periventricular nodular heterotopia (PNH) have a marked female predominance. Two females with SBH, mild mental retardation and seizures had sons with lissencephaly, severe retardation and seizures, and daughters with SBH. X-linked lissencephaly has been observed in several other families, and one girl with lissencephaly was found to have a de novo X-autosomal translocation with a breakpoint in chromosome Xq22. We have studied three families with two or more generations affected by PNH in females, a high frequency of spontaneous abortions and abnormal sex ratios in sibships. The clinical manifestations include seizures and normal intelligence. Three other families with PNH in females have been reported in the literature. Bilateral perisylvian polymicrogyria has been reported in monozygotic twins and in siblings, and we have studied a brother and sister with an affected maternal uncle. These findings suggest sex-linked dominant inheritance with male lethality or severe expression in males. The three disorders described above may represent different mutations of a single gene or mutations in two or more genes on the X-chromosome. At least one gene is probably located in chromosome band Xq22. Genetic linkage studies in families with NMD as well as a search for candidate genes such as adhesion molecules known to map on the X-chromosome should lead to the identification of the gene(s) responsible for these disorders.

  6. Population trends of grassland birds in North America are linked to the prevalence of an agricultural epizootic in Europe.

    PubMed

    Nocera, Joseph J; Koslowsky, Hannah M

    2011-03-22

    Globalization of trade has dramatic socioeconomic effects, and, intuitively, significant ecological effects should follow. However, few quantitative examples exist of the interrelationship of globalization, socioeconomics, and ecological patterns. We present a striking illustration of a cascade in which bovine spongiform encephalopathy (BSE; "mad cow disease") outbreaks in Europe exerted pressure on global beef markets, subsequently affecting North American hayfields and grassland bird populations. We examined competing models, which linked the prevalence of BSE in five focal countries, volume of beef exports to those countries from North America, and the amount of hayfield harvested and the abundance of grassland birds in North America. We found that (i) imports from North America increased 1 y after BSE outbreaks; (ii) probably because fewer cattle remained, the hay harvest in North America was reduced 2 y after the outbreak; (iii) the reduced hay harvest yielded a positive response in grassland bird populations 3 y after the outbreak. PMID:21383197

  7. Population trends of grassland birds in North America are linked to the prevalence of an agricultural epizootic in Europe

    PubMed Central

    Nocera, Joseph J.; Koslowsky, Hannah M.

    2011-01-01

    Globalization of trade has dramatic socioeconomic effects, and, intuitively, significant ecological effects should follow. However, few quantitative examples exist of the interrelationship of globalization, socioeconomics, and ecological patterns. We present a striking illustration of a cascade in which bovine spongiform encephalopathy (BSE; “mad cow disease”) outbreaks in Europe exerted pressure on global beef markets, subsequently affecting North American hayfields and grassland bird populations. We examined competing models, which linked the prevalence of BSE in five focal countries, volume of beef exports to those countries from North America, and the amount of hayfield harvested and the abundance of grassland birds in North America. We found that (i) imports from North America increased 1 y after BSE outbreaks; (ii) probably because fewer cattle remained, the hay harvest in North America was reduced 2 y after the outbreak; (iii) the reduced hay harvest yielded a positive response in grassland bird populations 3 y after the outbreak. PMID:21383197

  8. Birds, Birds, Birds!

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1992-01-01

    Ranger Rick's Nature Scope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. Contents are organized into the following sections: (1) "What Makes a Bird a Bird?," which provides…

  9. Competitive enzyme-linked immunoassay for sialoglycoprotein of edible bird's nest in food and cosmetics.

    PubMed

    Zhang, Shiwei; Lai, Xintian; Liu, Xiaoqing; Li, Yun; Li, Bifang; Huang, Xiuli; Zhang, Qinlei; Chen, Wei; Lin, Lin; Yang, Guowu

    2012-04-11

    The proliferation of fake and inferior edible bird's nest (EBN) products has recently become an increasingly serious concern. To identify and classify EBN products, a competitive enzyme-linked immunoassay (ELISA) was developed to quantitate sialoglycoprotein in EBN used in food and cosmetic applications. The characteristic sialoglycoprotein in EBN was found, extracted, purified, and analyzed. Sialoglycoprotein, considered the main carrier of sialic acid in EBN, consisted of 106 and 128 kDa proteins. A monoclonal antibody that could recognize both proteins was prepared. The heat-treated process did not change the affinity of sialoglycoprotein with the antibody. An optimized ELISA method was established with a cross-reactivity of less than 0.1% and an IC(50) of 3.3 μg/mL. On the basis of different food and cosmetic samples, the limits of detection (LOD) were 10-18 μg/g. Recoveries of fortified samples at levels of 20 and 80 μg/g ranged from 81.5 to 96.5%, respectively. The coefficients of variation were less than 8.0%. PMID:22439641

  10. Food-contact epoxy resin: co-variation between migration and degree of cross-linking.

    PubMed

    Lambert, C; Larroque, M; Lebrun, J C; Gérard, J F

    1997-01-01

    In order to predict the behaviour towards foodstuffs of an epoxy resin composed of bisphenol A diglycidyl ether (BADGE), 4,4'-methylenedianiline (MDA) and additives (plasticizers: dibutylphthalate (DBP), dioctylphthalate (DOP); accelerator: salicylic acid; inorganic fillers), a co-variation was established between the parameters evaluating the degree of cross-linking of the three-dimensional network and the migration of constituent molecules into various food simulants (distilled water, distilled water/ethanol/acetic acid, distilled water/ethanol). Varied degrees of cross-linking were obtained by subjecting the resin to different curing temperatures: respectively, 5 degrees C, 20 degrees C, 50 degrees C and 90 degrees C for 7 days. Irrespective of the food stimulant tested, specific migrations (DBP, DOP, salicylic acid, primary aromatic amines) diminished greatly as the curing temperature increased. At the same time, the degree of cross-linking increased with curing temperature, as indicated by the increase in glass transition temperature, the decrease in residual reaction exotherms and increased stability of the rubber storage modulus E'rub (increase in cross-link nodes), the fall in relaxation enthalpies (reduction in physical ageing) and the decreased amplitude of the loss-factor, tan delta (reduction in chain mobility). Maximum cross-linking was obtained in the resin cured at 90 degrees C (temperature above Tg infinity). In contrast to the degree of cross-linking, evaporation contributed little to the reduction of migration due to the elevation of curing temperature. PMID:9102353

  11. A landscape scale decision support tool for monitoring bird and bat migration across Wisconsin

    USGS Publications Warehouse

    Suarez, Manuel J.; Heglund, Patricia; 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.

  12. Population declines in North American birds that migrate to the neotropics

    USGS Publications Warehouse

    Robbins, C.S.; Sauer, J.R.; Greenberg, R.S.; Droege, S.

    1989-01-01

    Using data from the North American Breeding Bird Survey, we determined that most neotropical migrant bird species that breed in forests of the eastern United States and Canada have recently (1978-1987) declined in abundance after a period of stable or increasing populations. Most permanent residents and temperate-zone migrants did not show a general pattern of decrease during this period. Field data from Mexico were used to classify a subset of the neotropical migrants as using forest or scrub habitats during winter. Population declines during 1978-1987 were significantly greater among the forest-wintering species, while populations of scrub-wintering species increased. The same subset of neotropical migrants also showed overall declines in forest-breeding species, but no significant differences existed between species breeding in forest and scrub habitats. Neotropical migrant species that primarily use forested habitats in either wintering or breeding areas are declining, but a statistically significant association between habitat and population declines was detected only in the tropics.

  13. Differential migration and the link between winter latitude, timing of migration, and breeding in a songbird.

    PubMed

    Woodworth, Bradley K; Newman, Amy E M; Turbek, Sheela P; Dossman, Bryant C; Hobson, Keith A; Wassenaar, Leonard I; Mitchell, Greg W; Wheelwright, Nathaniel T; Norris, D Ryan

    2016-06-01

    Patterns of connectivity between breeding and wintering grounds can have important implications for individual fitness and population dynamics. Using light-level geolocators and stable hydrogen isotopes (δ(2)H) in feathers, we evaluated differential migration of Savannah sparrows (Passerculus sandwichensis) breeding on Kent Island in the Bay of Fundy, New Brunswick, Canada in relation to sex, age, and body size. Based on geolocators recovered from 38 individuals between 2012 and 2014, the winter distribution was centered in North Carolina (median latitude 34°, range 26°-41°), with males overwintering, on average, approximately 275 km further north than females. Based on analyses of tail feather samples collected from 106 individuals from the same population between 2008 and 2012, males and adults had more negative δ(2)H values than females and juveniles, respectively, providing additional evidence that males wintered north of females and that adults wintered north of juveniles. Winter latitude and δ(2)H values within each sex were not found to be related to body size. From geolocator data, males returned to the breeding grounds, on average, 14 days earlier than females. For males, there was some evidence that arrival date on the breeding grounds was negatively correlated with winter latitude and that individuals which arrived earlier tended to breed earlier. Thus, benefits for males of early arrival on the breeding grounds may have contributed to their wintering farther north than females. Social dominance may also have contributed to age and sex differences in winter latitude, whereby dominant males and adults forced subordinate females and juveniles further south. PMID:26888571

  14. Changing motivations during migration: linking movement speed to reproductive status in a migratory large mammal

    PubMed Central

    Singh, Navinder J.; Ericsson, Göran

    2014-01-01

    A challenge in animal ecology is to link animal movement to demography. In general, reproducing and non-reproducing animals may show different movement patterns. Dramatic changes in reproductive status, such as the loss of an offspring during the course of migration, might also affect movement. Studies linking movement speed to reproductive status require individual monitoring of life-history events and hence are rare. Here, we link movement data from 98 GPS-collared female moose (Alces alces) to field observations of reproductive status and calf survival. We show that reproductive females move more quickly during migration than non-reproductive females. Further, the loss of a calf over the course of migration triggered a decrease in speed of the female. This is in contrast to what might be expected for females no longer constrained by an accompanying offspring. The observed patterns demonstrate that females of different reproductive status may have distinct movement patterns, and that the underlying motivation to move may be altered by a change in reproductive status during migration. PMID:24942710

  15. Migrating birds : assessment of impact on 915-MHz radar wind profiler performance at the Atmospheric Radiation Measurement Program's southern great plains.

    SciTech Connect

    Pekour, M. S.

    2002-03-13

    The U. S. Department of Energy's Atmospheric Radiation Measurement Program is running a small network of 915-MHz radar wind profilers (RWPs) at its Southern Great Plains Cloud and Radiation Testbed site in northern Oklahoma and southern Kansas. Seasonal migration of passerines may cause significant interference with the operation of 915-MHz RWPs. The extent of this ''bird jamming'' depends on the radar's parameters, the place of deployment, the season, and the time of day. This poster presents a new diagnostic method for detecting possible bird contamination in RWP data, along with an evaluation of the method using a three-year data set for two RWPs.

  16. Loss of migration and urbanization in birds: a case study of the blackbird (Turdus merula).

    PubMed

    Møller, Anders Pape; Jokimäki, Jukka; Skorka, Piotr; Tryjanowski, Piotr

    2014-07-01

    Many organisms have invaded urban habitats, although the underlying factors initially promoting urbanization remain poorly understood. Partial migration may facilitate urbanization because such populations benefit from surplus food in urban environments during winter, and hence enjoy reduced fitness costs of migratory deaths. We tested this hypothesis in the European blackbird Turdus merula, which has been urbanized since the 19th century, by compiling information on timing of urbanization, migratory status, and population density for 99 cities across the continent. Timing of urbanization was spatially auto-correlated at scales up to 600 km. Analyses of timing of urbanization revealed that urbanization occurred earlier in partially migratory and resident populations than in migratory populations of blackbirds. Independently, this effect was most pronounced in the range of the distribution that currently has the highest population density, suggesting that urbanization facilitated population growth. These findings are consistent with the hypothesis that timing of urbanization is facilitated by partial migration, resulting in subsequent residency and population growth. PMID:24794076

  17. Displacement of p130Cas from focal adhesions links actomyosin contraction to cell migration.

    PubMed

    Machiyama, Hiroaki; Hirata, Hiroaki; Loh, Xia Kun; Kanchi, Madhu Mathi; Fujita, Hideaki; Tan, Song Hui; Kawauchi, Keiko; Sawada, Yasuhiro

    2014-08-15

    Cell adhesion complexes provide platforms where cell-generated forces are transmitted to the extracellular matrix (ECM). Tyrosine phosphorylation of focal adhesion proteins is crucial for cells to communicate with the extracellular environment. However, the mechanisms that transmit actin cytoskeletal motion to the extracellular environment to drive cell migration are poorly understood. We find that the movement of p130Cas (Cas, also known as BCAR1), a mechanosensor at focal adhesions, correlates with actin retrograde flow and depends upon actomyosin contraction and phosphorylation of the Cas substrate domain (CasSD). This indicates that CasSD phosphorylation underpins the physical link between Cas and the actin cytoskeleton. Fluorescence recovery after photobleaching (FRAP) experiments reveal that CasSD phosphorylation, as opposed to the association of Cas with Src, facilitates Cas displacement from adhesion complexes in migrating cells. Furthermore, the stabilization of Src-Cas binding and inhibition of myosin II, both of which sustain CasSD phosphorylation but mitigate Cas displacement from adhesion sites, retard cell migration. These results indicate that Cas promotes cell migration by linking actomyosin contractions to the adhesion complexes through a dynamic interaction with Src as well as through the phosphorylation-dependent association with the actin cytoskeleton. PMID:24928898

  18. Hyalomma ticks on northward migrating birds in southern Spain: Implications for the risk of entry of Crimean-Congo haemorrhagic fever virus to Great Britain.

    PubMed

    England, Marion E; Phipps, Paul; Medlock, Jolyon M; Atkinson, Peter M; Atkinson, Barry; Hewson, Roger; Gale, Paul

    2016-06-01

    Crimean-Congo haemorrhagic fever virus (CCHFV) is a zoonotic virus transmitted by Hyalomma ticks, the immature stages of which may be carried by migratory birds. In this study, a total of 12 Hyalomma ticks were recovered from five of 228 migratory birds trapped in Spring, 2012 in southern Spain along the East Atlantic flyway. All collected ticks tested negative for CCHFV. While most birds had zero Hyalomma ticks, two individuals had four and five ticks each and the statistical distribution of Hyalomma tick counts per bird is over-dispersed compared to the Poisson distribution, demonstrating the need for intensive sampling studies to avoid underestimating the total number of ticks. Rates of tick exchange on migratory birds during their northwards migration will affect the probability that a Hyalomma tick entering Great Britain is positive for CCHFV. Drawing on published data, evidence is presented that the latitude of a European country affects the probability of entry of Hyalomma ticks on wild birds. Further data on Hyalomma infestation rates and tick exchange rates are required along the East Atlantic flyway to further our understanding of the origin of Hyalomma ticks (i.e., Africa or southern Europe) and hence the probability of entry of CCHFV into GB. PMID:27232135

  19. Structure and Evolution of an Undular Bore on the High Plains and Its Effects on Migrating Birds.

    NASA Astrophysics Data System (ADS)

    Locatelli, John D.; Stoelinga, Mark T.; Hobbs, Peter V.; Johnson, Jim

    1998-06-01

    On 18 September 1992 a series of thunderstorms in Nebraska and eastern Colorado, which formed south of a synoptic-scale cold front and north of a Rocky Mountain lee trough, produced a cold outflow gust front that moved southeastward into Kansas, southeastern Colorado, and Oklahoma around sunset. When this cold outflow reached the vicinity of the lee trough, an undular bore developed on a nocturnally produced stable layer and moved through the range of the Dodge City WSR-88D Doppler radar. The radar data revealed that the undular bore, in the leading portion of a region of northwesterly winds about 45 km wide by 4 km high directly abutting the cold outflow, developed five undulations over the course of 3 h. Contrary to laboratory tank experiments, observations indicated that the solitary waves that composed the bore probably did not form from the enveloping of the head of the cold air outflow by the stable layer and the breaking off of the head of the cold air outflow. The synoptic-scale cold front subsequently intruded on the surface layer of air produced by the cold outflow, but there was no evidence for the formation of another bore.Profiler winds, in the region affected by the cold air outflow and the undular bore, contained signals from nocturnally, southward-migrating birds (most likely waterfowl) that took off in nonfavorable southerly winds and remained aloft for several hours longer than usual, thereby staying ahead of the turbulence associated with the undular bore.

  20. New software methods in radar ornithology using WSR-88D weather data and potential application to monitoring effects of climate change on bird migration

    USGS Publications Warehouse

    Mead, Reginald; Paxton, John; Sojda, Richard S.

    2010-01-01

    Radar ornithology has provided tools for studying the movement of birds, especially related to migration. Researchers have presented qualitative evidence suggesting that birds, or at least migration events, can be identified using large broad scale radars such as the WSR-88D used in the NEXRAD weather surveillance system. This is potentially a boon for ornithologists because such data cover a large portion of the United States, are constantly being produced, are freely available, and have been archived since the early 1990s. A major obstacle to this research, however, has been that identifying birds in NEXRAD data has required a trained technician to manually inspect a graphically rendered radar sweep. A single site completes one volume scan every five to ten minutes, producing over 52,000 volume scans in one year. This is an immense amount of data, and manual classification is infeasible. We have developed a system that identifies biological echoes using machine learning techniques. This approach begins with training data using scans that have been classified by experts, or uses bird data collected in the field. The data are preprocessed to ensure quality and to emphasize relevant features. A classifier is then trained using this data and cross validation is used to measure performance. We compared neural networks, naive Bayes, and k-nearest neighbor classifiers. Empirical evidence is provided showing that this system can achieve classification accuracies in the 80th to 90th percentile. We propose to apply these methods to studying bird migration phenology and how it is affected by climate variability and change over multiple temporal scales.

  1. Linking multi-temporal satellite imagery to coastal wetland dynamics and bird distribution

    USGS Publications Warehouse

    Pickens, Bradley A.; King, Sammy L.

    2014-01-01

    Ecosystems are characterized by dynamic ecological processes, such as flooding and fires, but spatial models are often limited to a single measurement in time. The characterization of direct, fine-scale processes affecting animals is potentially valuable for management applications, but these are difficult to quantify over broad extents. Direct predictors are also expected to improve transferability of models beyond the area of study. Here, we investigated the ability of non-static and multi-temporal habitat characteristics to predict marsh bird distributions, while testing model generality and transferability between two coastal habitats. Distribution models were developed for king rail (Rallus elegans), common gallinule (Gallinula galeata), least bittern (Ixobrychus exilis), and purple gallinule (Porphyrio martinica) in fresh and intermediate marsh types in the northern Gulf Coast of Louisiana and Texas, USA. For model development, repeated point count surveys of marsh birds were conducted from 2009 to 2011. Landsat satellite imagery was used to quantify both annual conditions and cumulative, multi-temporal habitat characteristics. We used multivariate adaptive regression splines to quantify bird-habitat relationships for fresh, intermediate, and combined marsh habitats. Multi-temporal habitat characteristics ranked as more important than single-date characteristics, as temporary water was most influential in six of eight models. Predictive power was greater for marsh type-specific models compared to general models and model transferability was poor. Birds in fresh marsh selected for annual habitat characterizations, while birds in intermediate marsh selected for cumulative wetness and heterogeneity. Our findings emphasize that dynamic ecological processes can affect species distribution and species-habitat relationships may differ with dominant landscape characteristics.

  2. Interspecific variation in dietary carotenoid assimilation in birds: links to phylogeny and color ornamentation.

    PubMed

    McGraw, K J

    2005-10-01

    Many birds use carotenoid pigments to acquire rich red, orange, and yellow coloration in feathers and bare parts that is used as a signal of mate quality. Because carotenoids are derived from foods, much attention has been paid to the role of diet in generating color variation both within and among avian species. Less consideration has been given to physiological underpinnings of color variability, especially among species. Here, I surveyed published literature (e.g. captive feeding studies) on carotenoid assimilation in six bird species and completed additional controlled carotenoid-supplementation experiments in two others to consider the ability of different taxa to extract carotenoids from the diet in relation to phylogeny and coloration. I found that, for a given level of carotenoids in the diet, passerine birds (zebra finch, Taeniopygia guttata; house finch, Carpodacus mexicanus; American goldfinch, Carduelis tristis; society finch, Lonchura domestica) exhibit higher levels of carotenoids in circulation than non-passerines like gamebirds (domestic chicken, Gallus domesticus; red junglefowl, Gallus gallus; Japanese quail, Coturnix coturnix; red-legged partridge, Alectoris rufa). This difference in carotenoid accumulation is likely due to interspecific variation in micelle, chylomicron, or lipoprotein concentrations or affinities for xanthophyll carotenoids. Passerine birds more commonly develop carotenoid-based colors than do birds from ancient avian lineages such as Galliformes, and the physiological differences I uncover may explain why songbirds especially capitalize on carotenoid pigments for color production. Ultimately, because we can deconstruct color traits into component biochemical, physical, and physiological parts, avian color signals may serve as a valuable model for illuminating the proximate mechanisms behind interspecific variation in signal use in animals. PMID:16129640

  3. Linked migration systems: immigration and internal labor flows in the United States.

    PubMed

    Walker, R; Ellis, M; Barff, R

    1992-07-01

    The relationship between immigration to and labor movements within the United States is examined using a model that links migration, occupations, production and institutional relations in the economy, and economic restructuring. The authors conclude that "native blue-collar workers have been spatially displaced by recent immigration and that the process of capital accumulation, as manifested in economic restructuring, is the driving force behind the mobility system, affecting both immigration patterns and the destination choices of white-collar workers. As a result, we suggest that previous estimates of immigrant impacts on local labor markets may be underestimated." PMID:12343935

  4. Migratory Birds. Issue Pac.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    The materials in this educational packet are designed for use with students in grades 4 through 7. They consist of an overview, teaching guides and student data sheets for three activities, and a poster. The overview discusses why, how, where, and when birds migrate as well as problems birds encounter while migrating; the importance of research…

  5. REMOTE SENSING, ECOLOGICAL VARIABLES, AND WILD BIRD MIGRATION RELATED TO OUTBREAKS OF HIGHLY PATHOGENIC H5N1 AVIAN INFLUENZA1

    PubMed Central

    Xiao, Xiangming; Gilbert, Marius; Slingenbergh, Jan; Lei, Fumin; Boles, Stephen

    2008-01-01

    Outbreaks of highly pathogenic avian influenza (HPAI) H5N1 subtype have occurred in many countries across Asia, Europe, and Africa since 2003. Better understanding of the ecology and risk factors of HPAI is critical for surveillance, risk assessment, and public health policy. We introduce satellite remote sensing as one important tool, and highlight the potential of using satellite images to monitor dynamics of climate and landscapes that are related to wild bird migration and agriculture in the context of avian influenza transmission. PMID:17347392

  6. Continental scale analysis of bird migration timing: influences of climate and life history traits—a generalized mixture model clustering and discriminant approach

    NASA Astrophysics Data System (ADS)

    Chambers, Lynda E.; Beaumont, Linda J.; Hudson, Irene L.

    2014-08-01

    There is substantial evidence of climate-related shifts to the timing of avian migration. Although spring arrival has generally advanced, variable species responses and geographical biases in data collection make it difficult to generalise patterns. We advance previous studies by using novel multivariate statistical techniques to explore complex relationships between phenological trends, climate indices and species traits. Using 145 datasets for 52 bird species, we assess trends in first arrival date (FAD), last departure date (LDD) and timing of peak abundance at multiple Australian locations. Strong seasonal patterns were found, i.e. spring phenological events were more likely to significantly advance, while significant advances and delays occurred in other seasons. However, across all significant trends, the magnitude of delays exceeded that of advances, particularly for FAD (+22.3 and -9.6 days/decade, respectively). Geographic variations were found, with greater advances in FAD and LDD, in south-eastern Australia than in the north and west. We identified four species clusters that differed with respect to species traits and climate drivers. Species within bird clusters responded in similar ways to local climate variables, particularly the number of raindays and rainfall. The strength of phenological trends was more strongly related to local climate variables than to broad-scale drivers (Southern Oscillation Index), highlighting the importance of precipitation as a driver of movement in Australian birds.

  7. A bird's eye view of the air pollution-cancer link in China.

    PubMed

    Huang, Yu-Bei; Song, Feng-Ju; Liu, Qun; Li, Wei-Qin; Zhang, Wei; Chen, Ke-Xin

    2014-04-01

    Air pollution in China comes from multiple sources, including coal consumption, construction and industrial dust, and vehicle exhaust. Coal consumption in particular directly determines the emissions of three major air pollutants: dust, sulfur dioxide (SO(2)), and nitrogen oxide (NOx). The rapidly increasing number of civilian vehicles is expected to bring NOx emission to a very high level. Contrary to expectations, however, existing data show that the concentrations of major pollutants [particulate matter-10 (PM10), SO(2), and nitrogen dioxide (NO(2))] in several large Chinese cities have declined during the past decades, though they still exceed the national standards of ambient air quality. Archived data from China does not fully support that the concentrations of pollutants directly depend on local emissions, but this is likely due to inaccurate measurement of pollutants. Analyses on the cancer registry data show that cancer burden related to air pollution is on the rise in China and will likely increase further, but there is a lack of data to accurately predict the cancer burden. Past experience from other countries has sounded alarm of the link between air pollution and cancer. The quantitative association requires dedicated research as well as establishment of needed monitoring infrastructures and cancer registries. The air pollution-cancer link is a serious public health issue that needs urgent investigation. PMID:24636232

  8. A bird's eye view of the air pollution-cancer link in China

    PubMed Central

    Huang, Yu-Bei; Song, Feng-Ju; Liu, Qun; Li, Wei-Qin; Zhang, Wei; Chen, Ke-Xin

    2014-01-01

    Air pollution in China comes from multiple sources, including coal consumption, construction and industrial dust, and vehicle exhaust. Coal consumption in particular directly determines the emissions of three major air pollutants: dust, sulfur dioxide (SO2), and nitrogen oxide (NOx). The rapidly increasing number of civilian vehicles is expected to bring NOx emission to a very high level. Contrary to expectations, however, existing data show that the concentrations of major pollutants [particulate matter-10 (PM10), SO2, and nitrogen dioxide (NO2)] in several large Chinese cities have declined during the past decades, though they still exceed the national standards of ambient air quality. Archived data from China does not fully support that the concentrations of pollutants directly depend on local emissions, but this is likely due to inaccurate measurement of pollutants. Analyses on the cancer registry data show that cancer burden related to air pollution is on the rise in China and will likely increase further, but there is a lack of data to accurately predict the cancer burden. Past experience from other countries has sounded alarm of the link between air pollution and cancer. The quantitative association requires dedicated research as well as establishment of needed monitoring infrastructures and cancer registries. The air pollution-cancer link is a serious public health issue that needs urgent investigation. PMID:24636232

  9. [Migration].

    PubMed

    Maccotta, W; Perotti, A; Thebaut, F; Cristofanelli, L; Pittau, F; Sergi, N; Pittau, L; Morelli, A; Morsella, M; Grinover, A P

    1990-01-01

    This is a collection of 11 individual articles on aspects of current migration problems affecting developed countries. The geographical focus is on immigration in Europe, with particular reference to Italy, although one paper is concerned with Quebec. The topical focus is on the social problems associated with immigration. The articles are in Italian, with one exception, which is in French. PMID:12343393

  10. Evidence for r- and K-selection in a wild bird population: a reciprocal link between ecology and evolution.

    PubMed

    Sæther, Bernt-Erik; Visser, Marcel E; Grøtan, Vidar; Engen, Steinar

    2016-04-27

    Understanding the variation in selection pressure on key life-history traits is crucial in our rapidly changing world. Density is rarely considered as a selective agent. To study its importance, we partition phenotypic selection in fluctuating environments into components representing the population growth rate at low densities and the strength of density dependence, using a new stochastic modelling framework. We analysed the number of eggs laid per season in a small song-bird, the great tit, and found balancing selection favouring large clutch sizes at small population densities and smaller clutches in years with large populations. A significant interaction between clutch size and population size in the regression for the Malthusian fitness reveals that those females producing large clutch sizes at small population sizes also are those that show the strongest reduction in fitness when population size is increased. This provides empirical support for ongoing r- and K-selection in this population, favouring phenotypes with large growth rates r at small population sizes and phenotypes with high competitive skills when populations are close to the carrying capacity K This selection causes long-term fluctuations around a stable mean clutch size caused by variation in population size, implying that r- and K-selection is an important mechanism influencing phenotypic evolution in fluctuating environments. This provides a general link between ecological dynamics and evolutionary processes, operating through a joint influence of density dependence and environmental stochasticity on fluctuations in population size. PMID:27122550

  11. Development of monoclonal antibodies and quantitative sandwich enzyme linked immunosorbent assay for the characteristic sialoglycoprotein of edible bird's nest.

    PubMed

    Zhang, Shiwei; Lai, Xintian; Liu, Xiaoqing; Li, Yun; Li, Bifang; Huang, Xiuli; Zhang, Qinlei; Chen, Wei; Lin, Lin; Yang, Guowu

    2013-01-01

    The article presents a sandwich enzyme linked immunosorbent assay (ELISA) for identification of edible bird's nest. The characteristic sialoglycoproteins were found by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and purified by liquid-phase isoelectric focusing (LIEF). According to the analysis, the molecular weight was 106-128 kDa and the isoelectric point was ≤pH 3.0. Two anti-characteristic sialoglycoprotein monoclonal antibodies were produced. The monoclonal antibodies were examined by western-blot assay. One of the monoclonal antibody was used as coating and the other as the enzyme-labeled antibody after being coupled to horseradish peroxidase (HRP). Based on the optimized ELISA condition, the method was established with IC(50) of 1.5 ng/mL, and low cross-reactivity with various fake materials (<0.01%). ELISA provided a suitable means for screening of a large number of samples. The coefficients of variation were between 2.9% and 5.8%. PMID:23323981

  12. Truncated Power Laws Reveal a Link between Low-Level Behavioral Processes and Grouping Patterns in a Colonial Bird

    PubMed Central

    Jovani, Roger; Serrano, David; Ursúa, Esperanza; Tella, José L.

    2008-01-01

    Background Departures from power law group size frequency distributions have been proposed as a useful tool to link individual behavior with population patterns and dynamics, although examples are scarce for wild animal populations. Methodology/Principal Findings We studied a population of Lesser kestrels (Falco naumanni) breeding in groups (colonies) from one to ca. 40 breeding pairs in 10,000 km2 in NE Spain. A 3.5 fold steady population increase occurred during the eight-year study period, accompanied by a geographical expansion from an initial subpopulation which in turn remained stable in numbers. This population instability was mainly driven by first-breeders, which are less competitive at breeding sites, being relegated to breed solitarily or in small colony sizes, and disperse farther than adults. Colony size frequency distributions shifted from an initial power law to a truncated power law mirroring population increase. Thus, we hypothesized that population instability was behind the truncation of the power law. Accordingly, we found a power law distribution through years in the initial subpopulation, and a match between the power law breakpoint (at ca. ten pairs) and those colony sizes from which the despotic behavior of colony owners started to impair the settlement of newcomers. Moreover, the instability hypothesis was further supported by snapshot data from another population of Lesser kestrels in SW Spain suffering a population decline. Conclusions/Significance Appropriate analysis of the scaling properties of grouping patterns has unraveled the link between local agonistic processes and large-scale (population) grouping patterns in a wild bird population. PMID:18431479

  13. Variation in early-life telomere dynamics in a long-lived bird: links to environmental conditions and survival.

    PubMed

    Watson, Hannah; Bolton, Mark; Monaghan, Pat

    2015-03-01

    Conditions experienced during early life can have profound consequences for both short- and long-term fitness. Variation in the natal environment has been shown to influence survival and reproductive performance of entire cohorts in wild vertebrate populations. Telomere dynamics potentially provide a link between the early environment and long-term fitness outcomes, yet we know little about how the environment can influence telomere dynamics in early life. We found that environmental conditions during growth have an important influence on early-life telomere length (TL) and attrition in nestlings of a long-lived bird, the European storm petrel Hydrobates pelagicus. Nestlings reared under unfavourable environmental conditions experienced significantly greater telomere loss during postnatal development compared with nestlings reared under more favourable natal conditions, which displayed a negligible change in TL. There was, however, no significant difference in pre-fledging TL between cohorts. The results suggest that early-life telomere dynamics could contribute to the marked differences in life-history traits that can arise among cohorts reared under different environmental conditions. Early-life TL was also found to be a significant predictor of survival during the nestling phase, providing further evidence for a link between variation in TL and individual fitness. To what extent the relationship between early-life TL and mortality during the nestling phase is a consequence of genetic, parental and environmental factors is currently unknown, but it is an interesting area for future research. Accelerated telomere attrition under unfavourable conditions, as observed in this study, might play a role in mediating the effects of the early-life environment on later-life performance. PMID:25617465

  14. Variation in early-life telomere dynamics in a long-lived bird: links to environmental conditions and survival

    PubMed Central

    Watson, Hannah; Bolton, Mark; Monaghan, Pat

    2015-01-01

    ABSTRACT Conditions experienced during early life can have profound consequences for both short- and long-term fitness. Variation in the natal environment has been shown to influence survival and reproductive performance of entire cohorts in wild vertebrate populations. Telomere dynamics potentially provide a link between the early environment and long-term fitness outcomes, yet we know little about how the environment can influence telomere dynamics in early life. We found that environmental conditions during growth have an important influence on early-life telomere length (TL) and attrition in nestlings of a long-lived bird, the European storm petrel Hydrobates pelagicus. Nestlings reared under unfavourable environmental conditions experienced significantly greater telomere loss during postnatal development compared with nestlings reared under more favourable natal conditions, which displayed a negligible change in TL. There was, however, no significant difference in pre-fledging TL between cohorts. The results suggest that early-life telomere dynamics could contribute to the marked differences in life-history traits that can arise among cohorts reared under different environmental conditions. Early-life TL was also found to be a significant predictor of survival during the nestling phase, providing further evidence for a link between variation in TL and individual fitness. To what extent the relationship between early-life TL and mortality during the nestling phase is a consequence of genetic, parental and environmental factors is currently unknown, but it is an interesting area for future research. Accelerated telomere attrition under unfavourable conditions, as observed in this study, might play a role in mediating the effects of the early-life environment on later-life performance. PMID:25617465

  15. A Nanoprinted Model of Interstitial Cancer Migration Reveals a Link between Cell Deformability and Proliferation.

    PubMed

    Panagiotakopoulou, Magdalini; Bergert, Martin; Taubenberger, Anna; Guck, Jochen; Poulikakos, Dimos; Ferrari, Aldo

    2016-07-26

    Metastatic progression of tumors requires the coordinated dissemination of cancerous cells through interstitial tissues and their replication in distant body locations. Despite their importance in cancer treatment decisions, key factors, such as cell shape adaptation and the role it plays in dense tissue invasion by cancerous cells, are not well understood. Here, we employ a 3D electrohydrodynamic nanoprinting technology to generate vertical arrays of topographical pores that mimic interstitial tissue resistance to the mesenchymal migration of cancerous cells, in order to determine the effect of nuclear size, cell deformability, and cell-to-substrate adhesion on tissue invasion efficiency. The high spatial and temporal resolution of our analysis demonstrates that the ability of cells to deform depends on the cell cycle phase, peaks immediately after mitosis, and is key to the invasion process. Increased pore penetration efficiency by cells in early G1 phase also coincided with their lower nuclear volume and higher cell deformability, compared with the later cell cycle stages. Furthermore, artificial decondensation of chromatin induced an increase in cell and nuclear deformability and improved pore penetration efficiency of cells in G1. Together, these results underline that along the cell cycle cells have different abilities to dynamically remodel their actin cytoskeleton and induce nuclear shape changes, which determines their pore penetration efficiency. Thus, our results support a mechanism in which cell proliferation and pore penetration are functionally linked to favor the interstitial dissemination of metastatic cells. PMID:27268411

  16. Characterizing stopover sites of migrating passerine birds in the lower Chesapeake Bay region for conservation: an integrated radar-habitat study

    USGS Publications Warehouse

    Mabey, S.; Watts, B.; Paxton, B.; Smith, F.; Truitt, B.; Dawson, D.

    2005-01-01

    Many conservation organizations and initiatives including Partners-in-Flight and the U.S. Fish and Wildlife Service's regional Joint Ventures have identified migratory songbird stopover habitat as a priority conservation target. However, the spatial and temporal variability inherent in migration presents a number of challenges to both identifying and characterizing stopover habitat. Scarce conservation resources further demand that stopover sites be classified on a scale of priority so that conservation action can proceed according to ecological value. We are applying weather surveillance radar data collected from the National Weather Service WSR-88D at Wakefield, VA, and NASA's Doppler radar, NPOL, in Oyster, VA, to identify passerine stopover sites in the lower Chesapeake Bay region and develop spatial models to characterize these sites based on relative migrant abundance and consistency of use between and within seasons. We are using the stopover patterns to generate hypotheses regarding the habitat, geographic, and stochastic factors contributing to the distribution of migrants at a regional scale. We are testing these hypotheses with detailed habitat data and ground surveys of migrating birds with the goal of creating a generalized prioritization system for stopover site conservation.

  17. Association between tensin 1 and p130Cas at focal adhesions links actin inward flux to cell migration

    PubMed Central

    Zhao, Zhihai; Tan, Song Hui; Machiyama, Hiroaki; Kawauchi, Keiko; Araki, Keigo; Hirata, Hiroaki; Sawada, Yasuhiro

    2016-01-01

    ABSTRACT Cell migration is a highly dynamic process that plays pivotal roles in both physiological and pathological processes. We have previously reported that p130Cas supports cell migration through the binding to Src as well as phosphorylation-dependent association with actin retrograde flow at focal adhesions. However, it remains elusive how phosphorylated Cas interacts with actin cytoskeletons. We observe that the actin-binding protein, tensin 1, co-localizes with Cas, but not with its phosphorylation-defective mutant, at focal adhesions in leading regions of migrating cells. While a truncation mutant of tensin 1 that lacks the phosphotyrosine-binding PTB and SH2 domains (tensin 1-SH2PTB) poorly co-localizes or co-immunoprecitates with Cas, bacterially expressed recombinant tensin 1-SH2PTB protein binds to Cas in vitro in a Cas phosphorylation-dependent manner. Furthermore, exogenous expression of tensin 1-SH2PTB, which is devoid of the actin-interacting motifs, interferes with the Cas-driven cell migration, slows down the inward flux of Cas molecules, and impedes the displacement of Cas molecules from focal adhesions. Taken together, our results show that tensin 1 links inwardly moving actin cytoskeletons to phosphorylated Cas at focal adhesions, thereby driving cell migration. PMID:27029899

  18. Birds of Prey of Wisconsin.

    ERIC Educational Resources Information Center

    Hamerstrom, Frances

    This copiously illustrated document is designed to be a field quide to birds of prey that are common to Wisconsin, as well as to some that enter the state occasionally. An introduction discusses birds of prey with regard to migration patterns, the relationship between common names and the attitudes of people toward certain birds, and natural signs…

  19. Linking El Niño, local rainfall, and migration timing in a tropical migratory species.

    PubMed

    Shaw, Allison K; Kelly, Kathryn A

    2013-11-01

    Current climate models project changes in both temperature and precipitation patterns across the globe in the coming years. Migratory species, which move to take advantage of seasonal climate patterns, are likely to be affected by these changes, and indeed, a number of studies have shown a relationship between changing climate and the migration timing of various species. However, these studies have almost exclusively focused on the effects of temperature change on species that inhabit temperate zones. Here, we explore the relationship between rainfall and migration timing in a tropical species, Gecarcoidea natalis (Christmas Island red crab). We find that the timing of the annual crab breeding migration is closely related to the amount of rain that falls during a 'migration window' period prior to potential egg release dates, which is in turn related to the Southern Oscillation Index, an atmospheric El Niño-Southern Oscillation Index. As reproduction in this species is conditional on successful migration, major changes in migration patterns could have detrimental consequences for the survival of the species. This study serves to broaden our understanding of the effects of climate change on migratory species and will hopefully inspire future work on rainfall and tropical migrations. PMID:23821605

  20. Antibiotic resistance in wild birds

    PubMed Central

    Bonnedahl, Jonas

    2014-01-01

    Wild birds have been postulated as sentinels, reservoirs, and potential spreaders of antibiotic resistance. Antibiotic-resistant bacteria have been isolated from a multitude of wild bird species. Several studies strongly indicate transmission of resistant bacteria from human rest products to wild birds. There is evidence suggesting that wild birds can spread resistant bacteria through migration and that resistant bacteria can be transmitted from birds to humans and vice versa. Through further studies of the spatial and temporal distribution of resistant bacteria in wild birds, we can better assess their role and thereby help to mitigate the increasing global problem of antibiotic resistance. PMID:24697355

  1. Connecting the dots: an invariant migration corridor links the Holocene to the present

    PubMed Central

    Berger, Joel; Cain, Steven L; Berger, Kim Murray

    2006-01-01

    Numerous species undergo impressive movements, but due to massive changes in land use, long distance migration in terrestrial vertebrates has become a highly fragile ecological phenomenon. Uncertainty about the locations of past migrations and the importance of current corridors hampers conservation planning. Using archeological data from historic kill sites and modern methods to track migration, we document an invariant, 150 km (one-way) migration corridor used for at least 6000 years by North America's sole extant endemic ungulate. Pronghorn (Antilocapra americana) from the Greater Yellowstone Ecosystem, like other long distant migrants including Serengeti wildebeest (Connochaetes taurinus) and Arctic caribou (Rangifer tarandus), move nearly 50 km d−1, but in contrast to these other species, rely on an invariant corridor averaging only 2 km wide. Because an entire population accesses a national park (Grand Teton) by passage through bottlenecks as narrow as 121 m, any blockage to movement will result in extirpation. Based on animation of real data coupled with the loss of six historic routes, alternative pathways throughout the 60 000 km2 Yellowstone ecosystem are no longer available. Our findings have implications for developing strategies to protect long distance land migrations in Africa, Asia and North America and to prevent the disappearance of ecological phenomena that have operated for millennia. PMID:17148280

  2. Connecting the dots: an invariant migration corridor links the Holocene to the present.

    PubMed

    Berger, Joel; Cain, Steven L; Berger, Kim Murray

    2006-12-22

    Numerous species undergo impressive movements, but due to massive changes in land use, long distance migration in terrestrial vertebrates has become a highly fragile ecological phenomenon. Uncertainty about the locations of past migrations and the importance of current corridors hampers conservation planning. Using archeological data from historic kill sites and modern methods to track migration, we document an invariant, 150 km (one-way) migration corridor used for at least 6000 years by North America's sole extant endemic ungulate. Pronghorn (Antilocapra americana) from the Greater Yellowstone Ecosystem, like other long distant migrants including Serengeti wildebeest (Connochaetes taurinus) and Arctic caribou (Rangifer tarandus), move nearly 50 km d-1, but in contrast to these other species, rely on an invariant corridor averaging only 2 km wide. Because an entire population accesses a national park (Grand Teton) by passage through bottlenecks as narrow as 121 m, any blockage to movement will result in extirpation. Based on animation of real data coupled with the loss of six historic routes, alternative pathways throughout the 60,000 km2 Yellowstone ecosystem are no longer available. Our findings have implications for developing strategies to protect long distance land migrations in Africa, Asia and North America and to prevent the disappearance of ecological phenomena that have operated for millennia. PMID:17148280

  3. Linking the Primary Cilium to Cell Migration in Tissue Repair and Brain Development

    PubMed Central

    Veland, Iben Rønn; Lindbæk, Louise; Christensen, Søren Tvorup

    2014-01-01

    Primary cilia are unique sensory organelles that coordinate cellular signaling networks in vertebrates. Inevitably, defects in the formation or function of primary cilia lead to imbalanced regulation of cellular processes that causes multisystemic disorders and diseases, commonly known as ciliopathies. Mounting evidence has demonstrated that primary cilia coordinate multiple activities that are required for cell migration, which, when they are aberrantly regulated, lead to defects in organogenesis and tissue repair, as well as metastasis of tumors. Here, we present an overview on how primary cilia may contribute to the regulation of the cellular signaling pathways that control cyclic processes in directional cell migration. PMID:26955067

  4. Prevalence of Mycobacterium tuberculosis in Taiwan: A Model for Strain Evolution Linked to Population Migration

    PubMed Central

    Dou, Horng-Yunn; Huang, Shu-Chen; Su, Ih-Jen

    2011-01-01

    The global evolution and spread of Mycobacterium tuberculosis (MTB), one of the most successful bacterial pathogens, remain a mystery. Advances in molecular technology in the past decade now make it possible to understand MTB strain evolution and transmission in the context of human population migration. Taiwan is a relatively isolated island, serving as a mixing vessel over the past four centuries as colonization by different waves of ethnic groups occurred. By using mycobacterial tandem repeat sequences as genetic markers, the prevalence of MTB strains in Taiwan revealed an interesting association with historical migrations of different ethnic populations, thus providing a good model to explore the global evolution and spread of MTB. PMID:21350639

  5. The Bird.

    ERIC Educational Resources Information Center

    Hannon, Jean

    2001-01-01

    Students use a dead bird to learn about bird life, anatomy, and death. Students examine a bird body and discuss what happened to the bird. Uses outdoor education as a resource for learning about animals. (SAH)

  6. Bird Flu

    MedlinePlus

    ... viruses infect birds, including chickens, other poultry, and wild birds such as ducks. Most bird flu viruses ... become sick. It may also be possible to catch bird flu by eating poultry or eggs that ...

  7. Space Based Ornithology: On the Wings of Migration and Biophysics

    NASA Technical Reports Server (NTRS)

    Smith, James A.

    2005-01-01

    The study of bird migration on a global scale is one of the compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties. Space based technology offers new opportunities to shed understanding on the distribution and migration of organisms on the planet and their sensitivity to human disturbances and environmental changes. Migration is an incredibly diverse and complex behavior. A broad outline of space based research must address three fundamental questions: (1) where could birds be, i.e. what is their fundamental niche constrained by their biophysical limits? (2) where do we actually find birds, i.e. what is their realizable niche as modified by local or regional abiotic and biotic factors, and (3) how do they get there (and how do we know?), that is what are their migration patterns and associated mechanisms? Our working hypothesis is that individual organism biophysical models of energy and water balance, driven by satellite measurements of spatio-temporal gradients in climate and habitat, will help us to explain the variability in avian species richness and distribution. Dynamic state variable modeling provides one tool for studying bird migration across multiple scales and can be linked to mechanistic models describing the time and energy budget states of migrating birds. Such models yield an understanding of how a migratory flyway and its component habitats function as a whole and link stop-over ecology with biological conservation and management. Further these models provide an ecological forecasting tool for science and application users to address what are the possible consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration.

  8. Anillin Regulates Neuronal Migration and Neurite Growth by Linking RhoG to the Actin Cytoskeleton.

    PubMed

    Tian, Dong; Diao, Min; Jiang, Yuxiang; Sun, Lingfei; Zhang, Yan; Chen, Zhucheng; Huang, Shanjin; Ou, Guangshuo

    2015-05-01

    Neuronal migration and neurite growth are essential events in neural development, but it remains unclear how guidance cues are transduced through receptors to the actin cytoskeleton, which powers these processes. We report that a cytokinetic scaffold protein, Anillin, is redistributed to the leading edge of the C. elegans Q neuroblast during cell migration and neurite growth. To bypass the requirement for Anillin in cytokinesis, we used the somatic CRISPR-Cas9 technique to generate conditional mutations in Anillin. We demonstrate that Anillin regulates cell migration and growth cone extension by stabilizing the F-actin network at the leading edge. Our biochemical analysis shows that the actin-binding domain of Anillin is sufficient to stabilize F-actin by antagonizing the F-actin severing activity of Cofilin. We further uncover that the active form of RhoG/MIG-2 directly binds to Anillin and recruits it to the leading edge. Our results reveal a novel pathway in which Anillin transduces the RhoG signal to the actin cytoskeleton during neuronal migration and neurite growth. PMID:25843030

  9. Distinctive metabolite profiles in in-migrating Sockeye salmon suggest sex-linked endocrine perturbation.

    PubMed

    Benskin, Jonathan P; Ikonomou, Michael G; Liu, Jun; Veldhoen, Nik; Dubetz, Cory; Helbing, Caren C; Cosgrove, John R

    2014-10-01

    The health of Skeena River Sockeye salmon (Onchorhychus nerka) has been of increasing concern due to declining stock returns over the past decade. In the present work, in-migrating Sockeye from the 2008 run were evaluated using a mass spectrometry-based, targeted metabolomics platform. Our objectives were to (a) investigate natural changes in a subset of the hepatic metabolome arising from migration-associated changes in osmoregulation, locomotion, and gametogenesis, and (b) compare the resultant profiles with animals displaying altered hepatic vitellogenin A (vtg) expression at the spawning grounds, which was previously hypothesized as a marker of xenobiotic exposure. Of 203 metabolites monitored, 95 were consistently observed in Sockeye salmon livers and over half of these changed significantly during in-migration. Among the most dramatic changes in both sexes were a decrease in concentrations of taurine (a major organic osmolyte), carnitine (involved in fatty acid transport), and two major polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid). In females, an increase in amino acids was attributed to protein catabolism associated with vitellogenesis. Animals with atypical vtg mRNA expression demonstrated unusual hepatic amino acid, fatty acid, taurine, and carnitine profiles. The cause of these molecular perturbations remains unclear, but may include xenobiotic exposure, natural senescence, and/or interindividual variability. These data provide a benchmark for further investigation into the long-term health of migrating Skeena Sockeye. PMID:25198612

  10. Links between fear of humans, stress and survival support a non-random distribution of birds among urban and rural habitats.

    PubMed

    Rebolo-Ifrán, Natalia; Carrete, Martina; Sanz-Aguilar, Ana; Rodríguez-Martínez, Sol; Cabezas, Sonia; Marchant, Tracy A; Bortolotti, Gary R; Tella, José L

    2015-01-01

    Urban endocrine ecology aims to understand how organisms cope with new sources of stress and maintain allostatic load to thrive in an increasingly urbanized world. Recent research efforts have yielded controversial results based on short-term measures of stress, without exploring its fitness effects. We measured feather corticosterone (CORTf, reflecting the duration and amplitude of glucocorticoid secretion over several weeks) and subsequent annual survival in urban and rural burrowing owls. This species shows high individual consistency in fear of humans (i.e., flight initiation distance, FID), allowing us to hypothesize that individuals distribute among habitats according to their tolerance to human disturbance. FIDs were shorter in urban than in rural birds, but CORTf levels did not differ, nor were correlated to FIDs. Survival was twice as high in urban as in rural birds and links with CORTf varied between habitats: while a quadratic relationship supports stabilizing selection in urban birds, high predation rates may have masked CORTf-survival relationship in rural ones. These results evidence that urban life does not constitute an additional source of stress for urban individuals, as shown by their near identical CORTf values compared with rural conspecifics supporting the non-random distribution of individuals among habitats according to their behavioural phenotypes. PMID:26348294

  11. Links between fear of humans, stress and survival support a non-random distribution of birds among urban and rural habitats

    PubMed Central

    Rebolo-Ifrán, Natalia; Carrete, Martina; Sanz-Aguilar, Ana; Rodríguez-Martínez, Sol; Cabezas, Sonia; Marchant, Tracy A.; Bortolotti, Gary R.; Tella, José L.

    2015-01-01

    Urban endocrine ecology aims to understand how organisms cope with new sources of stress and maintain allostatic load to thrive in an increasingly urbanized world. Recent research efforts have yielded controversial results based on short-term measures of stress, without exploring its fitness effects. We measured feather corticosterone (CORTf, reflecting the duration and amplitude of glucocorticoid secretion over several weeks) and subsequent annual survival in urban and rural burrowing owls. This species shows high individual consistency in fear of humans (i.e., flight initiation distance, FID), allowing us to hypothesize that individuals distribute among habitats according to their tolerance to human disturbance. FIDs were shorter in urban than in rural birds, but CORTf levels did not differ, nor were correlated to FIDs. Survival was twice as high in urban as in rural birds and links with CORTf varied between habitats: while a quadratic relationship supports stabilizing selection in urban birds, high predation rates may have masked CORTf-survival relationship in rural ones. These results evidence that urban life does not constitute an additional source of stress for urban individuals, as shown by their near identical CORTf values compared with rural conspecifics supporting the non-random distribution of individuals among habitats according to their behavioural phenotypes. PMID:26348294

  12. ATM regulation of IL-8 links oxidative stress to cancer cell migration and invasion

    PubMed Central

    Chen, Wei-Ta; Ebelt, Nancy D; Stracker, Travis H; Xhemalce, Blerta; Van Den Berg, Carla L; Miller, Kyle M

    2015-01-01

    Ataxia-telangiectasia mutated (ATM) protein kinase regulates the DNA damage response (DDR) and is associated with cancer suppression. Here we report a cancer-promoting role for ATM. ATM depletion in metastatic cancer cells reduced cell migration and invasion. Transcription analyses identified a gene network, including the chemokine IL-8, regulated by ATM. IL-8 expression required ATM and was regulated by oxidative stress. IL-8 was validated as an ATM target by its ability to rescue cell migration and invasion defects in ATM-depleted cells. Finally, ATM-depletion in human breast cancer cells reduced lung tumors in a mouse xenograft model and clinical data validated IL-8 in lung metastasis. These findings provide insights into how ATM activation by oxidative stress regulates IL-8 to sustain cell migration and invasion in cancer cells to promote metastatic potential. Thus, in addition to well-established roles in tumor suppression, these findings identify a role for ATM in tumor progression. DOI: http://dx.doi.org/10.7554/eLife.07270.001 PMID:26030852

  13. Miro-1 links mitochondria and microtubule Dynein motors to control lymphocyte migration and polarity.

    PubMed

    Morlino, Giulia; Barreiro, Olga; Baixauli, Francesc; Robles-Valero, Javier; González-Granado, José M; Villa-Bellosta, Ricardo; Cuenca, Jesús; Sánchez-Sorzano, Carlos O; Veiga, Esteban; Martín-Cófreces, Noa B; Sánchez-Madrid, Francisco

    2014-04-01

    The recruitment of leukocytes to sites of inflammation is crucial for a functional immune response. In the present work, we explored the role of mitochondria in lymphocyte adhesion, polarity, and migration. We show that during adhesion to the activated endothelium under physiological flow conditions, lymphocyte mitochondria redistribute to the adhesion zone together with the microtubule-organizing center (MTOC) in an integrin-dependent manner. Mitochondrial redistribution and efficient lymphocyte adhesion to the endothelium require the function of Miro-1, an adaptor molecule that couples mitochondria to microtubules. Our data demonstrate that Miro-1 associates with the dynein complex. Moreover, mitochondria accumulate around the MTOC in response to the chemokine CXCL12/SDF-1α; this redistribution is regulated by Miro-1. CXCL12-dependent cell polarization and migration are reduced in Miro-1-silenced cells, due to impaired myosin II activation at the cell uropod and diminished actin polymerization. These data point to a key role of Miro-1 in the control of lymphocyte adhesion and migration through the regulation of mitochondrial redistribution. PMID:24492963

  14. Local site variation in stopover physiology of migrating songbirds near the south shore of Lake Ontario is linked to fruit availability and quality

    PubMed Central

    Smith, Susan B.; Miller, Allyson C.; Merchant, Charmaine R.; Sankoh, Amie F.

    2015-01-01

    Birds that migrate long distances between breeding and wintering grounds are challenged to find adequate stopover sites that can provide a high-quality source of nutrition in order to refuel quickly and continue on their migratory journeys. Wild fruits are a well-documented component in the diets of many passerines during autumn migration. Thus, fruit availability and the proliferation of shrubs that bear low-quality fruits at important stopover sites may dictate the quality of food resources available for refuelling birds and present a conservation concern. We profiled plasma metabolites of two migratory passerine species at two different stopover sites near the south shore of Lake Ontario during the peak of autumn migration. We also measured diversity, availability and nutritional quality of fruits present at these sites. Site explained most of the variation in plasma triglyceride for both bird species, but was less important than other confounding variables for explaining concentrations of plasma β-hydroxybutyrate and plasma uric acid concentrations. Site differences in fat deposition, as indicated by plasma triglyceride, may in part be explained by the large differences in diversity and availability of high-quality fruits between the two sites. Our results suggest that abundant, lipid-rich native fruits with high-energy density are associated with increased fat deposition during autumn stopovers for some species, although other factors, such as proximity to the Lake Ontario shoreline and the opportunities to refuel in the surrounding landscape, are likely to play a role in stopover site use by birds. It is possible that local site characteristics that influence growing conditions may impact the quality of fruits produced by a plant species, altering the availability of critical nutrients for avian consumers. PMID:27293721

  15. Integrin-linked kinase affects signaling pathways and migration in thyroid cancer cells and is a potential therapeutic target

    PubMed Central

    Shirley, Lawrence A.; McCarty, Samantha; Yang, Ming-Chen; Saji, Motoyasu; Zhang, Xiaoli; Phay, John; Ringel, Matthew D.; Chen, Ching-Shih

    2016-01-01

    Background Integrin-linked kinase (ILK) is a serine-threonine kinase that regulates interactions between the cell and the extracellular matrix. In many cancers, overexpression of ILK leads to increased cell proliferation, motility, and invasion. We hypothesized that ILK functions as a regulator of viability and migration in thyroid cancer cells. Methods Eleven human thyroid cancer cell lines were screened for ILK protein expression. The cell lines with the greatest expression were treated with either ILK small interfering RNA (siRNA) or a novel ILK inhibitor, T315, and the effects were evaluated via Western blot and migration assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays were performed to assess cell viability. Results siRNA against ILK decreased phosphorylation of downstream effectors Akt and MLC, as well as decreased migration. Treatment with T315 showed a dose-related decrease in both Akt and MLC phosphorylation, as well as decreased migration. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays showed T315 to have an half maximal inhibitory concentration of less than 1 µM in cell lines with high ILK expression. Conclusion ILK is expressed differentially in thyroid cancer cell lines. Both ILK siRNA and T315 inhibit motility of thyroid cancer cell lines, and T315 is shown to be cytotoxic at low concentrations. Altogether, our study suggests that ILK may represent an important kinase in aggressive thyroid cancers. PMID:26549818

  16. Linking behavior, physiology, and survival of Atlantic Salmon smolts during estuary migration

    USGS Publications Warehouse

    Stich, Daniel S.; Zydlewski, Gayle B.; Kocik, John F.; Zydlewski, Joseph

    2015-01-01

    Decreased marine survival is identified as a component driver of continued declines of Atlantic Salmon Salmo salar. However, estimates of marine mortality often incorporate loss incurred during estuary migration that may be mechanistically distinct from factors affecting marine mortality. We examined movements and survival of 941 smolts (141 wild and 800 hatchery-reared fish) released in freshwater during passage through the Penobscot River estuary, Maine, from 2005 to 2013. We related trends in estuary arrival date, movement rate, and survival to fish characteristics, migratory history, and environmental conditions in the estuary. Fish that experienced the warmest thermal history arrived in the estuary 8 d earlier than those experiencing the coolest thermal history during development. Estuary arrival date was 10 d later for fish experiencing high flow than for fish experiencing low flow. Fish released furthest upstream arrived in the estuary 3 d later than those stocked further downstream but moved 0.5 km/h faster through the estuary. Temporally, movement rate and survival in the estuary both peaked in mid-May. Spatially, movement rate and survival both decreased from freshwater to the ocean. Wild smolts arrived in the estuary later than hatchery fish, but we observed no change in movement rate or survival attributable to rearing history. Fish with the highest gill Na+, K+-ATPase activity incurred 25% lower mortality through the estuary than fish with the lowest gill Na+, K+-ATPase activity. Smolt survival decreased (by up to 40%) with the increasing number of dams passed (ranging from two to nine) during freshwater migration. These results underscore the importance of physiological preparedness on performance and the delayed, indirect effects of dams on survival of Atlantic Salmon smolts during estuary migration, ultimately affecting marine survival estimates.

  17. Early life experiences linked to diabetes mellitus: a study of African-American migration.

    PubMed Central

    Schneider, D.; Greenberg, M.; Lu, L.

    1997-01-01

    African Americans experienced massive internal migrations that shifted more than 6 million Southern-born blacks to other sections of the United States over the past century, a trend that only recently has been reversed. Whenever mass migration takes place, there is an opportunity to examine the role of the native and relocated environments in the development of disease. This article examines those relationships for diabetes mellitus, a group of diseases that disproportionately affect African-Americans relative to other racial and ethnic groups in the United States. Age-specific and age-adjusted rates with 95% confidence intervals were calculated for males and females for combinations of five regions of birth and four regions of residence at time of death. Southern-born males had statistically significantly higher death rates from diabetes than did their counterparts who died in the same regions in 9 of 16 comparisons. For females, those born in the South had statistically significantly higher rates in 15 of 16 comparisons. The results of this study indicate that place of birth and early life experiences are statistically associated with diabetes mortality among African Americans regardless of place of residence at time of death. PMID:9002414

  18. [Possibilities and problems of linking nominal records to further the study of the Italian migration process].

    PubMed

    Baily, S

    1996-08-01

    "[Based] on research on emigration from Agnone, Italy, to the United States and Argentina, the author analyzes the possibilities of linking different sources available at the countries of origin and destination, classified in three main groups: sources at origin, sources at destination and sources linking origin with destination. The members of an Agnone community in Pueblo, Colorado, are traced by using Agnone Census and Family Files, Agnone Passport Records, U.S. Census, Ships Passenger Lists and Naturalization Records, as well as interviews with members of the community." (EXCERPT) PMID:12348149

  19. First wide-angle view of channelized turbidity currents links migrating cyclic steps to flow characteristics

    NASA Astrophysics Data System (ADS)

    Hughes Clarke, John E.

    2016-06-01

    Field observations of turbidity currents remain scarce, and thus there is continued debate about their internal structure and how they modify underlying bedforms. Here, I present the results of a new imaging method that examines multiple surge-like turbidity currents within a delta front channel, as they pass over crescent-shaped bedforms. Seven discrete flows over a 2-h period vary in speed from 0.5 to 3.0 ms-1. Only flows that exhibit a distinct acoustically attenuating layer at the base, appear to cause bedform migration. That layer thickens abruptly downstream of the bottom of the lee slope of the bedform, and the upper surface of the layer fluctuates rapidly at that point. The basal layer is inferred to reflect a strong near-bed gradient in density and the thickening is interpreted as a hydraulic jump. These results represent field-scale flow observations in support of a cyclic step origin of crescent-shaped bedforms.

  20. Metazoan Scc4 Homologs Link Sister Chromatid Cohesion to Cell and Axon Migration Guidance

    PubMed Central

    Seitan, Vlad C; Banks, Peter; Laval, Steve; Majid, Nazia A; Dorsett, Dale; Rana, Amer; Smith, Jim; Bateman, Alex; Krpic, Sanja; Hostert, Arnd; Rollins, Robert A; Erdjument-Bromage, Hediye; Tempst, Paul; Benard, Claire Y; Hekimi, Siegfried; Newbury, Sarah F

    2006-01-01

    Saccharomyces cerevisiae Scc2 binds Scc4 to form an essential complex that loads cohesin onto chromosomes. The prevalence of Scc2 orthologs in eukaryotes emphasizes a conserved role in regulating sister chromatid cohesion, but homologs of Scc4 have not hitherto been identified outside certain fungi. Some metazoan orthologs of Scc2 were initially identified as developmental gene regulators, such as Drosophila Nipped-B, a regulator of cut and Ultrabithorax, and delangin, a protein mutant in Cornelia de Lange syndrome. We show that delangin and Nipped-B bind previously unstudied human and fly orthologs of Caenorhabditis elegans MAU-2, a non-axis-specific guidance factor for migrating cells and axons. PSI-BLAST shows that Scc4 is evolutionarily related to metazoan MAU-2 sequences, with the greatest homology evident in a short N-terminal domain, and protein–protein interaction studies map the site of interaction between delangin and human MAU-2 to the N-terminal regions of both proteins. Short interfering RNA knockdown of human MAU-2 in HeLa cells resulted in precocious sister chromatid separation and in impaired loading of cohesin onto chromatin, indicating that it is functionally related to Scc4, and RNAi analyses show that MAU-2 regulates chromosome segregation in C. elegans embryos. Using antisense morpholino oligonucleotides to knock down Xenopus tropicalis delangin or MAU-2 in early embryos produced similar patterns of retarded growth and developmental defects. Our data show that sister chromatid cohesion in metazoans involves the formation of a complex similar to the Scc2-Scc4 interaction in the budding yeast. The very high degree of sequence conservation between Scc4 homologs in complex metazoans is consistent with increased selection pressure to conserve additional essential functions, such as regulation of cell and axon migration during development. PMID:16802858

  1. Metazoan Scc4 homologs link sister chromatid cohesion to cell and axon migration guidance.

    PubMed

    Seitan, Vlad C; Banks, Peter; Laval, Steve; Majid, Nazia A; Dorsett, Dale; Rana, Amer; Smith, Jim; Bateman, Alex; Krpic, Sanja; Hostert, Arnd; Rollins, Robert A; Erdjument-Bromage, Hediye; Tempst, Paul; Benard, Claire Y; Hekimi, Siegfried; Newbury, Sarah F; Strachan, Tom

    2006-07-01

    Saccharomyces cerevisiae Scc2 binds Scc4 to form an essential complex that loads cohesin onto chromosomes. The prevalence of Scc2 orthologs in eukaryotes emphasizes a conserved role in regulating sister chromatid cohesion, but homologs of Scc4 have not hitherto been identified outside certain fungi. Some metazoan orthologs of Scc2 were initially identified as developmental gene regulators, such as Drosophila Nipped-B, a regulator of cut and Ultrabithorax, and delangin, a protein mutant in Cornelia de Lange syndrome. We show that delangin and Nipped-B bind previously unstudied human and fly orthologs of Caenorhabditis elegans MAU-2, a non-axis-specific guidance factor for migrating cells and axons. PSI-BLAST shows that Scc4 is evolutionarily related to metazoan MAU-2 sequences, with the greatest homology evident in a short N-terminal domain, and protein-protein interaction studies map the site of interaction between delangin and human MAU-2 to the N-terminal regions of both proteins. Short interfering RNA knockdown of human MAU-2 in HeLa cells resulted in precocious sister chromatid separation and in impaired loading of cohesin onto chromatin, indicating that it is functionally related to Scc4, and RNAi analyses show that MAU-2 regulates chromosome segregation in C. elegans embryos. Using antisense morpholino oligonucleotides to knock down Xenopus tropicalis delangin or MAU-2 in early embryos produced similar patterns of retarded growth and developmental defects. Our data show that sister chromatid cohesion in metazoans involves the formation of a complex similar to the Scc2-Scc4 interaction in the budding yeast. The very high degree of sequence conservation between Scc4 homologs in complex metazoans is consistent with increased selection pressure to conserve additional essential functions, such as regulation of cell and axon migration during development. PMID:16802858

  2. Advances in Linking Wintering Migrant Birds to Their Breeding-Ground Origins Using Combined Analyses of Genetic and Stable Isotope Markers

    PubMed Central

    Chabot, Amy A.; Hobson, Keith A.; Van Wilgenburg, Steven L.; McQuat, Gregory J.; Lougheed, Stephen C.

    2012-01-01

    An enduring problem in avian ecology and conservation is linking breeding and wintering grounds of migratory species. As migratory species and populations vary in the degree to which individuals from distinct breeding locales mix on stop-over sites and wintering grounds, establishing migratory connectivity informs our understanding of population demography and species management. We present a new Bayesian approach for inferring breeding grounds of wintering birds of unknown origins in North America. We incorporate prior information from analysis of genetic markers into geographic origin assignment based upon stable-hydrogen isotope analysis of feathers (δ2Hf), using the Loggerhead Shrike (Lanius ludovicianus). Likely geographic origins derived from analyses of DNA microsatellites were used as priors for Bayesian analyses in which birds were assigned to a breeding-ground origin using their δ2Hf values. As with most applications of Bayesian methods, our approach greatly improved the results (i.e. decreased the size of the potential area of origin). Area of origin decreased by 3 to 5-fold on average, but ranged up to a 10-fold improvement. We recommend this approach in future studies of migratory connectivity and suggest that our methodology could be applied more broadly to the study of dispersal, sources of productivity of migratory populations, and a range of evolutionary phenomena. PMID:22916285

  3. The Variety of Shore Birds

    ERIC Educational Resources Information Center

    Varza, Dennis

    1977-01-01

    The types of habitats that exist along the ocean shore and the various types of birds inhabiting them are detailed. Topics discussed include shorebird feeding habits and methods, nesting patterns, and seasonal migration. (BT)

  4. First wide-angle view of channelized turbidity currents links migrating cyclic steps to flow characteristics.

    PubMed

    Hughes Clarke, John E

    2016-01-01

    Field observations of turbidity currents remain scarce, and thus there is continued debate about their internal structure and how they modify underlying bedforms. Here, I present the results of a new imaging method that examines multiple surge-like turbidity currents within a delta front channel, as they pass over crescent-shaped bedforms. Seven discrete flows over a 2-h period vary in speed from 0.5 to 3.0 ms(-1). Only flows that exhibit a distinct acoustically attenuating layer at the base, appear to cause bedform migration. That layer thickens abruptly downstream of the bottom of the lee slope of the bedform, and the upper surface of the layer fluctuates rapidly at that point. The basal layer is inferred to reflect a strong near-bed gradient in density and the thickening is interpreted as a hydraulic jump. These results represent field-scale flow observations in support of a cyclic step origin of crescent-shaped bedforms. PMID:27283503

  5. DHCR7 mutations linked to higher vitamin D status allowed early human migration to Northern latitudes

    PubMed Central

    2013-01-01

    Background Vitamin D is essential for a wide range of physiological processes including immune function and calcium homeostasis. Recent investigations have identified candidate genes which are strongly linked to concentrations of 25-hydroxyvitamin D. Since there is insufficient UVB radiation to induce year-round cutaneous synthesis of vitamin D at latitudes distant from the equator it is likely that these genes were subject to forces of natural selection. We used the fixation index (FST) to measure differences in allele frequencies in 993 individuals from ten populations to identify the presence of evolutionary selection in genes in the vitamin D pathway. We then explored the length of haplotypes in chromosomes to confirm recent positive selection. Results We find evidence of positive selection for DHCR7, which governs availability of 7-dehydrocholesterol for conversion to vitamin D3 by the action of sunlight on the skin. We show that extended haplotypes related to vitamin D status are highly prevalent at Northern latitudes (Europe 0.72, Northeast Asia 0.41). The common DHCR7 haplotype underwent a recent selective sweep in Northeast Asia, with relative extended haplotype homozygosity of 5.03 (99th percentile). In contrast, CYP2R1, which 25-hydroxylates vitamin D, is under balancing selection and we found no evidence of recent selection pressure on GC, which is responsible for vitamin D transport. Conclusions Our results suggest that genetic variation in DHCR7 is the major adaptation affecting vitamin D metabolism in recent evolutionary history which helped early humans to avoid severe vitamin D deficiency and enabled them to inhabit areas further from the equator. PMID:23837623

  6. Mutations in USP9X Are Associated with X-Linked Intellectual Disability and Disrupt Neuronal Cell Migration and Growth

    PubMed Central

    Homan, Claire C.; Kumar, Raman; Nguyen, Lam Son; Haan, Eric; Raymond, F. Lucy; Abidi, Fatima; Raynaud, Martine; Schwartz, Charles E.; Wood, Stephen A.; Gecz, Jozef; Jolly, Lachlan A.

    2014-01-01

    With a wealth of disease-associated DNA variants being recently reported, the challenges of providing their functional characterization are mounting. Previously, as part of a large systematic resequencing of the X chromosome in 208 unrelated families with nonsyndromic X-linked intellectual disability, we identified three unique variants (two missense and one protein truncating) in USP9X. To assess the functional significance of these variants, we took advantage of the Usp9x knockout mouse we generated. Loss of Usp9x causes reduction in both axonal growth and neuronal cell migration. Although overexpression of wild-type human USP9X rescued these defects, all three USP9X variants failed to rescue axonal growth, caused reduced USP9X protein localization in axonal growth cones, and (in 2/3 variants) failed to rescue neuronal cell migration. Interestingly, in one of these families, the proband was subsequently identified to have a microdeletion encompassing ARID1B, a known ID gene. Given our findings it is plausible that loss of function of both genes contributes to the individual's phenotype. This case highlights the complexity of the interpretations of genetic findings from genome-wide investigations. We also performed proteomics analysis of neurons from both the wild-type and Usp9x knockout embryos and identified disruption of the cytoskeleton as the main underlying consequence of the loss of Usp9x. Detailed clinical assessment of all three families with USP9X variants identified hypotonia and behavioral and morphological defects as common features in addition to ID. Together our data support involvement of all three USP9X variants in ID in these families and provide likely cellular and molecular mechanisms involved. PMID:24607389

  7. Mapping Global Diversity Patterns for Migratory Birds

    PubMed Central

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H. M.; Rodrigues, Ana S. L.

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world’s birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective. PMID:23951037

  8. Mapping global diversity patterns for migratory birds.

    PubMed

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H M; Rodrigues, Ana S L

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective. PMID:23951037

  9. Adaptations of a competitive enzyme-linked immunosorbent assays for the detection of antibodies to influenza a virus in horse sera for use in wild aquatic birds.

    PubMed

    Hoque, M A; Skerratt, L F; Garland, S; Burgess, G W; Selleck, P

    2012-12-01

    We applied a competitive enzyme-linked immunosorbent assay for the detection of antibodies for influenza A in equine sera to their detection in sera from wild aquatic birds. Suboptimal results were obtained for the optical density (OD) of the monoclonal antibody (MAb) control and reproducibility between duplicate analyses in the initial assessment. It was therefore necessary to modify the assay to deliver increased reliability and reproducibility while maintaining adequate sensitivity. We optimized reagent concentrations to obtain optimal OD values (close to 2) for the monoclonal antibody control and used 2, 2'-Azino-bis: 3-Benzthiazoline-6-Sulphonic Acid as an alternative chromogen to potentially reduce variability in duplicate analyses. The original assay was compared with the optimized versions, with and without post coating, for the detection of avian influenza viral antibodies in 240 sera obtained from wild plumed whistling ducks. A separate analytical sensitivity study on diluted positive field sera of plumed whistling ducks and a test of antigen stability after post coating were also performed. Some quantitative differences were detected between the original and modified assays. The original assay recorded higher percentage inhibition results which were potentially indicative of increased sensitivity. However, when reagent concentrations were increased in the original assay to the same levels as used in the modified versions, there were no quantitative differences for practical purposes. The original assay produced a median (OD) value of 0.81 for the (MAb) controls that is at the limit of acceptability. By contrast, the modified assays always produced acceptable optical density values for MAb controls. Our overall results indicated the modified assays were potentially more reliable (OD values close to 2), and of adequate sensitivity compared to the original assay in the detection of avian influenza viral antibodies in wild bird sera. Although further

  10. Rice production systems and avian influenza: Interactions between mixed-farming systems, poultry and wild birds

    USGS Publications Warehouse

    Muzaffar, S.B.; Takekawa, J.Y.; Prosser, D.J.; Newman, S.H.; Xiao, X.

    2010-01-01

    Wild waterfowl are the reservoir for avian influenza viruses (AIVs), a family of RNA viruses that may cause mild sickness in waterbirds. Emergence of H5N1, a highly pathogenic avian influenza (HPAI) strain, causing severe disease and mortality in wild birds, poultry and humans, had raised concerns about the role of wild birds in possible transmission of the disease. In this review, the link between rice production systems, poultry production systems, and wild bird ecology is examined to assess the extent to which these interactions could contribute towards the persistence and evolution of HPAI H5N1. The rice (Oryza sativa) and poultry production systems in Asia described, and then migration and movements of wild birds discussed. Mixed farming systems in Asia and wild bird movement and migration patterns create opportunities for the persistence of low pathogenic AIVs in these systems. Nonetheless, there is no evidence of long-term persistence of HPAI viruses (including the H5N1 subtype) in the wild. There are still significant gaps in the understanding of how AIVs circulate in rice systems. A better understanding of persistence of AIVs in rice farms, particularly of poultry origins, is essential in limiting exchange of AIVs between mixed-farming systems, poultry and wild birds.

  11. Bird guard

    DOEpatents

    Fairchild, Dana M.

    2010-03-02

    The bird guard provides a device to protect electrical insulators comprising a central shaft; a clamp attached to an end of the shaft to secure the device to a transmission tower; a top and bottom cover to shield transmission tower insulators; and bearings to allow the guard to rotate in order to frighten birds away from the insulators.

  12. Access to bird population data

    USGS Publications Warehouse

    Martin, E.; Peterjohn, B.G.; Koneff, M.D.

    2001-01-01

    Access to bird population data is critical for effective conservation planning and implementation. Although a tremendous volume of baseline data exists, it is often diffusely distributed and inaccessible to the resource manager and decision maker. A mechanism that facilitates assembly, documentation and delivery of avian data in a user-friendly manner is needed in order to integrate bird-related information resources across agencies and organizations. To address this fundamental need, the National Biological Information Infrastructure (NBII), in partnership with the U.S. Geological Survey's Patuxent Wildlife Research Center and the U.S. Fish and Wildlife Service, is developing a web-based interactive system that will focus on access to bird population and habitat data used in bird management and conservation. This system, known as the NBII Bird Conservation Node, will support planning and evaluation of bird conservation activities within the context of the North American Bird Conservation Initiative (NABCI), a framework for collaboration among organizations interested in bird conservation across North America. Initial development of the NBII Bird Conservation Node will focus on creating a prototype mapping application that will provide interactive access to data from the North American Breeding Bird Survey, the Colonial Waterbird Survey, the Breeding Waterfowl Population and Habitat Survey, and the Atlantic Flyway Mid-winter Waterfowl Survey. This prototype mapping application, to be available on-line at http://www.nbii.gov by Sep 2001, will lay the foundation for establishment of a Migratory Bird Data Center at Patuxent Wildlife Research Center, and will provide an opportunity for linking to and establishing partnerships with other sources of bird population and habitat data available over the Internet.

  13. Rab14 and Its Exchange Factor FAM116 Link Endocytic Recycling and Adherens Junction Stability in Migrating Cells

    PubMed Central

    Linford, Andrea; Yoshimura, Shin-ichiro; Bastos, Ricardo Nunes; Langemeyer, Lars; Gerondopoulos, Andreas; Rigden, Daniel J.; Barr, Francis A.

    2012-01-01

    Summary Rab GTPases define the vesicle trafficking pathways underpinning cell polarization and migration. Here, we find that Rab4, Rab11, and Rab14 and the candidate Rab GDP-GTP exchange factors (GEFs) FAM116A and AVL9 are required for cell migration. Rab14 and its GEF FAM116A localize to and act on an intermediate compartment of the transferrin-recycling pathway prior to Rab11 and after Rab5 and Rab4. This Rab14 intermediate recycling compartment has specific functions in migrating cells discrete from early and recycling endosomes. Rab14-depleted cells show increased N-cadherin levels at junctional complexes and cannot resolve cell-cell junctions. This is due to decreased shedding of cell-surface N-cadherin by the ADAM family protease ADAM10/Kuzbanian. In FAM116A- and Rab14-depleted cells, ADAM10 accumulates in a transferrin-positive endocytic compartment, and the cell-surface level of ADAM10 is correspondingly reduced. FAM116 and Rab14 therefore define an endocytic recycling pathway needed for ADAM protease trafficking and regulation of cell-cell junctions. PMID:22595670

  14. Birds, Examining Your Environment.

    ERIC Educational Resources Information Center

    MacBean, John C.; And Others

    Designed to provide new and different ways of observing birds rather than simply identifying them, this book attempts to develop skills for how to look at birds. Activities in each of the four sections, "Live Birds,""Birds' Eggs,""Birds' Nests," and "Dead Birds," are specifically planned to get one involved with birds in their natural environment.…

  15. Risk Considerations of Bird Strikes to Space Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Hales, Christy; Ring, Robert

    2016-01-01

    Within seconds after liftoff of the Space Shuttle during mission STS-114, a turkey vulture impacted the vehicle's external tank. The contact caused no apparent damage to the Shuttle, but the incident led NASA to consider the potential consequences of bird strikes during a Shuttle launch. The environment at Kennedy Space Center provides unique bird strike challenges due to the Merritt Island National Wildlife Refuge and the Atlantic Flyway bird migration routes. NASA is currently refining risk assessment estimates for the probability of bird strike to space launch vehicles. This paper presents an approach for analyzing the risks of bird strikes to space launch vehicles and presents an example. The migration routes, types of birds present, altitudes of those birds, exposed area of the launch vehicle, and its capability to withstand impacts affect the risk due to bird strike. A summary of significant risk contributors is discussed.

  16. Birds and Wetlands of Alaska. Alaska Sea Week Curriculum Series. Alaska Sea Grant Report 88-1.

    ERIC Educational Resources Information Center

    King, James G.; King, Mary Lou

    This curriculum guide is the fourth (Series V) in a six-volume set that comprises the Sea Week Curriculum Series developed in Alaska. Twelve units contain 45 activities with worksheets that cover the following topics: (1) bird lists and field guides; (2) definitions of a bird; (3) parts of a bird; (4) bird watching; (5) bird migration; (6) wetland…

  17. Pregnancy associated plasma protein-A links pregnancy and melanoma progression by promoting cellular migration and invasion.

    PubMed

    Prithviraj, Prashanth; Anaka, Matthew; McKeown, Sonja J; Permezel, Michael; Walkiewicz, Marzena; Cebon, Jonathan; Behren, Andreas; Jayachandran, Aparna

    2015-06-30

    Melanoma is the most common cancer diagnosed in pregnant women and an aggressive course with poorer outcomes is commonly described during pregnancy or shortly after childbirth. The underlying mechanisms for this are not understood. Here, we report that melanoma migration, invasiveness and progression are promoted by Pregnancy-Associated Plasma Protein-A (PAPPA), a pregnancy-associated metalloproteinase produced by the placenta that increases the bioavailability of IGF1 by cleaving it from a circulating complex formed with IGFBP4. We show that PAPPA is widely expressed by metastatic melanoma tumors and is elevated in melanoma cells exhibiting mesenchymal, invasive and label-retaining phenotypes. Notably, inhibition of PAPPA significantly reduced invasion and migration of melanoma cells in vitro and in vivo within the embryonic chicken neural tube. PAPPA-enriched pregnancy serum treatment enhanced melanoma motility in vitro. Furthermore, we report that IGF1 can induce the phenotypic and functional effects of epithelial-to-mesenchymal transition (EMT) in melanoma cells. In this study, we establish a clear relationship between a pregnancy-associated protein PAPPA, melanoma and functional effects mediated through IGF1 that provides a plausible mechanism for accelerated melanoma progression during pregnancy. This opens the possibility of targeting the PAPPA/IGF1 axis therapeutically. PMID:25940796

  18. Ogbu and the Debate on Educational Achievement: An Exploration of the Links between Education, Migration, Identity and Belonging

    ERIC Educational Resources Information Center

    Bhatti, Ghazala

    2006-01-01

    This paper looks at some of the issues raised by Ogbu's work in relation to the education of different minority ethnic groups. Ogbu poses questions such as the value attached to education, its links to the future and its measurable outcomes in terms of "success" as experienced by black participants. The desire for better life chances leads…

  19. Tracking radar techniques for studying migratory birds

    NASA Technical Reports Server (NTRS)

    Williams, T. C.; Williams, J. M.

    1972-01-01

    The use of NASA tracking radar at Wallops Island and the islands of Bermuda and Antigua to plot the paths of migatory birds in three dimensional space is discussed. Attempts were also made to obtain data on the direction, speed, and density of large numbers of migrating birds. Observational results show that the performance of tracking radars vary considerably with the density of bird migration. At light to moderate levels of migration it is possible to obtain tracks of a variety of types of targets, both large and small. During heavy periods of migration the sky is so filled with targets, that only the largest targets can be tracked for more than a few minutes.

  20. Phenotype and immune function of lymph node and peripheral blood CLL cells are linked to transendothelial migration.

    PubMed

    Pasikowska, Marta; Walsby, Elisabeth; Apollonio, Benedetta; Cuthill, Kirsty; Phillips, Elizabeth; Coulter, Eve; Longhi, Maria Serena; Ma, Yun; Yallop, Deborah; Barber, Linda D; Patten, Piers; Fegan, Chris; Ramsay, Alan G; Pepper, Chris; Devereux, Stephen; Buggins, Andrea G S

    2016-07-28

    Several lines of evidence suggest that homing of tumor cells to lymphoid tissue contributes to disease progression in chronic lymphocytic leukemia (CLL). Here, we demonstrate that lymph node (LN)-derived CLL cells possess a distinct phenotype, and exhibit enhanced capacity for T-cell activation and superior immune synapse formation when compared with paired peripheral blood (PB) samples. LN-derived CLL cells manifest a proliferative, CXCR4(dim)CD5(bright) phenotype compared with those in the PB and higher expression of T-cell activation molecules including CD80, CD86, and HLA-D-related (DR). In addition, LN-CLL cells have higher expression of α4β1 (CD49d) which, as well as being a co-stimulatory molecule, is required for CLL cells to undergo transendothelial migration (TEM) and enter the proliferation centers of the LNs. Using an in vitro system that models circulation and TEM, we showed that the small population of CLL cells that migrate are CXCR4(dim)CD5(bright) with higher CD49d, CD80, CD86, and HLA-DR compared with those that remain circulating; a phenotype strikingly similar to LN-derived CLL cells. Furthermore, sorted CD49d(hi) CLL cells showed an enhanced capacity to activate T cells compared with CD49d(lo) subpopulations from the same patient. Thus, although PB-CLL cells have a reduced capacity to form immune synapses and activate CD4(+) T cells, this was not the case for LN-CLL cells or those with the propensity to undergo TEM. Taken together, our study suggests that CLL cell immunologic function is not only modulated by microenvironmental interactions but is also a feature of a subpopulation of PB-CLL cells that are primed for lymphoid tissue homing and interaction with T cells. PMID:27252234

  1. Role of wild birds as carriers of multi-drug resistant Escherichia coli and Escherichia vulneris

    PubMed Central

    Shobrak, Mohammed Y.; Abo-Amer, Aly E.

    2014-01-01

    Emergence and distribution of multi-drug resistant (MDR) bacteria in environments pose a risk to human and animal health. A total of 82 isolates of Escherichia spp. were recovered from cloacal swabs of migrating and non-migrating wild birds. All bacterial isolates were identified and characterized morphologically and biochemically. 72% and 50% of isolates recovered from non-migrating and migrating birds, respectively, showed positive congo red dye binding (a virulence factor). Also, hemolysin production (a virulence factor) was showed in 8% of isolates recovered from non-migrating birds and 75% of isolates recovered from migrating birds. All isolates recovered from non-migrating birds were found resistant to Oxacillin while all isolates recovered from migrating birds demonstrated resistance to Oxacillin, Chloramphenicol, Oxytetracycline and Lincomycin. Some bacterial isolates recovered from non-migrating birds and migrating birds exhibited MDR phenotype. The MDR isolates were further characterized by API 20E and 16S rRNA as E. coli and E. vulneris. MDR Escherichia isolates contain ~1–5 plasmids of high-molecular weights. Accordingly, wild birds could create a potential threat to human and animal health by transmitting MDR bacteria to water streams and other environmental sources through their faecal residues, and to remote regions by migration. PMID:25763023

  2. Role of wild birds as carriers of multi-drug resistant Escherichia coli and Escherichia vulneris.

    PubMed

    Shobrak, Mohammed Y; Abo-Amer, Aly E

    2014-01-01

    Emergence and distribution of multi-drug resistant (MDR) bacteria in environments pose a risk to human and animal health. A total of 82 isolates of Escherichia spp. were recovered from cloacal swabs of migrating and non-migrating wild birds. All bacterial isolates were identified and characterized morphologically and biochemically. 72% and 50% of isolates recovered from non-migrating and migrating birds, respectively, showed positive congo red dye binding (a virulence factor). Also, hemolysin production (a virulence factor) was showed in 8% of isolates recovered from non-migrating birds and 75% of isolates recovered from migrating birds. All isolates recovered from non-migrating birds were found resistant to Oxacillin while all isolates recovered from migrating birds demonstrated resistance to Oxacillin, Chloramphenicol, Oxytetracycline and Lincomycin. Some bacterial isolates recovered from non-migrating birds and migrating birds exhibited MDR phenotype. The MDR isolates were further characterized by API 20E and 16S rRNA as E. coli and E. vulneris. MDR Escherichia isolates contain ~1-5 plasmids of high-molecular weights. Accordingly, wild birds could create a potential threat to human and animal health by transmitting MDR bacteria to water streams and other environmental sources through their faecal residues, and to remote regions by migration. PMID:25763023

  3. A birds-eye view of biological connectivity in mangrove systems

    NASA Astrophysics Data System (ADS)

    Buelow, Christina; Sheaves, Marcus

    2015-01-01

    contributed to shifting the initial, historical perception of mangrove-ecosystem functioning from that of a simple system based on nutrient and energy retention, to a view that includes fish-facilitated energy export. In a similar way, understanding the nature and implications of mangrove connectivity through bird movements and migrations affords new possibilities for revising our view of the extent of functional links between mangroves and other ecosystems.

  4. RLIP76 regulates Arf6-dependent cell spreading and migration by linking ARNO with activated R-Ras at recycling endosomes.

    PubMed

    Wurtzel, Jeremy G T; Lee, Seunghyung; Singhal, Sharad S; Awasthi, Sanjay; Ginsberg, Mark H; Goldfinger, Lawrence E

    2015-11-27

    R-Ras small GTPase enhances cell spreading and motility via RalBP1/RLIP76, an R-Ras effector that links GTP-R-Ras to activation of Arf6 and Rac1 GTPases. Here, we report that RLIP76 performs these functions by binding cytohesin-2/ARNO, an Arf GTPase guanine exchange factor, and connecting it to R-Ras at recycling endosomes. RLIP76 formed a complex with R-Ras and ARNO by binding ARNO via its N-terminus (residues 1-180) and R-Ras via residues 180-192. This complex was present in Rab11-positive recycling endosomes and the presence of ARNO in recycling endosomes required RLIP76, and was not supported by RLIP76(Δ1-180) or RLIP76(Δ180-192). Spreading and migration required RLIP76(1-180), and RLIP76(Δ1-180) blocked ARNO recruitment to recycling endosomes, and spreading. Arf6 activation with an ArfGAP inhibitor overcame the spreading defects in RLIP76-depleted cells or cells expressing RLIP76(Δ1-180). Similarly, RLIP76(Δ1-180) or RLIP76(Δ180-192) suppressed Arf6 activation. Together these results demonstrate that RLIP76 acts as a scaffold at recycling endosomes by binding activated R-Ras, recruiting ARNO to activate Arf6, thereby contributing to cell spreading and migration. PMID:26498519

  5. A preliminary investigation of bird classification by Doppler radar

    NASA Technical Reports Server (NTRS)

    Martinson, L. W.

    1973-01-01

    A preliminary study of the application of Doppler radar to the classification of birds is reported. The desirability for improvements in bird classification stems primarily from the hazards they present to jet aircraft in flight and in the vicinity of airports. A secondary need exists in the study of bird migration. The wing body and tail motion of a bird in flight reflect signals which, when analyzed properly present a signature of wing beat pattern which is unique for each bird species. Although the results of this investigation did not validate the feasibility of classifying bird species, they do indicate that a more thorough investigation is warranted. Certain gross characteristics such as wing beat rates, multiple bird patterns, and bird maneuverability, were indicated clearly in the results. Large birds with slow wing beat rates appear to be the most optimum subject for further study with the X-band Doppler radar used in this investigation.

  6. Experimental evidence of a link between breeding conditions and the decision to breed or to help in a colonial cooperative bird.

    PubMed Central

    Covas, Rita; Doutrelant, Claire; du Plessis, Morné A.

    2004-01-01

    In many species mature individuals delay independent reproduction and may help others to reproduce. This behaviour is often explained through ecological constraints, although recently attention has also been paid to the variation in habitat quality. If the quality of vacant habitat influences the fitness trade-off between delaying reproduction and breeding independently, individuals should delay reproduction when conditions for breeding are poor. Yet, no study has experimentally manipulated habitat quality or the conditions experienced during the breeding period to test this assertion conclusively. We report results from an experiment conducted on a colonial cooperative bird with no territory constraints on reproduction. We artificially improved breeding conditions in several colonies of sociable weavers, Philetairus socius, through the provision of an easily obtainable and unlimited supply of food. We provide experimental evidence showing that under enhanced conditions some individuals reduce their age at first reproduction, a greater proportion of colony members engage in independent breeding and proportionally fewer birds act as helpers. Hence, these results also provide evidence for a direct influence of reproductive costs on life-history decisions such as age at first reproduction and breeding and helping behaviours. PMID:15255101

  7. Assessment of bird response to the Migratory Bird Habitat Initiative using weather-surveillance radar

    USGS Publications Warehouse

    Sieges, Mason L.; Smolinsky, Jaclyn A.; Baldwin, Michael J.; Barrow, Wylie C.; Randall, Lori A.; Buler, Jeffrey J.

    2014-01-01

    In response to the Deepwater Horizon oil spill in spring 2010, the Natural Resources Conservation Service implemented the Migratory Bird Habitat Initiative (MBHI) to provide temporary wetland habitat for migrating and wintering waterfowl, shorebirds, and other birds along the northern Gulf of Mexico via managed flooding of agricultural lands. We used weather-surveillance radar to conduct broad regional assessments of bird response to MBHI activities within the Mississippi Alluvial Valley and the West Gulf Coastal Plain. Across both regions, birds responded positively to MBHI management by exhibiting greater relative bird densities within sites relative to pre-management conditions in prior years and relative to surrounding non-flooded agricultural lands. Bird density at MBHI sites was generally greatest during winter for both regions. Unusually high flooding in the years prior to implementation of the MBHI confounded detection of overall changes in remotely sensed soil wetness across sites. The magnitude of bird response at MBHI sites compared to prior years and to non-flooded agricultural lands was generally related to the surrounding landscape context: proximity to areas of high bird density, amount of forested wetlands, emergent marsh, non-flooded agriculture, or permanent open water. However, these relationships varied in strength and direction between regions and seasons, a finding which we attribute to differences in seasonal bird composition and broad regional differences in landscape configuration and composition. We detected greater increases in relative bird use at sites in closer proximity to areas of high bird density during winter in both regions. Additionally, bird density was greater during winter at sites with more emergent marsh in the surrounding landscape. Thus, bird use of managed wetlands could be maximized by enrolling lands located near areas of known bird concentration and within a mosaic of existing wetlands. Weather-radar observations

  8. The physiological basis of bird flight.

    PubMed

    Butler, Patrick J

    2016-09-26

    Flapping flight is energetically more costly than running, although it is less costly to fly a given body mass a given distance per unit time than it is for a similar mass to run the same distance per unit time. This is mainly because birds can fly faster than they can run. Oxygen transfer and transport are enhanced in migrating birds compared with those in non-migrators: at the gas-exchange regions of the lungs the effective area is greater and the diffusion distance smaller. Also, migrating birds have larger hearts and haemoglobin concentrations in the blood, and capillary density in the flight muscles tends to be higher. Species like bar-headed geese migrate at high altitudes, where the availability of oxygen is reduced and the energy cost of flapping flight increased compared with those at sea level. Physiological adaptations to these conditions include haemoglobin with a higher affinity for oxygen than that in lowland birds, a greater effective ventilation of the gas-exchange surface of the lungs and a greater capillary-to-muscle fibre ratio. Migrating birds use fatty acids as their source of energy, so they have to be transported at a sufficient rate to meet the high demand. Since fatty acids are insoluble in water, birds maintain high concentrations of fatty acid-binding proteins to transport fatty acids across the cell membrane and within the cytoplasm. The concentrations of these proteins, together with that of a key enzyme in the β-oxidation of fatty acids, increase before migration.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. PMID:27528774

  9. 9 CFR 93.104 - Certificate for pet birds, commercial birds, zoological birds, and research birds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Certificate for pet birds, commercial birds, zoological birds, and research birds. 93.104 Section 93.104 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND...

  10. 9 CFR 93.104 - Certificate for pet birds, commercial birds, zoological birds, and research birds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Certificate for pet birds, commercial birds, zoological birds, and research birds. 93.104 Section 93.104 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND...

  11. Birds Kept as Pets

    MedlinePlus

    ... restricts the importation of pet birds from certain countries and enforces a 30-day quarantine for all imported birds except those that come from Canada. People interested in importing pet birds should visit the USDA non-US Origin Pet Bird Importation website . Choosing a bird Match ...

  12. Diving birds

    NASA Astrophysics Data System (ADS)

    Clanet, Christophe; Masson, Lucien; McKinley, Gareth; Cohen, Robert; Ecole polytechnique Collaboration; MIT Collaboration

    2015-11-01

    Many seabirds (gannets, pelicans, gulls, albatrosses) dive into water at high speeds (25 m/s) in order to capture underwater preys. Diving depths of 20 body lengths are reported in the literature. This value is much larger than the one achieved by men, which is of the order of 5. We study this difference by comparing the impact of slender vs bluff bodies. We show that, contrary to bluff bodies, the penetration depth of slender bodies presents a maximum value for a specific impact velocity that we connect to the velocity of diving birds.

  13. Overseas seed dispersal by migratory birds.

    PubMed

    Viana, Duarte S; Gangoso, Laura; Bouten, Willem; Figuerola, Jordi

    2016-01-13

    Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution. PMID:26740610

  14. Ecomorphological predictors of natal dispersal distances in birds.

    PubMed

    Dawideit, Britta A; Phillimore, Albert B; Laube, Irina; Leisler, Bernd; Böhning-Gaese, Katrin

    2009-03-01

    1. Dispersal is one of the key ecological parameters but it is very difficult to quantify directly. As a consequence, empirical studies often ignore dispersal or use indirect measures. 2. Ringing data have previously been used to estimate the natal dispersal distances of 47 British passerine bird species. This provides an excellent opportunity to examine the potential of various indirect measures to predict natal dispersal distances in British birds. 3. We use a phylogenetic comparative framework and single- and multipredictor models including ecomorphological, behavioural or ecological traits to predict natal dispersal distance. 4. A multipredictor model that includes Kipp's distance (a measure of wing tip length), bill depth and tail graduation explains 45% of the interspecific variation in natal dispersal distance. These morphological characters all relate to aerodynamics with stronger flyers dispersing further. 5. However, an index of migration is a strong (but less informative) correlate of dispersal distance and Kipp's distance and bill depth are strong correlates of migration. Thus, we cannot disentangle whether these ecomorphological traits influence dispersal distance directly or whether the relationship between ecomorphology and dispersal is mediated through migratory behaviour. 6. Notwithstanding uncertainties regarding the causal links between dispersal distance and wing morphology, we suggest that two ecomorphological traits, Kipp's distance and bill depth, may provide a useful surrogate. PMID:19040685

  15. Cellular apoptosis susceptibility (CAS) is linked to integrin β1 and required for tumor cell migration and invasion in hepatocellular carcinoma (HCC)

    PubMed Central

    Winkler, Juliane; Roessler, Stephanie; Sticht, Carsten; DiGuilio, Amanda L.; Drucker, Elisabeth; Holzer, Kerstin; Eiteneuer, Eva; Herpel, Esther; Breuhahn, Kai; Gretz, Norbert; Schirmacher, Peter; Ori, Alessandro; Singer, Stephan

    2016-01-01

    Importins and exportins represent an integral part of the nucleocytoplasmic transport machinery with fundamental importance for eukaryotic cell function. A variety of malignancies including hepatocellular carcinoma (HCC) show de-regulation of nuclear transport factors such as overexpression of the exportin Cellular Apoptosis Susceptibility (CAS). The functional implications of CAS in hepatocarcinogenesis remain, however, poorly understood. Here we integrated proteomics, transcriptomics and functional assays with patient data to further characterize the role of CAS in HCC. By analyzing ∼ 1700 proteins using quantitative mass spectrometry in HCC cells we found that CAS depletion by RNAi leads to de-regulation of integrins, particularly down-regulation of integrin β1. Consistent with this finding, CAS knockdown resulted in substantially reduced migration and invasion of HCC cell lines as analyzed by 2D ‘scratch’ and invasion chamber assays, respectively. Supporting the potential in vivo relevance, high expression levels of CAS in HCC tissue samples were associated with macroangioinvasion and poorer patient outcome. Our data suggest a previously unanticipated link between CAS and integrin signaling which correlates with an aggressive HCC phenotype. PMID:27015362

  16. Information on bird navigation obtained by British long range radars

    NASA Technical Reports Server (NTRS)

    Evans, P. R.

    1972-01-01

    Radar observations of the migratory habits of passerine birds over a 10 year period are presented. The relationships between intensity of cloud cover and the frequency and density of migration are illustrated. The aspects of migration which were determined by the radar were: (1) migration under total overcast, (2) compensation for wind drift, (3) changes in flight direction during migration, and (4) effects of meteorological parameters.

  17. A survey of free-living falconiform birds for Salmonella.

    PubMed

    Kirkpatrick, C E; Trexler-Myren, V P

    1986-11-01

    Of 105 migrating falconiform birds of 7 species examined for Salmonella shedding in New Jersey, 2 (1.9%) were positive for Salmonella spp. Both positive birds were immature red-tailed hawks (Buteo jamaicensis). Salmonella enteritidis and S newport were the serotypes isolated. Neither serotype expressed multiple resistance when tested against a panel of 12 antimicrobial drugs. PMID:3506002

  18. Motorized Migrations: the Future or Mere Fantasy?

    USGS Publications Warehouse

    Ellis, D.H.; Sladen, William J. L.; Lishman, W.A.; Clegg, K.R.; Duff, J.W.; Gee, G.F.; Lewis, J.C.

    2003-01-01

    In 15 experiments from 1993-2002, we led cranes, geese, or swans on their first southward migration with either ultralight aircraft or vehicles on the ground. These experiments reveal that large birds can be readily trained to follow and most will return north (and south) in subsequent migrations unassisted. These techniques can now be used to teach birds new (or forgotten) migration paths. Although we are constantly improving our training techniques, we now have an operational program that can be broadly applied to those species where juveniles learn migration routes from their parents.

  19. Torn Paper Birds.

    ERIC Educational Resources Information Center

    Harrington, Carolyn Lang

    1998-01-01

    Describes a lesson for third-grade students that begins with an examination of bird prints done by John James Audubon and moves into the students creating their own torn paper birds. Introduces the students to the beauty of birds and focuses on the environmental issues that face birds and their habitats. (CMK)

  20. HPLC detection of loss rate and cell migration of HUVECs in a proanthocyanidin cross-linked recombinant human collagen-peptide (RHC)-chitosan scaffold.

    PubMed

    Zhang, Jing; Deng, Aipeng; Yang, Yang; Gao, Lihu; Xu, Na; Liu, Xin; Hu, Lunxiang; Chen, Junhua; Yang, Shulin

    2015-11-01

    Porous scaffolds with appropriate pore structure, biocompatibility, mechanical property and processability play an important role in tissue engineering. In this paper, we fabricated a recombinant human collagen-peptide (RHC)-chitosan scaffold cross-linked by premixing 30% proanthocyanidin (PA) in one-step freeze-drying. To remove the residual acetic acid, optimized 0.2M phosphate buffer of pH6.24 with 30% ethanol (PBSE) was selected to neutralize the lyophilized scaffold followed by three times deionized water rinse. Ninhydrin assay was used to characterize the components loss during the fabrication process. To detect the exact RHC loss under optimized neutralization condition, high performance liquid chromatography (HPLC) equipped size exclusion chromatography column was used and the total RHC loss rate through PBSE rinse was 19.5±5.08%. Fourier transform infrared spectroscopy (FT-IR) indicated hydrogen bonding among RHC, chitosan and PA, it also presented a probative but not strong hydrophobic interaction between phenyl rings of polyphenols and pyrrolidine rings of proline in RHC. Further, human umbilical vein endothelial cell (HUVEC) viability analyzed by a scanning electron microscope (SEM) and acridine orange/ethidium bromide (AO/EB) fluorescence staining exhibited that this scaffold could not only promote cell proliferation on scaffold surface but also permit cells migration into the scaffold. qRT-PCR exhibited that the optimized scaffold could stimulate angiogenesis associated genes VEGF and CD31 expression. These characterizations indicated that this scaffold can be considered as an ideal candidate for tissue engineering. PMID:26249627

  1. Avian influenza virus wild bird surveillance in the Azov and Black Sea regions of Ukraine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Azov and Black Sea basins are transcontinental migration routes of wild birds from Northern Asia and Europe to the Mediterranean, Africa and Southwest Asia. These regions constitute an area of transit, stops during migration, and nesting of many migratory bird species with a very high level of ...

  2. Contributions of bird studies to biology.

    PubMed

    Konishi, M; Emlen, S T; Ricklefs, R E; Wingfield, J C

    1989-10-27

    Birds are widely distributed, highly diversified, and exhibit behavior and social organizations equal in complexity to mammals, yet they are generally more conspicuous and approachable in natural environments. These attributes make birds excellent subjects in many areas of biological research. The topics in which studies on birds have figured prominently include the mechanisms of species formation, the regulation of the distribution and abundance of animals, the effects of the environment on behavior and physiology, the biological and evolutionary significance of variations in social organizations, the encoding of information in animal communication, the sensory basis for migration and navigation, the effects of hormones on nerve cells and behavior, the ontogeny of brain and behavior, and the structure and function of the vertebrate brain. The outstanding record of avian research suggests that birds will continue to provide important models for developing and testing new ideas in various fields of biology. PMID:2683069

  3. Inactivation of Arx, the Murine Ortholog of the X-Linked Lissencephaly with Ambiguous Genitalia Gene, Leads to Severe Disorganization of the Ventral Telencephalon with Impaired Neuronal Migration and Differentiation

    PubMed Central

    Colombo, Elena; Collombat, Patrick; Colasante, Gaia; Bianchi, Marta; Long, Jason; Mansouri, Ahmed; Rubenstein, John L. R.; Broccoli, Vania

    2016-01-01

    ARX loss-of-function mutations cause X-linked lissencephaly with ambiguous genitalia (XLAG), a severe neurological condition that results in profound brain malformations, including microcephaly, absence of corpus callosum, and impairment of the basal ganglia. Despite such dramatic defects, their nature and origin remain largely unknown. Here, we used Arx mutant mice as a model to characterize the cellular and molecular mechanisms underlying the basal ganglia alterations. In these animals, the early differentiation of this tissue appeared normal, whereas subsequent differentiation was impaired, leading to the periventricular accumulation of immature neurons in both the lateral ganglionic eminence and medial ganglionic eminence (MGE). Both tangential migration toward the cortex and striatum and radial migration to the globus pallidus and striatum were greatly reduced in the mutants, causing a periventricular accumulation of NPY+ or calretinin+ neurons in the MGE. Arx mutant neurons retained their differentiation potential in vitro but exhibited deficits in morphology and migration ability. These findings imply that cell-autonomous defects in migration underlie the neuronal localization defects. Furthermore, Arx mutants lacked a large fraction of cholinergic neurons and displayed a strong impairment of thalamocortical projections, in which major axon fiber tracts failed to traverse the basal ganglia. Altogether, these results highlight the critical functions of Arx in promoting neural migration and regulating basal ganglia differentiation in mice, consistent with the phenotype of XLAG patients. PMID:17460091

  4. Bird flight characteristics near wind turbines in Minnesota

    USGS Publications Warehouse

    Osborn, R.G.; Dieter, C.D.; Higgins, K.F.; Usgaard, R.E.

    1998-01-01

    During 1994-1995, we saw 70 species of birds on the Buffalo Ridge Wind Resource Area. In both years bird abundance peaked in spring. Red-winged blackbirds (Agelaius phoeniceus), mallards (Anas platyrhynchos), common grackles (Quiscalus quiscula), and barn swallows (Hirundo rustica) were the species most commonly seen. Most birds (82-84%) flew above or below the height range of wind turbine blades (22-55 m). The Buffalo Ridge Wind Resource Area poses little threat to resident or migrating birds at its current operating level.

  5. Why Birds with Deferred Sexual Maturity Are Sedentary on Islands: A Systematic Review

    PubMed Central

    Ferrer, Miguel; Bildstein, Keith; Penteriani, Vincenzo; Casado, Eva; de Lucas, Manuela

    2011-01-01

    Background Island faunas have played central roles in the development of evolutionary biology and ecology. Birds are among the most studied organisms on islands, in part because of their dispersal powers linked to migration. Even so, we lack of information about differences in the movement ecology of island versus mainland populations of birds. Methodology/Principal Findings Here we present a new general pattern indicating that large birds with deferred sexual maturity are sedentary on islands, and that they become so even when they are migratory on the mainland. Density-dependent variation in the age at first breeding affects the survivorship of insular populations and this, in turn, affects the movement ecology of large birds. Because density-dependent variation in the age of first breeding is critical to the long-term survival of small isolated populations of long-lived species, migratory forms can successfully colonize islands only if they become sedentary once there. Analyses of the movement ecology of continental and insular populations of 314 species of raptors, 113 species of Ciconiiformes and 136 species of passerines, along with individual-based population simulations confirm this prediction. Conclusions This finding has several consequences for speciation, colonization and survival of small isolated population of species with deferred sexual maturity. PMID:21811559

  6. North American Bird Banding and quantitative population ecology

    USGS Publications Warehouse

    Nichols, J.D.; Tautin, J.

    2008-01-01

    Early bird-banding programs in North America were developed to provide descriptions of bird migration and movement patterns. This initial interest in description quickly evolved into more quantitative interests in two ways. There was (1) interest in quantifying migration and movement patterns, and (2) rapid recognition that re-observations of marked birds provided information about other parameters relevant to population dynamics. These included survival rate, recruitment rate, and population size. The evolution of methods for estimating population size, survival, recruitment, and movement is reviewed and we show it to be closely tied to bird-banding data. These estimation methods have been used with bird-banding data to draw important inferences about evolutionary ecology, population ecology, and population management. Illustrative examples of such inferences are provided.

  7. ENDOHELMINTHS IN BIRD HOSTS FROM NORTHERN CALIFORNIA AND AN ANALYSIS OF THE ROLE OF LIFE HISTORY TRAITS ON PARASITE RICHNESS

    PubMed Central

    Hannon, Emily R.; Kinsella, John M.; Calhoun, Dana M.; Joseph, Maxwell B.; Johnson, Pieter T. J.

    2016-01-01

    The life history characteristics of hosts often influence patterns of parasite infection either by affecting the likelihood of parasite exposure or the probability of infection following exposure. In birds, migratory behavior has been suggested to affect both the composition and abundance of parasites within a host, although whether migratory birds have more or fewer parasites is unclear. To help address these knowledge gaps, we collaborated with airports, animal rescue/rehabilitation centers, and hunter check stations in the San Francisco Bay Area of California to collect 57 raptors, egrets, herons, ducks, and other waterfowl for parasitological analysis. Following dissections of the gastro-intestinal tract of each host, we identified 64 taxa of parasites: 5 acanthocephalans, 24 nematodes, 8 cestodes, and 27 trematodes. We then used a generalized linear mixed model to determine how life history traits influenced parasite richness among bird hosts, while controlling for host phylogeny. Parasite richness was greater in birds that were migratory with larger clutch sizes and lower in birds that were herbivorous. The effects of clutch size and diet are consistent with previous studies and have been linked to immune function and parasite exposure, respectively, whereas the effect of migration supports the hypothesis of ‘migratory exposure’ rather than that of ‘migratory escape’. PMID:26579621

  8. Endohelminths in Bird Hosts from Northern California and an Analysis of the Role of Life History Traits on Parasite Richness.

    PubMed

    Hannon, Emily R; Kinsella, John M; Calhoun, Dana M; Joseph, Maxwell B; Johnson, Pieter T J

    2016-04-01

    The life history characteristics of hosts often influence patterns of parasite infection either by affecting the likelihood of parasite exposure or the probability of infection after exposure. In birds, migratory behavior has been suggested to affect both the composition and abundance of parasites within a host, although whether migratory birds have more or fewer parasites is unclear. To help address these knowledge gaps, we collaborated with airports, animal rescue/rehabilitation centers, and hunter check stations in the San Francisco Bay Area of California to collect 57 raptors, egrets, herons, ducks, and other waterfowl for parasitological analysis. After dissections of the gastrointestinal tract of each host, we identified 64 taxa of parasites: 5 acanthocephalans, 24 nematodes, 8 cestodes, and 27 trematodes. We then used a generalized linear mixed model to determine how life history traits influenced parasite richness among bird hosts, while controlling for host phylogeny. Parasite richness was greater in birds that were migratory with larger clutch sizes and lower in birds that were herbivorous. The effects of clutch size and diet are consistent with previous studies and have been linked to immune function and parasite exposure, respectively, whereas the effect of migration supports the hypothesis of "migratory exposure" rather than that of "migratory escape." PMID:26579621

  9. Seasonal bird use of canopy gaps in a bottomland forest.

    SciTech Connect

    Bowen, Liessa, T,; Moorman, Christopher, E.; Kilgo, John, C.

    2007-04-01

    ABSTRACT.—Bird use of small canopy gaps within mature forests has not been well studied, particularly across multiple seasons. We investigated seasonal differences in bird use of gap and forest habitat within a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. Gaps were 0.13- to 0.5-ha, 7- to 8-year-old group-selection timber harvest openings. Our study occurred during four bird-use periods (spring migration, breeding, postbreeding, and fall migration) in 2001 and 2002. We used plot counts and mist netting to estimate bird abundance in canopy gaps and surrounding mature forest habitats. Using both survey methods, we observed more birds, including forest-interior species, forest-edge species, field-edge species, and several individual species in canopy gap and gap-edge habitats than in surrounding mature forest during all periods. Interactions between period and habitat type often were significant in models, suggesting a seasonal shift in habitat use. Bird activity generally shifted between the interior of canopy gaps and the immediate gap edge, but many species increased their use of forested habitat during the breeding period. This suggests that many species of birds selectively choose gap and gap-edge habitat over surrounding mature forest during the non-breeding period. Creation of small canopy gaps within a mature forest may increase local bird species richness. The reasons for increased bird activity in gaps remain unclear.

  10. On Connections Between Weather Types and the Arrival of Migratory Birds in Estonia

    NASA Astrophysics Data System (ADS)

    Sepp, M.; Päädam, K.; Palm, V.; Leito, A.

    2010-09-01

    Migration is one of the most energy-consuming activities in the lives of birds. The timing must be such that flying would not be overly strenuous and that there would be favourable conditions for feeding and nesting available at arrival. The wide year-to-year variation in the arrival dates of migratory birds suggests that birds are able to both accelerate and delay their migration according to the weather conditions in the destination area. Often, the arrival date cannot be explained by the average daily temperature or any other single meteorological parameter. Relatively simple tools for exploring the links between climate and wildlife are weather types that combine most of the meteorological variables. The aim of the present work is to study the connections between the arrival of migratory birds in Estonia and the weather types. We examine the weather types that most frequently occurred on those days when birds arrived in Tartu (located in the Eastern part of Estonian mainland) and in Kuressaare (West-Estonian archipelago). For this purpose, the arrival dates of 42 species of migratory birds were analysed and compared to the weather types of 73 classifications generated by COST 733 action (COST 733 catalogue 1.2). Since the weather type classifications were generated using ERA40 air pressure datasets, the period available for analysis is 1958-2002. We selected weather types that occurred on the arrival dates of each migratory bird species. Also, the data on two days prior to the arrival were analysed. We assume that birds "took the decision" to fly to Estonia due to the weather conditions on those two days. Frequency of the selected weather types was analysed and compared to the long term frequency of these types during the spring season (MAM). We assume that birds "prefer" those weather types whose frequency on migration days exceeds their long-term frequency. Similarly, we studied the weather types that birds seem to avoid. The results show that despite the

  11. Optimal moult strategies in migratory birds.

    PubMed

    Barta, Zoltán; McNamara, John M; Houston, Alasdair I; Weber, Thomas P; Hedenström, Anders; Feró, Orsolya

    2008-01-27

    Avian migration, which involves billions of birds flying vast distances, is known to influence all aspects of avian life. Here we investigate how birds fit moult into an annual cycle determined by the need to migrate. Large variation exists in moulting patterns in relation to migration: for instance, moult can occur after breeding in the summer or after arrival in the wintering quarters. Here we use an optimal annual routine model to investigate why this variation exists. The modelled bird's decisions depend on the time of year, its energy reserves, breeding status, experience, flight feather quality and location. Our results suggest that the temporal and spatial variations in food are an important influence on a migratory bird's annual cycle. Summer moult occurs when food has a high peak on the breeding site in the summer, but it is less seasonal elsewhere. Winter moult occurs if there is a short period of high food availability in summer and a strong winter peak at different locations (i.e. the food is very seasonal but in opposite phase on these areas). This finding might explain why only long-distance migrants have a winter moult. PMID:17681914

  12. What Makes a Bird a Bird?

    ERIC Educational Resources Information Center

    NatureScope, 1985

    1985-01-01

    Presents background information and activities that focus on how birds are classified, how they are different from other animals, and the main characteristics of the class "Aves." Activities include an objective, recommended age level(s), subject area(s), list of materials needed, and procedures. Two ready-to-copy pages with bird illustrations are…

  13. Avian Influenza in Birds

    MedlinePlus

    ... and even kill certain domesticated bird species including chickens, ducks, and turkeys. Infected birds can shed avian ... virus’ ability to cause disease and mortality in chickens in a laboratory setting [2.5 MB, 64 ...

  14. Birds: Old Questions and New.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    2002-01-01

    Discusses questions such as how birds fly and the meaning of bird songs. Explains the relationship between birds and ecological activism and points out the excitement in research and observation of birds. (Contains 34 references.) (YDS)

  15. Bird population trends detected by the North American breeding bird survey

    USGS Publications Warehouse

    Bystrak, D.R.; Robbins, C.S.

    1977-01-01

    Continental populations of most bird species have remained quite stable since 1966, but there have been many regional changes associated with migration disasters, breeding failures and range expansions, and a few dramatic increases in populations of introduced species. These changes often are better represented by curvilinear than by linear regressions.

  16. Audubon Bird Study Program.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    Included are a student reader, "The Story of Birds," a leaders' guide, a large colored Audubon bird chart, and a separate guide for the chart. The student reader is divided into eleven sections which relate to the various physical and behavioral features of birds such as feathers, feeding habits as related to the shape of bills and feet, nests,…

  17. Ethanol inhibition of aspartyl-asparaginyl-β-hydroxylase in fetal alcohol spectrum disorder: Potential link to the impairments in central nervous system neuronal migration

    PubMed Central

    de la Monte, Suzanne M.; Tong, Ming; Carlson, Rolf I.; Carter, Jade J.; Longato, Lisa; Silbermann, Elizabeth; Wands, Jack R.

    2010-01-01

    Fetal alcohol spectrum disorder (FASD) is caused by prenatal exposure to alcohol and associated with hypoplasia and impaired neuronal migration in the cerebellum. Neuronal survival and motility are stimulated by insulin and insulin-like growth factor (IGF), whose signaling pathways are major targets of ethanol neurotoxicity. To better understand the mechanisms of ethanol-impaired neuronal migration during development, we examined the effects of chronic gestational exposure to ethanol on aspartyl (asparaginyl)-β-hydroxylase (AAH) expression, because AAH is regulated by insulin/IGF and mediates neuronal motility. Pregnant Long—Evans rats were pair-fed isocaloric liquid diets containing 0, 8, 18, 26, or 37% ethanol by caloric content from gestation day 6 through delivery. Cerebella harvested from postnatal day 1 pups were used to examine AAH expression in tissue, and neuronal motility in Boyden chamber assays. We also used cerebellar neuron cultures to examine the effects of ethanol on insulin/IGF—stimulated AAH expression, and assess the role of GSK-3β—mediated phosphorylation on AAH protein levels. Chronic gestational exposure to ethanol caused dose-dependent impairments in neuronal migration and corresponding reductions in AAH protein expression in developing cerebella. In addition, prenatal ethanol exposure inhibited insulin and IGF-I—stimulated directional motility in isolated cerebellar granule neurons. Ethanol-treated neuronal cultures (50 mM × 96 h) also had reduced levels of AAH protein. Mechanistically, we showed that AAH protein could be phosphorylated on Ser residues by GSK-3β, and that chemical inhibition of GSK-3β and/or global Caspases increases AAH protein in both control- and ethanol-exposed cells. Ethanol-impaired neuronal migration in FASD is associated with reduced AAH expression. Because ethanol increases the activities of both GSK-3β and Caspases, the inhibitory effect of ethanol on neuronal migration could be mediated by increased

  18. Hemispheric-scale wind selection facilitates bar-tailed godwit circum-migration of the Pacific

    USGS Publications Warehouse

    Gill, Robert E., Jr.; 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

  19. Avian influenza virus wild bird surveillance in the Azov and Black Sea regions of Ukraine (2010-2011)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  20. Pair bonds: arrival synchrony in migratory birds.

    PubMed

    Gunnarsson, T G; Gill, J A; Sigurbjörnsson, T; Sutherland, W J

    2004-10-01

    Synchronous arrival of pairs of migratory birds at their breeding grounds is important for maintaining pair bonds and is achieved by pairs that remain together all year round. Here we show that arrival is also synchronized in paired individuals of a migratory shorebird, the black-tailed godwit (Limosa limosa islandica), even though they winter hundreds of kilometres apart and do not migrate together. The mechanisms required to achieve this synchrony and prevent 'divorce' illustrate the complexity of migratory systems. PMID:15470417

  1. Sensor fusion for the localisation of birds in flight

    NASA Astrophysics Data System (ADS)

    Millikin, Rhonda Lorraine

    Tracking and identification of birds in flight remains a goal of aviation safety worldwide and conservation in North America. Marine surveillance radar, tracking radar and more recently weather radar have been used to monitor mass movements of birds. The emphasis has been on prediction of migration fronts where thousands of birds follow weather patterns across a large geographic area. Microphones have been stationed over wide areas to receive calls of these birds and help catalogue the diversity of species comprising these migrations. A most critical feature of landbird migration is where the birds land to rest and feed. These habitats are not known and therefore cannot effectively be protected. For effective management of landbird migrants (nocturnal migrant birds), short-range flight behaviour (100--300 m above ground) is the critical air space to monitor. To ensure conservation efforts are focused on endangered species and species truly at risk, species of individual birds must be identified. Short-range monitoring of individual birds is also important for aviation safety. Up to 75% of bird-aircraft collisions occur within 500 ft (153 m) above the runway. Identification of each bird will help predict its flight path, a critical factor in the prevention of a collision. This thesis focuses on short-range identification of individual birds to localise birds in flight. This goal is achieved through fusing data from two sensor systems, radar and acoustic. This fusion provides more accurate tracking of birds in the lower airspace and allows for the identification of species of interest. In the fall of 1999, an experiment was conducted at Prince Edward Point, a southern projection of land on the north shore of Lake Ontario, to prove that the fusion of radar and acoustic sensors enhances the detection, location and tracking of nocturnal migrant birds. As these birds migrate at night, they are difficult to track visually. However, they are detectable with X

  2. Diseases Transmitted by Birds.

    PubMed

    Levison, Matthew E

    2015-08-01

    Although many people these days actually work very hard at leisure time activities, diseases are most commonly acquired from birds during the course of work in the usual sense of the term, not leisure. However, travel for pleasure to areas where the diseases are highly endemic puts people at risk of acquiring some of these bird-related diseases (for example, histoplasmosis and arbovirus infections), as does ownership of birds as pets (psittacosis). PMID:26350315

  3. Chewing lice (Phthiraptera) from wild birds in southern Portugal.

    PubMed

    Tomás, André; Palma, Ricardo L; Rebelo, Maria Teresa; da Fonseca, Isabel Pereira

    2016-06-01

    This study was carried out to determine chewing louse species of wild birds in the Ria Formosa Natural Park, located in southern Portugal. In addition, the hypothesis that bird age, avian migration and social behaviour have an impact on the louse prevalence was tested. Between September and December of 2013, 122 birds (belonging to 10 orders, 19 families, 31 genera and 35 species) captured in scientific ringing sessions and admitted to the Wildlife Rehabilitation and Investigation Centre of Ria Formosa were examined for lice. Twenty-six (21.3%) birds were found to be infested with at least one chewing louse species. The chewing lice identified include 18 species. Colonial birds (34.9%) and migratory birds (29.5%) had statistically significant higher prevalence than territorial birds (6.8%) and resident birds (13.1%), respectively. This paper records 17 louse species for the first time in southern Portugal: Laemobothrion maximum, Laemobothrion vulturis, Actornithophilus piceus lari, Actornithophilus umbrinus, Austromenopon lutescens, Colpocephalum heterosoma, Colpocephalum turbinatum, Eidmanniella pustulosa, Nosopon casteli, Pectinopygus bassani, Pseudomenopon pilosum, Trinoton femoratum, Trinoton querquedulae, Craspedorrhynchus platystomus, Degeeriella fulva, Falcolipeurus quadripustulatus, Lunaceps schismatus. Also a nymph of the genus Strigiphilus was collected from a Eurasian eagle-owl. These findings contribute to the knowledge of avian chewing lice from important birds areas in Portugal. PMID:26899014

  4. Modeling the distribution of migratory bird stopovers to inform landscape-scale siting of wind development.

    PubMed

    Pocewicz, Amy; Estes-Zumpf, Wendy A; Andersen, Mark D; Copeland, Holly E; Keinath, Douglas A; Griscom, Hannah R

    2013-01-01

    Conservation of migratory birds requires understanding the distribution of and potential threats to their migratory habitats. However, although migratory birds are protected under international treaties, few maps have been available to represent migration at a landscape scale useful to target conservation efforts or inform the siting of wind energy developments that may affect migratory birds. To fill this gap, we developed models that predict where four groups of birds concentrate or stopover during their migration through the state of Wyoming, USA: raptors, wetland, riparian and sparse grassland birds. The models were based on existing literature and expert knowledge concerning bird migration behavior and ecology and validated using expert ratings and known occurrences. There was significant agreement between migratory occurrence data and migration models for all groups except raptors, and all models ranked well with experts. We measured the overlap between the migration concentration models and a predictive model of wind energy development to assess the potential exposure of migratory birds to wind development and illustrate the utility of migratory concentration models for landscape-scale planning. Wind development potential is high across 15% of Wyoming, and 73% of this high potential area intersects important migration concentration areas. From 5.2% to 18.8% of each group's important migration areas was represented within this high wind potential area, with the highest exposures for sparse grassland birds and the lowest for riparian birds. Our approach could be replicated elsewhere to fill critical data gaps and better inform conservation priorities and landscape-scale planning for migratory birds. PMID:24098379

  5. Modeling the Distribution of Migratory Bird Stopovers to Inform Landscape-Scale Siting of Wind Development

    PubMed Central

    Pocewicz, Amy; Estes-Zumpf, Wendy A.; Andersen, Mark D.; Copeland, Holly E.; Keinath, Douglas A.; Griscom, Hannah R.

    2013-01-01

    Conservation of migratory birds requires understanding the distribution of and potential threats to their migratory habitats. However, although migratory birds are protected under international treaties, few maps have been available to represent migration at a landscape scale useful to target conservation efforts or inform the siting of wind energy developments that may affect migratory birds. To fill this gap, we developed models that predict where four groups of birds concentrate or stopover during their migration through the state of Wyoming, USA: raptors, wetland, riparian and sparse grassland birds. The models were based on existing literature and expert knowledge concerning bird migration behavior and ecology and validated using expert ratings and known occurrences. There was significant agreement between migratory occurrence data and migration models for all groups except raptors, and all models ranked well with experts. We measured the overlap between the migration concentration models and a predictive model of wind energy development to assess the potential exposure of migratory birds to wind development and illustrate the utility of migratory concentration models for landscape-scale planning. Wind development potential is high across 15% of Wyoming, and 73% of this high potential area intersects important migration concentration areas. From 5.2% to 18.8% of each group’s important migration areas was represented within this high wind potential area, with the highest exposures for sparse grassland birds and the lowest for riparian birds. Our approach could be replicated elsewhere to fill critical data gaps and better inform conservation priorities and landscape-scale planning for migratory birds. PMID:24098379

  6. Settling down of seasonal migrants promotes bird diversification

    PubMed Central

    Rolland, Jonathan; Jiguet, Frédéric; Jønsson, Knud Andreas; Condamine, Fabien L.; Morlon, Hélène

    2014-01-01

    How seasonal migration originated and impacted diversification in birds remains largely unknown. Although migratory behaviour is likely to affect bird diversification, previous studies have not detected any effect. Here, we infer ancestral migratory behaviour and the effect of seasonal migration on speciation and extinction dynamics using a complete bird tree of life. Our analyses infer that sedentary behaviour is ancestral, and that migratory behaviour evolved independently multiple times during the evolutionary history of birds. Speciation of a sedentary species into two sedentary daughter species is more frequent than speciation of a migratory species into two migratory daughter species. However, migratory species often diversify by generating a sedentary daughter species in addition to the ancestral migratory one. This leads to an overall higher migratory speciation rate. Migratory species also experience lower extinction rates. Hence, although migratory species represent a minority (18.5%) of all extant birds, they have a higher net diversification rate than sedentary species. These results suggest that the evolution of seasonal migration in birds has facilitated diversification through the divergence of migratory subpopulations that become sedentary, and illustrate asymmetrical diversification as a mechanism by which diversification rates are decoupled from species richness. PMID:24759866

  7. Using radar to advance migratory bird management: An interagency collaboration

    USGS Publications Warehouse

    Sojda, R.; Ruth, J.M.; Barrow, W.C.; Dawson, D.K.; Diehl, R.H.; Manville, A.; Green, M.T.; Krueper, D.J.; Johnston, S.

    2005-01-01

    Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.

  8. Differential autumn migration of the aquatic warbler Acrocephalus paludicola

    NASA Astrophysics Data System (ADS)

    Wojczulanis-Jakubas, Katarzyna; Jakubas, Dariusz; Foucher, Julien; Dziarska-Pałac, Joanna; Dugué, Hubert

    2013-11-01

    Relatively little attention has been paid to sex differences in the migration of birds in autumn. We studied the autumn migration strategy of molecularly sexed males and females in the globally threatened aquatic warbler Acrocephalus paludicola. We captured 176 birds at a stopover site in the Loire estuary at Donges, France. The median date for the passage of adults was 8 days earlier in males than females, although the timing of migration in first-year males and females was similar. This indicates that males, who are without parental duties, can start their migration earlier than females and first-year birds. Adults were significantly heavier than immature birds but did not have higher fat scores. In both age categories, more males (two to three times more) were captured. However, various factors (including tape-luring) can affect observed sex ratio.

  9. Differential autumn migration of the aquatic warbler Acrocephalus paludicola.

    PubMed

    Wojczulanis-Jakubas, Katarzyna; Jakubas, Dariusz; Foucher, Julien; Dziarska-Pałac, Joanna; Dugué, Hubert

    2013-11-01

    Relatively little attention has been paid to sex differences in the migration of birds in autumn. We studied the autumn migration strategy of molecularly sexed males and females in the globally threatened aquatic warbler Acrocephalus paludicola. We captured 176 birds at a stopover site in the Loire estuary at Donges, France. The median date for the passage of adults was 8 days earlier in males than females, although the timing of migration in first-year males and females was similar. This indicates that males, who are without parental duties, can start their migration earlier than females and first-year birds. Adults were significantly heavier than immature birds but did not have higher fat scores. In both age categories, more males (two to three times more) were captured. However, various factors (including tape-luring) can affect observed sex ratio. PMID:24154543

  10. Energetics and longevity in birds

    PubMed Central

    Furness, L. J.

    2008-01-01

    The links between energy expenditure and ageing are different at different levels of enquiry. When studies have examined the relationships between different species within a given class the association is generally negative—animals with greater metabolism per gram of tissue live shorter lives. Within species, or between classes (e.g. between birds and mammals) the association is the opposite—animals with higher metabolic rates live longer. We have previously shown in mammals that the negative association between lifespan and metabolic rate is in fact an artefact of using resting rather than daily energy expenditure, and of failing to adequately take into account the confounding effects of body size and the lack of phylogenetic independence of species data. When these factors are accounted for, across species of mammals, the ones with higher metabolism also have the largest lifetime expenditures of energy—consistent with the inter-class and intra-specific data. A previous analysis in birds did not yield the same pattern, but this may have been due to a lack of sufficient power in the analysis. Here we present an analysis of a much enlarged data set (>300 species) for metabolic and longevity traits in birds. These data show very similar patterns to those in mammals. Larger individuals have longer lives and lower per-gram resting and daily energy expenditures, hence there is a strong negative relationship between longevity and mass-specific metabolism. This relationship disappears when the confounding effects of body mass and phylogeny are accounted for. Across species of birds, lifetime expenditure of energy per gram of tissue based on both daily and resting energy expenditure is positively related to metabolic intensity, mirroring these statistical relationships in mammals and synergising with the positive associations of metabolism with lifespan within species and between vertebrate classes. PMID:19424858