Science.gov

Sample records for bird population trends

  1. Terrestrial bird population trends on Aguiguan (Goat Island), Mariana Islands

    USGS Publications Warehouse

    Amidon, Fred; Camp, Richard J.; Marshall, Ann P.; Pratt, Thane K.; Williams, Laura; Radley, Paul; Cruz, Justine B.

    2014-01-01

    The island of Aguiguan is part of the Mariana archipelago and currently supports populations of four endemic species, including one endemic genus, Cleptornis. Bird population trends since 1982 were recently assessed on the neighbouring islands of Saipan, Tinian, and Rota indicating declines in some native species. Point-transect surveys were conducted in 2008 by the U.S. Fish and Wildlife Service to assess population densities and trends on Aguiguan. Densities for six of the nine native birds—White-throated Ground-dove Gallicolumba xanthonura, Collared Kingfisher Todiramphus chloris, Rufous Fantail Rhipidura rufifrons, Golden White-eye Cleptornis marchei, Bridled White-eye Zosterops conspicillatus and Micronesian Starling Aplonis opaca—and the non-native bird—Island Collared-dove Streptopelia bitorquata—were significantly greater in 2008 than in 1982. No differences in densities were detected among the surveys for Mariana Fruit-dove Ptilinopus roseicapilla, and Micronesian MyzomelaMyzomela rubratra. Three federally and locally listed endangered birds—Nightingale Reed-warbler Acrocephalus luscinius, Mariana Swiftlet Collocalia bartschi, and Micronesian Megapode Megapodius laperous)—were either not detected during the point-transect counts, the surveys were not appropriate for the species, or the numbers of birds detected were too small to estimate densities. The factors behind the increasing trends for some species are unknown but may be related to increased forest cover on the island since 1982. With declining trends for some native species on neighbouring islands, the increasing and stable trends on Aguiguan is good news for forest bird populations in the region, as Aguiguan populations can help support conservation efforts on other islands in the archipelago.

  2. Oak Ridge Reservation Bird Records and Population Trends

    SciTech Connect

    Roy, W. K.; Giffen, N. R.; Wade, M. C.; Haines, A. M.; Evans, J. W.; Jett, R. T.

    2014-09-01

    Bird data have been collected through surveys, environmental assessments, and other observations for decades in the Oak Ridge National Environmental Research Park, located on the US Department of Energy’s Oak Ridge Reservation (ORR) in East Tennessee. Birds were recorded in a variety of habitats, including wetlands, interior forests, grasslands, ponds, corridors, forest edges, and more. Most of the information was gathered from waterfowl surveys conducted from 1990 to 2008, from Partners in Flight (PIF) breeding bird surveys conducted from 1995 to 2013, and from past publications and research on Reservation birds. We have also included our own observations and, in a few instances, credible observations of ORR birds of which we have been made aware through eBird or discussions with area ornithologists and bird watchers. For the period 1950-2014, we were able to document 228 species of birds on the ORR. Several of these species are known from historic records only, while others were not known to have ever occurred on the Reservation until recently. This report does not include PIF breeding bird data from the 2014 season or any records after July 2014. Twenty-two species--approximately 10% of the total number of species observed--have state-listed status in Tennessee as endangered, threatened, or in need of management. Of the 228 species we documented, 120 are believed to be breeding birds on the ORR.

  3. Oak Ridge Reservation Bird Records and Population Trends

    SciTech Connect

    Roy, W. Kelly; Giffen, Neil R.; Wade, Murray; Haines, Angelina; Evans, James W.; Jett, Robert Trent

    2014-11-01

    Bird data have been collected through surveys, environmental assessments, and other observations for decades in the Oak Ridge National Environmental Research Park, located on the US Department of Energy s Oak Ridge Reservation (ORR) in East Tennessee. Birds were recorded in a variety of habitats, including wetlands, interior forests, grasslands, ponds, corridors, forest edges, and more. Most of the information was gathered from waterfowl surveys conducted from 1990 to 2008, from Partners in Flight (PIF) breeding bird surveys conducted from 1995 to 2013, and from past publications and research on Reservation birds. We have also included our own observations and, in a few instances, credible observations of ORR birds of which we have been made aware through eBird or discussions with area ornithologists and bird watchers. For the period 1950 2014, we were able to document 228 species of birds on the ORR. Several of these species are known from historic records only, while others were not known to have ever occurred on the Reservation until recently. This report does not include PIF breeding bird data from the 2014 season or any records after July 2014. Twenty-two species approximately 10% of the total number of species observed have state-listed status in Tennessee as endangered, threatened, or in need of management. Of the 228 species we documented, 120 are believed to be breeding birds on the ORR.

  4. 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.

  5. Population trends for North American winter birds based on hierarchical models

    USGS Publications Warehouse

    Soykan, Candan U.; Sauer, John; Schuetz, Justin G.; LeBaron, Geoffrey S.; Dale, Kathy; Langham, Gary M.

    2016-01-01

    Managing widespread and persistent threats to birds requires knowledge of population dynamics at large spatial and temporal scales. For over 100 yrs, the Audubon Christmas Bird Count (CBC) has enlisted volunteers in bird monitoring efforts that span the Americas, especially southern Canada and the United States. We employed a Bayesian hierarchical model to control for variation in survey effort among CBC circles and, using CBC data from 1966 to 2013, generated early-winter population trend estimates for 551 species of birds. Selecting a subset of species that do not frequent bird feeders and have ≥25% range overlap with the distribution of CBC circles (228 species) we further estimated aggregate (i.e., across species) trends for the entire study region and at the level of states/provinces, Bird Conservation Regions, and Landscape Conservation Cooperatives. Moreover, we examined the relationship between ten biological traits—range size, population size, migratory strategy, habitat affiliation, body size, diet, number of eggs per clutch, age at sexual maturity, lifespan, and tolerance of urban/suburban settings—and CBC trend estimates. Our results indicate that 68% of the 551 species had increasing trends within the study area over the interval 1966–2013. When trends were examined across the subset of 228 species, the median population trend for the group was 0.9% per year at the continental level. At the regional level, aggregate trends were positive in all but a few areas. Negative population trends were evident in lower latitudes, whereas the largest increases were at higher latitudes, a pattern consistent with range shifts due to climate change. Nine of 10 biological traits were significantly associated with median population trend; however, none of the traits explained >34% of the deviance in the data, reflecting the indirect relationships between population trend estimates and species traits. Trend estimates based on the CBC are broadly congruent with

  6. Population trends of forest birds at Hakalau Forest National Wildlife Refuge, Hawai'i

    USGS Publications Warehouse

    Camp, Richard J.; Pratt, Thane K.; Gorresen, P. Marcos; Jeffrey, John J.; Woodworth, Bethany L.

    2010-01-01

    The Hakalau Forest National Wildlife Refuge was established to protect native Hawaiian forest birds, particularly endangered species. Management for forest restoration on the refuge has consisted mainly of removing feral ungulates, controlling invasive alien plants, and reforesting former pastures. To assess effects of this habitat improvement for forest birds, we estimated density annually by distance sampling and examined population trends for native and alien passerines over the 21 years since the refuge was established. We examined long-term trends and recent short-term trajectories in three study areas: (1) reforested pastureland, (2) heavily grazed open forest that was recovering, and (3) lightly grazed closed forest that was relatively intact. Three species of native birds and two species of alien birds had colonized the reforested pasture and were increasing. In the open forest, densities of all eight native species were either stable or increasing. Long-term trends for alien birds were also generally stable or increasing. Worryingly, however, during the most recent 9 years, in the open forest trajectories of native species were decreasing or inconclusive, but in the reforested pasture they generally increased. The closed forest was surveyed in only the most recent 9 years, and trajectories of native species there were mixed. Overall, long-term population trends in Hakalau are stable or increasing, contrasting with declines in most other areas of Hawai'i over the same period. However, more recent mixed results may indicate emergent problems for this important bird area.

  7. Wood duck population trends from the North American Breeding Bird Survey

    USGS Publications Warehouse

    Sauer, J.R.; Droege, S.; Fredrickson, Leigh H.; Burger, George V.; Havera, Stephen P.; Graber, David A.; Kirby, Ronald E.; Taylor, T. Scott

    1990-01-01

    The North American Breeding Bird Survey (BBS) has been conducted yearly since 1966, and can be used to describe relative population density and trends of birds in North America north of Mexico. Wood ducks (Air sponsa) are difficult to survey using conventional waterfowl monitoring techniques, but a large portion of their range is surveyed by the BBS. Wood ducks are detected at low densities on many BBS routes, and population trends can be estimated for most regions. Populations have been increasing throughout North America since 1966, but statistically significant increases generally occurred only in the early (1966-78) part of the period. Roadside survey methodology used in the BBS has limitations that make it inefficient as a survey technique for wood ducks, and we recommend using modified methodologies that specifically survey wood duck habitat.

  8. Mourning dove population trend estimates from Call-Count and North American Breeding Bird Surveys

    USGS Publications Warehouse

    Sauer, J.R.; Dolton, D.D.; Droege, S.

    1994-01-01

    The mourning dove (Zenaida macroura) Callcount Survey and the North American Breeding Bird Survey provide information on population trends of mourning doves throughout the continental United States. Because surveys are an integral part of the development of hunting regulations, a need exists to determine which survey provides precise information. We estimated population trends from 1966 to 1988 by state and dove management unit, and assessed the relative efficiency of each survey. Estimates of population trend differ (P lt 0.05) between surveys in 11 of 48 states; 9 of 11 states with divergent results occur in the Eastern Management Unit. Differences were probably a consequence of smaller sample sizes in the Callcount Survey. The Breeding Bird Survey generally provided trend estimates with smaller variances than did the Callcount Survey. Although the Callcount Survey probably provides more withinroute accuracy because of survey methods and timing, the Breeding Bird Survey has a larger sample size of survey routes and greater consistency of coverage in the Eastern Unit.

  9. Colonial, more widely distributed and less abundant bird species undergo wider population fluctuations independent of their population trend

    PubMed Central

    Møller, Anders P.

    2017-01-01

    Understanding temporal variability in population size is important for conservation biology because wide population fluctuations increase the risk of extinction. Previous studies suggested that certain ecological, demographic, life-history and genetic characteristics of species might be related to the degree of their population fluctuations. We checked whether that was the case in a large sample of 231 European breeding bird species while taking a number of potentially confounding factors such as population trends or similarities among species due to common descent into account. When species-specific characteristics were analysed one by one, the magnitude of population fluctuations was positively related to coloniality, habitat, total breeding range, heterogeneity of breeding distribution and natal dispersal, and negatively related to urbanisation, abundance, relative number of subspecies, parasitism and proportion of polymorphic loci. However, when abundance (population size) was included in the analyses of the other parameters, only coloniality, habitat, total breeding range and abundance remained significantly related to population fluctuations. The analysis including all these predictors simultaneously showed that population size fluctuated more in colonial, less abundant species with larger breeding ranges. Other parameters seemed to be related to population fluctuations only because of their association with abundance or coloniality. The unexpected positive relationship between population fluctuations and total breeding range did not seem to be mediated by abundance. The link between population fluctuations and coloniality suggests a previously unrecognized cost of coloniality. The negative relationship between population size and population fluctuations might be explained by at least three types of non-mutually exclusive stochastic processes: demographic, environmental and genetic stochasticity. Measurement error in population indices, which was unknown, may

  10. Colonial, more widely distributed and less abundant bird species undergo wider population fluctuations independent of their population trend.

    PubMed

    Cuervo, José J; Møller, Anders P

    2017-01-01

    Understanding temporal variability in population size is important for conservation biology because wide population fluctuations increase the risk of extinction. Previous studies suggested that certain ecological, demographic, life-history and genetic characteristics of species might be related to the degree of their population fluctuations. We checked whether that was the case in a large sample of 231 European breeding bird species while taking a number of potentially confounding factors such as population trends or similarities among species due to common descent into account. When species-specific characteristics were analysed one by one, the magnitude of population fluctuations was positively related to coloniality, habitat, total breeding range, heterogeneity of breeding distribution and natal dispersal, and negatively related to urbanisation, abundance, relative number of subspecies, parasitism and proportion of polymorphic loci. However, when abundance (population size) was included in the analyses of the other parameters, only coloniality, habitat, total breeding range and abundance remained significantly related to population fluctuations. The analysis including all these predictors simultaneously showed that population size fluctuated more in colonial, less abundant species with larger breeding ranges. Other parameters seemed to be related to population fluctuations only because of their association with abundance or coloniality. The unexpected positive relationship between population fluctuations and total breeding range did not seem to be mediated by abundance. The link between population fluctuations and coloniality suggests a previously unrecognized cost of coloniality. The negative relationship between population size and population fluctuations might be explained by at least three types of non-mutually exclusive stochastic processes: demographic, environmental and genetic stochasticity. Measurement error in population indices, which was unknown, may

  11. Disentangling the relative importance of changes in climate and land-use intensity in driving recent bird population trends.

    PubMed

    Eglington, Sarah M; Pearce-Higgins, James W

    2012-01-01

    Threats to biodiversity resulting from habitat destruction and deterioration have been documented for many species, whilst climate change is regarded as increasingly impacting upon species' distribution and abundance. However, few studies have disentangled the relative importance of these two drivers in causing recent population declines. We quantify the relative importance of both processes by modelling annual variation in population growth of 18 farmland bird species in the UK as a function of measures of land-use intensity and weather. Modelled together, both had similar explanatory power in accounting for annual fluctuations in population growth. When these models were used to retrodict population trends for each species as a function of annual variation in land-use intensity and weather combined, and separately, retrodictions incorporating land-use intensity were more closely linked to observed population trends than retrodictions based only on weather, and closely matched the UK farmland bird index from 1970 onwards. Despite more stable land-use intensity in recent years, climate change (inferred from weather trends) has not overtaken land-use intensity as the dominant driver of bird populations.

  12. An evaluation of marine bird population trends following the Exxon Valdez oil spill, Prince William Sound, Alaska.

    PubMed

    Lance, B K; Irons, D B; Kendall, S J; McDonald, L L

    2001-04-01

    We examined post-spill trends (1989-1998) of marine bird populations in Prince William Sound (PWS) following the Exxon Valdez oil spill (EVOS) to evaluate recovery of injured taxa. Two criteria were employed. First, we examined population trends of injured taxa only in the oiled area of PWS using regression models. Second, we examined population trends of injured taxa in the oiled area relative to the unoiled area using homogeneity of the slopes tests. We considered a population recovering if there was a positive trend using either criteria. We considered a population not recovering if there was no trend using either criteria or a negative trend in the oiled area. A significant negative trend in the oiled area relative to the unoiled area was considered a continuing and increasing effect. Most taxa for which injury was previously demonstrated were not recovering and some taxa showed evidence of increasing effects nine years after the oil spill. Four taxa (loons Gavia spp, Harlequin Duck Histrionicus histrionicus, Bufflehead Bucephala spp, and North-western Crow Corvus caurinus) showed weak to very weak evidence of recovery. None of these taxa showed positive trends in both winter and summer. Nine taxa (grebes Podiceps spp, cormorants Phalacrocorax spp, Black Oystercatcher Haematopus bachmani, Mew Gull Larus canus, Glaucous-winged Gull Larus glaucescens, terns Sterna spp, murres Uria spp, Pigeon Guillemot Cepphus columba, and murrelets Brachyramphus spp) showed no evidence of recovery during summer or winter. Four taxa (scoters Melanitta spp, mergansers Mergus spp, goldeneyes Bucephala spp, and Black-legged Kittiwaka Rissa tridactyla) showed evidence of continuing, increasing effects. We showed evidence of slow recovery, lack of recovery, and divergent population trends in many taxa which utilize shoreline and nearshore habitats where oil is likely to persist. Potential lingering spill effects and natural variability appear to be acting in concert in delaying

  13. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species.

    PubMed

    Flousek, Jiří; Telenský, Tomáš; Hanzelka, Jan; Reif, Jiří

    2015-01-01

    Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše), where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta). It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory.

  14. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species

    PubMed Central

    Flousek, Jiří; Telenský, Tomáš; Hanzelka, Jan; Reif, Jiří

    2015-01-01

    Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše), where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta). It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory. PMID:26426901

  15. New approaches to the analysis of population trends in land birds: Comment

    USGS Publications Warehouse

    Link, W.A.; Sauer, J.R.

    1997-01-01

    James et al. (1996, Ecology 77:13-27) used data from the North American Breeding Bird Survey (BBS) to examine geographic variability in patterns of population change for 26 species of wood warblers. They emphasized the importance of evaluating nonlinear patterns of change in bird populations, proposed LOESS-based non-parametric and semi-parametric analyses of BBS data, and contrasted their results with other analyses, including those of Robbins et al. (1989, Proceedings of the National Academy of Sciences 86: 7658-7662) and Peterjohn et al. (1995, Pages 3-39 in T. E. Martin and D. M. Finch, eds. Ecology and management of Neotropical migratory birds: a synthesis and review of critical issues. Oxford University Press, New York.). In this note, we briefly comment on some of the issues that arose from their analysis of BBS data, suggest a few aspects of the survey that should inspire caution in analysts, and review the differences between the LOESS-based procedures and other procedures (e.g., Link and Sauer 1994). We strongly discourage the use of James et al.'s completely non-parametric procedure, which fails to account for observer effects. Our comparisons of estimators adds to the evidence already present in the literature of the bias associated with omitting observer information in analyses of BBS data. Bias resulting from change in observer abilities should be a consideration in any analysis of BBS data.

  16. Current land bird distribution and trends in population abundance between 1982 and 2012 on Rota, Mariana Islands

    USGS Publications Warehouse

    Camp, Richard J.; Brinck, Kevin W.; Gorresen, P. Marcos; Amidon, Fred A.; Radley, Paul M.; Berkowitz, S. Paul; Banko, Paul C.

    2015-01-01

    The western Pacific island of Rota is the fourth largest human-inhabited island in the Mariana archipelago and designated an Endemic Bird Area. Between 1982 and 2012, 12 point-transect distance-sampling surveys were conducted to assess bird population status. Surveys did not consistently sample the entire island; thus, we used a ratio estimator to estimate bird abundances in strata not sampled during every survey. Trends in population size were reliably estimated for 11 of 13 bird species, and 7 species declined over the 30-y time series, including the island collared-dove Streptopelia bitorquata, white-throated ground-dove Gallicolumba xanthonura, Mariana fruit-dove Ptilinopus roseicapilla, collared kingfisher Todiramphus chloris orii, Micronesian myzomela Myzomela rubratra, black drongo Dicrurus macrocercus, and Mariana crow Corvus kubaryi. The endangered Mariana crow (x̄  =  81 birds, 95% CI 30–202) declined sharply to fewer than 200 individuals in 2012, down from 1,491 birds in 1982 (95% CI  =  815–3,115). Trends increased for white tern Gygis alba, rufous fantail Rhipidura rufifrons mariae, and Micronesian starling Aplonis opaca. Numbers of the endangered Rota white-eye Zosterops rotensis declined from 1982 to the late 1990s but returned to 1980s levels by 2012, resulting in an overall stable trend. Trends for the yellow bittern Ixobrychus sinensis were inconclusive. Eurasian tree sparrow Passer montanus trends were not assessed; however, their numbers in 1982 and 2012 were similar. Occupancy models of the 2012 survey data revealed general patterns of land cover use and detectability among 12 species that could be reliably modeled. Occupancy was not assessed for the Eurasian tree sparrow because of insufficient detections. Based on the 2012 survey, bird distribution and abundance across Rota revealed three general patterns: 1) range restriction, including Mariana crow, Rota white-eye, and Eurasian tree sparrow; 2) widespread distribution, low

  17. Determinants of bird conservation-action implementation and associated population trends of threatened species.

    PubMed

    Luther, David A; Brooks, Thomas M; Butchart, Stuart H M; Hayward, Matt W; Kester, Marieke E; Lamoreux, John; Upgren, Amy

    2016-12-01

    Conservation actions, such as habitat protection, attempt to halt the loss of threatened species and help their populations recover. The efficiency and the effectiveness of actions have been examined individually. However, conservation actions generally occur simultaneously, so the full suite of implemented conservation actions should be assessed. We used the conservation actions underway for all threatened and near-threatened birds of the world (International Union for Conservation of Nature Red List of Threatened Species) to assess which biological (related to taxonomy and ecology) and anthropogenic (related to geoeconomics) factors were associated with the implementation of different classes of conservation actions. We also assessed which conservation actions were associated with population increases in the species targeted. Extinction-risk category was the strongest single predictor of the type of conservation actions implemented, followed by landmass type (continent, oceanic island, etc.) and generation length. Species targeted by invasive nonnative species control or eradication programs, ex situ conservation, international legislation, reintroduction, or education, and awareness-raising activities were more likely to have increasing populations. These results illustrate the importance of developing a predictive science of conservation actions and the relative benefits of each class of implemented conservation action for threatened and near-threatened birds worldwide.

  18. Northern bobwhite, gray partridge, and ring-necked pheasant population trends (1966-1988) from the North American Breeding Bird Survey

    USGS Publications Warehouse

    Droege, S.; Sauer, J.R.; Church, Kevin E.; Warner, Richard E.; Brady, Stephen J.

    1990-01-01

    We use North American Breeding Bird Survey data to estimate population trends for 1966-1988 for northern bobwhite (Colinus virginianus), ring-necked pheasant (Phasianus colchicus), and gray partridge (Perdix perdix). Bobwhite populations have undergone widespread declines, pheasant have undergone major declines in eastern North America with mixed trends elsewhere, gray partridge have undergone primarily population increases. We present suggestions for further uses of these data.

  19. 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.

  20. Change Points in the Population Trends of Aerial-Insectivorous Birds in North America: Synchronized in Time across Species and Regions

    PubMed Central

    Smith, Adam C.; Hudson, Marie-Anne R.; Downes, Constance M.; Francis, Charles M.

    2015-01-01

    North American populations of aerial insectivorous birds are in steep decline. Aerial insectivores (AI) are a group of bird species that feed almost exclusively on insects in flight, and include swallows, swifts, nightjars, and flycatchers. The causes of the declines are not well understood. Indeed, it is not clear when the declines began, or whether the declines are shared across all species in the group (e.g., caused by changes in flying insect populations) or specific to each species (e.g., caused by changes in species’ breeding habitat). A recent study suggested that population trends of aerial insectivores changed for the worse in the 1980s. If there was such a change point in trends of the group, understanding its timing and geographic pattern could help identify potential causes of the decline. We used a hierarchical Bayesian, penalized regression spline, change point model to estimate group-level change points in the trends of 22 species of AI, across 153 geographic strata of North America. We found evidence for group-level change points in 85% of the strata. Change points for flycatchers (FC) were distinct from those for swallows, swifts and nightjars (SSN) across North America, except in the Northeast, where all AI shared the same group-level change points. During the 1980s, there was a negative change point across most of North America, in the trends of SSN. For FC, the group-level change points were more geographically variable, and in many regions there were two: a positive change point followed by a negative change point. This group-level synchrony in AI population trends is likely evidence of a response to a common environmental factor(s) with similar effects on many species across broad spatial extents. The timing and geographic patterns of the change points that we identify here should provide a spring-board for research into the causes behind aerial insectivore declines. PMID:26147572

  1. Change Points in the Population Trends of Aerial-Insectivorous Birds in North America: Synchronized in Time across Species and Regions.

    PubMed

    Smith, Adam C; Hudson, Marie-Anne R; Downes, Constance M; Francis, Charles M

    2015-01-01

    North American populations of aerial insectivorous birds are in steep decline. Aerial insectivores (AI) are a group of bird species that feed almost exclusively on insects in flight, and include swallows, swifts, nightjars, and flycatchers. The causes of the declines are not well understood. Indeed, it is not clear when the declines began, or whether the declines are shared across all species in the group (e.g., caused by changes in flying insect populations) or specific to each species (e.g., caused by changes in species' breeding habitat). A recent study suggested that population trends of aerial insectivores changed for the worse in the 1980s. If there was such a change point in trends of the group, understanding its timing and geographic pattern could help identify potential causes of the decline. We used a hierarchical Bayesian, penalized regression spline, change point model to estimate group-level change points in the trends of 22 species of AI, across 153 geographic strata of North America. We found evidence for group-level change points in 85% of the strata. Change points for flycatchers (FC) were distinct from those for swallows, swifts and nightjars (SSN) across North America, except in the Northeast, where all AI shared the same group-level change points. During the 1980s, there was a negative change point across most of North America, in the trends of SSN. For FC, the group-level change points were more geographically variable, and in many regions there were two: a positive change point followed by a negative change point. This group-level synchrony in AI population trends is likely evidence of a response to a common environmental factor(s) with similar effects on many species across broad spatial extents. The timing and geographic patterns of the change points that we identify here should provide a spring-board for research into the causes behind aerial insectivore declines.

  2. 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.

  3. Marine bird and sea otter population abundance of Prince william sound, Alaska: Trends following the t/v Exxon Valdez oil spill, 1989-93. Restoration project 93045. Exxon Valdez oil spill restoration project final report

    SciTech Connect

    Agler, B.A.; Seiser, P.E.; Kendall, S.J.; Irons, D.B.

    1994-05-01

    We conducted small boat surveys to estimate marine bird and sea otter (Enhdra lutris) populations in Prince William Sound, Alaska during March and July 1993, using methods developed for the 1989-91 surveys (Klosiewski and Laing 1994). During 1993, we recorded 65 birds and 13 mammal species. We estimated that 402,760 + or - 167,697 marine birds were in the Sound during March 1993, an increase of >200,000 birds over 1990 and 1991. To examine trends in our marine bird population estimates from 1989-93, we assumed that in the absence of oil spill effects, population estimates in the oiled zone would change at the same rate as those in the unoiled zone. For Prince William Sound as a whole, we examined population trends from 1989-1993, using regression analyses. We also examined the relative abundance of the species groups seen in Prince William Sound from 1972 to 1993. Sea otter populations in 1993 were estimated at 6,813 + or - 1,861 for March and 8,216 + or - 2,435 for July. We found no difference in the rate of change between the oiled and unoiled zones from 1989-93 for either the March or July population estimates. There was no significant trend in the total number of sea otters in Prince William Sound from 1989-93.

  4. Winter population trends of selected songbirds

    USGS Publications Warehouse

    Root, T.L.; McDaniel, Larry

    1995-01-01

    For this study we used the CBC data to examine population trends of songbirds with ranges that apparently are limited by lower temperatures in the North. We chose these species to track populations of birds that could be in peril in the future. These birds potentially will be more quickly affected by changing climate than other birds, and we need baseline information on them to document possible consequences of global climatic change. The species that are indeed declining need to be monitored because the possible synergistic effects of declining populations and changing climate could result in local and even regional extinctions.

  5. Population Trends and Prospects.

    ERIC Educational Resources Information Center

    Mauldin, W. Parker

    1980-01-01

    Future trends in population are described as they relate to developed and developing nations. It is suggested that for the next 20 years there will be a decrease in population growth rates for all areas of the world except Africa. (Author/SA)

  6. Can Ingestion of Lead Shot and Poisons Change Population Trends of Three European Birds: Grey Partridge, Common Buzzard, and Red Kite?

    PubMed Central

    Meyer, Carolyn B.; Meyer, Joseph S.; Francisco, Alex B.; Holder, Jennifer; Verdonck, Frederik

    2016-01-01

    Little is known about the magnitude of the effects of lead shot ingestion alone or combined with poisons (e.g., in bait or seeds/granules containing pesticides) on population size, growth, and extinction of non-waterbird avian species that ingest these substances. We used population models to create example scenarios demonstrating how changes in these parameters might affect three susceptible species: grey partridge (Perdix perdix), common buzzard (Buteo buteo), and red kite (Milvus milvus). We added or subtracted estimates of mortality due to lead shot ingestion (4–16% of mortality, depending on species) and poisons (4–46% of mortality) reported in the UK or France to observed mortality of studied populations after models were calibrated to observed population trends. Observed trends were decreasing for partridge (in continental Europe), stable for buzzard (in Germany), and increasing for red kite (in Wales). Although lead shot ingestion and poison at modeled levels did not change the trend direction for the three species, they reduced population size and slowed population growth. Lead shot ingestion at modeled rates reduced population size of partridges by 10%, and when combined with bait and pesticide poisons, by 18%. For buzzards, decrease in mean population size by lead shot and poisons combined was much smaller (≤ 1%). The red kite population has been recovering; however, modeled lead shot ingestion reduced its annual growth rate from 6.5% to 4%, slowing recovery. If mortality from poisoned baits could be removed, the kite population could potentially increase at a rapid annual rate of 12%. The effects are somewhat higher if ingestion of these substances additionally causes sublethal reproductive impairment. These results have uncertainty but suggest that declining or recovering populations are most sensitive to lead shot or poison ingestion, and removal of poisoned baits can have a positive impact on recovering raptor populations that frequently feed

  7. Winter bird population studies and project prairie birds for surveying grassland birds

    USGS Publications Warehouse

    Twedt, D.J.; Hamel, P.B.; Woodrey, M.S.

    2008-01-01

    We compared 2 survey methods for assessing winter bird communities in temperate grasslands: Winter Bird Population Study surveys are area-searches that have long been used in a variety of habitats whereas Project Prairie Bird surveys employ active-flushing techniques on strip-transects and are intended for use in grasslands. We used both methods to survey birds on 14 herbaceous reforested sites and 9 coastal pine savannas during winter and compared resultant estimates of species richness and relative abundance. These techniques did not yield similar estimates of avian populations. We found Winter Bird Population Studies consistently produced higher estimates of species richness, whereas Project Prairie Birds produced higher estimates of avian abundance for some species. When it is important to identify all species within the winter bird community, Winter Bird Population Studies should be the survey method of choice. If estimates of the abundance of relatively secretive grassland bird species are desired, the use of Project Prairie Birds protocols is warranted. However, we suggest that both survey techniques, as currently employed, are deficient and recommend distance- based survey methods that provide species-specific estimates of detection probabilities be incorporated into these survey methods.

  8. Global fertility and population trends.

    PubMed

    Bongaarts, John

    2015-01-01

    Over the past several decades, the world and most countries have undergone unprecedented demographic change. The most obvious example of this change is the rise in human numbers, and there are also important trends in fertility, family structure, mortality, migration, urbanization, and population aging. This paper summarizes past trends and projections in fertility and population. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013 and the projections expect this total to be 10.9 billion by 2100. World regions differ widely in their demographic trends, with rapid population growth and high fertility continuing in the poorest countries, particularly in sub-Saharan Africa, while population decline, population aging, and very low fertility are now a key concern in many developed countries. These trends have important implications for human welfare and are of interest to policy makers. The conclusion comments briefly on policy options to address these adverse trends.

  9. Bird Population, Book B, Explorations in Biology.

    ERIC Educational Resources Information Center

    Mid-Continent Regional Educational Lab., Inc., Kansas City, MO.

    This booklet is part of a series that tests some skills biologists use in their investigations. Students are presented with several possible experiments to investigate one of the explanations for the changes in bird populations illustrated in Booklet A (SE 011 334). A separate series of data interpretation questions is presented for each…

  10. [Trends in population aging].

    PubMed

    Valkovics, E

    1990-11-01

    The age structure of the world population between 1950 and 1985 is analyzed according to changes in fertility, mortality, and international migration in developing and developed countries. "Relying on the results of the medium scenario of the population forecasts prepared by the U.N. Division of International Economic and Social Affairs, the author demonstrates that aging of the world population will become a global phenomenon, characteristic of every region and county of the world, between 1985 and 2025." (SUMMARY IN ENG AND RUS)

  11. Estimating population trends with a linear model

    USGS Publications Warehouse

    Bart, J.; Collins, B.; Morrison, R.I.G.

    2003-01-01

    We describe a simple and robust method for estimating trends in population size. The method may be used with Breeding Bird Survey data, aerial surveys, point counts, or any other program of repeated surveys at permanent locations. Surveys need not be made at each location during each survey period. The method differs from most existing methods in being design based, rather than model based. The only assumptions are that the nominal sampling plan is followed and that sample size is large enough for use of the t-distribution. Simulations based on two bird data sets from natural populations showed that the point estimate produced by the linear model was essentially unbiased even when counts varied substantially and 25% of the complete data set was missing. The estimating-equation approach, often used to analyze Breeding Bird Survey data, performed similarly on one data set but had substantial bias on the second data set, in which counts were highly variable. The advantages of the linear model are its simplicity, flexibility, and that it is self-weighting. A user-friendly computer program to carry out the calculations is available from the senior author.

  12. Dynamics of North American breeding bird populations

    NASA Astrophysics Data System (ADS)

    Keitt, Timothy H.; Stanley, H. Eugene

    1998-05-01

    Population biologists have long been interested in the variability of natural populations. One approach to dealing with ecological complexity is to reduce the system to one or a few species, for which meaningful equations can be solved. Here we explore an alternative approach, by studying the statistical properties of a data set containing over 600 species, namely the North American breeding bird survey. The survey has recorded annual species abundances over a 31-year period along more than 3,000 observation routes. We now analyse the dynamics of population variability using this data set, and find scaling features in common with inanimate systems composed of strongly interacting subunits. Specifically, we find that the distribution of changes in population abundance over a one-year interval is remarkably symmetrical, with long tails extending over six orders of magnitude. The variance of the population over a time series increases as a power-law with increasing time lag, indicating long-range correlation in population size fluctuations. We also find that the distribution of species lifetimes (the time between colonization and local extinction) within local patches is a power-law with an exponential cutoff imposed by the finite length of the time series. Our results provide a quantitative basis for modelling the dynamics of large species assemblages.

  13. Power to detect trends in abundance of secretive marsh birds: effects of species traits and sampling effort

    USGS Publications Warehouse

    Steidl, Robert J.; Conway, Courtney J.; Litt, Andrea R.

    2013-01-01

    Standardized protocols for surveying secretive marsh birds have been implemented across North America, but the efficacy of surveys to detect population trends has not been evaluated. We used survey data collected from populations of marsh birds across North America and simulations to explore how characteristics of bird populations (proportion of survey stations occupied, abundance at occupied stations, and detection probability) and aspects of sampling effort (numbers of survey routes, stations/route, and surveys/station/year) affect statistical power to detect trends in abundance of marsh bird populations. In general, the proportion of survey stations along a route occupied by a species had a greater relative effect on power to detect trends than did the number of birds detected per survey at occupied stations. Uncertainty introduced by imperfect detection during surveys reduced power to detect trends considerably, but across the range of detection probabilities for most species of marsh birds, variation in detection probability had only a minor influence on power. For species that occupy a relatively high proportion of survey stations (0.20), have relatively high abundances at occupied stations (2.0 birds/station), and have high detection probability (0.50), ≥40 routes with 10 survey stations per route surveyed 3 times per year would provide an 80% chance of detecting a 3% annual decrease in abundance after 20 years of surveys. Under the same assumptions but for species that are less common, ≥100 routes would be needed to achieve the same power. Our results can help inform the design of programs to monitor trends in abundance of marsh bird populations, especially with regards to the amount of sampling effort necessary to meet programmatic goals.

  14. Monitoring bird populations in small geographic areas

    USGS Publications Warehouse

    Dunn, Erica H.; Bart, J.; Collins, B.T.; Craig, B.; Dale, B.; Downes, C.M.; Francis, C.M.; Woodley, S.; Zorn, P.

    2006-01-01

    Numerous methods exist for monitoring bird populations, and there is a large literature describing them. There are few resources, however, that provide comprehensive advice on every step of organizing and carrying out a survey, from the early stages of planning to final use of the data. Even fewer resources are designed to meet the needs of a wide variety of potential users, from amateurs interested in change of bird life in a local study preserve to professionals testing hypotheses on the response of birds to habitat management, although much of the advice should be the same for every monitoring program. Whether survey objectives are very modest or rigorously scientific, samples must be sufficiently numerous and well distributed to provide meaningful results, and the survey should be well designed to ensure that the money and effort going into it are not wasted. This document is intended to be a complete resource for anyone planning to organize monitoring of noncolonial landbirds within a relatively small geographic area (e.g., from the size of a woodlot to a large park). The first of its two parts provides background explaining the importance of good study design and gives specific advice on all aspects of project planning and execution of high-quality data collection for the purpose of hypothesis testing. The second part is self-contained and nontechnical and describes complete plans for a site-specific checklist survey, suitable for addressing monitoring questions frequently asked by amateurs and for involvement of volunteers in data collection. Throughout are references to additional resources, from background literature to sources of existing survey protocols, analysis software, and tools for archiving data.

  15. Modeling trends from North American breeding bird survey data: a spatially explicit approach.

    PubMed

    Bled, Florent; Sauer, John; Pardieck, Keith; Doherty, Paul; Royle, J Andrew

    2013-01-01

    Population trends, defined as interval-specific proportional changes in population size, are often used to help identify species of conservation interest. Efficient modeling of such trends depends on the consideration of the correlation of population changes with key spatial and environmental covariates. This can provide insights into causal mechanisms and allow spatially explicit summaries at scales that are of interest to management agencies. We expand the hierarchical modeling framework used in the North American Breeding Bird Survey (BBS) by developing a spatially explicit model of temporal trend using a conditional autoregressive (CAR) model. By adopting a formal spatial model for abundance, we produce spatially explicit abundance and trend estimates. Analyses based on large-scale geographic strata such as Bird Conservation Regions (BCR) can suffer from basic imbalances in spatial sampling. Our approach addresses this issue by providing an explicit weighting based on the fundamental sample allocation unit of the BBS. We applied the spatial model to three species from the BBS. Species have been chosen based upon their well-known population change patterns, which allows us to evaluate the quality of our model and the biological meaning of our estimates. We also compare our results with the ones obtained for BCRs using a nonspatial hierarchical model (Sauer and Link 2011). Globally, estimates for mean trends are consistent between the two approaches but spatial estimates provide much more precise trend estimates in regions on the edges of species ranges that were poorly estimated in non-spatial analyses. Incorporating a spatial component in the analysis not only allows us to obtain relevant and biologically meaningful estimates for population trends, but also enables us to provide a flexible framework in order to obtain trend estimates for any area.

  16. Modeling trends from North American Breeding Bird Survey data: a spatially explicit approach

    USGS Publications Warehouse

    Bled, Florent; Sauer, John R.; Pardieck, Keith L.; Doherty, Paul; Royle, J. Andy

    2013-01-01

    Population trends, defined as interval-specific proportional changes in population size, are often used to help identify species of conservation interest. Efficient modeling of such trends depends on the consideration of the correlation of population changes with key spatial and environmental covariates. This can provide insights into causal mechanisms and allow spatially explicit summaries at scales that are of interest to management agencies. We expand the hierarchical modeling framework used in the North American Breeding Bird Survey (BBS) by developing a spatially explicit model of temporal trend using a conditional autoregressive (CAR) model. By adopting a formal spatial model for abundance, we produce spatially explicit abundance and trend estimates. Analyses based on large-scale geographic strata such as Bird Conservation Regions (BCR) can suffer from basic imbalances in spatial sampling. Our approach addresses this issue by providing an explicit weighting based on the fundamental sample allocation unit of the BBS. We applied the spatial model to three species from the BBS. Species have been chosen based upon their well-known population change patterns, which allows us to evaluate the quality of our model and the biological meaning of our estimates. We also compare our results with the ones obtained for BCRs using a nonspatial hierarchical model (Sauer and Link 2011). Globally, estimates for mean trends are consistent between the two approaches but spatial estimates provide much more precise trend estimates in regions on the edges of species ranges that were poorly estimated in non-spatial analyses. Incorporating a spatial component in the analysis not only allows us to obtain relevant and biologically meaningful estimates for population trends, but also enables us to provide a flexible framework in order to obtain trend estimates for any area.

  17. Monitoring bird population trends in North America

    USGS Publications Warehouse

    Robbins, C.S.; Bystrak, D.; Geissler, P.H.; Purroy, F.J.

    1983-01-01

    Se ofrece un nuevo metodo para computar las oscilaciones demograficas de las aves a lo largo de los anos. Con los datos suministrados por el proyecto 'Aves nidificantes en Norteamerica' , se indican en la Tabla 1 las pautas de cambio numerico de una serie seleccionada de aves holarticas.

  18. Temporal Trends in Metal Pollution: Using Bird Excrement as Indicator

    PubMed Central

    Berglund, Åsa M. M.; Rainio, Miia J.; Eeva, Tapio

    2015-01-01

    Past mining and smelting activities have resulted in metal polluted environments all over the world, but long-term monitoring data is often scarce, especially in higher trophic levels. In this study we used bird (Parus major and Ficedula hypoleuca) excrement to monitor metal pollution in the terrestrial environment following 16 years of continuously reduced emissions from a copper/nickel smelter in Finland. In the early 1990s, lead and cadmium concentrations dropped significantly in excrement, but the reduction did not directly reflect the changes in atmospheric emission from the smelter. This is likely due to a continuous contribution of metals also from the soil pool. We conclude that bird excrement can be used to assess changes in the environment as a whole but not specifically changes in atmospheric emission. Inter-annual variation in excrement concentration of especially copper and nickel demonstrates the importance of long-term monitoring to discern significant trends. PMID:25680108

  19. Bird population density estimated from acoustic signals

    USGS Publications Warehouse

    Dawson, D.K.; Efford, M.G.

    2009-01-01

    Many animal species are detected primarily by sound. Although songs, calls and other sounds are often used for population assessment, as in bird point counts and hydrophone surveys of cetaceans, there are few rigorous methods for estimating population density from acoustic data. 2. The problem has several parts - distinguishing individuals, adjusting for individuals that are missed, and adjusting for the area sampled. Spatially explicit capture-recapture (SECR) is a statistical methodology that addresses jointly the second and third parts of the problem. We have extended SECR to use uncalibrated information from acoustic signals on the distance to each source. 3. We applied this extension of SECR to data from an acoustic survey of ovenbird Seiurus aurocapilla density in an eastern US deciduous forest with multiple four-microphone arrays. We modelled average power from spectrograms of ovenbird songs measured within a window of 0??7 s duration and frequencies between 4200 and 5200 Hz. 4. The resulting estimates of the density of singing males (0??19 ha -1 SE 0??03 ha-1) were consistent with estimates of the adult male population density from mist-netting (0??36 ha-1 SE 0??12 ha-1). The fitted model predicts sound attenuation of 0??11 dB m-1 (SE 0??01 dB m-1) in excess of losses from spherical spreading. 5.Synthesis and applications. Our method for estimating animal population density from acoustic signals fills a gap in the census methods available for visually cryptic but vocal taxa, including many species of bird and cetacean. The necessary equipment is simple and readily available; as few as two microphones may provide adequate estimates, given spatial replication. The method requires that individuals detected at the same place are acoustically distinguishable and all individuals vocalize during the recording interval, or that the per capita rate of vocalization is known. We believe these requirements can be met, with suitable field methods, for a significant

  20. ESTIMATING AVIAN POPULATION TRENDS USING A DETECTION-CORRECTED ABUNDANCE MODEL

    EPA Science Inventory

    Paper presents a new model for controlling detection heterogeneity in temporally stratified bird counts. The method will allow researchers to control for variation in observer ability in large-scale studies of avian population trends.

  1. North American Bird Banding and quantitative population ecology

    USGS Publications Warehouse

    Nichols, J.D.; Tautin, J.; Davis, William E.=; Jackson, Jerome A.; Tautin, John

    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.

  2. Hawaiian forest bird trends: using log-linear models to assess long-term trends is supported by model diagnostics and assumptions (reply to Freed and Cann 2013)

    USGS Publications Warehouse

    Camp, Richard J.; Pratt, Thane K.; Gorresen, P. Marcos; Woodworth, Bethany L.; Jeffrey, John J.

    2014-01-01

    Freed and Cann (2013) criticized our use of linear models to assess trends in the status of Hawaiian forest birds through time (Camp et al. 2009a, 2009b, 2010) by questioning our sampling scheme, whether we met model assumptions, and whether we ignored short-term changes in the population time series. In the present paper, we address these concerns and reiterate that our results do not support the position of Freed and Cann (2013) that the forest birds in the Hakalau Forest National Wildlife Refuge (NWR) are declining, or that the federally listed endangered birds are showing signs of imminent collapse. On the contrary, our data indicate that the 21-year long-term trends for native birds in Hakalau Forest NWR are stable to increasing, especially in areas that have received active management.

  3. Bird populations on the Island of Tinian: persistence despite wholesale loss of native forests

    USGS Publications Warehouse

    Camp, Richard J.; Amidon, Frederick A.; Marshall, Ann P.; Pratt, Thane K.

    2012-01-01

    Bird habitat on the island of Tinian, Mariana Islands, has been substantially altered, and only around 5% of the island has native forest today. The modern bird fauna is likely to be a subset of the original avifauna where only species tolerant to native forest loss and human disturbance have survived. Avian surveys were conducted on the island in 2008 by the U.S. Fish and Wildlife Service to provide current densities and abundances of the remaining species, and assess population trends using data collected from previous surveys. During the three surveys (1982, 1996, and 2008), 18 species were detected, and abundances and trends were assessed for 11 species. Five of the nine native species and one alien bird have increased since 1982. Three native birds—Mariana Fruit-Dove (Ptilinopusroseicapilla), Micronesian Honeyeater (Myzomela rubratra), and Tinian Monarch (Monarcha takatsukasae)—have decreased since 1982. Trends for the remaining two birds (one native and one alien) were considered relatively stable. Only five birds, including the Tinian Monarch, showed significant differences among regions of Tinian by year. Increased development on Tinian may result in increases in habitat clearing and expansion of human-dominated habitats, and declines in some bird populations would likely continue or be exacerbated with these actions. Expanded development activities on Tinian would also mean increased cargo movement between Guam and Tinian, elevating the probability of transporting the Brown Tree Snake (Boiga irregularis) to Tinian, which would lead to precipitous decreases and extinctions.

  4. Interannual variation and long-term trends in proportions of resident individuals in partially migratory birds.

    PubMed

    Meller, Kalle; Vähätalo, Anssi V; Hokkanen, Tatu; Rintala, Jukka; Piha, Markus; Lehikoinen, Aleksi

    2016-03-01

    Partial migration - a part of a population migrates and another part stays resident year-round on the breeding site - is probably the most common type of migration in the animal kingdom, yet it has only lately garnered more attention. Theoretical studies indicate that in partially migratory populations, the proportion of resident individuals (PoR) should increase in high latitudes in response to the warming climate, but empirical evidence exists for few species. We provide the first comprehensive overview of the environmental factors affecting PoR and the long-term trends in PoR by studying 27 common partially migratory bird species in Finland. The annual PoR values were calculated by dividing the winter bird abundance by the preceding breeding abundance. First, we analysed whether early-winter temperature, winter temperature year before or the abundance of tree seeds just before overwintering explains the interannual variation in PoR. Secondly, we analysed the trends in PoR between 1987 and 2011. Early-winter temperature explained the interannual variation in PoR in the waterbirds (waterfowl and gulls), most likely because the temperature affects the ice conditions and thereby the feeding opportunities for the waterbirds. In terrestrial species, the abundance of seeds was the best explanatory variable. Previous winter's temperature did not explain PoR in any species, and thus, we conclude that the variation in food availability caused the interannual variation in PoR. During the study period, PoR increased in waterbirds, but did not change in terrestrial birds. Partially migratory species living in physically contrasting habitats can differ in their annual and long-term population-level behavioural responses to warming climate, possibly because warm winter temperatures reduce ice cover and improve the feeding possibilities of waterbirds but do not directly regulate the food availability for terrestrial birds.

  5. Long-term trends in breeding birds in an old-growth Adirondack forest and the surrounding region

    USGS Publications Warehouse

    McNulty, S.A.; Droege, S.; Masters, R.D.

    2008-01-01

    Breeding bird populations were sampled between 1954 and 1963, and 1990 and 2000 in an old-growth forest, the Natural Area of Huntington Wildlife Forest (HWF), in the Adirondack Mountains of New York. Trends were compared with data from regional North American Breeding Bird Surveys (BBS) and from a forest plot at Hubbard Brook Experimental Forest, New Hampshire. Trends for 22 species in the HWF Natural Area were negative, eight were positive, and one was zero; 20 were significant. Fifteen of 17 long-distance migrants declined, whereas 7 of 14 short-distance migrants and permanent residents declined. Most (74%) HWF Natural Area species, despite differences in sampling periods and local habitat features, matched in sign of trend when compared to Adirondack BBS routes, 61% matched northeastern BBS routes, and 71% matched eastern United States BBS routes, while 66% matched Hubbard Brook species. The agreement in population trends suggests that forest interior birds, especially long-distance migrants, are affected more by regional than local factors. The analysis indicated that bird trends generated from BBS routes may not be as biased toward roads as previously suggested.

  6. Modeling seasonal interactions in the population dynamics of migratory birds

    USGS Publications Warehouse

    Runge, M.C.; Marra, P.P.; Greenberg, Russell; Marra, Peter P.

    2005-01-01

    Understanding the population dynamics of migratory birds requires understanding the relevant biological events that occur during breeding, migratory, and overwintering periods. The few available population models for passerine birds focus on breeding-season events, disregard or oversimplify events during nonbreeding periods, and ignore interactions that occur between periods of the annual cycle. Identifying and explicitly incorporating seasonal interactions into population models for migratory birds could provide important insights about when population limitation actually occurs in the annual cycle. We present a population model for the annual cycle of a migratory bird, based on the American Redstart (Setophaga ruticilla) but more generally applicable, that examines the importance of seasonal interactions by incorporating: (1) density dependence during the breeding and winter seasons, (2) a carry-over effect of winter habitat on breeding-season productivity, and (3) the effects of behavioral dominance on seasonal and habitat specific demographic rates. First, we show that habitat availability on both the wintering and breeding grounds can strongly affect equilibrium population size and sex ratio. Second, sex ratio dynamics, as mediated by behavioral dominance, can affect all other aspects of population dynamics. Third, carry-over effects can be strong, especially when winter events are limiting. These results suggest that understanding the population dynamics of migratory birds may require more consideration of the seasonal interactions induced by carry-over effects and density dependence in multiple seasons. This model provides a framework in which to explore more fully these seasonal dynamics and a context for estimation of life history parameters.

  7. Assessing vulnerability of marine bird populations to offshore wind farms.

    PubMed

    Furness, Robert W; Wade, Helen M; Masden, Elizabeth A

    2013-04-15

    Offshore wind farms may affect bird populations through collision mortality and displacement. Given the pressures to develop offshore wind farms, there is an urgent need to assess population-level impacts on protected marine birds. Here we refine an approach to assess aspects of their ecology that influence population vulnerability to wind farm impacts, also taking into account the conservation importance of each species. Flight height appears to be a key factor influencing collision mortality risk but improved data on flight heights of marine birds are needed. Collision index calculations identify populations of gulls, white-tailed eagles, northern gannets and skuas as of particularly high concern in Scottish waters. Displacement index calculations identify populations of divers and common scoters as most vulnerable to population-level impacts of displacement, but these are likely to be less evident than impacts of collision mortality. The collision and displacement indices developed here for Scottish marine bird populations could be applied to populations elsewhere, and this approach will help in identifying likely impacts of future offshore wind farms on marine birds and prioritising monitoring programmes, at least until data on macro-avoidance rates become available.

  8. Bird Population, Book A, Explorations in Biology.

    ERIC Educational Resources Information Center

    Mid-Continent Regional Educational Lab., Inc., Kansas City, MO.

    The booklet is part of a series which tests some skills biologists use in their investigations. A series of diagrams of a biological community over a period of 10 years indicates an increasing bird mortality, and students are asked to choose a puzzling event that they would want to investigate if they were biologists. A scrambled programed text…

  9. Development of a practical modeling framework for estimating the impact of wind technology on bird populations

    SciTech Connect

    Morrison, M.L.; Pollock, K.H.

    1997-11-01

    One of the most pressing environmental concerns related to wind project development is the potential for avian fatalities caused by the turbines. The goal of this project is to develop a useful, practical modeling framework for evaluating potential wind power plant impacts that can be generalized to most bird species. This modeling framework could be used to get a preliminary understanding of the likelihood of significant impacts to birds, in a cost-effective way. The authors accomplish this by (1) reviewing the major factors that can influence the persistence of a wild population; (2) briefly reviewing various models that can aid in estimating population status and trend, including methods of evaluating model structure and performance; (3) reviewing survivorship and population projections; and (4) developing a framework for using models to evaluate the potential impacts of wind development on birds.

  10. Hawaii Forest Bird Interagency Database Project: Collecting, Understanding, and Sharing Population Data on Hawaiian Forest Birds

    USGS Publications Warehouse

    Pratt, Thane K.; Woodworth, Bethany L.; Camp, Richard J.; Gorresen, P. Marcos

    2006-01-01

    The forest birds of the Hawaiian Islands are distinguished by the diversity of endemic forms derived from a small number of ancestral colonists. However, the avifauna has been decimated by human activities both before and after Western contact. At least 71 species or subspecies disappeared before the arrival of Capt. James Cook in 1778, and an additional 24 went extinct after 1778, of which 11 were lost since the 1960s alone. Many of the remaining Hawaiian bird populations are declining or are in danger of extinction. Vigorous efforts to survey and monitor bird populations over the past 3 decades have generated considerable information from which to assess the current status of the Hawaiian forest birds.

  11. Population Trends and the Status of Population Policy in Africa.

    ERIC Educational Resources Information Center

    Rogge, John R.

    1982-01-01

    The major trend towards worldwide easing of the birthrate does not include the current population patterns in Africa. The population policies of African nations range along a continuum from totally pronatal to strongly antinatal. However, even antinatal policies have had little effect on the overall spiralling upward population trend. (JA)

  12. Measuring Global Trends in the Status of Biodiversity: Red List Indices for Birds

    PubMed Central

    Stattersfield, Alison J; Bennun, Leon A; Shutes, Sue M; Akçakaya, H. Resit; Baillie, Jonathan E. M; Stuart, Simon N; Hilton-Taylor, Craig; Mace, Georgina M

    2004-01-01

    The rapid destruction of the planet's biodiversity has prompted the nations of the world to set a target of achieving a significant reduction in the rate of loss of biodiversity by 2010. However, we do not yet have an adequate way of monitoring progress towards achieving this target. Here we present a method for producing indices based on the IUCN Red List to chart the overall threat status (projected relative extinction risk) of all the world's bird species from 1988 to 2004. Red List Indices (RLIs) are based on the number of species in each Red List category, and on the number changing categories between assessments as a result of genuine improvement or deterioration in status. The RLI for all bird species shows that their overall threat status has continued to deteriorate since 1988. Disaggregated indices show that deteriorations have occurred worldwide and in all major ecosystems, but with particularly steep declines in the indices for Indo-Malayan birds (driven by intensifying deforestation of the Sundaic lowlands) and for albatrosses and petrels (driven by incidental mortality in commercial longline fisheries). RLIs complement indicators based on species population trends and habitat extent for quantifying global trends in the status of biodiversity. Their main weaknesses are that the resolution of status changes is fairly coarse and that delays may occur before some status changes are detected. Their greatest strength is that they are based on information from nearly all species in a taxonomic group worldwide, rather than a potentially biased subset. At present, suitable data are only available for birds, but indices for other taxonomic groups are in development, as is a sampled index based on a stratified sample from all major taxonomic groups. PMID:15510230

  13. Measuring global trends in the status of biodiversity: red list indices for birds.

    PubMed

    Butchart, Stuart H M; Stattersfield, Alison J; Bennun, Leon A; Shutes, Sue M; Akçakaya, H Resit; Baillie, Jonathan E M; Stuart, Simon N; Hilton-Taylor, Craig; Mace, Georgina M

    2004-12-01

    The rapid destruction of the planet's biodiversity has prompted the nations of the world to set a target of achieving a significant reduction in the rate of loss of biodiversity by 2010. However, we do not yet have an adequate way of monitoring progress towards achieving this target. Here we present a method for producing indices based on the IUCN Red List to chart the overall threat status (projected relative extinction risk) of all the world's bird species from 1988 to 2004. Red List Indices (RLIs) are based on the number of species in each Red List category, and on the number changing categories between assessments as a result of genuine improvement or deterioration in status. The RLI for all bird species shows that their overall threat status has continued to deteriorate since 1988. Disaggregated indices show that deteriorations have occurred worldwide and in all major ecosystems, but with particularly steep declines in the indices for Indo-Malayan birds (driven by intensifying deforestation of the Sundaic lowlands) and for albatrosses and petrels (driven by incidental mortality in commercial longline fisheries). RLIs complement indicators based on species population trends and habitat extent for quantifying global trends in the status of biodiversity. Their main weaknesses are that the resolution of status changes is fairly coarse and that delays may occur before some status changes are detected. Their greatest strength is that they are based on information from nearly all species in a taxonomic group worldwide, rather than a potentially biased subset. At present, suitable data are only available for birds, but indices for other taxonomic groups are in development, as is a sampled index based on a stratified sample from all major taxonomic groups.

  14. Song Diversity Predicts the Viability of Fragmented Bird Populations

    PubMed Central

    Laiolo, Paola; Vögeli, Matthias; Serrano, David; Tella, José L.

    2008-01-01

    In the global scenario of increasing habitat fragmentation, finding appropriate indicators of population viability is a priority for conservation. We explored the potential of learned behaviours, specifically acoustic signals, to predict the persistence over time of fragmented bird populations. We found an association between male song diversity and the annual rate of population change, population productivity and population size, resulting in birds singing poor repertoires in populations more prone to extinction. This is the first demonstration that population viability can be predicted by a cultural trait (acquired via social learning). Our results emphasise that cultural attributes can reflect not only individual-level characteristics, but also the emergent population-level properties. This opens the way to the study of animal cultural diversity in the increasingly common human-altered landscapes. PMID:18350158

  15. Effect of forest fragmentation on bird populations

    USGS Publications Warehouse

    Robbins, C.S.

    1979-01-01

    Many of the insectivorous songbird species that winter in the tropics are dependent on large unbroken tracts of forest during the breeding season. These species are disappearing from localities where forests are becoming fragmented. By long-range planning, managers can prevent local extinctions of these area-sensitive birds through use of such techniques as management in large units, retention of connecting corridors, and prevention of excessive isolation of forest fragments. Edge conditions can be provided, where appropriate to meet the needs of upland game species.

  16. Seasonal distribution of bird populations at the Patuxent Research Refuge

    USGS Publications Warehouse

    Stewart, R.E.; Cope, J.B.; Robbins, C.S.; Brainerd, J.W.

    2000-01-01

    A detailed study of seasonal changes in bird populationswas made at the Patuxent Research Refuge, located between Bowie and Laurel, Maryland during the years 1936-1949. The history of the Refuge is reviewed and its physical and biological characteristlcs summarized.. The methods of study used during the investigation mcluded: periodic censuses of a representative 304-acre study area over a two-year period; a census of the breeding population of the entire. Refuge during one year; detailed population studies of representative habitats during the breeding season; censuses of the wintering population of. the entire Refuge during two years; general surveys of wintering populations for seven years; and general observations of seasonal changes in bird populatlons over a fourteen-year period, including data from an extensive banding program and from many special types of censuses. The phenology of the Refuge is described in conslderable detail throughout the year, with special attention given to major fluctuatIons in bIrd populations as correlated with climatic changes and with seasonal aspectlon. of the vegetation. The component specIes of birds m the more important migration waves are listed. Figures approximating the Refuge breeding and wmtering populations are given, while indices representing the relative abundance of bird populations, based on figures from the two-year seasonal populatlon study, were obtained for the entire year. The greatest variety of species as well as the greatest number of individuals occurred on the Refuge during the migration .periods in spring and fall, the variety of species being slightly higher in spring than in fa!l, while the population of individuals was considerably higher in fall. Wmtering and breeding populations were low and relatively stable compared to the populations at other seasons.The ecological affinities of the bird populations differed greatly from one season to another. Species characteristic of edge habitats were much

  17. Wildlife population trends in protected areas predicted by national socio-economic metrics and body size

    PubMed Central

    Barnes, Megan D.; Craigie, Ian D.; Harrison, Luke B.; Geldmann, Jonas; Collen, Ben; Whitmee, Sarah; Balmford, Andrew; Burgess, Neil D.; Brooks, Thomas; Hockings, Marc; Woodley, Stephen

    2016-01-01

    Ensuring that protected areas (PAs) maintain the biodiversity within their boundaries is fundamental in achieving global conservation goals. Despite this objective, wildlife abundance changes in PAs are patchily documented and poorly understood. Here, we use linear mixed effect models to explore correlates of population change in 1,902 populations of birds and mammals from 447 PAs globally. On an average, we find PAs are maintaining populations of monitored birds and mammals within their boundaries. Wildlife population trends are more positive in PAs located in countries with higher development scores, and for larger-bodied species. These results suggest that active management can consistently overcome disadvantages of lower reproductive rates and more severe threats experienced by larger species of birds and mammals. The link between wildlife trends and national development shows that the social and economic conditions supporting PAs are critical for the successful maintenance of their wildlife populations. PMID:27582180

  18. Wildlife population trends in protected areas predicted by national socio-economic metrics and body size

    NASA Astrophysics Data System (ADS)

    Barnes, Megan D.; Craigie, Ian D.; Harrison, Luke B.; Geldmann, Jonas; Collen, Ben; Whitmee, Sarah; Balmford, Andrew; Burgess, Neil D.; Brooks, Thomas; Hockings, Marc; Woodley, Stephen

    2016-09-01

    Ensuring that protected areas (PAs) maintain the biodiversity within their boundaries is fundamental in achieving global conservation goals. Despite this objective, wildlife abundance changes in PAs are patchily documented and poorly understood. Here, we use linear mixed effect models to explore correlates of population change in 1,902 populations of birds and mammals from 447 PAs globally. On an average, we find PAs are maintaining populations of monitored birds and mammals within their boundaries. Wildlife population trends are more positive in PAs located in countries with higher development scores, and for larger-bodied species. These results suggest that active management can consistently overcome disadvantages of lower reproductive rates and more severe threats experienced by larger species of birds and mammals. The link between wildlife trends and national development shows that the social and economic conditions supporting PAs are critical for the successful maintenance of their wildlife populations.

  19. Flood trends and population dynamics

    NASA Astrophysics Data System (ADS)

    Di Baldassarre, G.

    2012-04-01

    Since the earliest recorded civilizations, such as those in Mesopotamia and Egypt that developed in the fertile floodplains of the Tigris and Euphrates and Nile rivers, humans tend to settle in flood prone areas as they offer favorable conditions for economic development. However, floodplains are also exposed to flood disasters that might cause severe socio-economic and environmental damages not to mention losses of human lives. A flood event turns to be a disaster when it coincides with a vulnerable environment exceeding society's capacity to manage the adverse consequences. This presentation discusses the link between hydrological risk and population change by referring to the outcomes of scientific works recently carried out in Africa and Europe. More specifically, it is shown that the severity of flood disasters, currently affecting more than 100 million people a year, might be seriously exacerbated because of population change. In fact, flood exposure and/or vulnerability might increase because of rapid population growth (and its spatial and temporal dynamics, e.g. urbanization) in the African continent and because of population ageing in many European countries. Lastly, timely and economically sustainable actions to mitigate this increasing hydrological risk are critically evaluated.

  20. Studying disability trends in aging populations.

    PubMed

    Gu, Danan; Gomez-Redondo, Rosa; Dupre, Matthew E

    2015-03-01

    This article reviews the current literature on disability trends in aging populations and proposes a framework for studying disability trends built upon existing models of disablement. In addition to considering disablement and its associated factors, our framework also includes factors at population level and the interplays among personal resources and health behaviors, intervention programs, technological advances, and the consequences of disability trends in the context of life course and socio-ecological perspective. The framework is abbreviated FE-BRIT-SE to denote individual-level (F)ixed attributes, including genetic factors, personality, age, sex, and earlier life conditions, and the (E)nvironment; individual (B)ehaviors, (R)esources, (I)nterventions, (T)echnology; and (S)ocioeconomic and (E)cological consequences of disability trends. The overview offers an integrated framework for understanding the disablement process, trends and their complex milieu of causes and consequences.

  1. Temporal variation in population size of European bird species: effects of latitude and marginality of distribution.

    PubMed

    Cuervo, José J; Møller, Anders P

    2013-01-01

    In the Northern Hemisphere, global warming has been shown to affect animal populations in different ways, with southern populations in general suffering more from increased temperatures than northern populations of the same species. However, southern populations are also often marginal populations relative to the entire breeding range, and marginality may also have negative effects on populations. To disentangle the effects of latitude (possibly due to global warming) and marginality on temporal variation in population size, we investigated European breeding bird species across a latitudinal gradient. Population size estimates were regressed on years, and from these regressions we obtained the slope (a proxy for population trend) and the standard error of the estimate (SEE) (a proxy for population fluctuations). The possible relationships between marginality or latitude on one hand and slopes or SEE on the other were tested among populations within species. Potentially confounding factors such as census method, sampling effort, density-dependence, habitat fragmentation and number of sampling years were controlled statistically. Population latitude was positively related to regression slopes independent of marginality, with more positive slopes (i.e., trends) in northern than in southern populations. The degree of marginality was positively related to SEE independent of latitude, with marginal populations showing larger SEE (i.e., fluctuations) than central ones. Regression slopes were also significantly related to our estimate of density-dependence and SEE was significantly affected by the census method. These results are consistent with a scenario in which southern and northern populations of European bird species are negatively affected by marginality, with southern populations benefitting less from global warming than northern populations, thus potentially making southern populations more vulnerable to extinction.

  2. Estimating population trends with a linear model: Technical comments

    USGS Publications Warehouse

    Sauer, John R.; Link, William A.; Royle, J. Andrew

    2004-01-01

    Controversy has sometimes arisen over whether there is a need to accommodate the limitations of survey design in estimating population change from the count data collected in bird surveys. Analyses of surveys such as the North American Breeding Bird Survey (BBS) can be quite complex; it is natural to ask if the complexity is necessary, or whether the statisticians have run amok. Bart et al. (2003) propose a very simple analysis involving nothing more complicated than simple linear regression, and contrast their approach with model-based procedures. We review the assumptions implicit to their proposed method, and document that these assumptions are unlikely to be valid for surveys such as the BBS. One fundamental limitation of a purely design-based approach is the absence of controls for factors that influence detection of birds at survey sites. We show that failure to model observer effects in survey data leads to substantial bias in estimation of population trends from BBS data for the 20 species that Bart et al. (2003) used as the basis of their simulations. Finally, we note that the simulations presented in Bart et al. (2003) do not provide a useful evaluation of their proposed method, nor do they provide a valid comparison to the estimating- equations alternative they consider.

  3. Population trends of Alaskan seabirds

    USGS Publications Warehouse

    Hatch, Scott A.

    1993-01-01

    Ornithology in Alaska formally began with the observations of Georg Wilhelm Steller during Vitus Bering's voyage of discovery in 1741. Steller's journal makes brief mention of various seabird species he encountered during his travels in the Gulf of Alaska and Aleutian Islands (Frost and Engel 1988). For more than 100 years following Steller, the Russian-American Company was active in commercial fur harvesting throughout southern coastal Alaska, but this period saw little contribution to a scientific understanding of the region's avifauna. With the purchase of Alaska by the United States in 1867, a period of American exploration began that included significant work by pioneering naturalists such as Dall (1873, 1874), Elliot (1881), Nelson (1883), and Turner (1885, 1886). While this activity established a comprehensive list and general knowledge of the distribution of seabird species occurring in Alaska, early observers provided no quantitative estimates of abundance for any colony or region.The observations of Heath (1915) and Willett (1912, 1915, 1917) at two locations in southeastern Alaska are notable for including the first numerical estimates of any seabird populations for comparison with recent data. Willett's (1912, 1915) estimates of 13 species are given in Table 1 with results from a 1976 Survey at Forrester Island (DeGange et al. 1977) and a 1981 survey at St. Lazaria Island (Nelson et al 1982). In the aggregate, seabird numbers appeared to increase dramatically at both sites, but the differences may be largely artificial. Because Willett (1915) did not employ rigorous sampling methods, DeGange et al. (1977) surmised that he grossly underestimated the populations of burrowing species such as storm-petrels, Cassin's Auklets. and Rhinoceros Aulkets. Nelson et al. (1982) offered a similar interpretation of total storm-petrel numbers at St. Lazaria, but felt that a shift in the species ratio of Leach's and Fork-tailed Storm-Petrels had likely occurred. It

  4. Heroin users in Australia: population trends.

    PubMed

    Kaya, C Yalçin; Tugai, Yuliya; Filar, Jerzy A; Agrawal, Manju R; Ali, Robert L; Gowing, Linda R; Cooke, Richard

    2004-03-01

    The aim of this paper is to identify certain important population trends among heroin users in Australia for the period 1971 - 97, such as: population growth, initiation, i.e. the number who were initiated to heroin in a given year, and quitting, i.e. the number that quit using heroin. For this purpose, we summarize and extract relevant characteristics from data from National Drug Strategy Household Survey (NDSHS 1998) conducted in Australia in 1998. We devise a systematic procedure to estimate historical trends from questions concerning past events. It is observed from our findings that the size of the heroin user population in Australia is in a sharp increase, especially from the early 1980s onwards. The general trend obtained for the period 1971 - 97 is strikingly similar to that obtained by Hall et al. (2000) for the dependent heroin user population in Australia, even though their study was based on different datasets and a different methodology. In our reconstruction of the time history we also detect a levelling-off prior to 1990. Initiation is also observed to be on a sharp increase. The latter trend is accompanied by a similar trend of quitting, perhaps indicating a relatively short heroin use career. A sharp decrease in both initiation and quitting is observed after 1990. In conclusion, in the case of the trend in the population of heroin users a high rate of growth has been identified that is consistent with the existing literature. In the process, we demonstrated that even a static survey such as NDSHS 1998 can, sometimes, be used to extract historical (dynamic) trends of certain important variables.

  5. Recovery trends in marine mammal populations.

    PubMed

    Magera, Anna M; Mills Flemming, Joanna E; Kaschner, Kristin; Christensen, Line B; Lotze, Heike K

    2013-01-01

    Marine mammals have greatly benefitted from a shift from resource exploitation towards conservation. Often lauded as symbols of conservation success, some marine mammal populations have shown remarkable recoveries after severe depletions. Others have remained at low abundance levels, continued to decline, or become extinct or extirpated. Here we provide a quantitative assessment of (1) publicly available population-level abundance data for marine mammals worldwide, (2) abundance trends and recovery status, and (3) historic population decline and recent recovery. We compiled 182 population abundance time series for 47 species and identified major data gaps. In order to compare across the largest possible set of time series with varying data quality, quantity and frequency, we considered an increase in population abundance as evidence of recovery. Using robust log-linear regression over three generations, we were able to classify abundance trends for 92 spatially non-overlapping populations as Significantly Increasing (42%), Significantly Decreasing (10%), Non-Significant Change (28%) and Unknown (20%). Our results were comparable to IUCN classifications for equivalent species. Among different groupings, pinnipeds and other marine mammals (sirenians, polar bears and otters) showed the highest proportion of recovering populations, likely benefiting from relatively fast life histories and nearshore habitats that provided visibility and protective management measures. Recovery was less frequent among cetaceans, but more common in coastal than offshore populations. For marine mammals with available historical abundance estimates (n = 47), larger historical population declines were associated with low or variable recent recoveries so far. Overall, our results show that many formerly depleted marine mammal populations are recovering. However, data-deficient populations and those with decreasing and non-significant trends require attention. In particular, increased study of

  6. Recovery Trends in Marine Mammal Populations

    PubMed Central

    Magera, Anna M.; Mills Flemming, Joanna E.; Kaschner, Kristin; Christensen, Line B.; Lotze, Heike K.

    2013-01-01

    Marine mammals have greatly benefitted from a shift from resource exploitation towards conservation. Often lauded as symbols of conservation success, some marine mammal populations have shown remarkable recoveries after severe depletions. Others have remained at low abundance levels, continued to decline, or become extinct or extirpated. Here we provide a quantitative assessment of (1) publicly available population-level abundance data for marine mammals worldwide, (2) abundance trends and recovery status, and (3) historic population decline and recent recovery. We compiled 182 population abundance time series for 47 species and identified major data gaps. In order to compare across the largest possible set of time series with varying data quality, quantity and frequency, we considered an increase in population abundance as evidence of recovery. Using robust log-linear regression over three generations, we were able to classify abundance trends for 92 spatially non-overlapping populations as Significantly Increasing (42%), Significantly Decreasing (10%), Non-Significant Change (28%) and Unknown (20%). Our results were comparable to IUCN classifications for equivalent species. Among different groupings, pinnipeds and other marine mammals (sirenians, polar bears and otters) showed the highest proportion of recovering populations, likely benefiting from relatively fast life histories and nearshore habitats that provided visibility and protective management measures. Recovery was less frequent among cetaceans, but more common in coastal than offshore populations. For marine mammals with available historical abundance estimates (n = 47), larger historical population declines were associated with low or variable recent recoveries so far. Overall, our results show that many formerly depleted marine mammal populations are recovering. However, data-deficient populations and those with decreasing and non-significant trends require attention. In particular, increased

  7. Climate Change Influences on Antarctic Bird Populations

    NASA Astrophysics Data System (ADS)

    Korczak-Abshire, Małgorzata

    2010-01-01

    Rapid changes in the major environmental variables like: temperature, wind and precipitation have occurred in the Antarctic region during the last 50 years. In this very sensitive region, even small changes can potentially lead to major environmental perturbations. Then the climate change poses a new challenge to the survival of Antarctic wildlife. As important bioindicators of changes in the ecosystem seabirds and their response to the climate perturbations have been recorded. Atmospheric warming and consequent changes in sea ice conditions have been hypothesized to differentially affect predator populations due to different predator life-history strategies and substantially altered krill recruitment dynamics.

  8. Using Christmas Bird Count data in analysis of population change

    USGS Publications Warehouse

    Sauer, J.R.; Link, W.A.

    2002-01-01

    The scientific credibility of Christmas Bird Count (CBC) results depend on the development and implementation of appropriate methods of statistical analysis. The key to any successful analysis of CBC data is to begin with a careful review of how the limitations of the data are likely to influence the results of the analysis, then to choose methods of analysis that accommodate as much as possible the limitations of the survey. For our analyses of CBC data, we develop a flexible model for effort adjustment and use information from the data to guide the selection of the best model. We include geographic structuring to accommodate the regional variation in number of samples, use a model that allows for overdispersed poisson data appropriate for counts, and employ empirical Bayes procedures to accommodate differences in quality of information in regional summaries. This generalized linear model approach is very flexible, and can be applied to a variety of studies focused on factors influencing wintering bird populations. In particular, the model can be easily modified to contain covariates, allowing for assessment of associations between CBC counts and winter weather, disturbance, and a variety of other environmental factors. These new survey analysis methods have added value in that they provide insights into changes in survey design that can enhance the value of the information. The CBC has been extremely successful as a tool for increasing public interest in birding and bird conservation. Use of the information for bird conservation creates new demands on quality of information, and it is important to maintain a dialogue between users of the information, information needs for the analyses, and survey coordinators and participants. Our work as survey analysts emphasizes the value and limitations of existing data, and provides some indications of what features of the survey could be modified to make the survey a more reliable source of bird population data. Surveys

  9. Demographic routes to variability and regulation in bird populations

    PubMed Central

    Sæther, Bernt-Erik; Grøtan, Vidar; Engen, Steinar; Coulson, Tim; Grant, Peter R.; Visser, Marcel E.; Brommer, Jon E.; Rosemary Grant, B.; Gustafsson, Lars; Hatchwell, Ben J.; Jerstad, Kurt; Karell, Patrik; Pietiäinen, Hannu; Roulin, Alexandre; Røstad, Ole W.; Weimerskirch, Henri

    2016-01-01

    There is large interspecific variation in the magnitude of population fluctuations, even among closely related species. The factors generating this variation are not well understood, primarily because of the challenges of separating the relative impact of variation in population size from fluctuations in the environment. Here, we show using demographic data from 13 bird populations that magnitudes of fluctuations in population size are mainly driven by stochastic fluctuations in the environment. Regulation towards an equilibrium population size occurs through density-dependent mortality. At small population sizes, population dynamics are primarily driven by environment-driven variation in recruitment, whereas close to the carrying capacity K, variation in population growth is more strongly influenced by density-dependent mortality of both juveniles and adults. Our results provide evidence for the hypothesis proposed by Lack that population fluctuations in birds arise from temporal variation in the difference between density-independent recruitment and density-dependent mortality during the non-breeding season. PMID:27328710

  10. Consistent response of bird populations to climate change on two continents

    USGS Publications Warehouse

    Stephens, Philip A.; Mason, Lucy R.; Green, Rhys E.; Gregory, Richard D.; Sauer, John R.; Alison, Jamie; Aunins, Ainars; Brotons, Lluís; Butchart, Stuart H.M.; Campedelli, Tommaso; Chodkiewicz, Tomasz; Chylarecki, Przemyslaw; Crowe, Olivia; Elts, Jaanus; Escandell, Virginia; Foppen, Ruud P.B.; Heldbjerg, Henning; Herrando, Sergi; Husby, Magne; Jiguet, Frédéric; Lehikoinen, Aleksi; Lindström, Åke; Noble, David G.; Paquet, Jean-Yves; Reif, Jiri; Sattler, Thomas; Szép, Tibor; Teufelbauer, Norbert; Trautmann, Sven; Van Strien, Arco; van Turnhout, Chris A.M.; Vorisek, Petr; Willis, Stephen G.

    2016-01-01

    Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends.

  11. Consistent response of bird populations to climate change on two continents.

    PubMed

    Stephens, Philip A; Mason, Lucy R; Green, Rhys E; Gregory, Richard D; Sauer, John R; Alison, Jamie; Aunins, Ainars; Brotons, Lluís; Butchart, Stuart H M; Campedelli, Tommaso; Chodkiewicz, Tomasz; Chylarecki, Przemysław; Crowe, Olivia; Elts, Jaanus; Escandell, Virginia; Foppen, Ruud P B; Heldbjerg, Henning; Herrando, Sergi; Husby, Magne; Jiguet, Frédéric; Lehikoinen, Aleksi; Lindström, Åke; Noble, David G; Paquet, Jean-Yves; Reif, Jiri; Sattler, Thomas; Szép, Tibor; Teufelbauer, Norbert; Trautmann, Sven; van Strien, Arco J; van Turnhout, Chris A M; Vorisek, Petr; Willis, Stephen G

    2016-04-01

    Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends.

  12. Population models for passerine birds: structure, parameterization, and analysis

    USGS Publications Warehouse

    Noon, B.R.; Sauer, J.R.; McCullough, D.R.; Barrett, R.H.

    1992-01-01

    Population models have great potential as management tools, as they use infonnation about the life history of a species to summarize estimates of fecundity and survival into a description of population change. Models provide a framework for projecting future populations, determining the effects of management decisions on future population dynamics, evaluating extinction probabilities, and addressing a variety of questions of ecological and evolutionary interest. Even when insufficient information exists to allow complete identification of the model, the modelling procedure is useful because it forces the investigator to consider the life history of the species when determining what parameters should be estimated from field studies and provides a context for evaluating the relative importance of demographic parameters. Models have been little used in the study of the population dynamics of passerine birds because of: (1) widespread misunderstandings of the model structures and parameterizations, (2) a lack of knowledge of life histories of many species, (3) difficulties in obtaining statistically reliable estimates of demographic parameters for most passerine species, and (4) confusion about functional relationships among demographic parameters. As a result, studies of passerine demography are often designed inappropriately and fail to provide essential data. We review appropriate models for passerine bird populations and illustrate their possible uses in evaluating the effects of management or other environmental influences on population dynamics. We identify environmental influences on population dynamics. We identify parameters that must be estimated from field data, briefly review existing statistical methods for obtaining valid estimates, and evaluate the present status of knowledge of these parameters.

  13. Forest management under uncertainty for multiple bird population objectives

    USGS Publications Warehouse

    Moore, C.T.; Plummer, W.T.; Conroy, M.J.; Ralph, C. John; Rich, Terrell D.

    2005-01-01

    We advocate adaptive programs of decision making and monitoring for the management of forest birds when responses by populations to management, and particularly management trade-offs among populations, are uncertain. Models are necessary components of adaptive management. Under this approach, uncertainty about the behavior of a managed system is explicitly captured in a set of alternative models. The models generate testable predictions about the response of populations to management, and monitoring data provide the basis for assessing these predictions and informing future management decisions. To illustrate these principles, we examine forest management at the Piedmont National Wildlife Refuge, where management attention is focused on the recovery of the Red-cockaded Woodpecker (Picoides borealis) population. However, managers are also sensitive to the habitat needs of many non-target organisms, including Wood Thrushes (Hylocichla mustelina) and other forest interior Neotropical migratory birds. By simulating several management policies on a set of-alternative forest and bird models, we found a decision policy that maximized a composite response by woodpeckers and Wood Thrushes despite our complete uncertainty regarding system behavior. Furthermore, we used monitoring data to update our measure of belief in each alternative model following one cycle of forest management. This reduction of uncertainty translates into a reallocation of model influence on the choice of optimal decision action at the next decision opportunity.

  14. Forest Bird Distribution, Density and Trends in the Ka'u Region of Hawai'i Island

    USGS Publications Warehouse

    Gorresen, P. Marcos; Camp, Richard J.; Pratt, Thane K.

    2007-01-01

    An accurate and current measure of population status and trend is necessary for conservation and management efforts. Scott and Kepler (1985) provided a comprehensive review of the status of native Hawaiian birds based on the extensive Hawaii Forest Bird Survey (HFBS) of the main islands (Scott et al. 1986). At that time, they documented declining populations and decreasing ranges for most species, and the extinction of several species over the previous 50 years. Many native bird species continue to decline throughout Hawai`i (Camp et al. In review, Gorresen et al. In prep.). The focus of this study is the mid-to-high elevation rainforest on the southeast windward slopes of Mauna Loa Volcano (Figure 1). Known as Ka`u, the region encompasses forest lands protected by Kamehameha Schools, The Nature Conservancy, Hawai`i Volcanoes National Park (HVNP), and the State of Hawai'i's Ka`u Forest Reserve, Kapapala Forest Reserve and Kapapala Cooperative Game Management Area,. Together these lands support one of three main concentrations of native forest birds on the Hawai`i Island (the other two being centered on the Hakalau Forest National Wildlife Refuge and Kulani-Keauhou area in the north and central windward part of the island, respectively.) Because this region harbors important populations of native and endangered forest birds in some of the best remaining forest habitat on the island, it has been a focus of forest bird surveys since the 1970s. The Ka`u region was first quantitatively surveyed in 1976 by the Hawaii Forest Bird Survey (Scott et al. 1986). Surveys were conducted by State of Hawai`i Division of Forestry and Wildlife in 1993 and 2002 and by the U.S. National Park Service and the U.S. Geological Survey in 2004 and 2005. In this report, we present analyses of the density, distribution and trends of native and introduced forest bird within the Ka`u region of Hawai`i Island. The analyses cover only those species with sufficient detections to model detection

  15. Education, Population Trends and Technological Change.

    ERIC Educational Resources Information Center

    Bowman, Mary Jean

    1985-01-01

    Focuses on three sets of generalized interrelationships among population growth, technological change, and education: human resources and technological change; parental education, child services, and demographic transition; and relationships affecting household health and contraception. Outlines current demographic trends and predicts effects of…

  16. Forest bird and fruit bat populations on Sarigan, Mariana Islands

    USGS Publications Warehouse

    Fancy, Steven G.; Craig, Robert J.; Kessler, Curt T.

    1999-01-01

    We conducted the first quantitative surveys of forest bird and bat populations on the uninhabited island of Sarigan, Commonwealth of the Northern Mariana Islands. Severe habitat degradation has occurred on Sarigan because of overgrazing by introduced goats and pigs. Planting of coconut palms (Cocos nucifera) for copra production has also eliminated much of the island’s native forest. We recorded five species of forest birds on Sarigan: Micronesian Honeyeater (Myzomela rubratra), Micronesian Megapode (Megapodius laperouse laperouse), Micronesian Starling (Aplonis opaca), Collared Kingfisher (Halcyon chloris), and White-throated Ground Dove (Gallicolumba xanthonura). Estimated population sizes (95% confidence interval) in 1997 were 1,821 (1,617–2,026) for Micronesian Honeyeater, 677 (545–810) for Micronesian Megapode, 497 (319–675) for Micronesian Starling, 107 (82–131) for Collared Kingfisher, and 170 (101–238) for Mariana Fruit Bat (Pteropus mariannus).

  17. Status and trends of the land bird avifauna on Tinian and Aguiguan, Mariana Islands.

    USGS Publications Warehouse

    Camp, Richard J.; Pratt, Thane K.; Amidon, Fred; Marshall, Ann P.; Kremer, Shelly; Laut, Megan

    2012-01-01

    Avian surveys were conducted on the islands of Tinian and Aguiguan, Marianas Islands, in 2008 by the U.S. Fish and Wildlife Service to provide current baseline densities and abundances and assess population trends using data collected from previous surveys. On Tinian, during the three surveys (1982, 1996, and 2008), 18 species were detected, and abundances and trends were assessed for 12 species. Half of the 10 native species—Yellow Bittern (Ixobrychus sinensis), White-throated Ground-Dove (Gallicolumba xanthonura), Collared Kingfisher (Todiramphus chloris), Rufous Fantail (Rhipidura rufifrons), and Micronesian Starling (Aplonis opaca)—and one alien bird—Island Collared-Dove (Streptopelia bitorquata)—have increased since 1982. Three native birds—Mariana Fruit-Dove (Ptilinopus roseicapilla), Micronesian Honeyeater (Myzomela rubratra), and Tinian Monarch (Monarcha takatsukasae)—have decreased since 1982. Trends for the remaining two native birds—White Tern (Gygis alba) and Bridled White-eye (Zosterops saypani)—and one alien bird—Eurasian Tree Sparrow (Passer montanus)—were considered relatively stable. Only five birds—White-throated Ground-Dove, Mariana Fruit-Dove, Tinian Monarch, Rufous Fantail, and Bridled White-eye—showed significant differences among regions of Tinian by year. Tinian Monarch was found in all habitat types, with the greatest monarch densities observed in limestone forest, secondary forest, and tangantangan (Leucaena leucocephala) thicket and the smallest densities found in open fields and urban/residential habitats. On Aguiguan, 19 species were detected on one or both of the surveys (1982 and 2008), and abundance estimates were produced for nine native and one alien species. Densities for seven of the nine native birds—White-throated Ground-Dove, Mariana Fruit-Dove, Collared Kingfisher, Rufous Fantail, Bridled White-eye, Golden White-eye (Cleptornis marchei), and Micronesian Starling—and the alien bird— Island

  18. Advanced Technologies for Acoustic Monitoring of Bird Populations

    DTIC Science & Technology

    2009-04-01

    Dr. Kenneth Rosenberg (Cornell Lab of Ornithology ) titled ―Migratory Bird Monitoring Using Automated Acoustic and Internet Technologies‖ (Legacy... Ornithology . At the time that SI-1461 was awarded to Cornell University (April 2005), Fristrup was named as Principal Investigator. In November 2005...1986; Wilson and Watts 2006). Standard protocols for monitoring whip-poor-will populations call for an observer to listen for a six-minute sample period

  19. Recent developments in population trends and policies.

    PubMed

    1987-01-01

    A review of recent trends in world population growth indicates that growth rate continues to decelerate. However, there are marked differences in the pattern among regions and among individual countries. Furthermore, it is expected that the annual increments will increase for some time. There are and will continue to be differential growth rates among various age/sex groups with rapid increases in the working-age population and women of child-bearing age. There will also be an increase in the number and proportion of elderly persons. Though the declining population growth rate is largely due to fertility trends, there remains a substantial unmet need for family planning in developing countries. Furtheremore, desired family size is likely to fall as more women find employment in modern occupations. While fertility has been declining, so also has mortality, though there is a great variation in levels and trends among regions and individual countries. Many developing countries are experiencing rates of urban growth that greatly exceed the overall growth rates of their populations. Though that growth is increasingly concentrated in the largest cities, it is but 1 aspect of a complex pattern of population movements within individual countries. Furthermore, there continue to be substantial flows of workers and refugees across international borders. Those demographic trends have taken place against a background of depressed economic conditions that have made it difficult for developing countries to meet the needs of their growing population for more employment, educational opportunities, agricultural land, and industrial capital. The juxtaposition of static economies and rapidly growing populations was recognized in the statements of Governments at the International Conference on Population in 1984. They affirmed the need to implement population policies in the context of respect for human rights and cultural values. Action was especially necessary if the status of women

  20. Noninvasive methods for monitoring bear population trends

    USGS Publications Warehouse

    Kendall, Katherine

    2010-01-01

    The U.S. Geological Survey began a grizzly bear research project in 2009 in the Northern Continental Divide Ecosystem (NCDE) of northwestern Montana. This work uses hair collection and DNA analysis methods similar to those used in the 2004 Northern Divide Grizzly Bear Project. However, instead of producing a snapshot of population size, the objectives of this new work are to estimate population growth rates by collecting hair at natural bear rubs along trails, roads, and fence and power lines. This approach holds promise of providing reliable estimates of population trends in an efficient, cost-effective, and unobtrusive way.

  1. Effects of restoring oak savannas on bird communities and populations.

    PubMed

    Brawn, Jeffrey D

    2006-04-01

    Efforts to restore and maintain oak savannas in North America, with emphasis on the use of prescribed fire, have become common. Little is known, however about how restoration affects animal populations, especially those of birds. I compared the breeding densities, community structure, and reproductive success of birds in oak savannas maintained by prescribed fire (12 sites) with those in closed-canopy forests (13 sites). All sampling was conducted in Illinois (U.S.A.). Of the 31 bird species analyzed, 12 were more common in savannas, 14 were not affected by habitat structure, and 5 were more common in forest habitat. The species favored by disturbance and restoration included Northern Bobwhites (Colinus virginianus), Mourning Doves (Zenaida macroura), Red-headed Woodpeckers (Melanerpes erythrocephalus), Indigo Buntings (Passerina cyanea), and Baltimore Orioles (Icterus galbula). Those more common in closed-canopy forest included Ovenbirds (Seiurus aurocapilla) and Wood Thrushes (Hylocichla mustelina). Few species were unique to one type of habitat, but overall avian community structure in oak savannas and closed-canopy forests was generally distinctive. Estimates of nesting success (derived from 785 nests) revealed that 6 of the 13 species considered experienced greater productivity in the savanna habitat. Rates of brood parasitism were unaffected by restoration and habitat structure. Within savannas, tract size had little effect on breeding abundances and reproductive success. My results illustrate that restoration techniques can significantly affect the ecology of constituent animal populations and communities and have key implications regarding avian conservation and the management of forest habitat in fragmented landscapes. Small patches of forest habitat that regularly function as population sinks may offer far better prospects for birds if they are subjected to disturbance and ecosystem restoration.

  2. Population trends influence species ability to track climate change.

    PubMed

    Ralston, Joel; DeLuca, William V; Feldman, Richard E; King, David I

    2017-04-01

    Shifts of distributions have been attributed to species tracking their fundamental climate niches through space. However, several studies have now demonstrated that niche tracking is imperfect, that species' climate niches may vary with population trends, and that geographic distributions may lag behind rapid climate change. These reports of imperfect niche tracking imply shifts in species' realized climate niches. We argue that quantifying climate niche shifts and analyzing them for a suite of species reveal general patterns of niche shifts and the factors affecting species' ability to track climate change. We analyzed changes in realized climate niche between 1984 and 2012 for 46 species of North American birds in relation to population trends in an effort to determine whether species differ in the ability to track climate change and whether differences in niche tracking are related to population trends. We found that increasingly abundant species tended to show greater levels of niche expansion (climate space occupied in 2012 but not in 1980) compared to declining species. Declining species had significantly greater niche unfilling (climate space occupied in 1980 but not in 2012) compared to increasing species due to an inability to colonize new sites beyond their range peripheries after climate had changed at sites of occurrence. Increasing species, conversely, were better able to colonize new sites and therefore showed very little niche unfilling. Our results indicate that species with increasing trends are better able to geographically track climate change compared to declining species, which exhibited lags relative to changes in climate. These findings have important implications for understanding past changes in distribution, as well as modeling dynamic species distributions in the face of climate change.

  3. A reassessment of world population trends.

    PubMed

    Coale, A J

    1982-01-01

    This reassessment is limited to observations concerning trends in mortality and fertility and concerning longrun prospects for population growth. Recorded changes in mortality are compared with 3 projections made many years ago. Projections of European mortality made in 1941-42 understated by a wide margin the actual increase in expectation of life because of unforeseen technological changes in the prevention and cure of fatal disease. On the other hand, a projection made in 1955 for India, foreseeing a rapid rise in the 1950s and slower progress later on because of the exhaustion of the easier gains, appears to have been accurate and also to depict the prospects in other populations of relatively high mortality and low income. A different projection of life expectancy in Mexico was also quite close to actual changes in Mexican mortality; it was based on a universal curve constructed to represent how life expectancy rises, increasing ever more slowly as it approaches an upper limit. This curve (1 for each sex), constructed for projection of Mexican mortality, is employed as a standard of comparison for mortality changes in many countries. A number have followed the standard for females very closely for more than 3 decades; in developed countries, male life expectancy has generally fallen short of the standard. The almost universal low fertility in developed countries contrasts with the great diversity of levels and trends of fertility in developing countries, some of which retain undiminished high fertility and others of which have recently attained rates of childbearing as low as in the developed areas. Instances of surprisingly little change and surprisingly rapid change in fertility are described. In the future, growth of populations of developed countries will probably be slight; the future rate of increase in the developing areas depends on the unpredictable timing and pace of childbearing reduction in populations where fertility remains high. In the long run

  4. Trend estimation in populations with imperfect detection

    USGS Publications Warehouse

    Kery, Marc; Dorazio, Robert M.; Soldaat, Leo; Van Strien, Arco; Zuiderwijk, Annie; Royle, J. Andrew

    2009-01-01

    1. Trends of animal populations are of great interest in ecology but cannot be directly observed owing to imperfect detection. Binomial mixture models use replicated counts to estimate abundance, corrected for detection, in demographically closed populations. Here, we extend these models to open populations and illustrate them using sand lizard Lacerta agilis counts from the national Dutch reptile monitoring scheme. 2. Our model requires replicated counts from multiple sites in each of several periods, within which population closure is assumed. Counts are described by a hierarchical generalized linear model, where the state model deals with spatio-temporal patterns in true abundance and the observation model with imperfect counts, given that true state. We used WinBUGS to fit the model to lizard counts from 208 transects with 1–10 (mean 3) replicate surveys during each spring 1994–2005. 3. Our state model for abundance contained two independent log-linear Poisson regressions on year for coastal and inland sites, and random site effects to account for unexplained heterogeneity. The observation model for detection of an individual lizard contained effects of region, survey date, temperature, observer experience and random survey effects. 4. Lizard populations increased in both regions but more steeply on the coast. Detectability increased over the first few years of the study, was greater on the coast and for the most experienced observers, and highest around 1 June. Interestingly, the population increase inland was not detectable when the observed counts were analysed without account of detectability. The proportional increase between 1994 and 2005 in total lizard abundance across all sites was estimated at 86% (95% CRI 35–151). 5. Synthesis and applications. Open-population binomial mixture models are attractive for studying true population dynamics while explicitly accounting for the observation process, i.e. imperfect detection. We emphasize the important

  5. Recent Trends in Bird Abundance on Rhode Island Salt Marshes

    EPA Science Inventory

    Salt marsh habitat is under pressure from development on the landward side, and sea level rise from the seaward side. The resulting loss of habitat is potentially disastrous for salt marsh dependent species. To assess the population status of three species of salt marsh dependent...

  6. Effects of DDT on bird population of scrub forest

    USGS Publications Warehouse

    Robbins, C.S.; Stewart, R.E.

    1949-01-01

    An oil spray of DDT was applied at the rate of five pounds per acre to a 90-acre tract of 5-year-old scrub and sapling growth at Beltsville, Maryland. Bird population studies were carried on in a 30-acre plot at the center of the sprayed area, and in a 30-acre check area of the same habitat one-half mile away. Of the five commonest species in the sprayed area, the Maryland yellowthroat, prairie warbler, and house wren were reduced 80 per cent, and the red-eyed towhee was apparently reduced 35 per cent; while no appreciable change in the numbers of yellow-breasted chats was noted. The total decrease for the five commonest species, which represented 77 per cent of the original population, was 65 per cent.

  7. World population trends in 1960-70.

    PubMed

    Tabah, L; Kono, S

    1974-01-01

    burdens are associated with child-rearing while welfare for the aged is the great concern in the more developed areas of the world. The great trend toward urbanization in all parts of the world means that the population problems commanding greatest attention are those associated with large and fast-growing cities.

  8. Demographic trends, population policy and public opinion.

    PubMed

    Palomba, R; Bonifazi, C; Menniti, A

    1989-01-01

    Findings are analyzed of the Instituto di Richerche solla poplazione survey carried out in Italy in 1987 which focused on: 1) those variables which may be indirectly affecting Italian's fertility intentions, and 2) the degree of acceptability of a global social policy i.e., one that is not only restricted to economic incentives to be offered to families. Data was obtained from a national sample of 1500 people between 18-49 years. Italians have a good awareness of demographic issues; 61% knew of the decline in marriages; 72% were aware of the increasing aging population; 50% viewed the fall in birth rate negatively; and 41% thought that population and fertility trends would remain at the present low level or would decrease even further (49%). The birth rate decline was contributed to economic reasons at both reasons at both a global and an individual level. The majority of people did not show any signs of prejudice toward immigrants; however, they did favor limiting the number of foreigners in general with the exception of political refugees. The majority were also in favor of helping 3rd World countries. Although Italians value their children and the parent-child relationship very highly, a reduction in the value of children with increasing educational level of the respondents was observed. 83% thought that couples should be allowed to have as many children as they wanted; 81% agreed that measures regarding contraceptive knowledge and availability should be improved; and 49% were in favor of measures to increase births. Regarding possible new policy measures, 50% were in full agreement on the development and increased efficiency of social services to enable women to go out to work. (author's modified)

  9. Re-evaluating the use of beached bird oiling rates to assess long-term trends in chronic oil pollution.

    PubMed

    Wilhelm, Sabina I; Robertson, Gregory J; Ryan, Pierre C; Tobin, Stan F; Elliot, Richard D

    2009-02-01

    The oiling rate (oiled birds/total birds) has become the international standard to analyze beached bird survey data. However, this index may not reliably track long-term changes in marine oil pollution in regions where other activities that kill seabirds vulnerable to oil, such as hunting and gill-netting, are also changing. We compare the oiling rate from beached bird surveys conducted in southeastern Newfoundland between 1984 and 2006 to an alternative approach, namely trends derived from a model examining the linear density of oiled birds (birds/km). In winter, there was no change in the oiling rate since 1984, while in summer oiling rates significantly increased. In contrast, the number of oiled birds/km showed a significant decline in both winter and summer. The discrepancy in these trends was attributed to steep declines in the number of unoiled birds found in both seasons. In winter, the decline in unoiled birds/km was related to a reduction in the legal murre hunt and less onshore winds, while in summer a reduced cod fishery resulting in fewer murres drowning in nets and warming summers may have lead to the decline. The significant declines in oiled birds/km over the past three decades are hopefully an indication of less oil being present in the marine environment. Although oiled bird densities since 2000 have remained relatively low for the region (winter: 0.58 birds/km, summer: 0.27 birds/km), they still exceed densities reported elsewhere in the world.

  10. Painted Bunting Breeding Bird Survey trends associated with landscape changes in Georgia and South Carolina

    USGS Publications Warehouse

    Meyers, J.M.

    2000-01-01

    Landscape changes during the first 3 decades of the Breeding Bird Survey (BBS) may account for the Painted Bunting's declining population trend. In the southeastern U.S., it is estimated that this bunting has declined 3.5 % per year since 1966. I collected landscape data centered on identical 5-stop areas (n = 33, 306 ha each) of the BBS during early (1960s - 1970s) and late decades (1980s - 1990s). Peak 30-yr counts for Painted Buntings were found at the center of the 5-stop areas. I used stepwise multiple regression analysis to model the mean number of Painted Buntings (in the area during 3 yr, dependent variable) associated with landscape metrics (independent variables). During the early decades the average amount of edge on developed land (p = 0.10), average patch size of agriculture land (p = 0.01), average size of shrub-scrub and young forest (p = 0.09), and average amount of edge for emergent wetlands (p = 0.03) explained 40% of the variation in Painted Buntings counts. In the late decades average amount of edge on developed land (p = 0.04) and average amount of edge on emergent wetlands (p = 0.005) explained 35% of the variation in Painted Bunting counts. Large losses of agricultural land (proportion = 0.177 to 0.094), which was developed or converted to intensively managed pin plantations, may have reduced potential bunting breeding habitat. Shrub-scrub and young forest habitat was constant (proportion = 0.136 to 0.134) but did not affect mean counts of buntings in the late decades. Protected emergent wetlands remained constnat also from the early to late decades (proportion = 0.056 to 0.06) and may provide habitat to maintain a smaller Painted Bunting population. At this time, it's unclear how develped land, which is increasing (proportion = 0.036 to 0.088), may be affecting the Painted Bunting population in GS and SC.

  11. Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends

    PubMed Central

    Paprocki, Neil; Heath, Julie A.; Novak, Stephen J.

    2014-01-01

    Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975–2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs) were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus) and Golden Eagles (Aquila chrysaetos) showed the fastest rate of change, with 8.41 km yr−1 and 7.74 km yr−1 shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally change as

  12. Regional distribution shifts help explain local changes in wintering raptor abundance: implications for interpreting population trends.

    PubMed

    Paprocki, Neil; Heath, Julie A; Novak, Stephen J

    2014-01-01

    Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975-2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs) were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus) and Golden Eagles (Aquila chrysaetos) showed the fastest rate of change, with 8.41 km yr(-1) and 7.74 km yr(-1) shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally change as

  13. Surveillance of avian coronaviruses in wild bird populations of Korea.

    PubMed

    Kim, Hye-Ryoung; Oem, Jae-Ku

    2014-10-01

    We examined the role of wild birds in the epidemiology of avian coronaviruses by studying oropharyngeal swabs from 32 wild bird species. The 14 avian coronaviruses detected belonged to the gamma-coronaviruses and shared high nucleotide sequence identity with some previously identified strains in wild waterfowl, but not with infectious bronchitis viruses.

  14. Marine bird populations of Prince William Sound, Alaska, before and after the Exxon Valdez oil spill. Bird study number 2. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Klosiewski, S.P.; Laing, K.K.

    1994-06-01

    We estimated the summer and winter abundance of marine birds in Prince William Sound, Alaska, following the 1989 Exxon Valdez oil spill, examined changes in population size between pre-spill and post-spill surveys, and compared pre- to post-oil spill population trends in the oiled zone of the Sound relative to trends in the unoiled zone. Ninety-nine species of birds were observed on surveys. Estimated populations of 15 to 32 species/species groups demonstrated declines over the 17-19 year period between pre- and post-spill surveys. However, because of the long time period between surveys, we could not directly associate overall population declines with the oil spill.

  15. Effects of habitat change along Breeding Bird Survey routes in the central Appalachians on Cerulean Warbler population

    USGS Publications Warehouse

    McElhone, P.; Wood, P.W.; Dawson, D.

    2007-01-01

    The cerulean warbler (Dendroica cerulea) is one of the highest priority bird species in the eastern United States because populations have declined 4.3% annually during 1966?2005 based on Breeding Bird Survey (BBS) data. Habitat loss and fragmentation due to land use changes is thought to be one of the major factors contributing to the decline. BBS routes, the primary source for monitoring bird population trends, include 50 sampling stops every 0.8 km. Although data from BBS routes are extrapolated to determine regional trends in bird populations, it is important to understand the effects of habitat changes at the stop-level along BBS routes. Route-level analysis of habitat changes may mask important changes that are occurring at a smaller scale particularly for the cerulean warbler which displays several micro-scale habitat preferences. We are examining cerulean warbler habitat and population changes in its core breeding range of the Ohio Hills and Cumberland Plateau physiographic regions. We quantified land cover changes within 300 m of BBS routes in the core cerulean warbler breeding range of Ohio, West Virginia, and Kentucky by digitizing aerial photographs from two time periods: the 1980s and 2004. We also quantified land cover changes within 300 m of BBS routes with the National Land Cover Dataset (NLCD) from 1992 and 2001. The hand-digitized aerial photos will be compared with the NLCD to determine how similar the two methods are in quantifying land cover changes. We then compared stop-level land cover changes with stop level changes in cerulean warbler detections within the same time periods along the BBS routes. This will allow for a more detailed analysis of how well habitat changes along BBS routes reflect the changes in cerulean warbler populations.

  16. Climate change affects populations of northern birds in boreal protected areas.

    PubMed

    Virkkala, Raimo; Rajasärkkä, Ari

    2011-06-23

    Human land-use effects on species populations are minimized in protected areas and population changes can thus be more directly linked with changes in climate. In this study, bird population changes in 96 protected areas in Finland were compared using quantitative bird census data, between two time slices, 1981-1999 and 2000-2009, with the mean time span being 14 years. Bird species were categorized by distribution pattern and migratory strategy. Our results showed that northern bird species had declined by 21 per cent and southern species increased by 29 per cent in boreal protected areas during the study period, alongside a clear rise (0.7-0.8 °C) in mean temperatures. Distribution pattern was the main factor, with migratory strategy interacting in explaining population changes in boreal birds. Migration strategy interacted with distribution pattern so that, among northern birds, densities of both migratory and resident species declined, whereas among southern birds they both increased. The observed decline of northern species and increase in southern species are in line with the predictions of range shifts of these species groups under a warming climate, and suggest that the population dynamics of birds are already changing in natural boreal habitats in association with changing climate.

  17. Abundance-occupancy dynamics in a human dominated environment: linking interspecific and intraspecific trends in British farmland and woodland birds.

    PubMed

    Webb, Thomas J; Noble, David; Freckleton, Robert P

    2007-01-01

    1. Range size, population size and body size, the key macroecological variables, vary temporally both within and across species in response to anthropogenic and natural environmental change. However, resulting temporal trends in the relationships between these variables (i.e. macroecological patterns) have received little attention. 2. Positive relationships between the local abundance and regional occupancy of species (abundance-occupancy relationships) are among the most pervasive of all macroecological patterns. In the absence of formal predictions of how abundance-occupancy relationships may vary temporally, we outline several scenarios of how changes in abundance within species might affect interspecific patterns. 3. We use data on the distribution and abundance of 73 farmland and 55 woodland bird species in Britain over a 32-year period encompassing substantial habitat modification to assess the likelihood of these scenarios. 4. In both farmland and woodland habitats, the interspecific abundance-occupancy relationship changed markedly over the period 1968-99, with a significant decline in the strength of the relationship. 5. Consideration of intraspecific dynamics shows that this has been due to a decoupling of abundance and occupancy particularly in rare and declining species. Insights into the intraspecific processes responsible for the interspecific trend are obtained by analysis of temporal trends in the distribution of individuals between sites, which show patterns consistent with habitat quality declines. 6. This study shows that a profitable approach to ascertaining the nature of human impacts is to link intra- and interspecific processes. In the case of British farmland and woodland birds, changes to the environment lead to species-specific responses in large-scale distributions. These species-specific changes are the driver of the observed changes in the form and strength of the interspecific relationship.

  18. 1984 Population Trends for Washington State.

    ERIC Educational Resources Information Center

    Washington State Office of Financial Management, Olympia.

    As of April 1, 1984, Washington's population was estimated at 4,328,100, an increase of 43,000 over last year's population. This report provides data pertaining to the: official April 1, 1984 population and housing estimates for cities, towns, and counties and components of population change. The following special reports are also presented:…

  19. Estimating regional landbird populations from enhanced North American Breeding Bird Surveys

    USGS Publications Warehouse

    Twedt, Daniel J.

    2015-01-01

    Estimating the size of bird populations is central to effective conservation planning and prudent management. I updated estimated regional bird populations for the East Gulf Coastal Plain of Mississippi using data from 275 North American Breeding Bird Surveys from 2009 to 2013. However, regional bird populations estimated from count surveys of breeding birds may be biased due to lack of empirical knowledge of the distance at which a species is effectively detected and the probability of detecting a species if it is present. I used data recorded within two distance classes (0–50 m and >50–400 m) and three 1-min time intervals on 130 Breeding Bird Surveys to estimate detection probability and effective detection distance for 77 species. Incorporating these empirical estimates of detection probability and detection distance resulted in estimated regional populations for these species that were markedly greater than regional populations estimated without species-specific estimates of detection parameters. Using the same Breeding Bird Survey data, I also estimated probability of site occupancy for 66 species and extrapolated this to the proportion of area occupied in the East Gulf Coastal Plain of Mississippi. I combined the area occupied with the reported range of breeding territory size for 54 species to obtain independent estimates of regional bird populations. Although the true population of these species is unknown, estimated populations that incorporated empirical estimates of detection probability and detection distance were more likely to be within the range of independently estimated, occupancy-based, regional population estimates than were population estimates that lacked empirical detection and distance information.

  20. Pricing implications of trends in population mortality and underwriting effectiveness.

    PubMed

    Pokorski, Robert J

    2004-01-01

    Pricing actuaries try to anticipate insured lives mortality rates for decades into the future by considering historic relationships between population and insured lives mortality and trends in population mortality. The degree to which underwriting might decrease insured lives mortality relative to population mortality is of particular importance. A comparison of trends in population and insured mortality is presented to illustrate historic relationships. Two theories for future life expectancy trends are: 1) no foreseeable limit to life expectancy, and 2) life expectancy limited by biological forces. Factors that may increase or decrease the future effectiveness of underwriting are reviewed.

  1. Population trends of North American shorebirds based on the International Shorebird Survey

    USGS Publications Warehouse

    Howe, M.A.; Geissler, P.H.; Harrington, B.A.

    1989-01-01

    Shorebirds (Charadiiformes) are prime candidates for population decline because of their dependence on wetlands that are being lost at a rapid pace. Thirty-six of the 49 species of shorebirds that breed in North America spend most of the year in Latin America. Because populations of most species breed and winter at remote sites , it may be feasible to monitor their numbers at migration stopovers. In this study, we used statistical trend analysis methods, developed for the North American Breeding Bird Survey, to analyze data on shorebird populations during south-bound migration in the United States. Survey data were collected by volunteers in the International Shorebird Survey (ISS). Methodological concerns over both the ISS and the trend analysis procedures are discussed in detail and biological interpretations of the results are suggested.

  2. Population Trends and the Implications for Education.

    ERIC Educational Resources Information Center

    Hauser, Philip M.

    There are three developments which have profoundly affected mans' values, attitudes, social institutions, and behaviorisms. These are the population explosion, the population implosion, and population differentiation. These three developments are interrelated and are affected by accelerating rates of technological and social change. By reason of…

  3. 1988 Population Trends for Washington State.

    ERIC Educational Resources Information Center

    Washington State Office of Financial Management, Olympia.

    This statistical profile provides current demographic data for Washington State and its counties, incorporated cities and towns. Seventeen tables show population by age and sex; population for counties, incorporated cities and towns, and the state; components of population change; a rank order of total persons in incorporated cities and towns;…

  4. Contaminant effects on Great Lakes' fish-eating birds: a population perspective

    USGS Publications Warehouse

    Heinz, G.H.; Kendall, Ronald J.; Dickerson, Richard L.; Giesy, John P.; Suk, William P.

    1998-01-01

    Preventing environmental contaminants from reducing wildlife populations is the greatest concern in wildlife toxicology. In the Great Lakes, environmental contaminants have a history of reducing populations of many species of fish-eating birds. Endocrine effects may have contributed to declines in fish-eating bird populations, but the overriding harm was caused by DDE-induced eggshell thinning. Toxic effects may still be occurring today, but apparently they are not of a sufficient magnitude to depress populations of most fish-eating birds. Once DDE levels in the Great Lakes declined, eggshells of birds began to get thicker and reproductive success improved. Populations of double-crested cormorants (Phalacrocorax auritus) and ring-billed gulls (Larus delawarensis) have increased dramatically since the bans on DDT and other organochlorine pesticides. Bald eagles (Haliaeetus leucocephalus) are still not reproducing at a normal rate along the shores of the Great Lakes, but success is much improved compared to earlier records when eggshell thinning was worse. Other species, such as herring gulls (Larus argentatus) and black-crowned night-herons (Nycticorax nycticorax), seem to be having improved reproductive success, but data on Great Lakes'-wide population changes are incomplete. Reproductive success of common terns (Sterna hirundo), Caspian terns (Sterna caspia), and Forster's terns (Sterna forsteri) seems to have improved in recent years, but, again, data on population changes are not very complete, and these birds face many habitat related problems as well as contaminant problems. Although contaminants are still producing toxic effects, and these effects may include endocrine disfunction, fish-eating birds in the Great Lakes seem to be largely weathering these effects, at least as far as populations are concerned. A lack of obvious contaminant effects on populations of fish-eating birds in the Great Lakes, however, should not be equated with a lack of any harm to

  5. Reproduction and population levels of Peruvian Guano Birds, 1980 to 1986

    NASA Astrophysics Data System (ADS)

    Tovar, H.; GuilléN, V.; Cabrera, D.

    1987-12-01

    The three species of guano birds, guanay cormorant (Phalacrocorax bougainvillii), Peruvian booby (Sula variegate), and Peruvian pelican (Pelecanus occidentalis thagus), depend mainly on the Peruvian anchovy (Engraulis ringens) for sustenance. A naturally occurring limitation on the population size of these birds is the oceanographic phenomenon known as "El Niño". The industrialization of the anchovy fishery during the 1960s and 1970s has also affected seabird populations: The annual extraction of huge volumes offish has decreased the availability of food for the guano birds, causing large population fluctuations and considerable changes in the relative abundance of the birds. Because of its great intensity and duration, the 1982-1983 El Niño caused high avian mortality, depressing populations to levels from which they have not yet recovered.

  6. Global population collapse in a superabundant migratory bird and illegal trapping in China.

    PubMed

    Kamp, Johannes; Oppel, Steffen; Ananin, Alexandr A; Durnev, Yurii A; Gashev, Sergey N; Hölzel, Norbert; Mishchenko, Alexandr L; Pessa, Jorma; Smirenski, Sergey M; Strelnikov, Evgenii G; Timonen, Sami; Wolanska, Kolja; Chan, Simba

    2015-12-01

    Persecution and overexploitation by humans are major causes of species extinctions. Rare species, often confined to small geographic ranges, are usually at highest risk, whereas extinctions of superabundant species with very large ranges are rare. The Yellow-breasted Bunting (Emberiza aureola) used to be one of the most abundant songbirds of the Palearctic, with a very large breeding range stretching from Scandinavia to the Russian Far East. Anecdotal information about rapid population declines across the range caused concern about unsustainable trapping along the species' migration routes. We conducted a literature review and used long-term monitoring data from across the species' range to model population trend and geographical patterns of extinction. The population declined by 84.3-94.7% between 1980 and 2013, and the species' range contracted by 5000 km. Quantitative evidence from police raids suggested rampant illegal trapping of the species along its East Asian flyway in China. A population model simulating an initial harvest level of 2% of the population, and an annual increase of 0.2% during the monitoring period produced a population trajectory that matched the observed decline. We suggest that trapping strongly contributed to the decline because the consumption of Yellow-breasted Bunting and other songbirds has increased as a result of economic growth and prosperity in East Asia. The magnitude and speed of the decline is unprecedented among birds with a comparable range size, with the exception of the Passenger Pigeon (Ectopistes migratorius), which went extinct in 1914 due to industrial-scale hunting. Our results demonstrate the urgent need for an improved monitoring of common and widespread species' populations, and consumption levels throughout East Asia.

  7. Population trends in Malaysia: 1970-2010

    NASA Astrophysics Data System (ADS)

    Rashid, Saharani Abdul; Ghani, Puzziawati Ab; Daud, Noorizam

    2014-12-01

    The size of population in Malaysia had reached 28.3 million in 2010 and is expected to increase to 38.6 million in the next 30 years. This demographic milestone that is causing renewed attention to the challenges caused by population growth. This paper looks at the last 40 years of changes in Malaysia population structure due to the changes in demographic phenomenon using data obtained from the Department of Statistics Malaysia. The principal finding of this research indicates that population structure in Malaysia had changed dramatically from the year 1970 to 2010. At the same time, Malaysia has completed its demographic transition in less than four decades. The fall in fertility and mortality rates have led to an improvement in the life expectancy of the population which has resulted an ageing population in Malaysia.

  8. Temporally increasing spatial synchrony of North American temperature and bird populations

    NASA Astrophysics Data System (ADS)

    Koenig, Walter D.; Liebhold, Andrew M.

    2016-06-01

    The ecological impacts of modern global climate change are detectable in a wide variety of phenomena, ranging from shifts in species ranges to changes in community composition and human disease dynamics. So far, however, little attention has been given to temporal changes in spatial synchrony--the coincident change in abundance or value across the landscape--despite the importance of environmental synchrony as a driver of population trends and the central role of environmental variability in population rescue and extinction. Here we demonstrate that across North America, spatial synchrony of a significant proportion of 49 widespread North American wintering bird species has increased over the past 50 years--the period encompassing particularly intense anthropogenic effects in climate--paralleling significant increases in spatial synchrony of mean maximum air temperature. These results suggest the potential for increased spatial synchrony in environmental factors to be affecting a wide range of ecological phenomena. These effects are likely to vary, but for North American wildlife species, increased spatial synchrony driven by environmental factors may be the basis for a previously unrecognized threat to their long-term persistence in the form of more synchronized population dynamics reducing the potential for demographic rescue among interacting subpopulations.

  9. A method of studying wild bird populations by mist-netting and banding

    USGS Publications Warehouse

    Stamm, D.D.; Davis, D.E.; Robbins, C.S.

    1960-01-01

    1. Progress is reported toward development of a method of bird-population study based on mist-netting and banding. A definite pattern of arrangement and schedule of operation are presented. 2. Nets were operated for a total of 4200 net-hours during which 966 captures were made (23.0 birds per 100 net-hours). A total of 431 adult breeding birds were banded and 38 per cent of them were recaptured. 3. A breeding bird census was made simultaneously in the same area by the Williams spot-mapping technique. 4. Estimates of population by recapture agreed closely with the spot-mappmg census. 5. Some birds are demonstrated to have overlapping home-ranges much larger than their singing territories. 6. Recruitment and net-shyness distort recapture estimates of population .but the method allows detection and assessment of their influence in the population dealt with here. 7. The method produced integrated information on population density and dynamics, movement and behavior. 8. The procedure is especially well adapted to studies of disease agents in bird populations. 9. A simple scheme for description of the habitat in terms of relative abundance and frequency of occurrence of tree species was used.

  10. Winter marine bird and sea otter abundance of Prince William Sound, Alaska: Trends following the t/v Exxon Valdez oil spill from 1990-94. Restoration project 94159. Exxon Valdez oil spill restoration project final report

    SciTech Connect

    Agler, B.A.; Seiser, P.E.; Kendall, S.J.; Irons, D.B.

    1995-05-01

    We conducted small boat surveys to determine population abundance of marine birds and sea otters (Enhydra lutris) in Prince William Sound, Alaska during March 1994. We observed 45 bird and 8 mammal species in Prince William Sound, and we estimated that 320,470 + or - 63,640 marine birds were present. We estimated trends in the March population estimates from 1990-94 by determining whether estimates in the oiled zone changed at the same rate as those in the unoiled zone. For Prince William Sound as a whole, we also examined the population trends from 1990-94 using regression analyses. We found significant positive trends for harlequin duck (Histrionicus), goldeneye, merganser, bald eagle (Haliaeetus leucocephalus), black-legged kittiwake (Rissa tridactyla) and gull (Larus and Rissa spp.) populations. We also examined the relative abundance of marine bird species groups from 1972 to 1994. During March 1994, we estimated that the sea otter population was 7,746 + or - 2,073 otters. We found no difference in the rate of change between the oiled and unoiled zones from 1990-94, and there was no significant trend in the total number of sea otters in Prince William Sound from 1990-94.

  11. Global Population Trends: Challenges Facing World Leaders.

    ERIC Educational Resources Information Center

    Scommegna, Paola, Ed.

    This pamphlet explores the dynamics of world population, highlighting steps world leaders can take to address population problems and improve the lives of people worldwide. With jet-age transportation and electronic communication, economic and social interdependence of nations is greater than ever before and is likely to increase in the future.…

  12. 1987 Population Trends for Washington State.

    ERIC Educational Resources Information Center

    Washington State Office of Financial Management, Olympia.

    This statistical profile provides current demographic data for Washington State and is also broken down by counties, incorporated cities, and towns. Fifteen tables show population figures; components of population change; housing units by structure type; annexations, incorporations and municipal boundary changes; growth of households; estimates of…

  13. Developing accurate survey methods for estimating population sizes and trends of the critically endangered Nihoa Millerbird and Nihoa Finch.

    USGS Publications Warehouse

    Gorresen, P. Marcos; Camp, Richard J.; Brinck, Kevin W.; Farmer, Chris

    2012-01-01

    Point-transect surveys indicated that millerbirds were more abundant than shown by the striptransect method, and were estimated at 802 birds in 2010 (95%CI = 652 – 964) and 704 birds in 2011 (95%CI = 579 – 837). Point-transect surveys yielded population estimates with improved precision which will permit trends to be detected in shorter time periods and with greater statistical power than is available from strip-transect survey methods. Mean finch population estimates and associated uncertainty were not markedly different among the three survey methods, but the performance of models used to estimate density and population size are expected to improve as the data from additional surveys are incorporated. Using the pointtransect survey, the mean finch population size was estimated at 2,917 birds in 2010 (95%CI = 2,037 – 3,965) and 2,461 birds in 2011 (95%CI = 1,682 – 3,348). Preliminary testing of the line-transect method in 2011 showed that it would not generate sufficient detections to effectively model bird density, and consequently, relatively precise population size estimates. Both species were fairly evenly distributed across Nihoa and appear to occur in all or nearly all available habitat. The time expended and area traversed by observers was similar among survey methods; however, point-transect surveys do not require that observers walk a straight transect line, thereby allowing them to avoid culturally or biologically sensitive areas and minimize the adverse effects of recurrent travel to any particular area. In general, pointtransect surveys detect more birds than strip-survey methods, thereby improving precision and resulting population size and trend estimation. The method is also better suited for the steep and uneven terrain of Nihoa

  14. 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.

  15. World population. Past, present and future trends.

    PubMed

    Tarcă, M

    1990-01-01

    The history of, and prospect for, world population growth is presented in this study. The study is based mainly on data compiled and published in the last years by the population Division, the Food and Agriculture Organisation, the International Labour Organisation of the United Nations and the World Bank. The population of the world grew from about 300 million at the beginning of the Christian era to half billion in 1650 to one billion in 1800, to two billion in 1927, to three billion in 1960, to four billion in 1974, and to five billion in 1987. According to the medium variant of the United Nations projections the population of the world will reach six billion in 1988, seven billion in 2010, eight in 2023, nine in 2050, and ten around 2100. This number demonstrate the acceleration growth rate of world population which is explained be the theory of demographic transition. In 1985 developing countries had 3663 million persons or about three-fourths of the total population of the world. According to medium variant of projection the less-developed areas would increase their population to 4845 person by the end of the century or by four-fifths of the total. In contrast the developed countries would increase from 1174 million persons in 1985 to only 1277 million in 2000. Examining estimates of total and per capita income we must be impressed with the wide difference between the wealthiest and the poorest countries. The developed countries having the highest average incomes have undergone industrialization and modernization of the economy; the developing countries with lowest incomes are those with a predominance of agriculture in most cases. Statistical data shows that the disparity between the prosperity of the industrial countries and the poverty of the preindustrial countries was increasing in the last two decades.

  16. A comparison of landscapes occupied by increasing and decreasing populations of grassland birds.

    PubMed

    Veech, Joseph A

    2006-10-01

    For several decades, many grassland bird species have been declining in abundance throughout the Midwest and Great Plains regions of the United States, possibly due to loss of natural grassland habitat and increasing urbanization. I used 20 years of data from the North American Breeding Bird Survey to identify increasing, decreasing, and stable populations of 36 grassland-nesting bird species. I characterized the immediate landscape (circle with radius = 30 km) surrounding each population based on data from the National Resources Inventory. For each landscape, I calculated the proportion of eight different land-cover types: restored grassland, rangeland, cultivated cropland, pasture, noncultivated cropland, forest, urban land, and water. Using a null model, I compared landscape composition of increasing, decreasing, and stable populations. As predicted on the basis of the habitat preferences of grassland birds, increasing populations inhabited landscapes that contained significantly more restored grassland and rangeland but significantly less forest land and urban land than landscapes inhabited by decreasing populations. There was no significant difference in the proportion of cropland within the landscapes of increasing and decreasing populations, although cropland composed a large proportion (>30%) of many landscapes. In contrast, restored grassland typically composed a very small proportion (<3.5%) of total land cover, yet it was significantly more common in the landscapes of increasing than decreasing populations. These results suggest that grassland birds may benefit from government initiatives, such as the Conservation Reserve Program, that promote the restoration of grassland at a landscape scale.

  17. Status and trends of native birds in the Keauhou and Kilauea forest, Hawai`i Island.

    USGS Publications Warehouse

    Camp, Richard J.; Jacobi, James D.; Pratt, Thane K.; Gorresen, P. Marcos; Rubenstein, Tanya

    2010-01-01

    A Safe Harbor Agreement (SHA) is a voluntary arrangement between the U.S. Fish and Wildlife Service and non-Federal landowners to promote the protection, conservation, and recovery of listed species without imposing further land use restrictions on the landowners. Kamehameha Schools is considering entering into a SHA for their Keauhou and Kīlauea Forest lands on the island of Hawai′i. Bird surveys were conducted in 2008 to determine the current occurrence and density of listed species for the Keauhou and Kīlauea Forest, a prerequisite for establishing an agreement. Because of different management practices in the proposed SHA area we stratified the survey data into intact and altered forest strata. The listed passerines—′Akiapōlā′au (Hemignathus munroi), Hawai′i Creeper (Oreomystis mana), and Hawai′i ′Ākepa (Loxops coccineus)—occur in both strata but at low densities. The endangered ′Io (Hawaiian Hawk; Buteo solitarius) also occurs within both strata at low densities. This report was prepared for the U.S. Fish and Wildlife Service and Kamehameha Schools to provide information they can use to establish baseline levels for the SHA. In addition, we describe the status and trends of the non-listed native birds.

  18. Population Size and Decadal Trends of Three Penguin Species Nesting at Signy Island, South Orkney Islands.

    PubMed

    Dunn, Michael J; Jackson, Jennifer A; Adlard, Stacey; Lynnes, Amanda S; Briggs, Dirk R; Fox, Derren; Waluda, Claire M

    2016-01-01

    We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual

  19. Population Size and Decadal Trends of Three Penguin Species Nesting at Signy Island, South Orkney Islands

    PubMed Central

    Dunn, Michael J.; Jackson, Jennifer A.; Adlard, Stacey; Lynnes, Amanda S.; Briggs, Dirk R.; Fox, Derren; Waluda, Claire M.

    2016-01-01

    We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual

  20. A retrospective perspective: evaluating population changes by repeating historic bird surveys

    USGS Publications Warehouse

    Igl, Lawrence D.; Johnson, Douglas H.

    2005-01-01

    Acquiring an accurate picture of the changes in bird populations often involves a tradeoff between the time and effort required to complete the surveys and the number of years spent surveying the bird populations. An alternative approach to long-term monitoring efforts is to collect current data and contrast those with data collected earlier in a similar fashion on the same study site(s). To evaluate changes in bird populations, we repeated two extensive surveys, one in North Dakota (1967 vs. 1992-1993) and the other in the Platte River Valley of Nebraska (1979-1980 vs. 2001), where large areas of native vegetation had been converted to agriculture. We use these examples and others from the literature to illustrate the advantages and disadvantages of using historical data as a frame of reference for population changes.

  1. Breeding bird populations and habitat associations within the Savannah River Site (SRS).

    SciTech Connect

    Gauthreaux, Sidney, A.; Steven J. Wagner.

    2005-06-29

    Gauthreaux, Sidney, A., and Steven J. Wagner. 2005. Breeding bird populations and habitat associations within the Savannah River Site (SRS). Final Report. USDA Forest Service, Savannah River, Aiken, SC. 48 pp. Abstract: During the 1970's and 1980's a dramatic decline occurred in the populations of Neotropical migratory birds, species that breed in North America and winter south of the border in Central and South America and in the Caribbean. In 1991 an international initiative was mounted by U. S. governmental land management agencies, nongovernmental conservation agencies, and the academic and lay ornithological communities to understand the decline of Neotropical migratory birds in the Americas. In cooperation with the USDA Forest Service - Savannah River (FS - SR) we began 1992 a project directed to monitoring population densities of breeding birds using the Breeding Bird Census (BBC) methodology in selected habitats within the Savannah River Site SRS. In addition we related point count data on the occurrence of breeding Neotropical migrants and other bird species to the habitat data gathered by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service and data on habitat treatments within forest stands.

  2. U.S. Population Trends Break with Past.

    ERIC Educational Resources Information Center

    Beale, Calvin L.

    1985-01-01

    Examines and explains unexpected population trends since 1970: substantial rural and small-town growth, regional shifts to the South and West, lower birth rates, increased life expectancy, smaller household size, and population growth from immigration. Illustrates how demographic events offer classic examples of the difficulty of predicting human…

  3. Estimating trends in alligator populations from nightlight survey data

    USGS Publications Warehouse

    Fujisaki, Ikuko; Mazzotti, Frank J.; Dorazio, Robert M.; Rice, Kenneth G.; Cherkiss, Michael; Jeffery, Brian

    2011-01-01

    Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends of American alligators (Alligator mississippiensis) in subareas of Everglades wetlands in Florida using nightlight survey data. During 2001–2008, there were declining trends in abundance of small and/or medium sized animals in a majority of subareas, whereas abundance of large sized animals had either demonstrated an increased or unclear trend. For small and large sized class animals, estimated detection probability declined as water depth increased. Detection probability of small animals was much lower than for larger size classes. The declining trend of smaller alligators may reflect a natural population response to the fluctuating environment of Everglades wetlands under modified hydrology. It may have negative implications for the future of alligator populations in this region, particularly if habitat conditions do not favor recruitment of offspring in the near term. Our study provides a foundation to improve inferences made from nightlight surveys of other crocodilian populations.

  4. Estimating trends in alligator populations from nightlight survey data

    USGS Publications Warehouse

    Fujisaki, Ikuko; Mazzotti, F.J.; Dorazio, R.M.; Rice, K.G.; Cherkiss, M.; Jeffery, B.

    2011-01-01

    Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends of American alligators (Alligator mississippiensis) in subareas of Everglades wetlands in Florida using nightlight survey data. During 2001-2008, there were declining trends in abundance of small and/or medium sized animals in a majority of subareas, whereas abundance of large sized animals had either demonstrated an increased or unclear trend. For small and large sized class animals, estimated detection probability declined as water depth increased. Detection probability of small animals was much lower than for larger size classes. The declining trend of smaller alligators may reflect a natural population response to the fluctuating environment of Everglades wetlands under modified hydrology. It may have negative implications for the future of alligator populations in this region, particularly if habitat conditions do not favor recruitment of offspring in the near term. Our study provides a foundation to improve inferences made from nightlight surveys of other crocodilian populations. ?? 2011 US Government.

  5. From daily movements to population distributions: weather affects competitive ability in a guild of soaring birds

    PubMed Central

    Shepard, Emily L. C.; Lambertucci, Sergio A.

    2013-01-01

    The ability of many animals to access and exploit food is dependent on the ability to move. In the case of scavenging birds, which use soaring flight to locate and exploit ephemeral resources, the cost and speed of movement vary with meteorological factors. These factors are likely to modify the nature of interspecific interactions, as well as individual movement capacity, although the former are less well understood. We used aeronautical models to examine how soaring performance varies with weather within a guild of scavenging birds and the consequences this has for access to a common resource. Birds could be divided broadly into those with low wing loading that are more competitive in conditions with weak updraughts and low winds (black vultures and caracaras), and those with high wing loading that are well adapted for soaring in strong updraughts and moderate to high winds (Andean condors). Spatial trends in meteorological factors seem to confine scavengers with high wing loading to the mountains where they out-compete other birds; a trend that is borne out in worldwide distributions of the largest species. However, model predictions and carcass observations suggest that the competitive ability of these and other birds varies with meteorological conditions in areas where distributions overlap. This challenges the view that scavenging guilds are structured by fixed patterns of dominance and suggests that competitive ability varies across spatial and temporal scales, which may ultimately be a mechanism promoting diversity among aerial scavengers. PMID:24026471

  6. From daily movements to population distributions: weather affects competitive ability in a guild of soaring birds.

    PubMed

    Shepard, Emily L C; Lambertucci, Sergio A

    2013-11-06

    The ability of many animals to access and exploit food is dependent on the ability to move. In the case of scavenging birds, which use soaring flight to locate and exploit ephemeral resources, the cost and speed of movement vary with meteorological factors. These factors are likely to modify the nature of interspecific interactions, as well as individual movement capacity, although the former are less well understood. We used aeronautical models to examine how soaring performance varies with weather within a guild of scavenging birds and the consequences this has for access to a common resource. Birds could be divided broadly into those with low wing loading that are more competitive in conditions with weak updraughts and low winds (black vultures and caracaras), and those with high wing loading that are well adapted for soaring in strong updraughts and moderate to high winds (Andean condors). Spatial trends in meteorological factors seem to confine scavengers with high wing loading to the mountains where they out-compete other birds; a trend that is borne out in worldwide distributions of the largest species. However, model predictions and carcass observations suggest that the competitive ability of these and other birds varies with meteorological conditions in areas where distributions overlap. This challenges the view that scavenging guilds are structured by fixed patterns of dominance and suggests that competitive ability varies across spatial and temporal scales, which may ultimately be a mechanism promoting diversity among aerial scavengers.

  7. Golden eagle population trends in the western United States: 1968-2010

    USGS Publications Warehouse

    Millsap, Brian A.; Zimmerman, Guthrie S.; Sauer, John R.; Nielson, Ryan M.; Otto, Mark; Bjerre, Emily; Murphy, Robert K.

    2013-01-01

    In 2009, the United States Fish and Wildlife Service promulgated permit regulations for the unintentional lethal take (anthropogenic mortality) and disturbance of golden eagles (Aquila chrysaetos). Accurate population trend and size information for golden eagles are needed so agency biologists can make informed decisions when eagle take permits are requested. To address this need with available data, we used a log-linear hierarchical model to average data from a late-summer aerial-line-transect distance-sampling survey (WGES) of golden eagles in the United States portions of Bird Conservation Region (BCR) 9 (Great Basin), BCR 10 (Northern Rockies), BCR 16 (Southern Rockies/Colorado Plateau), and BCR 17 (Badlands and Prairies) from 2006 to 2010 with late-spring, early summer Breeding Bird Survey (BBS) data for the same BCRs and years to estimate summer golden eagle population size and trends in these BCRs. We used the ratio of the density estimates from the WGES to the BBS index to calculate a BCR-specific adjustment factor that scaled the BBS index (i.e., birds per route) to a density estimate. Our results indicated golden eagle populations were generally stable from 2006 to 2010 in the 4 BCRs, with an estimated average rate of population change of −0.41% (95% credible interval [CI]: −4.17% to 3.40%) per year. For the 4 BCRs and years, we estimated annual golden eagle population size to range from 28,220 (95% CI: 23,250–35,110) in 2007 to 26,490 (95% CI: 21,760–32,680) in 2008. We found a general correspondence in trends between WGES and BBS data for these 4 BCRs, which suggested BBS data were providing useful trend information. We used the overall adjustment factor calculated from the 4 BCRs and years to scale BBS golden eagle counts from 1968 to 2005 for the 4 BCRs and for 1968 to 2010 for the 8 other BCRs (without WGES data) to estimate golden eagle population size and trends across the western United States for the period 1968 to 2010. In general, we

  8. Population trends for common prairie pothole carnivores

    USGS Publications Warehouse

    Greenwood, Raymond J.; Sovada, Marsha A.; Mac, M.J.; Opler, P.A.; Puckett Haecker, C. E.; Doran, P.D.

    1998-01-01

    Since settlement of the prairie pothole region of the northern Great Plains by Europeans in the late 1800’s, carnivore populations have changed considerably—mostly due to habitat alteration and humaninflicted mortality. At least 19 species of carnivorous mammals once occurred in the prairie pothole region (Jones et al. 1983). Presently, only eight are common throughout the region—coyote, red fox, raccoon, American badger, striped skunk, mink, ermine, and long-tailed weasel (Sargeant et al. 1993). Other species that occur locally or intermittently are mountain lion, lynx, bobcat, gray wolf, gray fox, swift fox, spotted skunk, and least weasel. Grizzly bears, wolverines, and river otters once occurred in the region but are now extirpated. Competition among species affects the distribution of coyotes, wolves, and foxes (Carbyn 1982; Rudzinski et al. 1982; Sargeant et al. 1987; Bailey 1992). These larger canids are keystone species that suppress the distribution of smaller canids (Johnson and Sargeant 1977; Dekker 1989; Johnson et al. 1989).

  9. Estimates of population change in selected species of tropical birds using mark-recapture data

    USGS Publications Warehouse

    Brawn, J.; Nichols, J.D.; Hines, J.E.; Nesbitt, J.

    2000-01-01

    The population biology of tropical birds is known for a only small sample of species; especially in the Neotropics. Robust estimates of parameters such as survival rate and finite rate of population change (A) are crucial for conservation purposes and useful for studies of avian life histories. We used methods developed by Pradel (1996, Biometrics 52:703-709) to estimate A for 10 species of tropical forest lowland birds using data from a long-term (> 20 yr) banding study in Panama. These species constitute a ecologically and phylogenetically diverse sample. We present these estimates and explore if they are consistent with what we know from selected studies of banded birds and from 5 yr of estimating nesting success (i.e., an important component of A). A major goal of these analyses is to assess if the mark-recapture methods generate reliable and reasonably precise estimates of population change than traditional methods that require more sampling effort.

  10. Contributions of the Conservation Reserve Program to populations of breeding birds in North Dakota

    USGS Publications Warehouse

    Johnson, D.H.; Igl, L.D.

    1995-01-01

    Previous studies have shown that habitat provided by the Conservation Reserve Program (CRP), a feature of the 1985 farm bill, is used by many birds. The present study quantitatively assesses the importance of the CRP by estimating changes in breeding-bird populations of North Dakota projected if CRP land would revert to cultivation. Of 18 species that were common in CRP or crop fields or both, 12 were more abundant in CRP habitats. Six of these species had suffered significant population declines during 1967-1990, according to the North American Breeding Bird Survey. In contrast, none of the six species that were more common in cropland than in CRP fields had declined significantly. Termination of the Conservation Reserve Program and a return of enrolled land to cultivation is projected to cause population declines in North Dakota exceeding 17% for Sedge wren (Cistothorus platensis), Grasshopper sparrow (Ammodramus savannarum), Savannah Sparrow (Passerculus sandwichensis), Dickcissel (Spiza americana), and Lark Bunting (Calamospiza melanocorys).

  11. Living in the city: resource availability, predation, and bird population dynamics in urban areas.

    PubMed

    Anderies, John M; Katti, Madhusudan; Shochat, Eyal

    2007-07-07

    This article explores factors that shape population structure in novel environments that have received scant theoretical attention: cities. Urban bird populations exhibit higher densities and lower diversity. Some work suggests this may result from lower predation pressure and more predictable and abundant resources. These factors may lead to populations with few winners and many losers regarding access to food, body condition, and reproductive success. We explore these hypotheses with an individual-energy-based competition model with two phenotypes of differing foraging ability. We show that low frequency resource fluctuations favor strong competitors and vice versa. We show that low predation skews equilibrium populations in favor of weak competitors and vice versa. Increasing the time between resource pulses can thus shift population structure from weak to strong competitor dominance. Given recent evidence for more constant resource input and lower predation in urban areas, the model helps understand observed urban bird population structure.

  12. Dynamics of a recovering Arctic bird population: the importance of climate, density dependence, and site quality.

    PubMed

    Bruggeman, Jason E; Swem, Ted; Andersen, David E; Kennedy, Patricia L; Nigro, Debora

    2015-10-01

    Intrinsic and extrinsic factors affect vital rates and population-level processes, and understanding these factors is paramount to devising successful management plans for wildlife species. For example, birds time migration in response, in part, to local and broadscale climate fluctuations to initiate breeding upon arrival to nesting territories, and prolonged inclement weather early in the breeding season can inhibit egg-laying and reduce productivity. Also, density-dependent regulation occurs in raptor populations, as territory size is related to resource availability. Arctic Peregrine Falcons (Falco peregrinus tundrius; hereafter Arctic peregrine) have a limited and northern breeding distribution, including the Colville River Special Area (CRSA) in the National Petroleum Reserve-Alaska, USA. We quantified influences of climate, topography, nest productivity, prey habitat, density dependence, and interspecific competition affecting Arctic peregrines in the CRSA by applying the Dail-Madsen model to estimate abundance and vital rates of adults on nesting cliffs from 1981 through 2002. Arctic peregrine abundance increased throughout the 1980s, which spanned the population's recovery from DDT-induced reproductive failure, until exhibiting a stationary trend in the 1990s. Apparent survival rate (i.e., emigration; death) was negatively correlated with the number of adult Arctic peregrines on the cliff the previous year, suggesting effects of density-dependent population regulation. Apparent survival and arrival rates (i.e., immigration; recruitment) were higher during years with earlier snowmelt and milder winters, and apparent survival was positively correlated with nesting season maximum daily temperature. Arrival rate was positively correlated with average Arctic peregrine productivity along a cliff segment from the previous year and initial abundance was positively correlated with cliff height. Higher cliffs with documented higher productivity (presumably

  13. Changes in breeding bird populations in North Dakota: 1967 to 1992-93

    USGS Publications Warehouse

    Igl, L.D.; Johnson, D.H.

    1997-01-01

    We compared breeding bird populations in North Dakota using surveys conducted in 1967 and 1992-93. In decreasing order, the five most frequently occurring species were Horned Lark (Eremophila alpestris), Brown-headed Cowbird (Molothrus ater), Western Meadowlark (Sturnella neglecta), Red-winged Blackbird (Agelaius phoeniceus), and Eastern Kingbird (Tyrannus tyrannus). The five most abundant species--Horned Lark, Chestnut-collared Longspur (Calcarius ornatus), Red-winged Blackbird, Western Meadowlark, and Brown-headed Cowbird-accounted for 31-41% of the estimated statewide breeding bird population in the three years. Although species composition remained relatively similar among years, between-year patterns in abundance and frequency varied considerably among species. Data from this survey and the North American Breeding Bird Survey indicated that species exhibiting significant declines were primarily grassland- and wetland-breeding birds, whereas species exhibiting significant increases primarily were those associated with human structures and woody vegetation. Population declines and increases for species with similar habitat associations paralleled breeding habitat changes, providing evidence that factors on the breeding grounds are having a detectable effect on breeding birds in the northern Great Plains.

  14. Climate change and the risks associated with delayed breeding in a tropical wild bird population.

    PubMed

    Senapathi, Deepa; Nicoll, Malcolm A C; Teplitsky, Celine; Jones, Carl G; Norris, Ken

    2011-11-07

    There is growing evidence of changes in the timing of important ecological events, such as flowering in plants and reproduction in animals, in response to climate change, with implications for population decline and biodiversity loss. Recent work has shown that the timing of breeding in wild birds is changing in response to climate change partly because individuals are remarkably flexible in their timing of breeding. Despite this work, our understanding of these processes in wild populations remains very limited and biased towards species from temperate regions. Here, we report the response to changing climate in a tropical wild bird population using a long-term dataset on a formerly critically endangered island endemic, the Mauritius kestrel. We show that the frequency of spring rainfall affects the timing of breeding, with birds breeding later in wetter springs. Delays in breeding have consequences in terms of reduced reproductive success as birds get exposed to risks associated with adverse climatic conditions later on in the breeding season, which reduce nesting success. These results, combined with the fact that frequency of spring rainfall has increased by about 60 per cent in our study area since 1962, imply that climate change is exposing birds to the stochastic risks of late reproduction by causing them to start breeding relatively late in the season.

  15. Estimating population change from count data: Application to the North American Breeding Bird Survey

    USGS Publications Warehouse

    Link, William A.; Sauer, John R.

    1998-01-01

    For birds and many other animal taxa, surveys that collect count data form a primary source of information on population change. Because counts are only indices to population size, care must be taken in using them in analyses of population change. Temporal or geographic differences in the proportion of animals counted can be misinterpreted as differences in population size. Therefore, temporally or geographically varying factors that influence the proportion of animals counted must be incorporated as covariables in the analysis of population parameters from count data. We describe the North American Breeding Bird Survey (BBS) for illustration. The BBS is a major, landscape-level survey of birds in North America; it is typical of many count surveys, in that the same sample units (survey routes) are sampled each year, and change is modeled on these routes over time. We identify covariables related to observer ability, the omission of which can bias estimation of population change from BBS data. Controlling for observer effects or other potential sources of confounding requires the specification of models relating counts to population size. We begin with a partial model specification relating expected counts to population sizes; we describe estimators currently in use in relation to this partial specification. Additional assumptions lead to a class of over-dispersed multinomial models, for which we describe estimators of population change and procedures for parsimonious model selection. We illustrate the use of over-dispersed multinomial models by an application to data for Carolina Wren (Thryothorus ludovicianus).

  16. Trends in spawning populations of Pacific anadromous salmonids

    USGS Publications Warehouse

    Konkel, G.W.; McIntyre, J.D.

    1987-01-01

    Annual escapement records for 1968-1984 for five species of Pacific salmon-chinook (Oncorhynchus tshawytscha), coho (O. kisutch), sockeye (O. nerka), pink (O. gorbuscha), and chum (O. keta)—and steelhead (Salmo gairdneri) were obtained from published and unpublished sources and organized in a computer database. More than 25,500 escapement records were obtained for more than 1,100 locations throughout Alaska, Washington, Idaho, Oregon, and California. Escapement trends for naturally reproducing populations for which data were available for at least 7 years from 1968 to 1984 and at least 4 years from 1975 to 1984 were analyzed by linear regression. Significant trends were observed in about 30% of the 886 populations examined. Trends were summarized by species for three geographic regions in Alaska and four in the Pacific Northwest (including California). For chinook, sockeye, and pink salmon, trends were predominantly increasing in the Alaska regions and either lacking or predominantly decreasing in most of the Pacific Northwest regions; for coho and chum salmon, trends were predominantly decreasing in one or more Alaska regions as well as in most of the Pacific Northwest regions. For steelhead, too few populations were examined to enable us to characterize trends throughout their range. Among the 657 salmonid populations excluded from the trend analysis because the data sets were incomplete, 13 (of which 2 were in Alaska) declined to zero during the period of analysis. For coho, sockeye, pink, and chum salmon and steelhead, major data gaps were revealed by a comparison of the geographic distribution of escapement records with the spawning distribution of the species. For chinook salmon, escapement records were more geographically representative of the spawning distribution.

  17. Testing the environmental Kuznets curve hypothesis with bird populations as habitat-specific environmental indicators: evidence from Canada.

    PubMed

    Lantz, Van; Martínez-Espiñeira, Roberto

    2008-04-01

    The traditional environmental Kuznets curve (EKC) hypothesis postulates that environmental degradation follows an inverted U-shaped relationship with gross domestic product (GDP) per capita. We tested the EKC hypothesis with bird populations in 5 different habitats as environmental quality indicators. Because birds are considered environmental goods, for them the EKC hypothesis would instead be associated with a U-shaped relationship between bird populations and GDP per capita. In keeping with the literature, we included other variables in the analysis-namely, human population density and time index variables (the latter variable captured the impact of persistent and exogenous climate and/or policy changes on bird populations over time). Using data from 9 Canadian provinces gathered over 37 years, we used a generalized least-squares regression for each bird habitat type, which accounted for the panel structure of the data, the cross-sectional dependence across provinces in the residuals, heteroskedasticity, and fixed- or random-effect specifications of the models. We found evidence that supports the EKC hypothesis for 3 of the 5 bird population habitat types. In addition, the relationship between human population density and the different bird populations varied, which emphasizes the complex nature of the impact that human populations have on the environment. The relationship between the time-index variable and the different bird populations also varied, which indicates there are other persistent and significant influences on bird populations over time. Overall our EKC results were consistent with those found for threatened bird species, indicating that economic prosperity does indeed act to benefit some bird populations.

  18. Recent status and trends of the land bird avifauna on Saipan, Mariana Islands, with emphasis on the endangered Nightingale Reed-warbler Acrocephalus luscinia

    USGS Publications Warehouse

    Camp, R.J.; Pratt, T.K.; Marshall, A.P.; Amidon, F.; Williams, L.L.

    2009-01-01

    The avifauna of the Mariana Islands, an archipelago in the western Pacific, faces the threats of rapid economic development and the spread of non-native species, particularly a devastating predator, Brown Tree Snake Boiga irregularis. In this paper, we examine the status and trends of the land bird fauna of Saipan Island based on three island-wide surveys conducted in 1982, 1997, and 2007. During this period, the human population on Saipan increased more than four-fold and much of the island has been developed. The surveys employed standard point-transect methods based on Distance Sampling. Remarkably, we found nearly all species of land birds - 11 native species and three introduced species - to be common or abundant. The exception was the Micronesian Megapode Megapodius laperouse, a historically rare species that was not observed on the 2007 survey, although it does persist on Saipan and other Mariana islands. A comparison of species densities among the three surveys showed that seven species, mainly fruit and seed-eaters, had increased and three species of insectivorous birds had decreased - Rufous Fantail Rhipidura rufifrons, Nightingale Reed-warbler Acrocephalus luscinia, and Golden White-eye Cleptornis marchei. Of these three, Nightingale Reed-warbler is listed as Endangered on the IUCN Red List and as an Endangered Species by the U.S. Fish and Wildlife Service. Reed-warbler densities on Saipan decreased by more than half between 1982 and 2007. Although point transect sampling worked well for this species, density estimates and trends assessment could be improved by reallocating sampling stations among habitats and by more frequent sampling. ?? BirdLife International 2009.

  19. Predatory bird populations in the east Mojave Desert, California

    USGS Publications Warehouse

    Knight, R.L.; Camp, R.J.; Boarman, W.I.; Knight, H.A.L.

    1999-01-01

    We surveyed 7 species of predatory birds weekly during a 12-month period (December 1992 through November 1993) in the east Mojave Desert, California. The Common Raven (Corvus corax) was the most frequently observed species with an average of 6.9 sightings per 100 km. Turkey Vultures (Cathartes aura), Red-tailed Hawks (Buteo jamaicensis), Loggerhead Shrikes (Lanius ludovicianus), American Kestrels (Falco sparverius), Golden Eagles (Aquila chrysaetos), and Prairie Falcons (Falco mexicanus) were seen in decreasing order of frequency of observation through the study period. Ravens, Red-tailed Hawks, Loggerhead Shrikes, American Kestrels, and Prairie Falcons were seen throughout the year. Turkey Vultures were not present during winter months, while Golden Eagles were seen only during November and December. Turkey Vultures, Red-tailed Hawks, and ravens were most numerous on agricultural lands, while Loggerhead Shrikes were most Common at urban areas. Raven numbers increased with increasing number of linear rights-of-way parallel to the survey route. Perching was the most common behavior type, although Turkey Vultures and ravens were often observed soaring, flying, or standing on the ground near highways. Transmission powerline towers and telephone poles were used as perch sites disproportionately to availability.

  20. Marked host specificity and lack of phylogeographic population structure of Campylobacter jejuni in wild birds.

    PubMed

    Griekspoor, Petra; Colles, Frances M; McCarthy, Noel D; Hansbro, Philip M; Ashhurst-Smith, Chris; Olsen, Björn; Hasselquist, Dennis; Maiden, Martin C J; Waldenström, Jonas

    2013-03-01

    Zoonotic pathogens often infect several animal species, and gene flow among populations infecting different host species may affect the biological traits of the pathogen including host specificity, transmissibility and virulence. The bacterium Campylobacter jejuni is a widespread zoonotic multihost pathogen, which frequently causes gastroenteritis in humans. Poultry products are important transmission vehicles to humans, but the bacterium is common in other domestic and wild animals, particularly birds, which are a potential infection source. Population genetic studies of C. jejuni have mainly investigated isolates from humans and domestic animals, so to assess C. jejuni population structure more broadly and investigate host adaptation, 928 wild bird isolates from Europe and Australia were genotyped by multilocus sequencing and compared to the genotypes recovered from 1366 domestic animal and human isolates. Campylobacter jejuni populations from different wild bird species were distinct from each other and from those from domestic animals and humans, and the host species of wild bird was the major determinant of C. jejuni genotype, while geographic origin was of little importance. By comparison, C. jejuni differentiation was restricted between more phylogenetically diverse farm animals, indicating that domesticated animals may represent a novel niche for C. jejuni and thereby driving the evolution of those bacteria as they exploit this niche. Human disease is dominated by isolates from this novel domesticated animal niche.

  1. Seasonal distribution of bird populations at the Patuxent Research Refuge

    USGS Publications Warehouse

    Hoffman, D.J.; Henny, C.J.; Hill, E.F.; Keith, J.A.; Grove, R.A.

    2000-01-01

    High concentrations of mercury from past mining activities have accumulated in the food chain of fish-eating birds nesting along the mid to lower Carson River. Activities of nine plasma and tissue enzymes, and concentrations of other plasma and tissue constituents were measured for black-crowned night-heron, Nycticorax nycticorax, (BCNH) and snowy egret, Egretta thula, (SE) nestlings from two high mercury sites and one low mercury site. Geometric mean blood Hg concentrations for BCNHs at the high mercury sites were 2.6 and 2.8 ppm (ww) and 0.6 ppm at the low mercury site. Blood concentrations for SEs were 3.6 and 1.9 ppm at the high mercury sites and 0.7 ppm at the low mercury site. In BCNHs plasma glutathione peroxidase (GSH peroxidase) activity was lower in both high mercury sites relative to the low mercury site. Butyryl cholinesterase (BuChe), ALT, glutathione reductase (GSSG-reductase) and LDH-L activities were lower in one high mercury site. In SEs significant differences were lower BuChe and LDH-L, but elevated GGT activities. Evidence of renal stress in both species at high mercury sites included increased plasma uric acid, blood urea nitrogen, and creatinine concentrations as well as oxidative stress in the kidney tissue itself where oxidized glutathione increased. A number of the mercury site-related effects, including decreased plasma GSH-peroxidase and hepatic G-6-PDH activities, higher GSSG-reductase activity, and lower hepatic concentrations of reduced thiols have been reported in methylmercury feeding studies with great egrets and mallards. These findings suggest the utility of herons and egrets for monitoring mercury sites.

  2. Habitat-Specific Population Growth of a Farmland Bird

    PubMed Central

    Arlt, Debora; Forslund, Pär; Jeppsson, Tobias; Pärt, Tomas

    2008-01-01

    Background To assess population persistence of species living in heterogeneous landscapes, the effects of habitat on reproduction and survival have to be investigated. Methodology/Principal Findings We used a matrix population model to estimate habitat-specific population growth rates for a population of northern wheatears Oenanthe oenanthe breeding in farmland consisting of a mosaic of distinct habitat (land use) types. Based on extensive long-term data on reproduction and survival, habitats characterised by tall field layers (spring- and autumn-sown crop fields, ungrazed grasslands) displayed negative stochastic population growth rates (log λs: −0.332, −0.429, −0.168, respectively), that were markedly lower than growth rates of habitats characterised by permanently short field layers (pastures grazed by cattle or horses, and farmyards, log λs: −0.056, +0.081, −0.059). Although habitats differed with respect to reproductive performance, differences in habitat-specific population growth were largely due to differences in adult and first-year survival rates, as shown by a life table response experiment (LTRE). Conclusions/Significance Our results show that estimation of survival rates is important for realistic assessments of habitat quality. Results also indicate that grazed grasslands and farmyards may act as source habitats, whereas crop fields and ungrazed grasslands with tall field layers may act as sink habitats. We suggest that the strong decline of northern wheatears in Swedish farmland may be linked to the corresponding observed loss of high quality breeding habitat, i.e. grazed semi-natural grasslands. PMID:18714351

  3. The effects of predation by wading birds (Ardeidae) and blue crabs ( Callinectes sapidus) on the population size structure of the common mummichog, Fundulus heteroclitus

    NASA Astrophysics Data System (ADS)

    Kneib, R. T.

    1982-02-01

    Preliminary observations suggested that predation by herons and egretsaffected the size structure of a mummichog ( Fundulus heteroclitus) population in Tar Landing Marsh, North Carolina. The hypothesis was tested by placing 300 mummichogs represented equally in three size classes into each half of an enclosed, divided, high marsh pool. Nylon cord was strung in a grid over one side to inhibit predation by wading birds. Although mummichog losses were higher in the side of the pool which was open to bird predation, the same trend in size-specific losses also occurred in the bird-exclusion side. Repeating the experiment after the removal of several blue crabs ( Callinectes sapidus) improved mummichog survivorship and suggested that crabs and not birds were responsible for the fish losses previously observed. In a final experiment, birds were excluded and crabs were removed from one side but added to the other side of the pool. After 24 days losses due to C. sapidus occurred in all mummichog size classes, but size-specific predation by blue crabs produced the highest losses (90%) among the largest (>70 mm total length) fish. Blue crab predation on mummichog populations may influence the community structure of salt marsh infauna and may also function in the movement of marsh production to open coastal waters.

  4. The Natural Reservoirs of Salmonella Enteritidis in Populations of Wild Birds

    PubMed Central

    Obukhovska, Olga

    2013-01-01

    Objective The aim of our study was to identify possible natural reservoirs of Salmonella Enteritidis among wild birds. Introduction Salmonella Enteritidis is dangerous for human due the reason of toxicoinfaction. These pathogen demonstrate high virulence for small children and people with chronic pathologies and can causes people die. The main source of infection to humans is birds (poultry and wild). Wild birds represent the natural reservoir of same bacterial pathogens. It is known that Salmonella can occupy an intestinal tract of birds. This colonization in general is constant, sometimes proceeds with an alternating fever, and usually, without clinical signs. Infected birds can transmit pathogens to other isolates in close contact. This usually occurs on the nesting during seasonal migrations. In the southern region of Ukraine are several points of intersection of migration routes of wild birds on the way from Europe to Africa and Asia (National Park “Askania Nova”and others). Methods The study was conducted in populations of wild birds in National Park “Askania Nova” and peninsula “Arabat arrow” (the Azov Sea coast). From bird selected samples of blood serum and egg yolks for research in serum plate agglutination test (SPA) and litter samples for bacteriological research. Results The serological monitoring in populations of wild waterfowl in National Park “Askania Nova” (Ichthyaetus relictus, Sterna nilotica, Sterna herundo, Casarca ferruginea) has shown the presence of seropozitive individuals in adult birds (average 18%) and egg yolks (avarrage 12%). The bacteriological investigations confirmed circulation of Salmonella in this group of birds. 32.3% of all bacterial pathogens was Salmonella and more then half of them was the reprezentatives of serovar Salmonella Enteritidis. Similar studies were conducted on territory of peninsula “Arabat arrow” (the Azov Sea coast). The serological monitoring among of wild waterfowl (Ardea cinerea, Sterna

  5. Very Low Population Structure in a Highly Mobile and Wide-Ranging Endangered Bird Species

    PubMed Central

    Kvistad, Lynna; Ingwersen, Dean; Pavlova, Alexandra; Bull, James K.; Sunnucks, Paul

    2015-01-01

    The loss of biodiversity following fragmentation and degradation of habitat is a major issue in conservation biology. As competition for resources increases following habitat loss and fragmentation, severe population declines may occur even in common, highly mobile species; such demographic decline may cause changes within the population structure of the species. The regent honeyeater, Anthochaera phrygia, is a highly nomadic woodland bird once common in its native southeast Australia. It has experienced a sharp decline in abundance since the late 1970s, following clearing of large areas of its preferred habitat, box-ironbark woodland, within the last 200 years. A captive breeding program has been established as part of efforts to restore this species. This study used genetic data to examine the range-wide population structure of regent honeyeaters, including spatial structure, its change through time, sex differences in philopatry and mobility, and genetic differences between the captive and wild populations. There was low genetic differentiation between birds captured in different geographic areas. Despite the recent demographic decline, low spatial structure appears to have some temporal consistency. Both sexes appear to be highly mobile, and there does not seem to be significant genetic differentiation between the captive and wild populations. We conclude that management efforts for survival of this species, including habitat protection, restoration, and release of captive-bred birds into the wild, can treat the species as effectively a single genetic population. PMID:26649426

  6. Very Low Population Structure in a Highly Mobile and Wide-Ranging Endangered Bird Species.

    PubMed

    Kvistad, Lynna; Ingwersen, Dean; Pavlova, Alexandra; Bull, James K; Sunnucks, Paul

    2015-01-01

    The loss of biodiversity following fragmentation and degradation of habitat is a major issue in conservation biology. As competition for resources increases following habitat loss and fragmentation, severe population declines may occur even in common, highly mobile species; such demographic decline may cause changes within the population structure of the species. The regent honeyeater, Anthochaera phrygia, is a highly nomadic woodland bird once common in its native southeast Australia. It has experienced a sharp decline in abundance since the late 1970s, following clearing of large areas of its preferred habitat, box-ironbark woodland, within the last 200 years. A captive breeding program has been established as part of efforts to restore this species. This study used genetic data to examine the range-wide population structure of regent honeyeaters, including spatial structure, its change through time, sex differences in philopatry and mobility, and genetic differences between the captive and wild populations. There was low genetic differentiation between birds captured in different geographic areas. Despite the recent demographic decline, low spatial structure appears to have some temporal consistency. Both sexes appear to be highly mobile, and there does not seem to be significant genetic differentiation between the captive and wild populations. We conclude that management efforts for survival of this species, including habitat protection, restoration, and release of captive-bred birds into the wild, can treat the species as effectively a single genetic population.

  7. The dynamics, transmission, and population impacts of avian malaria in native hawaiian birds: A modeling approach

    USGS Publications Warehouse

    Samuel, M.D.; Hobbelen, P.H.F.; Decastro, F.; Ahumada, J.A.; Lapointe, D.A.; Atkinson, C.T.; Woodworth, B.L.; Hart, P.J.; Duffy, D.C.

    2011-01-01

    We developed an epidemiological model of avian malaria (Plasmodium relictum) across an altitudinal gradient on the island of Hawaii that includes the dynamics of the host, vector, and parasite. This introduced mosquito-borne disease is hypothesized to have contributed to extinctions and major shifts in the altitudinal distribution of highly susceptible native forest birds. Our goal was to better understand how biotic and abiotic factors influence the intensity of malaria transmission and impact on susceptible populations of native Hawaiian forest birds. Our model illustrates key patterns in the malaria-forest bird system: high malaria transmission in low-elevation forests with minor seasonal or annual variation in infection;episodic transmission in mid-elevation forests with site-to-site, seasonal, and annual variation depending on mosquito dynamics;and disease refugia in high-elevation forests with only slight risk of infection during summer. These infection patterns are driven by temperature and rainfall effects on parasite incubation period and mosquito dynamics across an elevational gradient and the availability of larval habitat, especially in mid-elevation forests. The results from our model suggest that disease is likely a key factor in causing population decline or restricting the distribution of many susceptible Hawaiian species and preventing the recovery of other vulnerable species. The model also provides a framework for the evaluation of factors influencing disease transmission and alternative disease control programs, and to evaluate the impact of climate change on disease cycles and bird populations. ??2011 by the Ecological Society of America.

  8. Effects of fire on bird populations in mixed-grass prairie: Chapter 8

    USGS Publications Warehouse

    Johnson, Douglas H.; Knopf, F.L.; Samson, F.B.

    1997-01-01

    The mixed-grass prairie is one of the largest ecosystems in North America, originally covering about 69 million hectares (Bragg and Steuter 1995). Although much of the natural vegetation has been replaced by cropland and other uses (Samson and Knopf 1994, Bragg and Steuter 1995), significant areas have been preserved in national wildlife refuges, waterfowl production areas, state game management areas, and nature preserves. Mixed-grass prairie evolved with fire (Bragg 1995), and fire is frequently used as a management tool for prairie (Berkey et al. 1993). Much of the mixed-grass prairie that has been protected is managed to enhance the reproductive success of waterfowl and other gamebirds, but nongame birds now are receiving increasing emphasis. Despite the importance of the area to numerous species of birds and the aggressive management applied to many sites, relatively little is known about the effects of fire on the suitability of mixed-grass prairie for breeding birds. Several studies have examined effects of fire on breeding birds in the tallgrass prairie (e.g., Tester and Marshall 1961, Eddleman 1974, Halvorsen and Anderson 1983, Westenmeier and Buhnerkempe 1983, Zimmerman 1992, Herkert 1994), in western sagebrush grasslands (Peterson and Best 1987), and in shrubsteppe (Bock and Bock 1987). Studies of fire effects in the mixed-grass prairie are limited. Huber and Steuter (1984) examined the effects on birds during the breeding season following an early-May prescribed burn on a 122-ha site in South Dakota. They contrasted the bird populations on that site to those on a nearby 462-ha unburned site that had been lightly grazed by bison (Bison bison). Pylypec (1991) monitored breeding bird populations occurring in fescue prairies of Canada on a single 12.9-ha burned area and on an adjacent 5.6-ha unburned fescue prairie for three years after a prescribed burn. This chapter describes the effects of prescribed fire on common terrestrial birds at a mixed

  9. Comparison of neotropical winter bird populations in isolated patches versus extensive forest

    USGS Publications Warehouse

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.; Colon, J.; Espinoza, F.; Rodriguez, J.; Sutton, R.; Vargas, T.

    1987-01-01

    Wintering birds were captured with mist nets at 12 pairs of forested sites in the New World tropics in 1984 and 1985 to compare populations in small isolated woodlands (generally 5-50 ha) with those in extensive forests (> 1,000 ha). Net-hours of effort were similar in large and small sites, as were total birds captured and banded, but species composition was very different. Members of the Todidae, Dendrocolaptidae, Formicariidae and Thraupinae were significantly more common in extensive forest than in small isolated tracts, indicating that these birds are especially vulnerable to effects of forest fragmentation. However, in winter many species of North American migrants, even species that are restricted to extensive forest during the breeding season, were just as common in small forest fragments as in extensive forest. A high percentage of the North American migrants banded in January 1984 (40 to 50 % for some species) were recaptured in 1985.

  10. [Mortality trends of Krasnoyarsk Region population from oncological diseases].

    PubMed

    Mazharov, V F; Gornyĭ, B E; Tikhonova, I V

    1991-01-01

    An increasing general trend in aging of population during the last decade stipulates the necessity to conduct a comparison (both in time and territory aspect) of either age-specific health indices or their standard variants because without age peculiarities of population during different years the results might be misrepresented. The data acquired in the course of the present study indicate that oncological morbidity of population in the Krasnoyarsk region in the majority of age and social groups (urban and rural inhabitants) not only have not increased but even dropped in 1989 as compared with 1959. One should be careful in assessing general indices of population health along with obligatory use of methods permitting to take into account the demographic peculiarities of population in the years compared.

  11. Nonrandom dispersal drives phenotypic divergence within a bird population

    PubMed Central

    Camacho, Carlos; Canal, David; Potti, Jaime

    2013-01-01

    Gene flow through dispersal has traditionally been thought to function as a force opposing evolutionary differentiation. However, directional gene flow may actually reinforce divergence of populations in close proximity. This study documents the phenotypic differentiation over more than two decades in body size (tarsus length) at a very short spatial scale (1.1 km) within a population of pied flycatchers Ficedula hypoleuca inhabiting deciduous and coniferous habitats. Unlike females, males breeding in the deciduous forest were consistently larger than those from the managed coniferous forest. This assortment by size is likely explained by preset habitat preferences leading to dominance of the largest males and exclusion of the smallest ones toward the nonpreferred coniferous forest coupled with directional dispersal. Movements of males between forests were nonrandom with respect to body size and flow rate, which might function to maintain the phenotypic variation in this heritable trait at such a small spatial scale. However, a deeply rooted preference for the deciduous habitat might not be in line with its quality due to the increased levels of breeding density of hole-nesting competitors therein. These results illustrate how eco-evolutionary scenarios can develop under directional gene flow over surprisingly small spatial scales. Our findings come on top of recent studies concerning new ways in which dispersal and gene flow can influence microevolution. PMID:24363908

  12. The effects of climate change on the phenology of selected Estonian plant, bird and fish populations.

    PubMed

    Ahas, Rein; Aasa, Anto

    2006-09-01

    This paper summarises the trends of 943 phenological time-series of plants, fishes and birds gathered from 1948 to 1999 in Estonia. More than 80% of the studied phenological phases have advanced during springtime, whereas changes are smaller during summer and autumn. Significant values of plant and bird phases have advanced 5-20 days, and fish phases have advanced 10-30 days in the spring period. Estonia's average air temperature has become significantly warmer in spring, while at the same time a slight decrease in air temperature has been detected in autumn. The growing season has become significantly longer in the maritime climate area of Western Estonia. The investigated phenological and climate trends are related primarily to changes in the North Atlantic Oscillation Index (NAOI) during the winter months. Although the impact of the winter NAOI on the phases decreases towards summer, the trends of the investigated phases remain high. The trends of phenophases at the end of spring and the beginning of summer may be caused by the temperature inertia of the changing winter, changes in the radiation balance or the direct consequences of human impacts such as land use, heat islands or air pollution.

  13. High urban population density of birds reflects their timing of urbanization.

    PubMed

    Møller, Anders Pape; Diaz, Mario; Flensted-Jensen, Einar; Grim, Tomas; Ibáñez-Álamo, Juan Diego; Jokimäki, Jukka; Mänd, Raivo; Markó, Gábor; Tryjanowski, Piotr

    2012-11-01

    Living organisms generally occur at the highest population density in the most suitable habitat. Therefore, invasion of and adaptation to novel habitats imply a gradual increase in population density, from that at or below what was found in the ancestral habitat to a density that may reach higher levels in the novel habitat following adaptation to that habitat. We tested this prediction of invasion biology by analyzing data on population density of breeding birds in their ancestral rural habitats and in matched nearby urban habitats that have been colonized recently across a continental latitudinal gradient. We estimated population density in the two types of habitats using extensive point census bird counts, and we obtained information on the year of urbanization when population density in urban habitats reached levels higher than that of the ancestral rural habitat from published records and estimates by experienced ornithologists. Both the difference in population density between urban and rural habitats and the year of urbanization were significantly repeatable when analyzing multiple populations of the same species across Europe. Population density was on average 30 % higher in urban than in rural habitats, although density reached as much as 100-fold higher in urban habitats in some species. Invasive urban bird species that colonized urban environments over a long period achieved the largest increases in population density compared to their ancestral rural habitats. This was independent of whether species were anciently or recently urbanized, providing a unique cross-validation of timing of urban invasions. These results suggest that successful invasion of urban habitats was associated with gradual adaptation to these habitats as shown by a significant increase in population density in urban habitats over time.

  14. Estimation of Coast-Wide Population Trends of Marbled Murrelets in Canada Using a Bayesian Hierarchical Model.

    PubMed

    Bertram, Douglas F; Drever, Mark C; McAllister, Murdoch K; Schroeder, Bernard K; Lindsay, David J; Faust, Deborah A

    2015-01-01

    Species at risk with secretive breeding behaviours, low densities, and wide geographic range pose a significant challenge to conservation actions because population trends are difficult to detect. Such is the case with the Marbled Murrelet (Brachyramphus marmoratus), a seabird listed as 'Threatened' by the Species at Risk Act in Canada largely due to the loss of its old growth forest nesting habitat. We report the first estimates of population trend of Marbled Murrelets in Canada derived from a monitoring program that uses marine radar to detect birds as they enter forest watersheds during 923 dawn surveys at 58 radar monitoring stations within the six Marbled Murrelet Conservation Regions on coastal British Columbia, Canada, 1996-2013. Temporal trends in radar counts were analyzed with a hierarchical Bayesian multivariate modeling approach that controlled for variation in tilt of the radar unit and day of year, included year-specific deviations from the overall trend ('year effects'), and allowed for trends to be estimated at three spatial scales. A negative overall trend of -1.6%/yr (95% credibility interval: -3.2%, 0.01%) indicated moderate evidence for a coast-wide decline, although trends varied strongly among the six conservation regions. Negative annual trends were detected in East Vancouver Island (-9%/yr) and South Mainland Coast (-3%/yr) Conservation Regions. Over a quarter of the year effects were significantly different from zero, and the estimated standard deviation in common-shared year effects between sites within each region was about 50% per year. This large common-shared interannual variation in counts may have been caused by regional movements of birds related to changes in marine conditions that affect the availability of prey.

  15. Estimation of Coast-Wide Population Trends of Marbled Murrelets in Canada Using a Bayesian Hierarchical Model

    PubMed Central

    Schroeder, Bernard K.; Lindsay, David J.; Faust, Deborah A.

    2015-01-01

    Species at risk with secretive breeding behaviours, low densities, and wide geographic range pose a significant challenge to conservation actions because population trends are difficult to detect. Such is the case with the Marbled Murrelet (Brachyramphus marmoratus), a seabird listed as ‘Threatened’ by the Species at Risk Act in Canada largely due to the loss of its old growth forest nesting habitat. We report the first estimates of population trend of Marbled Murrelets in Canada derived from a monitoring program that uses marine radar to detect birds as they enter forest watersheds during 923 dawn surveys at 58 radar monitoring stations within the six Marbled Murrelet Conservation Regions on coastal British Columbia, Canada, 1996–2013. Temporal trends in radar counts were analyzed with a hierarchical Bayesian multivariate modeling approach that controlled for variation in tilt of the radar unit and day of year, included year-specific deviations from the overall trend (‘year effects’), and allowed for trends to be estimated at three spatial scales. A negative overall trend of -1.6%/yr (95% credibility interval: -3.2%, 0.01%) indicated moderate evidence for a coast-wide decline, although trends varied strongly among the six conservation regions. Negative annual trends were detected in East Vancouver Island (-9%/yr) and South Mainland Coast (-3%/yr) Conservation Regions. Over a quarter of the year effects were significantly different from zero, and the estimated standard deviation in common-shared year effects between sites within each region was about 50% per year. This large common-shared interannual variation in counts may have been caused by regional movements of birds related to changes in marine conditions that affect the availability of prey. PMID:26258803

  16. Population genetic structure and long-distance dispersal of a recently expanding migratory bird.

    PubMed

    Ramos, Raül; Song, Gang; Navarro, Joan; Zhang, Ruiying; Symes, Craig T; Forero, Manuela G; Lei, Fumin

    2016-06-01

    Long-distance dispersal events and their derivable increases of genetic diversity have been highlighted as important ecological and evolutionary determinants that improve performances of range-expanding species. In the context of global environmental change, specific dispersal strategies have to be understood and foreseen if we like to prevent general biodiversity impoverishment or the spread of allochthonous diseases. We explored the genetic structure and potential population mixing on the recently range-expanding European bee-eater Merops apiaster. In addition, the species is suspected of harbouring and disseminating the most relevant disease for bees and apiculture, Nosema microsporidia. In agreement with complementary ringing recovery data and morphometric measurements, genetic results on two mitochondrial genes and 12 microsatellites showed a reasonably well-structured population partitioning along its breeding distribution. Microsatellite results indicated that not only did a few birds recently disperse long distance during their return migrations and change their natal breeding areas, but also that a group of allochthonous birds together founded a new colony. Although we did not provide evidence on the direct implication of birds in the widespread of Nosema parasites, our finding on the long-distance dispersal of bird flocks between remote breeding colonies adds concern about the role of European bee-eaters in the spread of such disease at a large, inter-continental scale.

  17. Challenge infection as a means of determining the rate of disease resistant Trichomonas gallinae-free birds in a population

    USGS Publications Warehouse

    Kocan, R.M.; Knisley, J.O.

    1970-01-01

    Trichomonas gallinae-free pigeons and mourning doves were infected with the Jones' Barn strain of T. gallinae to determine the rate of disease resistant T. gallinae-free birds in each population. Although all birds became infected 88% of the pigeons were resistant to trichomoniasis while 82% of the mourning doves were resistant. It was concluded that these birds had been previously infected and spontaneously lost their trichomonad fauna while retaining their resistance to fatal infection.

  18. The early bird gets the shrimp: Confronting assumptions of isotopic equilibrium and homogeneity in a wild bird population

    USGS Publications Warehouse

    Wunder, Michael B.; Jehl, Joseph R.; Stricker, Craig A.

    2012-01-01

    1. Because stable isotope distributions in organic material vary systematically across energy gradients that exist in ecosystems, community and population structures, and in individual physiological systems, isotope values in animal tissues have helped address a broad range of questions in animal ecology. It follows that every tissue sample provides an isotopic profile that can be used to study dietary or movement histories of individual animals. Interpretations of these profiles depend on the assumption that metabolic pools are isotopically well mixed and in equilibrium with dietary resources prior to tissue synthesis, and they extend to the population level by assuming isotope profiles are identically distributed for animals using the same proximal dietary resource. As these assumptions are never fully met, studying structure in the variance of tissue isotope values from wild populations is informative. 2. We studied variation in δ13C, δ15N, δ2H and δ18O data for feathers from a population of eared grebes (Podiceps nigricollis) that migrate to Great Salt Lake each fall to moult feathers. During this time, they cannot fly and feed almost exclusively on superabundant brine shrimp (Artemia franciscana). The ecological simplicity of this situation minimized the usual spatial and trophic complexities often present in natural studies of feather isotope values. 3. Ranges and variances of isotope values for the feathers were larger than those from previously published studies that report feather isotopic variance, but they were bimodally distributed in all isotope dimensions. Isotope values for proximal dietary resources and local surface water show that some of the feathers we assumed to have been grown locally must have been grown before birds reached isotopic equilibrium with local diet or immediately prior to arrival at Great Salt Lake. 4. Our study provides novel insights about resource use strategies in eared grebes during migration. More generally, it

  19. The early bird gets the shrimp: confronting assumptions of isotopic equilibrium and homogeneity in a wild bird population.

    PubMed

    Wunder, Michael B; Jehl, Joseph R; Stricker, Craig A

    2012-11-01

    1. Because stable isotope distributions in organic material vary systematically across energy gradients that exist in ecosystems, community and population structures, and in individual physiological systems, isotope values in animal tissues have helped address a broad range of questions in animal ecology. It follows that every tissue sample provides an isotopic profile that can be used to study dietary or movement histories of individual animals. Interpretations of these profiles depend on the assumption that metabolic pools are isotopically well mixed and in equilibrium with dietary resources prior to tissue synthesis, and they extend to the population level by assuming isotope profiles are identically distributed for animals using the same proximal dietary resource. As these assumptions are never fully met, studying structure in the variance of tissue isotope values from wild populations is informative. 2. We studied variation in δ(13) C, δ(15) N, δ(2) H and δ(18) O data for feathers from a population of eared grebes (Podiceps nigricollis) that migrate to Great Salt Lake each fall to moult feathers. During this time, they cannot fly and feed almost exclusively on superabundant brine shrimp (Artemia franciscana). The ecological simplicity of this situation minimized the usual spatial and trophic complexities often present in natural studies of feather isotope values. 3. Ranges and variances of isotope values for the feathers were larger than those from previously published studies that report feather isotopic variance, but they were bimodally distributed in all isotope dimensions. Isotope values for proximal dietary resources and local surface water show that some of the feathers we assumed to have been grown locally must have been grown before birds reached isotopic equilibrium with local diet or immediately prior to arrival at Great Salt Lake. 4. Our study provides novel insights about resource use strategies in eared grebes during migration. More generally

  20. Emerging Infectious Disease Leads to Rapid Population Declines of Common British Birds

    PubMed Central

    Toms, Mike P.; Peck, Kirsi M.; Kirkwood, James K.; Chantrey, Julian; Clatworthy, Innes R.; Evans, Andy D.; Hughes, Laura A.; Hutchinson, Oliver C.; John, Shinto K.; Pennycott, Tom W.; Perkins, Matthew W.; Rowley, Peter S.; Simpson, Vic R.; Tyler, Kevin M.; Cunningham, Andrew A.

    2010-01-01

    Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period. PMID:20805869

  1. Breeding Bird Survey and bird banding data: Applications to raptor research and management

    USGS Publications Warehouse

    Sauer, J.R.; Droege, S.; Bystrak, D.

    1991-01-01

    The Breeding Bird Survey (BBS) and Bird Banding Laboratory (BBL) are sources of information for raptor biologists. The BBS has been conducted each year since 1966 in the United States and Canada; historical bird banding records extend back to the early 20th century. BBS data can be used to document population trends and breeding distributions of many bird species. Banding data are generally collected for specific and local studies of bird populations or behavior. Past use of these data has been limited by their volume and relative inaccessibility. In this paper, we present an overview of BBS and BBL raptor data and their uses, limitations and availability.

  2. Surveys of forest bird populations found in the vicinity of proposed geothermal project subzones in the district of Puna, Hawaii

    SciTech Connect

    Jacobi, J.D.; Reynolds, M.; Ritchotte, G.; Nielsen, B.; Viggiano, A.; Dwyer, J.

    1994-10-01

    This report presents data on the distribution and status of forest bird species found within the vicinity of proposed geothermal resource development on the Island of Hawaii. Potential impacts of the proposed development on the native bird populations found in the project are are addressed.

  3. Climate warming, ecological mismatch at arrival and population decline in migratory birds.

    PubMed

    Saino, Nicola; Ambrosini, Roberto; Rubolini, Diego; von Hardenberg, Jost; Provenzale, Antonello; Hüppop, Kathrin; Hüppop, Ommo; Lehikoinen, Aleksi; Lehikoinen, Esa; Rainio, Kalle; Romano, Maria; Sokolov, Leonid

    2011-03-22

    Climate is changing at a fast pace, causing widespread, profound consequences for living organisms. Failure to adjust the timing of life-cycle events to climate may jeopardize populations by causing ecological mismatches to the life cycle of other species and abiotic factors. Population declines of some migratory birds breeding in Europe have been suggested to depend on their inability to adjust migration phenology so as to keep track of advancement of spring events at their breeding grounds. In fact, several migrants have advanced their spring arrival date, but whether such advancement has been sufficient to compensate for temporal shift in spring phenophases or, conversely, birds have become ecologically mismatched, is still an unanswered question, with very few exceptions. We used a novel approach based on accumulated winter and spring temperatures (degree-days) as a proxy for timing of spring biological events to test if the progress of spring at arrival to the breeding areas by 117 European migratory bird species has changed over the past five decades. Migrants, and particularly those wintering in sub-Saharan Africa, now arrive at higher degree-days and may have therefore accumulated a 'thermal delay', thus possibly becoming increasingly mismatched to spring phenology. Species with greater 'thermal delay' have shown larger population decline, and this evidence was not confounded by concomitant ecological factors or by phylogenetic effects. These findings provide general support to the largely untested hypotheses that migratory birds are becoming ecologically mismatched and that failure to respond to climate change can have severe negative impacts on their populations. The novel approach we adopted can be extended to the analysis of ecological consequences of phenological response to climate change by other taxa.

  4. Older driver population and crash involvement trends, 1974-1988.

    PubMed

    Stutts, J C; Martell, C

    1992-08-01

    North Carolina motor vehicle crash data for even-numbered years 1974-1988, inclusive, are analyzed in conjunction with North Carolina population, licensed driver, and mileage data to examine trends in motor vehicle crash involvement by driver age, sex, and race. Crash rates per licensed driver are presented along with crash rates per estimated vehicle miles travelled calculated on the basis of induced exposure. Results focus particularly on older drivers. They show that older drivers' representation in the licensed driver population has increased at a greater rate than their representation in either the census or crash involvement populations. These trends are particularly strong for females and for nonwhites. Furthermore, crash rates have declined more for drivers aged 55 and older than for younger drivers. The greatest declines, both in terms of crashes per licensed driver and crashes per estimated miles travelled, have been experienced by drivers age 65 and older, particularly nonwhites. Males show higher overall crash rates per miles travelled than females, but this effect decreases with age and disappears entirely in the oldest age categories. Results are discussed in light of the changing nature of the overall driving population and the cohort of older drivers in particular.

  5. Lifespan is unrelated to investment in reproduction in populations of mammals and birds in captivity.

    PubMed

    Ricklefs, Robert E; Cadena, Carlos Daniel

    2007-10-01

    We examined the relationship between number of offspring produced to a certain age and subsequent longevity in captive zoo populations of 18 species of mammal and 12 species of bird. The age cut-offs in each analysis were set to include 50%, 75% and 90% of the offspring produced in each of the population samples. Only one of 68 regressions was significant, and its slope was positive. In addition, we examined the relationship between age at first reproduction up to a certain age and longevity after that age, generally 5 years (3-8), among 17 species of mammal and 12 species of bird. Only one of these regressions had a significantly positive slope, indicating that early reproduction rarely reduces lifespan. Overall, we found no evidence that producing offspring in a zoo environment influences the age at death. Thus, although trade-offs might apply in natural populations under resource limitation, neither pregnancy, growth of the foetus and lactation in mammals, nor egg production in birds, reduces lifespan in the absence of such stress. If genetically based or other intrinsic antagonistic pleiotropy underlies the evolution of senescence, it was not evident in our analyses.

  6. Power of Sign Surveys to Monitor Population Trends.

    PubMed

    Kendall, Katherine C; Metzgar, Lee H; Patterson, David A; Steele, Brian M

    1992-11-01

    The urgent need for an effective monitoring scheme for grizzly bear (Ursus arctos) populations led us to investigate the effort required to detect changes in populations of low-density dispersed animals, using sign (mainly scats and tracks) they leave on trails. We surveyed trails in Glacier National Park for bear tracks and scats during five consecutive years. Using these data, we modeled the occurrence of bear sign on trails, then estimated the power of various sampling schemes. Specifically, we explored the power of bear sign surveys to detect a 20% decline in sign occurrence. Realistic sampling schemes appear feasible if the density of sign is high enough, and we provide guidelines for designs with adequate replication to monitor long-term trends of dispersed populations using sign occurrences on trails.

  7. Power of sign surveys to monitor population trend

    USGS Publications Warehouse

    Kendall, Katherine C.; Metzgar, Lee H.; Patterson, David A.; Steele, Brian M.

    1992-01-01

    The urgent need for an effective monitoring scheme for grizzly bear (Ursus arctos) populations led us to investigate the effort required to detect changes in populations of low—density dispersed animals, using sign (mainly scats and tracks) they leave on trails. We surveyed trails in Glacier National Park for bear tracks and scats during five consecutive years. Using these data, we modeled the occurrence of bear sign on trails, then estimated the power of various sampling schemes. Specifically, we explored the power of bear sign surveys to detect a 20% decline in sign occurrence. Realistic sampling schemes appear feasible if the density of sign is high enough, and we provide guidelines for designs with adequate replication to monitor long—term trends of dispersed populations using sign occurrences on trails.

  8. Population dynamics of neotropical migratory birds using agriculture-forest mosaics in Campeche, Mexico

    USGS Publications Warehouse

    Wilson, M.H.; Berlanga, M.; Dawson, D.; Wood, P.; Sauer, J.; Robbins, C.S.; Wilson, Marcia H.; Sader, Steven A.

    1995-01-01

    In many areas of the tropics, forests are being converted to agriculture and other uses at a rapid rate. Previous research has documented that forest-breeding migratory birds are distributed across a wide variety of habitat types during midwinter. However, to evaluate the relative importance of different habitat types to wintering birds, we need to examine habitat-specific estimates of survival. During the winter of 1992-1993, mist nets, observations of individually marked birds and point counts were used to sample bird populations in a pasture-forest mosaic in southern Mexico. Sampling was conducted four times throughout the winter on a total of six grids. Twenty nets were run for two days in each grid. A total of 129 species were captured and 3,585 individuals banded. Neotropical migrants made up 31% of the species captured and 47% of the individuals banded. The banding data were used to estimate species richness for permanent and winter residents in different habitats and at different time periods. Capture-recapture models were used to estimate overwintering survival for selected species.

  9. The demographic drivers of local population dynamics in two rare migratory birds.

    PubMed

    Schaub, Michael; Reichlin, Thomas S; Abadi, Fitsum; Kéry, Marc; Jenni, Lukas; Arlettaz, Raphaël

    2012-01-01

    The exchange of individuals among populations can have strong effects on the dynamics and persistence of a given population. Yet, estimation of immigration rates remains one of the greatest challenges for animal demographers. Little empirical knowledge exists about the effects of immigration on population dynamics. New integrated population models fitted using Bayesian methods enable simultaneous estimation of fecundity, survival and immigration, as well as the growth rate of a population of interest. We applied this novel analytical framework to the demography of two populations of long-distance migratory birds, hoopoe Upupa epops and wryneck Jynx torquilla, in a study area in south-western Switzerland. During 2002-2010, the hoopoe population increased annually by 11%, while the wryneck population remained fairly stable. Apparent juvenile and adult survival probability was nearly identical in both species, but fecundity and immigration were slightly higher in the hoopoe. Hoopoe population growth rate was strongly correlated with juvenile survival, fecundity and immigration, while that of wrynecks strongly correlated only with immigration. This indicates that demographic components impacting the arrival of new individuals into the populations were more important for their dynamics than demographic components affecting the loss of individuals. The finding that immigration plays a crucial role in the population growth rates of these two rare species emphasizes the need for a broad rather than local perspective for population studies, and the development of wide-scale conservation actions.

  10. Experimental evaluation of population trend and harvest composition in a Wyoming cougar population

    USGS Publications Warehouse

    Anderson, C.R.; Lindzey, F.G.

    2005-01-01

    Cougar (Puma concolor) management has been hindered by inability to identify population trends. We documented changes in sex and age of harvested cougars during an experimentally induced reduction in population size and subsequent recovery to better understand the relationship between sex-age composition and population trend in exploited populations. The cougar population in the Snowy Range, southeast Wyoming, was reduced by increased harvest (treatment phase) from 58 independent cougars (>1 year old) (90% CI = 36-81) in the autumn of 1998 to 20 by the spring of 2000 (mean exploitation rate = 43%) and then increased to 46 by spring 2003 following 3 years of reduced harvests (mean exploitation rate = 18%). Pretreatment harvest composition was 63% subadults (1.0-2.5 years old), 23% adult males, and 14% adult females (2 seasons; n = 22). A reduction in subadult harvest, an initial increase followed by a reduction in adult male harvest, and a steady increase in adult female harvest characterized harvest composition trends during the treatment phase. Harvest composition was similar at high and low densities when harvest was light, but proportion of harvested subadult males increased at low density as they replaced adult males removed during the treatment period (high harvest). While sex ratio of harvested cougars alone appears of limited value in identifying population change, when combined with age class the 2 appear to provide an index to population change. Composition of the harvest can be applied to adaptively manage cougar populations where adequate sex and age data are collected from harvested animals.

  11. Population pressure on coral atolls: trends and approaching limits.

    PubMed

    Rapaport, M

    1990-09-01

    Trends and approaching limits of population pressure on coral atolls is discussed by examining the atoll environment in terms of the physical geography, the production systems, and resource distribution. Atoll populations are grouped as dependent and independent, and demographic trends in population growth, migraiton, urbanization, and political dependency are reviewed. Examination of the carrying capacity includes a dynamic model, the influences of the West, and philopsophical considerations. The carrying capacity is the "maximal population supportable in a given area". Traditional models are criticized because of a lack in accounting for external linkages. The proposed model is dynamic and considers perceived needs and overseas linkages. It also explains regional disparities in population distribution, and provides a continuing model for population movement from outer islands to district centers and mainland areas. Because of increased expectations and perceived needs, there is a lower carrying capacity for outlying areas, and expanded capacity in district centers. This leads to urbanization, emigration, and carrying capacity overshot in regional and mainland areas. Policy intervention is necessary at the regional and island community level. Atolls, which are islands surrounding deep lagoons, exist in archipelagoes across the oceans, and are rich in aquatic life. The balance in this small land area with a vulnerable ecosystem may be easily disturbed by scarce water supplies, barren soils, rising sea levels in the future, hurricanes, and tsunamis. Traditionally, fisheries and horticulture (pit-taro, coconuts, and breadfruit) have sustained populations, but modern influences such as blasting, reef mining, new industrial technologies, population pressure, and urbanization threaten the balance. Population pressure, which has lead to pollution, epidemics, malnutrition, crime, social disintegration, and foreign dependence, is evidenced in the areas of Tuvalu, Kiribati

  12. 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…

  13. Changes in size and trends of North American sea duck populations associated with North Pacific oceanic regime shifts

    USGS Publications Warehouse

    Flint, Paul L.

    2013-01-01

    Broad-scale multi-species declines in populations of North American sea ducks for unknown reasons is cause for management concern. Oceanic regime shifts have been associated with rapid changes in ecosystem structure of the North Pacific and Bering Sea. However, relatively little is known about potential effects of these changes in oceanic conditions on marine bird populations at broad scales. I examined changes in North American breeding populations of sea ducks from 1957 to 2011 in relation to potential oceanic regime shifts in the North Pacific in 1977, 1989, and 1998. There was strong support for population-level effects of regime shifts in 1977 and 1989, but little support for an effect of the 1998 shift. The continental-level effects of these regime shifts differed across species groups and time. Based on patterns of sea duck population dynamics associated with regime shifts, it is unclear if the mechanism of change relates to survival or reproduction. Results of this analysis support the hypothesis that population size and trends of North American sea ducks are strongly influenced by oceanic conditions. The perceived population declines appear to have halted >20 years ago, and populations have been relatively stable or increasing since that time. Given these results, we should reasonably expect dramatic changes in sea duck population status and trends with future oceanic regime shifts.

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

    USGS Publications Warehouse

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

    2014-01-01

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

  15. No Association between Personality and Candidate Gene Polymorphisms in a Wild Bird Population.

    PubMed

    Edwards, Hannah A; Hajduk, Gabriela K; Durieux, Gillian; Burke, Terry; Dugdale, Hannah L

    2015-01-01

    Consistency of between-individual differences in behaviour or personality is a phenomenon in populations that can have ecological consequences and evolutionary potential. One way that behaviour can evolve is to have a genetic basis. Identifying the molecular genetic basis of personality could therefore provide insight into how and why such variation is maintained, particularly in natural populations. Previously identified candidate genes for personality in birds include the dopamine receptor D4 (DRD4), and serotonin transporter (SERT). Studies of wild bird populations have shown that exploratory and bold behaviours are associated with polymorphisms in both DRD4 and SERT. Here we tested for polymorphisms in DRD4 and SERT in the Seychelles warbler (Acrocephalus sechellensis) population on Cousin Island, Seychelles, and then investigated correlations between personality and polymorphisms in these genes. We found no genetic variation in DRD4, but identified four polymorphisms in SERT that clustered into five haplotypes. There was no correlation between bold or exploratory behaviours and SERT polymorphisms/haplotypes. The null result was not due to lack of power, and indicates that there was no association between these behaviours and variation in the candidate genes tested in this population. These null findings provide important data to facilitate representative future meta-analyses on candidate personality genes.

  16. Brominated flame retardant trends in aquatic birds from the Salish Sea region of the west coast of North America, including a mini-review of recent trends in marine and estuarine birds.

    PubMed

    Miller, Aroha; Elliott, John E; Elliott, Kyle H; Guigueno, Mélanie F; Wilson, Laurie K; Lee, Sandi; Idrissi, Abde

    2015-01-01

    Polybrominated diphenyl ethers (PBDEs) increased in many matrices during the 1990s and early 2000s. Since voluntary restrictions and regulations on PBDEs were implemented in North America circa early 2000s, decreases in PBDEs have occurred in many of these same matrices. To examine temporal trends in the North Pacific, we retrospectively analysed PBDEs and eight non-PBDE flame retardants (FR) in eggs of two aquatic bird species, great blue herons, Ardea herodias, and double-crested cormorants, Phalacrocorax auritus, collected along the British Columbia coast, Canada from 1979 to 2012. Increasing PBDE concentrations were observed in both species followed by significant decreases post-2000 for all dominant congeners and ΣPBDE. Non-PBDE FRs were generally undetected in cormorant eggs, or detected at very low levels in heron eggs, except for hexabromocyclododecane (HBCDD). HBCDD, currently unregulated in North America, was not detected in early sampling years; however low concentrations were observed in both species in recent sampling years (2003-2012). Dietary tracers (δ(13)C and δ(15)N) did not change significantly over time, indicating that temporal changes in PBDEs are likely caused by implemented regulations. A comparison with recently published temporal trends of ΣPBDE in marine birds from North America and Europe is given.

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

    USGS Publications Warehouse

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

    2005-01-01

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

  18. Relationships between nesting populations of wading birds and wetland habitat features

    USGS Publications Warehouse

    Erwin, R.M.; Spendelow, J.A.; Geissler, P.H.; Williams, B.K.

    1986-01-01

    We used data from censuses of wading bird colonies on the Atlantic coast from Maine to Florida {1976-1977) to examine relationships between population sizes of wading birds {herons, egrets, ibises) and 9 key habitat features. Variables included features of the colony site {island size, dimensions, isolation from adjacent land) and surrounding (5 km circle) potential feeding habitat {wetland area). Measurements were made on nautical charts using a planimeter. For 122 colonies on islands, 5 multivariate procedures were used. Because of high correlations among habitat variables, a reduced regression model using only 4 variables performed best. The only variable that approached statistical significance (P = 0.06) was land-water interface distance (i.e., wetland 'edge' within the 5 km circle centered on the colony site).

  19. First Evidence and Predictions of Plasmodium Transmission in Alaskan Bird Populations

    PubMed Central

    Loiseau, Claire; Harrigan, Ryan J.; Cornel, Anthony J.; Guers, Sue L.; Dodge, Molly; Marzec, Timothy; Carlson, Jenny S.; Seppi, Bruce; Sehgal, Ravinder N. M.

    2012-01-01

    The unprecedented rate of change in the Arctic climate is expected to have major impacts on the emergence of infectious diseases and host susceptibility to these diseases. It is predicted that malaria parasites will spread to both higher altitudes and latitudes with global warming. Here we show for the first time that avian Plasmodium transmission occurs in the North American Arctic. Over a latitudinal gradient in Alaska, from 61°N to 67°N, we collected blood samples of resident and migratory bird species. We found both residents and hatch year birds infected with Plasmodium as far north as 64°N, providing clear evidence that malaria transmission occurs in these climates. Based on our empirical data, we make the first projections of the habitat suitability for Plasmodium under a future-warming scenario in Alaska. These findings raise new concerns about the spread of malaria to naïve host populations. PMID:23028595

  20. First evidence and predictions of Plasmodium transmission in Alaskan bird populations.

    PubMed

    Loiseau, Claire; Harrigan, Ryan J; Cornel, Anthony J; Guers, Sue L; Dodge, Molly; Marzec, Timothy; Carlson, Jenny S; Seppi, Bruce; Sehgal, Ravinder N M

    2012-01-01

    The unprecedented rate of change in the Arctic climate is expected to have major impacts on the emergence of infectious diseases and host susceptibility to these diseases. It is predicted that malaria parasites will spread to both higher altitudes and latitudes with global warming. Here we show for the first time that avian Plasmodium transmission occurs in the North American Arctic. Over a latitudinal gradient in Alaska, from 61°N to 67°N, we collected blood samples of resident and migratory bird species. We found both residents and hatch year birds infected with Plasmodium as far north as 64°N, providing clear evidence that malaria transmission occurs in these climates. Based on our empirical data, we make the first projections of the habitat suitability for Plasmodium under a future-warming scenario in Alaska. These findings raise new concerns about the spread of malaria to naïve host populations.

  1. Aging in france: population trends, policy issues, and research institutions.

    PubMed

    Béland, Daniel; Viriot Durandal, Jean-Philippe

    2013-04-01

    Like in other advanced industrial countries, in France, demographic aging has become a widely debated research and policy topic. This article offers a brief overview of major aging-related trends in France. The article describes France's demographics of aging, explores key policy matters, maps the institutional field of French social gerontology research, and, finally, points to several emerging issues about aging. In France, these issues include active and healthy aging, the improvement of knowledge on specific vulnerable segments of the elderly population, and the adaptation of the urban landscape and infrastructure to an aging population. At the broadest level, one of the key points formulated in this article is that in France, aging research is dominated by the state, yet it is scattered and compartmentalized, posing a crucial challenge in an era dominated by European and other international networks and coordination efforts in aging policy and knowledge.

  2. Population genetics of Cryptosporidium meleagridis in humans and birds: evidence for cross-species transmission.

    PubMed

    Wang, Yuanfei; Yang, Wenli; Cama, Vitaliano; Wang, Lin; Cabrera, Lilia; Ortega, Ynes; Bern, Caryn; Feng, Yaoyu; Gilman, Robert; Xiao, Lihua

    2014-07-01

    Population genetic studies have been used to understand the transmission of pathogens in humans and animals, especially the role of zoonotic infections and evolution and dispersal of virulent subtypes. In this study, we analysed the genetic diversity and population structure of Cryptosporidium meleagridis, the only known Cryptosporidium species that infects both avian and mammalian hosts and is responsible for approximately 10% of human cryptosporidiosis in some areas. A total of 62 C. meleagridis specimens from children, AIDS patients, and birds in Lima, Peru were characterised by sequence analysis of the ssrRNA gene and five minisatellite, microsatellite and polymorphic markers in chromosome 6, including the 60 kDa glycoprotein (gp60), 47 kDa glycoprotein (CP47), a serine repeat antigen (MSC6-5), retinitis pigmentosa GTPase regulator (RPGR) and thrombospondin protein 8 (TSP8). The multilocus sequence analysis identified concurrent infections with Cryptosporidium hominis in four AIDS patients and three children. Unique subtypes of C. meleagridis ranged from eight at the gp60 locus (gene diversity -Hd=0.651), three at the RPGR (Hd=0.556), three at the MSC6-5 locus (Hd=0.242), two at TSP8 (Hd=0.198), to one at CP47 (monomorphic), much lower than that of C. hominis in the same area. Intragenic linkage disequilibrium was strong and complete at all gene loci. Intergenic linkage disequilibrium was highly significant (P<0.001) for all pairs of polymorphic loci. Two major groups of subtypes were seen, with most subtypes belonging to group 1. Within group 1, there was no clear population segregation, and two of the 14 multilocus subtypes of C. meleagridis were found in both AIDS patients and birds. We believe that these results provide the first evidence of a clonal population structure of C. meleagridis and the likely occurrence of cross-species transmission of C. meleagridis between birds and humans.

  3. [Urbanization mechanisms in bird species: population systems transformations or adaptations at the individual level?].

    PubMed

    Fridman, V S; Eremkin, G S; Zakharova-Kubareva, N Iu

    2008-01-01

    The present research deals with urbanization of wild bird and mammal species. Forms and mechanisms of population steadiness in the urban landscape have been examined. The urbanization process turned out to be a directed change of the population system forming de novo in the urbolandscape leading to a sustainable organization peculiar for the particular environment. The population organization of different types in urbolandscape is found to provide its stability under conditions of directed and fast changes accompanied with instability and heterogenous structure of habitats. It is shown that the same type of population organization meets the corresponding demands among different species settling in the urban environment. Its features are "openness" and "flowage" of the groups, far order of settlement levels and other units of population system, constant movements of the individuals between the groups as a respond to the signals of urboenvironment significant changes. The "urban" variant of the population system organization turns out to be opposite to that of the same species in the non-urban habitats. After formation of the urban types by the species and successful developing of the town, the urban population becomes separated from the maternal local population and begins to exist independently in the urban landscape. The variety of adaptation aberrations in ecology, behavior, and mode of life of urban birds is the population system stability function in the urban landscape and is not a results of individual selection. It is shown that the urbanization process of the species goes firstly on the population level being the system structure transformation developed by the species towards the most stable state in the town (city) territory. Only after the appearance of stable urban population, the urban individuals show the rapid growth of different changes in ecology, behavior, mode of life that was traditionally described by naturalists as species adaptation to the

  4. Z chromosome divergence, polymorphism and relative effective population size in a genus of lekking birds

    USGS Publications Warehouse

    Oyler-McCance, Sara J.; Cornman, Robert S.; Kenneth L. Jones,; Fike, Jennifer

    2015-01-01

    Sex chromosomes contribute disproportionately to species boundaries as they diverge faster than autosomes and often have reduced diversity. Their hemizygous nature contributes to faster divergence and reduced diversity, as do some types of selection. In birds, other factors (mating system and bottlenecks) can further decrease the effective population size of Z-linked loci and accelerate divergence (Fast-Z). We assessed Z-linked divergence and effective population sizes for two polygynous sage-grouse species and compared them to estimates from birds with various mating systems. We found lower diversity and higher FST for Z-linked loci than for autosomes, as expected. The πZ/πA ratio was 0.38 in Centrocercus minimus, 0.48 in Centrocercus urophasianus and 0.59 in a diverged, parapatric population of C. urophasianus, a broad range given the mating system among these groups is presumably equivalent. The full data set had unequal males and females across groups, so we compared an equally balanced reduced set of C. minimus and individuals pooled from both C. urophasianus subgroups recovering similar estimates: 0.54 for C. urophasianus and 0.38 for C. minimus. We provide further evidence that NeZ/NeA in birds is often lower than expected under random mating or monogamy. The lower ratio in C. minimus could be a consequence of stronger selection or drift acting on Z loci during speciation, as this species differs strongly from C. urophasianus in sexually selected characters with minimal mitochondrial divergence. As C. minimus also exhibited lower genomic diversity, it is possible that a more severe demographic history may contribute to its lower ratio.

  5. Demographic drivers of decline and recovery in an Afro-Palaearctic migratory bird population

    PubMed Central

    Robinson, Robert A.; Butler, Simon J.; Clark, Jacquie A.; Gill, Jennifer A.

    2016-01-01

    Across Europe, rapid population declines are ongoing in many Afro-Palaearctic migratory bird species, but the development of appropriate conservation actions across such large migratory ranges is severely constrained by lack of understanding of the demographic drivers of these declines. By constructing regional integrated population models (IPMs) for one of the suite of migratory species that is declining in the southeast of Britain but increasing in the northwest, we show that, while annual population growth rates in both regions vary with adult survival, the divergent regional trajectories are primarily a consequence of differences in productivity. Between 1994 and 2012, annual survival and productivity rates ranged over similar levels in both regions, but high productivity rates were rarer in the declining southeast population and never coincided with high survival rates. By contrast, population growth in the northwest was fuelled by several years in which higher productivity coincided with high survival rates. Simulated population trajectories suggest that realistic improvements in productivity could have reversed the decline (i.e. recovery of the population index to more than or equal to 1) in the southeast. Consequently, actions to improve productivity on European breeding grounds are likely to be a more fruitful and achievable means of reversing migrant declines than actions to improve survival on breeding, passage or sub-Saharan wintering grounds. PMID:27807267

  6. Demographic drivers of decline and recovery in an Afro-Palaearctic migratory bird population.

    PubMed

    Morrison, Catriona A; Robinson, Robert A; Butler, Simon J; Clark, Jacquie A; Gill, Jennifer A

    2016-11-16

    Across Europe, rapid population declines are ongoing in many Afro-Palaearctic migratory bird species, but the development of appropriate conservation actions across such large migratory ranges is severely constrained by lack of understanding of the demographic drivers of these declines. By constructing regional integrated population models (IPMs) for one of the suite of migratory species that is declining in the southeast of Britain but increasing in the northwest, we show that, while annual population growth rates in both regions vary with adult survival, the divergent regional trajectories are primarily a consequence of differences in productivity. Between 1994 and 2012, annual survival and productivity rates ranged over similar levels in both regions, but high productivity rates were rarer in the declining southeast population and never coincided with high survival rates. By contrast, population growth in the northwest was fuelled by several years in which higher productivity coincided with high survival rates. Simulated population trajectories suggest that realistic improvements in productivity could have reversed the decline (i.e. recovery of the population index to more than or equal to 1) in the southeast. Consequently, actions to improve productivity on European breeding grounds are likely to be a more fruitful and achievable means of reversing migrant declines than actions to improve survival on breeding, passage or sub-Saharan wintering grounds.

  7. Are southern California's fragmented saltmarshes capable of sustaining endemic bird populations?

    USGS Publications Warehouse

    Powell, A.N.; ,

    2006-01-01

    Loss of coastal saltmarshes in southern California has been estimated at 75-90% since presettlement times. The remaining wetlands are mostly fragmented and degraded, and most frequently have harsh edges adjacent to urban landscapes. Non-migratory Belding's Savannah Sparrows (Passerculus sandwichensis beldingi) and Light-footed Clapper Rails (Rallus longirostris levipes) are endemic to saltmarshes in southern California and Baja California, Mexico. Population sizes of Belding's Savannah Sparrows show a positive relationship with saltmarsh area, but few large wetland fragments remain within their range in California. Belding's Savannah Sparrows are sensitive to fragmentation and isolation, with small isolated marshes acting as population sinks. In addition, this subspecies shows low genetic variability, limited dispersal, and small effective population sizes. Light-footed Clapper Rails are habitat specialists, found in marshes with good tidal flushing that support California cordgrass (Spartina foliosa) habitats. Light-footed Clapper rails also show low genetic variability and limited dispersal and the remnant populations of clapper rails are relatively isolated from one another. Large wetland complexes may serve as population sources for both species, while small, isolated marshes may act as population sinks but more research is needed to estimate and model the dynamics of these two metapopulations. Mitigation for wetland loss and restoration projects should not be evaluated simply by presence of rare bird species alone, but instead efforts should be made to determine population sustainability.

  8. 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.; 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.

  9. 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.

  10. 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

  11. Habitat-independent spatial structure in populations of some forest birds in eastern North America.

    PubMed

    Ricklefs, Robert E

    2013-01-01

    The extent to which populations fill available ecological space is critical to evaluating niche-based theories of community assembly, but habitat suitability for populations is difficult to assess. The absence of a species from areas of otherwise suitable habitat might indicate localized species-specific influences, including biological interactions with competitors, consumers or pathogens, on local population persistence. I used Bray-Curtis ordination axis scores, based on the distributions of forest birds across census plots in eastern North America, as proxies of general features of habitat suitability to predict local abundances of each species of small land bird. I then applied spatial analysis to identify significant spatial structure (Moran's I) in residuals (positive or negative) from predicted local densities, which would indicate localized species-specific influences on population size. Fifty-eight of 79 species exhibited no significant spatial structure in residual abundances, indicating that the ordination axes reflect most of the spatial variation in environmental conditions and habitat characteristics that influence population distribution and density or that samples were too small to detect significant spatial variation. Twenty-one species exhibited significant habitat-independent spatial structure of residuals within distances of 100 km. Aggregations of residuals for these species were independently located, for the most part, and thus probably unrelated to general features of the environment that affect many species. Among factors considered as potential causes of spatial anomalies, positive density dependence (Allee effects), intraspecific social aggregation and area sensitivity in response to forest fragmentation find little support in this analysis. Because of the species-specific nature of these clustered residuals, specialized pathogens are potential candidates to drive spatial anomalies in host abundance.

  12. Timing and proximate causes of mortality in wild bird populations: testing Ashmole’s hypothesis

    USGS Publications Warehouse

    Barton, Daniel C.; Martin, Thomas E.

    2012-01-01

    Fecundity in birds is widely recognized to increase with latitude across diverse phylogenetic groups and regions, yet the causes of this variation remain enigmatic. Ashmole’s hypothesis is one of the most broadly accepted explanations for this pattern. This hypothesis suggests that increasing seasonality leads to increasing overwinter mortality due to resource scarcity during the lean season (e.g., winter) in higher latitude climates. This mortality is then thought to yield increased per-capita resources for breeding that allow larger clutch sizes at high latitudes. Support for this hypothesis has been based on indirect tests, whereas the underlying mechanisms and assumptions remain poorly explored. We used a meta-analysis of over 150 published studies to test two underlying and critical assumptions of Ashmole’s hypothesis: first, that ad ult mortality is greatest during the season of greatest resource scarcity, and second, t hat most mortality is caused by starvation. We found that the lean season (winter) was generally not the season of greatest mortality. Instead, spring or summer was most frequently the season of greatest mortality. Moreover, monthly survival rates were not explained by monthly productivity, again opposing predictions from Ashmole’s hypothesis. Finally, predation, rather than starvation, was the most frequent proximate cause o f mortality. Our results do not support the mechanistic predictions of Ashmole‘s hypothesis, and suggest alternative explanations of latitudinal variation in clutch size should remain under consideration. Our meta-analysis also highlights a paucity of data available on the timing and causes of mortality in many bird populations, particularly tropical bird populations, despite the clear theoretical and empirical importance of such data.

  13. Survival and population size of a resident bird species are declining as temperature increases.

    PubMed

    Santisteban, Leonard; Benkman, Craig W; Fetz, Trevor; Smith, Julie W

    2012-03-01

    1. A large number of migratory bird species appear to be declining as the result of climate change, but whether resident bird species have or will be adversely affected by climate change is less clear. We focus on the South Hills crossbill (Loxia curvirostra complex), which is endemic to about 70 km(2) of Rocky Mountain lodgepole pine (Pinus contorta latifolia) forest in southern Idaho, USA. 2. Our results indicate that the South Hills crossbill has declined by over 60% between 2003 and 2008, and that decreasing adult survival drives this population decline. 3. We evaluated the relative support for multiple hypotheses linking crossbill survival to climate, an ectoparasitic mite (scaly-leg mites Knemidokoptes jamaicensis), and the recent emergence of West Nile virus. Changes in adult apparent survival rate were closely associated with average spring and annual temperatures, and with high temperatures (≥32 °C) during summer, which have increased during the last decade. In contrast, there was little evidence that scaly-leg mites or West Nile virus contributed to recent declines in adult survival. 4. The most probable mechanism causing the decline in adult survival and population size is a decrease in the availability of their primary food resource, seeds in serotinous pine cones. Cone production has declined with increasing annual temperatures, and these cones appear to be prematurely opening owing to increasingly hot summer conditions releasing their seeds and reducing the carrying capacity for crossbills later in the year. 5. In light of regional climate change forecasts, which include an increase in both annual temperature and hot days (>32 °C), and the likely disappearance of lodgepole pine from southern Idaho by the end of this century, additional research is needed to determine how to maintain lodgepole pine forests and their supply of seeds to conserve one of the few bird species endemic to the continental United States.

  14. Use of the superpopulation approach to estimate breeding population size: An example in asynchronously breeding birds

    USGS Publications Warehouse

    Williams, K.A.; Frederick, P.C.; Nichols, J.D.

    2011-01-01

    Many populations of animals are fluid in both space and time, making estimation of numbers difficult. Much attention has been devoted to estimation of bias in detection of animals that are present at the time of survey. However, an equally important problem is estimation of population size when all animals are not present on all survey occasions. Here, we showcase use of the superpopulation approach to capture-recapture modeling for estimating populations where group membership is asynchronous, and where considerable overlap in group membership among sampling occasions may occur. We estimate total population size of long-legged wading bird (Great Egret and White Ibis) breeding colonies from aerial observations of individually identifiable nests at various times in the nesting season. Initiation and termination of nests were analogous to entry and departure from a population. Estimates using the superpopulation approach were 47-382% larger than peak aerial counts of the same colonies. Our results indicate that the use of the superpopulation approach to model nesting asynchrony provides a considerably less biased and more efficient estimate of nesting activity than traditional methods. We suggest that this approach may also be used to derive population estimates in a variety of situations where group membership is fluid. ?? 2011 by the Ecological Society of America.

  15. Population trends in the European Community, 1960-1986.

    PubMed

    Chesnais, J C

    1988-07-01

    Recent trends in fertility, marriage patterns and family formation in the 12 nations of the European Community are discussed. The total period fertility rate in this group of nations has dropped sharply (42%) since 1960, so that the annual growth was 0.15% in 1986. Immigration and the rate of mortality decline have also slowed. There are some variations in regional or national fertility, and in population growth as a result of age structure. The rate of population growth is slowing in all nations except Greece, Ireland and Portugal. The U.K., Belgium, Luxembourg and Denmark have experienced zero growth since 1980. Italy is close to zero growth. France, Netherlands and Spain have higher growth due to age structure. Ireland continues to grow at 1% yearly. In general, large families are disappearing, although different patterns are evident in various states. France shows high progression to the 1st child; many German couples choose to remain childless. People are marrying older, remaining unmarried, divorcing sooner, cohabiting before or after marriage. Non-marital births are common, especially in nordic countries, but still rare in Mediterranean countries. The restricted family norm, of 0, 1, or 2 children is becoming uniform, resulting in fertility well below, 15-40% of replacement.

  16. West Nile virus and greater sage-grouse: estimating infection rate in a wild bird population.

    PubMed

    Walker, Brett L; Naugle, David E; Doherty, Kevin E; Cornish, Todd E

    2007-09-01

    Understanding impacts of disease on wild bird populations requires knowing not only mortality rate following infection, but also the proportion of the population that is infected. Greater sage-grouse (Centrocercus urophasianus) in western North America are known to have a high mortality rate following infection with West Nile virus (WNv), but actual infection rates in wild populations remain unknown. We used rates of WNv-related mortality and seroprevalence from radiomarked females to estimate infection rates in a wild greater sage-grouse population in the Powder River basin (PRB) of Montana and Wyoming from 2003 to 2005. Minimum WNv-related mortality rates ranged from 2.4% to 13.3% among years and maximum possible rates ranged from 8.2% to 28.9%. All live-captured birds in 2003 and 2004 tested seronegative. In spring 2005 and spring 2006, 10.3% and 1.8% respectively, of newly captured females tested seropositive for neutralizing antibodies to WNv. These are the first documented cases of sage-grouse surviving infection with WNv. Low to moderate WNv-related mortality in summer followed by low seroprevalence the following spring in all years indicates that annual infection rates were between 4% and 29%. This suggests that most sage-grouse in the PRB have not yet been exposed and remain susceptible. Impacts of WNv in the PRB in the near future will likely depend more on annual variation in temperature and changes in vector distribution than on the spread of resistance. Until the epizootiology of WNv in sagebrush-steppe ecosystems is better understood, we suggest that management to reduce impacts of WNv focus on eliminating man-made water sources that support breeding mosquitoes known to vector the virus. Our findings also underscore problems with using seroprevalence as a surrogate for infection rate and for identifying competent hosts in highly susceptible species.

  17. Trends in the exploitation of South Atlantic shark populations.

    PubMed

    Barreto, Rodrigo; Ferretti, Francesco; Flemming, Joanna M; Amorim, Alberto; Andrade, Humber; Worm, Boris; Lessa, Rosangela

    2016-08-01

    Approximately 25% of globally reported shark catches occur in Atlantic pelagic longline fisheries. Strong declines in shark populations have been detected in the North Atlantic, whereas in the South Atlantic the situation is less clear, although fishing effort has been increasing in this region since the late 1970s. We synthesized information on shark catch rates (based on 871,177 sharks caught on 86,492 longline sets) for the major species caught by multiple fleets in the South Atlantic between 1979 and 2011. We complied records from fishing logbooks of fishing companies, fishers, and onboard observers that were supplied to Brazilian institutions. By using exploratory data analysis and literature sources, we identified 3 phases of exploitation in these data (Supporting Information). From 1979 to 1997 (phase A), 5 fleets (40 vessels) fished mainly for tunas. From 1998 to 2008 (phase B), 20 fleets (100 vessels) fished for tunas, swordfishes, and sharks. From 2008 to 2011 (phase C), 3 fleets (30 vessels) fished for multiple species, but restrictive measures were implemented. We used generalized linear models to standardize catch rates and identify trends in each of these phases. Shark catch rates increased from 1979 to 1997, when fishing effort was low, decreased from 1998 to 2008, when fishing effort increased substantially, and remained stable or increased from 2008 to 2011, when fishing effort was again low. Our results indicate that most shark populations affected by longlines in the South Atlantic are currently depleted, but these populations may recover if fishing effort is reduced accordingly. In this context, it is problematic that comprehensive data collection, monitoring, and management of these fisheries ceased after 2012. Concurrently with the fact that Brazil is newly identified by FAO among the largest (and in fastest expansion) shark sub-products consumer market worldwide.

  18. High Genetic Diversity of Newcastle Disease Virus in Wild and Domestic Birds in Northeastern China from 2013 to 2015 Reveals Potential Epidemic Trends

    PubMed Central

    Zhang, Pingze; Xie, Guangyao; Liu, Xinxin; Ai, Lili; Chen, Yanyu; Meng, Xin; Bi, Yuhai; Chen, Jianjun; Sun, Yuzhang; Stoeger, Tobias; Ding, Zhuang

    2015-01-01

    Newcastle disease (ND), caused by the virulent Newcastle disease virus (NDV), is one of the most important viral diseases of birds globally, but little is currently known regarding enzootic trends of NDV in northeastern China, especially for class I viruses. Thus, we performed a surveillance study for NDV in northeastern China from 2013 to 2015. A total 755 samples from wild and domestic birds in wetlands and live bird markets (LBMs) were collected, and 10 isolates of NDV were identified. Genetic and phylogenetic analyses showed that five isolates from LBMs belong to class I subgenotype 1b, two (one from wild birds and one from LBMs) belong to the vaccine-like class II genotype II, and three (all from wild birds) belong to class II subgenotype Ib. Interestingly, the five class I isolates had epidemiological connections with viruses from southern, eastern, and southeastern China. Our findings, together with recent prevalence trends of class I and virulent class II NDV in China, suggest possible virus transmission between wild and domestic birds and the potential for an NDV epidemic in the future. PMID:26712543

  19. High Genetic Diversity of Newcastle Disease Virus in Wild and Domestic Birds in Northeastern China from 2013 to 2015 Reveals Potential Epidemic Trends.

    PubMed

    Zhang, Pingze; Xie, Guangyao; Liu, Xinxin; Ai, Lili; Chen, Yanyu; Meng, Xin; Bi, Yuhai; Chen, Jianjun; Sun, Yuzhang; Stoeger, Tobias; Ding, Zhuang; Yin, Renfu

    2015-12-28

    Newcastle disease (ND), caused by the virulent Newcastle disease virus (NDV), is one of the most important viral diseases of birds globally, but little is currently known regarding enzootic trends of NDV in northeastern China, especially for class I viruses. Thus, we performed a surveillance study for NDV in northeastern China from 2013 to 2015. A total 755 samples from wild and domestic birds in wetlands and live bird markets (LBMs) were collected, and 10 isolates of NDV were identified. Genetic and phylogenetic analyses showed that five isolates from LBMs belong to class I subgenotype 1b, two (one from wild birds and one from LBMs) belong to the vaccine-like class II genotype II, and three (all from wild birds) belong to class II subgenotype Ib. Interestingly, the five class I isolates had epidemiological connections with viruses from southern, eastern, and southeastern China. Our findings, together with recent prevalence trends of class I and virulent class II NDV in China, suggest possible virus transmission between wild and domestic birds and the potential for an NDV epidemic in the future.

  20. Wired: impacts of increasing power line use by a growing bird population

    NASA Astrophysics Data System (ADS)

    Moreira, Francisco; Encarnação, Vitor; Rosa, Gonçalo; Gilbert, Nathalie; Infante, Samuel; Costa, Julieta; D’Amico, Marcello; Martins, Ricardo C.; Catry, Inês

    2017-02-01

    Power lines are increasingly widespread across many regions of the planet. Although these linear infrastructures are known for their negative impacts on bird populations, through collision and electrocution, some species take advantage of electricity pylons for nesting. In this case, estimation of the net impact of these infrastructures at the population level requires an assessment of trade-offs between positive and negative impacts. We compiled historical information (1958–2014) of the Portuguese white stork Ciconia ciconia population to analyze long-term changes in numbers, distribution range and use of nesting structures. White stork population size increased 660% up to 12000 breeding pairs between 1984 and 2014. In the same period, the proportion of nests on electricity pylons increased from 1% to 25%, likely facilitated by the 60% increase in the length of the very high tension power line grid (holding the majority of the nests) in the stork’s distribution range. No differences in breeding success were registered for storks nesting on electricity pylons versus other structures, but a high risk of mortality by collision and electrocution with power lines was estimated. We discuss the implications of this behavioral change, and of the management responses by power line companies, both for stork populations and for managers.

  1. Ranges of North American breeding birds: visualizing long-term population changes in North American breeding birds

    USGS Publications Warehouse

    Price, Jeff

    1995-01-01

    These maps show changes in the distribution and abundance patterns of some North American birds for the last 20 years. For each species there are four maps, each representing the average distribution and abundance pattern over the five-year periods 1970-1974, 1975-1979, 1980-1984, and 1985-1989. The maps are based on data collected by the USFWS/CWS Breeding Bird Survey (BBS). Only BBS routes that were run at least once during each of the five-year periods were used (about 1300 routes). The maps were created in the software package Surfer using a kriging technique to interpolate mean relative abundances for areas where no routes were run. On each map, a portion of northeast Canada was blanked out because there were not enough routes to allow for adequate interpolation. All of the maps in this presentation use the same color scale (shown below). The minimum value mapped was 0.5 birds per route, which represents the edge of the species range.

  2. Migratory connectivity and population-specific migration routes in a long-distance migratory bird.

    PubMed

    Trierweiler, Christiane; Klaassen, Raymond H G; Drent, Rudi H; Exo, Klaus-Michael; Komdeur, Jan; Bairlein, Franz; Koks, Ben J

    2014-03-07

    Knowledge about migratory connectivity, the degree to which individuals from the same breeding site migrate to the same wintering site, is essential to understand processes affecting populations of migrants throughout the annual cycle. Here, we study the migration system of a long-distance migratory bird, the Montagu's harrier Circus pygargus, by tracking individuals from different breeding populations throughout northern Europe. We identified three main migration routes towards wintering areas in sub-Saharan Africa. Wintering areas and migration routes of different breeding populations overlapped, a pattern best described by 'weak (diffuse) connectivity'. Migratory performance, i.e. timing, duration, distance and speed of migration, was surprisingly similar for the three routes despite differences in habitat characteristics. This study provides, to our knowledge, a first comprehensive overview of the migration system of a Palaearctic-African long-distance migrant. We emphasize the importance of spatial scale (e.g. distances between breeding populations) in defining patterns of connectivity and suggest that knowledge about fundamental aspects determining distribution patterns, such as the among-individual variation in mean migration directions, is required to ultimately understand migratory connectivity. Furthermore, we stress that for conservation purposes it is pivotal to consider wintering areas as well as migration routes and in particular stopover sites.

  3. Anthropogenic natal environmental effects on life histories in a wild bird population.

    PubMed

    Cartwright, Samantha J; Nicoll, Malcolm A C; Jones, Carl G; Tatayah, Vikash; Norris, Ken

    2014-03-03

    Recent work suggests that the environment experienced in early life can alter life histories in wild populations, but our understanding of the processes involved remains limited. Since anthropogenic environmental change is currently having a major impact on wild populations, this raises the possibility that life histories may be influenced by human activities that alter environmental conditions in early life. Whether this is the case and the processes involved remain unexplored in wild populations. Using 23 years of longitudinal data on the Mauritius kestrel (Falco punctatus), a tropical forest specialist, we found that females born in territories affected by anthropogenic habitat change shifted investment in reproduction to earlier in life at the expense of late life performance. They also had lower survival rates as young adults. This shift in life history strategy appears to be adaptive, because fitness was comparable to that of other females experiencing less anthropogenic modification in their natal environment. Our results suggest that human activities can leave a legacy on wild birds through natal environmental effects. Whether these legacies have a detrimental effect on populations will depend on life history responses and the extent to which these reduce individual fitness.

  4. Trends and effects of organochlorine residues on Oregon and Nevada wading birds, 1979-83

    USGS Publications Warehouse

    Henny, C.J.; Blus, L.J.; Hulse, C.S.

    1985-01-01

    The incidence of DDT (parent compound) declined significantly in the eggs of Black-crowned Night-Herons (Nycticorax nycticorax), White-faced Ibis (Plegadis chihi), and Black-necked Stilts (Himantopus mexicanus), and showed a downward trend in Snowy Egrets (Egretta thula). Mean DDE residues (breakdown product of DDT) in eggs declined significantly in Black-crowned Night-Herons and showed a downward trend in Black-necked Stilts and Snowy Egrets; however, no trend was apparent for White-faced Ibis. Some night-herons, egrets, and ibis laid thin-shelled eggs that cracked; eggshell thickness was negatively correlated with DDE residues in the egg contents. Ibis were the most sensitive species to DDE- induced shell thinning. Generally, reduced reproductive success for ibis started at lower DDE egg residues (3 ppm) than for either Snowy Egrets (5 ppm) or night-herons (8 ppm). Egg residue profiles, band recoveries, biotelemetry studies, and residues in fish and other prey items implicate the southwestern United States (a wintering area) as an important source of DDT-DDE that caused the most serious reproductive problem encountered during the study (in night-herons nesting at Ruby Lake, Nevada). Available evidence indicates that the three other species, together with night- herons from Oregon and Idaho, winter in Latin America.

  5. Dimensions of global population projections: what do we know about future population trends and structures?

    PubMed

    Lutz, Wolfgang; K C, Samir

    2010-09-27

    The total size of the world population is likely to increase from its current 7 billion to 8-10 billion by 2050. This uncertainty is because of unknown future fertility and mortality trends in different parts of the world. But the young age structure of the population and the fact that in much of Africa and Western Asia, fertility is still very high makes an increase by at least one more billion almost certain. Virtually, all the increase will happen in the developing world. For the second half of the century, population stabilization and the onset of a decline are likely. In addition to the future size of the population, its distribution by age, sex, level of educational attainment and place of residence are of specific importance for studying future food security. The paper provides a detailed discussion of different relevant dimensions in population projections and an evaluation of the methods and assumptions used in current global population projections and in particular those produced by the United Nations and by IIASA.

  6. Effects of five-year DDT application on breeding bird population

    USGS Publications Warehouse

    Robbins, C.S.; Springer, P.F.; Webster, C.G.

    1951-01-01

    Aerial applications of DDT in oil at the rate of 2 pounds per acre applied over a four-year interval on bottomland forest resulted in a 26 percent decrease in the breeding bird population by the fifth spring. The American redstart, parula warbler, and red-eyed vireo suffered decreases of 44 percent, 40. percent, and 28 percent, respectively, over the four-year period. Only the redstart decreased significantly immediately following application of the spray; a few days after the first, second, and fifth annual sprayings an average of 23 percent of redstart territories were deserted. No significant decrease was observed for other species, either immediately following spraying, or over the four-year period.

  7. Recommendations for the use of mist nets for inventory and monitoring of bird populations

    USGS Publications Warehouse

    Ralph, C. John; Dunn, Erica H.; Peach, Will J.; Handel, Colleen M.; Ralph, C. John; Dunn, Erica H.

    2004-01-01

    We provide recommendations on the best practices for mist netting for the purposes of monitoring population parameters such as abundance and demography. Studies should be carefully thought out before nets are set up, to ensure that sampling design and estimated sample size will allow study objectives to be met. Station location, number of nets, type of nets, net placement, and schedule of operation should be determined by the goals of the particular project, and we provide guidelines for typical mist-net studies. In the absence of study-specific requirements for novel protocols, commonly used protocols should be used to enable comparison of results among studies. Regardless of the equipment, net layout, or netting schedule selected, it is important for all studies that operations be strictly standardized, and a well-written operation protocol will help in attaining this goal. We provide recommendations for data to be collected on captured birds, and emphasize the need for good training of project personnel

  8. Second generation anticoagulant rodenticides in predatory birds: Probabilistic characterisation of toxic liver concentrations and implications for predatory bird populations in Canada.

    PubMed

    Thomas, Philippe J; Mineau, Pierre; Shore, Richard F; Champoux, Louise; Martin, Pamela A; Wilson, Laurie K; Fitzgerald, Guy; Elliott, John E

    2011-07-01

    Second-generation anticoagulant rodenticides (SGARs) are widely used to control rodent pests but exposure and poisonings occur in non-target species, such as birds of prey. Liver residues are often analysed to detect exposure in birds found dead but their use to assess toxicity of SGARs is problematic. We analysed published data on hepatic rodenticide residues and associated symptoms of anticoagulant poisoning from 270 birds of prey using logistic regression to estimate the probability of toxicosis associated with different liver SGAR residues. We also evaluated exposure to SGARs on a national level in Canada by analysing 196 livers from great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) found dead at locations across the country. Analysis of a broader sample of raptor species from Quebec also helped define the taxonomic breadth of contamination. Calculated probability curves suggest significant species differences in sensitivity to SGARs and significant likelihood of toxicosis below previously suggested concentrations of concern (<0.1mg/kg). Analysis of birds from Quebec showed that a broad range of raptor species are exposed to SGARs, indicating that generalised terrestrial food chains could be contaminated in the vicinity of the sampled areas. Of the two species for which we had samples from across Canada, great horned owls are exposed to SGARs to a greater extent than red-tailed hawks and the liver residue levels were also higher. Using our probability estimates of effect, we estimate that a minimum of 11% of the sampled great horned owl population is at risk of being directly killed by SGARs. This is the first time the potential mortality impact of SGARs on a raptor population has been estimated.

  9. Selenium teratogenesis in natural populations of aquatic birds in central California

    USGS Publications Warehouse

    Hoffman, D.J.; Ohlendorf, H.M.; Aldrich, T.W.

    1988-01-01

    The frequency and types of malformations are described that were encountered during the spring of 1983 in a natural population of aquatic birds exposed to agricultural drainwater ponds and food items containing high concentrations of selenium in central California. A total of 347 nests of aquatic birds containing 1,681 eggs was selected for study at Kesterson Reservoir located in the Kesterson National Wildlife Refuge (NWR), Merced County, California. Embryos collected during incubation or from eggs that failed to hatch were examined to determine the age at death and presence of malformations. Embryonic death was generally high; approximately 17?60% of the nests of different species contained at least one dead embryo. The incidence of malformed embryos was also high; approximately 22?65% of the nests where at least two embryos were examined contained abnormal embryos. American coots (Fulica americana) and black-necked stilts (Himantopus mexicanus) experienced the highest incidence of malformed embryos. For all species, the average percentage of eggs containing dead or live abnormal embryos was 16.1 whereas the average percentage containing live abnormal embryos was 10.7. Multiple gross malformations of the eyes, brain, and feet were often present. Brain defects included hydrocephaly and exencephaly. Eye defects included both unilateral and bilateral anophthalmia and microphthalmia. Eye and foot defects with ectrodactyly and swollen joints were the most common in coots. Beak defects also occurred frequently and most often included incomplete development of the lower beak of ducks (Anas spp.) and stilts. Wing and leg defects were most prevalent in stilts and ducks, with ectromelia and amelia most prevalent in stilts. Other malformations occurring at lower frequencies included enlarged hearts with thin ventricular walls, liver hypopiasia, and gastroschisis. Based upon simultaneous examination of a control population of aquatic birds of the same species and published

  10. The North American Breeding Bird Survey, results and analysis 1966 - 2015

    USGS Publications Warehouse

    Sauer, John; Niven, Daniel; Hines, James; Ziolkowski Jr., David; Pardieck, Keith L.; Fallon, J.E.; Link, William

    2017-01-01

    This website presents population change information for more than 400 species of North American birds, as estimated from the North American Breeding Bird Survey. Estimates of trend (interval-specific estimates of population change), annual indices of abundance, and maps of abundance and population change for these species are presented for a variety of regions.

  11. Persistent impacts of West Nile virus on North American bird populations

    PubMed Central

    George, T. Luke; Harrigan, Ryan J.; LaManna, Joseph A.; DeSante, David F.; Saracco, James F.; Smith, Thomas B.

    2015-01-01

    Since its introduction to North America in 1999, West Nile virus (WNV) has had devastating impacts on native host populations, but to date these impacts have been difficult to measure. Using a continental-scale dataset comprised of a quarter-million birds captured over nearly two decades and a recently developed model of WNV risk, we estimated the impact of this emergent disease on the survival of avian populations. We find that populations were negatively affected by WNV in 23 of the 49 species studied (47%). We distinguished two groups of species: those for which WNV negatively impacted survival only during initial spread of the disease (n = 11), and those that show no signs of recovery since disease introduction (n = 12). Results provide a novel example of the taxonomic breadth and persistent impacts of this wildlife disease on a continental scale. Phylogenetic analyses further identify groups (New World sparrows, finches, and vireos) disproportionally affected by temporary or persistent WNV effects, suggesting an evolutionary dimension of disease risk. Identifying the factors affecting the persistence of a disease across host species is critical to mitigating its effects, particularly in a world marked by rapid anthropogenic change. PMID:26578774

  12. Trends in chronic marine oil pollution in Danish waters assessed using 22 years of beached bird surveys.

    PubMed

    Larsen, Jørn Lennart; Durinck, Jan; Skov, Henrik

    2007-09-01

    Beached bird surveys provide an important tool for monitoring the level of oil pollution at sea, which is the most significant observable cause of death for a large number of waterbird species and pose a serious threat to wintering seabird populations. Linear regression analyses of oil rates from the Danish 22 year dataset show a decline in the oil pollution level in offshore areas of the eastern North Sea and Skagerrak and in near-shore parts of the Kattegat; but a worsening in the offshore areas of the Kattegat. These results raise concern for species such as common scoter, velvet scoter, eider and razorbill, for which the Kattegat serves as a globally important wintering area. It is recommended that surveillance for oil spills is intensified in inner Danish waters, and that action is taken to make responses towards offenders faster, and penalties for oil seepage higher.

  13. Polybrominated diphenyl ether trends in eggs of marine and freshwater birds from British Columbia, Canada, 1979-2002.

    PubMed

    Elliott, John E; Wilson, Laurie K; Wakeford, Bryan

    2005-08-01

    Temporal, spatial, and interspecific trends in polybrominated diphenyl ether (PBDE) flame retardants were determined in eggs of marine and freshwater bird species from the province of British Columbia, Canada. Temporal trends in the Fraser River estuary, 1983-2002, were examined by analysis of eggs of great blue herons (Ardea herodias) and from the Strait of Georgia marine ecosystem, 1979-2002, in eggs of double-crested cormorants (Phalacrocorax auritus). Results were compared to those from eggs of the osprey (Pandion haliaetus) taken along the lower Fraser River and along the Columbia River near Castlegar, British Columbia, and of a pelagic seabird, the Leach's storm-petrel (Oceanodroma leucorhoa), collected at a colony on the Queen Charlotte Islands. Mean concentration of sigmaPBDE, 455 microg/kg w.w., were highest in heron eggs collected in 2002 from the Fraser estuary. Concentrations in eggs of cormorants and ospreys taken from sites of varying urban influence tended to be about half that value. Leach's storm petrel eggs had only trace amounts of sigmaPBDE (3.38 microg/kg), despite having similar concentrations of PCBs and organochlorine pesticides to the other species. PBDEs increased exponentially with a doubling time of 5.7 years in eggs of both herons and cormorants. Over this period of increasing PBDEs, major chlorinated hydrocarbons, such as PCBs and DDE, were stable or decreased. The PBDE pattern was relatively consistent in most years and sites, with BDEs 47 > 100 > 99 > 153 > 154 > 28 > 183. This was interpreted as evidence of technical pentaBDE formulations as primary sources of the contamination, with the octaBDE formulations as secondary. Higher resolution analysis of a subsample of the eggs revealed the presence of up to nine other congeners, including BDE209 (range: 0.9-1.8 microg/kg), indicating exposure and uptake of decaBDE sourced congeners in North American foodchains. At some locations, concentrations of pentabrominated congeners and

  14. Distribution and abundance of marine bird and pinniped populations within Port Foster, Deception Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Kendall, Katrina A.; Ruhl, Henry A.; Wilson, Robert C.

    2003-06-01

    Seabirds and pinnipeds were surveyed during four cruises from March 1999 to November 2000 at Port Foster, Deception Island, Antarctica. Abundances and distributions of three species of pinnipeds, Arctocephalus gazella (Antarctic fur seals), Leptonychotes weddelli (Weddell seals), and Lobodon carcinophagus (crabeater seals), and 11 species of marine birds were documented within Port Foster. A. gazella was the dominant pinniped within Port Foster; its abundance has increased since the 1986/87 austral summer season. A. gazella were concentrated at the entrance to Port Foster. More pinnipeds were observed during the austral summer than during the spring. The most dominant seabird, Pygoscelis antarctica (chinstrap penguin), was concentrated along the rocky cliffs behind the beaches where A. gazella hauled out. Larus dominicanus (kelp gull) and Daption capense (cape petrel) were the most dominant flying seabirds. All other seabird species were more widely distributed around Port Foster than P. antarctica. There was no clear trend in abundances of seabirds over the study period. It is possible that the protected area of Port Foster provides refuge for vagrants of colonies along the outer periphery of the island and as a stopover point for migrating species.

  15. Chicago Children and Youth 1990-2010: Changing Population Trends and their Implications for Services

    ERIC Educational Resources Information Center

    Goerge, Robert; Dilts, John; Yang, Duck-Hye; Wasserman, Miriam; Clary, Anne

    2007-01-01

    This report draws on demographic data to examine and project trends in the size and composition of the child population in all seventy-seven Chicago communities up to the year 2010. The report highlights the changing age mix of Chicago children and provides some context in which to consider these demographic trends. It describes population changes…

  16. Mississippi's Farming & Nonfarming Population: A Comparison of Characteristics and Trends, 1950 to 1970.

    ERIC Educational Resources Information Center

    Bryant, Ellen S.

    Trends and changes in Mississippi farms, farmers, and farm populations were investigated for the period between 1950 and 1970 and comparisons were made between the farm population and that of the urban and rural nonfarm segments in terms of growth trends and 1970 characteristics. Data were drawn from both the Censuses of Agriculture (taken at five…

  17. Spatial and temporal trends of contaminants in eggs of wading birds from San Francisco Bay, California

    USGS Publications Warehouse

    Hothem, R.L.; Roster, D.L.; King, K.A.; Keldsen, T.J.; Marois, Katherine C.; Wainwright, S.E.

    1995-01-01

    Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California's San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p,p'-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time, At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element.

  18. Spatial and temporal trends of contaminants in eggs of wading birds from San Francisco Bay, California

    SciTech Connect

    Hothem, R.L.; Marois, K.C.; Wainwright, S.E.; Roster, D.L.; King, K.A.; Keldsen, T.J.

    1995-08-01

    Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California`s San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p,p{prime}-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time. At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element.

  19. Trends in population blood pressure and determinant factors for population blood pressure.

    PubMed

    Andersen, Ulla Overgaard

    2017-03-01

    Strategies to reduce the burden of blood pressure attributable diseases require knowledge of secular trend in PBP and its determinants. The issues were investigated in the Copenhagen City Heart Study. The design of CCHS is a repeated measures study. Such designs are uniquely suited to studying changes of an outcome and what risk factors may be associated with that outcome. Repeated measures studies are very well suited for trend analysis by using mixed effect analyses. SBP decreased about 2 mmHg in 25 years. The risk factors age, gender and BMI were found valid as determinant factors for secular trends in SBP. In addition, the following factors were identified: household income and the interactions ''gender*age'' and ''survey*age''. The interaction ''gender*age'' stated that the difference between SBP in the two genders was great in the young individuals and diminished by age. The interaction ''survey*age'' stated that SBP in the young individuals decreased more with survey than SBP in the older individuals. Thus, the 20 years old subjects in survey 2, 3 and 4 have lower SBP than the 20 years old subjects in preceding surveys. The slopes were less steep in higher ages. In the group of elderly and old subjects the trend is partly explained by treatment bias because more and more subjects leave the untreated group and start treatment. The factor ''household income'' was significant only in the female population and stated that high-income women had lower SBP and a more beneficial secular trend in SBP than low-income women. Marital status, self-reported physical exercise and alcohol intake were not significant factors. A number of factors, that are interesting in relation to SBP, were not included in the CCHS and therefore not investigated. Among them are salt intake, childhood factors, genetic factors and the DASH diet. A survival study was performed to investigate the mortality rate in relation to SBP changes during the observation period. A Cox regression analysis

  20. Bird community composition

    USGS Publications Warehouse

    Antrobus, T.J.; Guilfoyle, M.P.; Barrow, W.C.; Hamel, P.B.; Wakeley, J.S.

    2000-01-01

    Neotropical migrants are birds that breed in North America and winter primarily in Central and South America. Long-term population studies of birds in the Eastern United States indicated declines of some forest-dwelling birds, many of which winter in the Neotropics (Peterjohn and others 1995). These declines were attributed to loss of wintering and breeding habitat due to deforestation and fragmentation, respectively. Many species of Nearctic migrants--birds that breed in the northern regions of North America and winter in the Southern United States--are also experiencing population declines. Because large areas of undistrubed, older, bottomland hardwood forests oftern contain large numbers of habitat specialists, including forest-interior neotropical migrants and wintering Nearctic migrants, these forests may be critical in maintaining avian diversity. This study had two primary objectivs: (1) to create a baseline data set that can be used as a standard against which other bottomland hardwood forests can be compared, and (2) to establish long-term monitoring stations during both breeding and wintering seasons to discern population trends of avian species using bottomland hardwood forests.

  1. Changes in patch features may exacerbate or compensate for the effect of habitat loss on forest bird populations.

    PubMed

    Magrach, Ainhoa; Larrinaga, Asier R; Santamaría, Luis

    2011-01-01

    One and a half centuries after Darwin visited Chiloe Island, what he described as "…an island covered by one great forest…" has lost two-thirds of its forested areas. At this biodiversity hotspot, forest surface is becoming increasingly fragmented due to unregulated logging, clearing for pastures and replacement by exotic tree plantations. Decrease in patch size, increased isolation and "edge effects" can influence the persistence of forest species in remnant fragments. We assessed how these variables affect local density for six forest birds, chosen to include the most important seed dispersers (four species) and bird pollinators (two species, one of which acts also as seed disperser), plus the most common insectivore (Aphrastura spinicauda). Based on cue-count point surveys (8 points per fragment), we estimated bird densities for each species in 22 forest fragments of varying size, shape, isolation and internal-habitat structure (e.g. tree size and epiphyte cover). Bird densities varied with fragment connectivity (three species) and shape (three species), but none of the species was significantly affected by patch size. Satellite image analyses revealed that, from 1985 to 2008, forested area decreased by 8.8% and the remaining forest fragments became 16% smaller, 58-73% more isolated and 11-50% more regular. During that period, bird density estimates for the northern part of Chiloé (covering an area of 1214.75 km(2)) decreased for one species (elaenia), increased for another two (chucao and hummingbird) and did not vary for three (rayadito, thrust and blackbird). For the first three species, changes in patch features respectively exacerbated, balanced and overcame the effects of forest loss on bird population size (landscape-level abundance). Hence, changes in patch features can modulate the effect of habitat fragmentation on forest birds, suggesting that spatial planning (guided by spatially-explicit models) can be an effective tool to facilitate their

  2. Changes in Patch Features May Exacerbate or Compensate for the Effect of Habitat Loss on Forest Bird Populations

    PubMed Central

    Magrach, Ainhoa; Larrinaga, Asier R.; Santamaría, Luis

    2011-01-01

    One and a half centuries after Darwin visited Chiloe Island, what he described as “…an island covered by one great forest…” has lost two-thirds of its forested areas. At this biodiversity hotspot, forest surface is becoming increasingly fragmented due to unregulated logging, clearing for pastures and replacement by exotic tree plantations. Decrease in patch size, increased isolation and “edge effects” can influence the persistence of forest species in remnant fragments. We assessed how these variables affect local density for six forest birds, chosen to include the most important seed dispersers (four species) and bird pollinators (two species, one of which acts also as seed disperser), plus the most common insectivore (Aphrastura spinicauda). Based on cue-count point surveys (8 points per fragment), we estimated bird densities for each species in 22 forest fragments of varying size, shape, isolation and internal-habitat structure (e.g. tree size and epiphyte cover). Bird densities varied with fragment connectivity (three species) and shape (three species), but none of the species was significantly affected by patch size. Satellite image analyses revealed that, from 1985 to 2008, forested area decreased by 8.8% and the remaining forest fragments became 16% smaller, 58–73% more isolated and 11–50% more regular. During that period, bird density estimates for the northern part of Chiloé (covering an area of 1214.75 km2) decreased for one species (elaenia), increased for another two (chucao and hummingbird) and did not vary for three (rayadito, thrust and blackbird). For the first three species, changes in patch features respectively exacerbated, balanced and overcame the effects of forest loss on bird population size (landscape-level abundance). Hence, changes in patch features can modulate the effect of habitat fragmentation on forest birds, suggesting that spatial planning (guided by spatially-explicit models) can be an effective tool to facilitate

  3. Avian malaria in Hawaiian forest birds: Infection and population impacts across species and elevations

    USGS Publications Warehouse

    Samuel, Michael D.; Woodworth, Bethany L.; Atkinson, Carter T.; Hart, P. J.; LaPointe, Dennis

    2015-01-01

    Wildlife diseases can present significant threats to ecological systems and biological diversity, as well as domestic animal and human health. However, determining the dynamics of wildlife diseases and understanding the impact on host populations is a significant challenge. In Hawai‘i, there is ample circumstantial evidence that introduced avian malaria (Plasmodium relictum) has played an important role in the decline and extinction of many native forest birds. However, few studies have attempted to estimate disease transmission and mortality, survival, and individual species impacts in this distinctive ecosystem. We combined multi-state capture-recapture (longitudinal) models with cumulative age-prevalence (cross-sectional) models to evaluate these patterns in Apapane, Hawai‘i Amakihi, and Iiwi in low-, mid-, and high-elevation forests on the island of Hawai‘i based on four longitudinal studies of 3–7 years in length. We found species-specific patterns of malaria prevalence, transmission, and mortality rates that varied among elevations, likely in response to ecological factors that drive mosquito abundance. Malaria infection was highest at low elevations, moderate at mid elevations, and limited in high-elevation forests. Infection rates were highest for Iiwi and Apapane, likely contributing to the absence of these species in low-elevation forests. Adult malaria fatality rates were highest for Iiwi, intermediate for Amakihi at mid and high elevations, and lower for Apapane; low-elevation Amakihi had the lowest malaria fatality, providing strong evidence of malaria tolerance in this low-elevation population. Our study indicates that hatch-year birds may have greater malaria infection and/or fatality rates than adults. Our study also found that mosquitoes prefer feeding on Amakihi rather than Apapane, but Apapane are likely a more important reservoir for malaria transmission to mosquitoes. Our approach, based on host abundance and infection rates, may be an

  4. Relationships between nesting populations of wading birds and habitat features along the Atlantic Coast

    USGS Publications Warehouse

    Erwin, R.M.; Spendelow, J.A.; Geissler, P.H.; Williams, B.K.; Whitman, William R.; Meredith, William H.

    1987-01-01

    Using previously published atlas data for 122 mixed-species wading bird colonies on islands along the Atlantic coast (Maine to Florida, 1976-77), we examined relationships between population sizes of 11 species of egrets, herons, ibises, and wood storks (Mycteria americana) and nine habitat variables. On nautical charts, we measured four island characteristics (area, length, width, shape), three isolation factors (distances to nearest island, mainland, and a water barrier),, and two variables related to potential feeding habitat within 5 km of the center of the colony (wetland area and land-water interface, i.e., the linear distance between the marsh/upland and all water bodies within the same 5-km radius). One univariable and five multivariable .procedures were used to determine which habitat features were best related to population size .(all species combined). Multicollinearity problems among the variables limited interpretation for most procedures. Both univariable and the multivariable procedures indicated that land-water interface was the most important of the nine variables, but for all models, less than 10% of the total variance was explained (rz is less than 0.10). The size of the colony was not related to the amount of wetland area (within 5-km).per se. Colony data showed better 'structure' when examined on the basis of geographic and disturbance gradients. Population sizes of colonies near man-altered habitats were compared with those surrounded by relatively natural habitats in three geographic zones: north, middle, and south. Significant differences were found in colony size among the three zones (south largest) and between disturbance types. Surprisingly, in all three zones, colonies near man-altered areas were larger on average than those near more natural habitats in this region. A possible reason for this difference is suggested.

  5. A reduced progenitor pool population accounts for the rudimentary appearance of the septum, medial pallium and dorsal pallium in birds.

    PubMed

    Charvet, Christine J

    2010-01-01

    To date, most studies comparing birds and mammals have focused on the similarities in brain development, architecture and connectivity. However, major differences in size, anatomy and organization exist in the telencephalon of adult birds and mammals. For instance, the septum, medial pallium and dorsal pallium of birds appear rudimentary compared with those of mammals. To identify the developmental processes that give rise to this difference in size and anatomy of the septum, medial pallium and dorsal pallium, the thickness of the ventricular zone that encompasses these regions was measured in embryonic birds (i.e. chickens, sparrows) and mammals (i.e. rabbits, hedgehogs, shrews, platypus). Cumulative bromodeoxyuridine (BrdU) labeling in chickens at embryonic day 7 and 8 was also used to examine levels of cell proliferation in the ventricular zone of the septum, medial pallium and dorsal pallium. The study's main finding is that the ventricular zone of the septum, medial pallium and dorsal pallium is thinner in birds than in mammals. In chickens, the septum, medial pallium and dorsal pallium ventricular zone harbor few proliferating (i.e. BrdU+) cells. Collectively, these findings suggest that a reduced progenitor pool population account for the 'rudimentary' appearance of the avian septum, medial pallium and dorsal pallium.

  6. Geographic variation in onset of singing among populations of two migratory birds

    NASA Astrophysics Data System (ADS)

    Gordo, Oscar; Sanz, Juan José; Lobo, Jorge M.

    2008-07-01

    Even though singing plays a major role in bird communication, environmental variables affecting the geographic patterns observed in the variation of singing onset within large areas have not previously been studied. The singing phenology of two long-distance migrants, the Cuckoo Cuculus canorus and the Nightingale Luscinia megarhynchos, recorded in thousands of sites throughout Spain, was related to a set of 51 explanatory variables by partial least squares regression. Observed variability in singing onset among localities follows spatial trends on an Iberian scale at 10 × 10 km resolution, and was well modelled by some environmental variables. Of these variables, climate was the most influential. Males of both species sang earlier in warmer and drier sites. Males who were near the Straits of Gibraltar and in the southern Iberian basins, which are geographic gradients closely related with climate in the Iberian Peninsula, were also heard earlier. Most environmental variables affected the singing activity of both species equally, i.e., the same environmental gradients are linked to singing onset. However, the models' predictions indicated differences in the geographical pattern in singing onset between both species, mainly related to their rates of progression during spring migration through Spain. Local variables, such as land uses, vegetation productivity or species abundance, played a minor role on singing onset spatial patterns. Therefore, models' composition supports the hypothesis that singing onset is a good proxy of arrival dates in migratory species, since those variables related to indirect effects on singing onset phenology through migratory progression and arrival to the breeding grounds showed the highest influence.

  7. Aging in France: Population Trends, Policy Issues, and Research Institutions

    ERIC Educational Resources Information Center

    Beland, Daniel; Durandal, Jean-Philippe Viriot

    2013-01-01

    Like in other advanced industrial countries, in France, demographic aging has become a widely debated research and policy topic. This article offers a brief overview of major aging-related trends in France. The article describes France's demographics of aging, explores key policy matters, maps the institutional field of French social gerontology…

  8. Bergmann's rule and climate change revisited: disentangling environmental and genetic responses in a wild bird population.

    PubMed

    Teplitsky, Céline; Mills, James A; Alho, Jussi S; Yarrall, John W; Merilä, Juha

    2008-09-09

    Ecological responses to on-going climate change are numerous, diverse, and taxonomically widespread. However, with one exception, the relative roles of phenotypic plasticity and microevolution as mechanisms in explaining these responses are largely unknown. Several recent studies have uncovered evidence for temporal declines in mean body sizes of birds and mammals, and these responses have been interpreted as evidence for microevolution in the context of Bergmann's rule-an ecogeographic rule predicting an inverse correlation between temperature and mean body size in endothermic animals. We used a dataset of individually marked red-billed gulls (Larus novaehollandiae scopulinus) from New Zealand to document phenotypic and genetic changes in mean body mass over a 47-year (1958-2004) period. We found that, whereas the mean body mass had decreased over time as ambient temperatures increased, analyses of breeding values estimated with an "animal model" approach showed no evidence for any genetic change. These results indicate that the frequently observed climate-change-related responses in mean body size of animal populations might be due to phenotypic plasticity, rather than to genetic microevolutionary responses.

  9. Productivity, mortality, and population trends of wolves in northeastern Minnesota

    USGS Publications Warehouse

    Mech, L.D.

    1977-01-01

    Population parameters, mortality causes, and mechanisms of a population decline were studied in wolves (Canis lupus lycaon) from 1968 to 1976 in the Superior National Forest. The main method was aerial radio-tracking of 129 wolves and their packmates. Due to a decline in white-tailed deer (Odocoileus virginianus), the wolf population decreased during most of the study. Average annual productivity varied from 1.5 to 3.3 pups per litter, and annual mortality rates from 7 to 65 percent. Malnutrition and intraspecific strife accounted equally for 58 percent of the mortality; human causes accounted for the remainder. As wolf numbers began to decline, pup starvation became apparent, followed by lower pup production, and then by increased intraspecific strife. At higher densities, adult pack wolves were the most secure members of the population, but as the population declined, they became the least secure because of intraspecific strife.

  10. Standardized North American marsh bird monitoring protocol

    USGS Publications Warehouse

    Conway, Courtney J.

    2011-01-01

    Little is known about the population status of many marsh-dependent birds in North America but recent efforts have focused on collecting more reliable information and estimates of population trends. As part of that effort, a standardized survey protocol was developed in 1999 that provided guidance for conducting marsh bird surveys throughout North America such that data would be consistent among locations. The original survey protocol has been revised to provide greater clarification on many issues as the number of individuals using the protocol has grown. The Standardized North American Marsh Bird Monitoring Protocol instructs surveyors to conduct an initial 5-minute passive point-count survey followed by a series of 1-minute segments during which marsh bird calls are broadcast into the marsh following a standardized approach. Surveyors are instructed to record each individual bird from the suite of 26 focal species that are present in their local area on separate lines of a datasheet and estimate the distance to each bird. Also, surveyors are required to record whether each individual bird was detected within each 1-minute subsegment of the survey. These data allow analysts to use several different approaches for estimating detection probability. The Standardized North American Marsh Bird Monitoring Protocol provides detailed instructions that explain the field methods used to monitor marsh birds in North America.

  11. Supplementary feeding of wild birds indirectly affects ground beetle populations in suburban gardens.

    PubMed

    Orros, Melanie E; Thomas, Rebecca L; Holloway, Graham J; Fellowes, Mark D E

    Supplementary feeding of wild birds by domestic garden-holders is a globally widespread and popular form of human-wildlife interaction, particularly in urban areas. Vast amounts of energy are thus being added to garden ecosystems. However, the potential indirect effects of this activity on non-avian species have been little studied to date, with the only two previous studies taking place under experimentally manipulated conditions. Here we present the first evidence of a localised depletive effect of wild bird feeding on ground beetles (Coleoptera: Carabidae) in suburban gardens under the usual feeding patterns of the garden-holders. We trapped significantly fewer ground beetles directly under bird-feeding stations than in matched areas of habitat away from feeders. Video analysis also revealed significantly higher activity by ground-foraging birds under the feeding stations than in the control areas. Small mammal trapping revealed no evidence that these species differ in abundance between gardens with and without bird feeders. We therefore suggest that local increases in ground-foraging activity by bird species whose diets encompass arthropods as well as seed material are responsible for the reduction in ground beetle numbers. Our work therefore illustrates that providing food for wild birds can have indirect negative effects on palatable prey species under typical conditions.

  12. Population, consumption trends call for new environmental policies.

    PubMed

    1998-04-01

    This article highlights the need for new environmental policies. 38 industrialized countries gave commitments to protect the environment by reducing greenhouse gas emissions. But, a report on "Population Change, Resources, and the Environment" indicated that high levels of resource consumption in developed countries are a problem also, as are the complex environmental consequences of rapid population growth in developing countries. Global population is expected to include at least another 2 billion people by the mid-21st century. This growth will occur mostly in countries that lack the resources to invest in sound environmental policies and that may not adopt economic growth with little environmental impact. Additional population requires additional food, water, and shelter. The links between the environment and population include social structures, political systems, and lifestyles. Population is increasing the fastest in countries with the least efficient food production and distribution systems. Access to safe drinking water is constrained by poverty, poor infrastructure, and pollution of waterways and groundwater. A major share of economic growth will occur in cities. Population shifts to cities will create demand for health care and education, and encroach on surrounding farmland. Global marine fish stocks are being depleted. Logging and agriculture threaten forest resources. The report stresses that government policies that minimize the environmental impact of humans should promote recycling, eliminate subsidies that distort environmental costs of scarce resources, and implement better forest and fishery management. Politicians must think globally and act locally.

  13. Aging in Mexico: Population Trends and Emerging Issues.

    PubMed

    Angel, Jacqueline L; Vega, William; López-Ortega, Mariana

    2016-12-07

    Although all nations in the America's face a common demographic reality of longevity, declining fertility rates and changes in family roles a growing body of research points to a dramatic demographic transformation in Mexico. Although Mexico's population is relatively young, with a median age of 27.9 in 2015, it will age rapidly in coming years, increasing to 42 years by 2050. The rapid median age in the nation also reflects the growing proportion of people 65 or older, and is expected to triple to 20.2% by 2050. This article examines how the age and gender structure of Mexico offers important insights about current and future political and social stability, as well as economic development. Mexico is the world's eleventh largest country in terms of population size and the "demographic dividend" of a large youthful population is giving way to a growing older population that will inevitably place demands on health care and social security. The shift in age structure will result in increased dependency of retirees on the working-age population in the next 20 years. Mexico does not provide universal coverage of social security benefits and less than half of the labor force is covered by any pension or retirement plan. As a result, elderly Mexicans often continue working into old age. The high total poverty rate in the country, especially among the older population magnifies the problem of the potential dependency burden. The article ends with a discussion of key public policy issues related to aging in Mexico.

  14. Integrating paleoecology and genetics of bird populations in two sky island archipelagos

    PubMed Central

    McCormack, John E; Bowen, Bonnie S; Smith, Thomas B

    2008-01-01

    Background Genetic tests of paleoecological hypotheses have been rare, partly because recent genetic divergence is difficult to detect and time. According to fossil plant data, continuous woodland in the southwestern USA and northern Mexico became fragmented during the last 10,000 years, as warming caused cool-adapted species to retreat to high elevations. Most genetic studies of resulting 'sky islands' have either failed to detect recent divergence or have found discordant evidence for ancient divergence. We test this paleoecological hypothesis for the region with intraspecific mitochondrial DNA and microsatellite data from sky-island populations of a sedentary bird, the Mexican jay (Aphelocoma ultramarina). We predicted that populations on different sky islands would share common, ancestral alleles that existed during the last glaciation, but that populations on each sky island, owing to their isolation, would contain unique variants of postglacial origin. We also predicted that divergence times estimated from corrected genetic distance and a coalescence model would post-date the last glacial maximum. Results Our results provide multiple independent lines of support for postglacial divergence, with the predicted pattern of shared and unique mitochondrial DNA haplotypes appearing in two independent sky-island archipelagos, and most estimates of divergence time based on corrected genetic distance post-dating the last glacial maximum. Likewise, an isolation model based on multilocus gene coalescence indicated postglacial divergence of five pairs of sky islands. In contrast to their similar recent histories, the two archipelagos had dissimilar historical patterns in that sky islands in Arizona showed evidence for older divergence, suggesting different responses to the last glaciation. Conclusion This study is one of the first to provide explicit support from genetic data for a postglacial divergence scenario predicted by one of the best paleoecological records in the

  15. Seasonality of Ankle Swelling: Population Symptom Reporting Using Google Trends.

    PubMed

    Liu, Fangwei; Allan, G Michael; Korownyk, Christina; Kolber, Michael; Flook, Nigel; Sternberg, Harvey; Garrison, Scott

    2016-07-01

    In our experience, complaints of ankle swelling are more common in summer, typically from patients with no obvious cardiovascular disease. Surprisingly, this observation has never been reported. To objectively establish this phenomenon, we sought evidence of seasonality in the public's Internet searches for ankle swelling. Our data, obtained from Google Trends, consisted of all related Google searches in the United States from January 4, 2004, to January 26, 2016. Consistent with our expectations and confirmed by similar data for Australia, Internet searches for information on ankle swelling are highly seasonal (highest in midsummer), with seasonality explaining 86% of search volume variability.

  16. Genetically diverse coronaviruses in captive bird populations in a Brazilian zoological park.

    PubMed

    Cardoso, Tereza C; Teixeira, Maria Cecília B; Gomes, Deriane E; Jerez, Antônio José

    2011-02-01

    This study aimed to investigate the occurrence of coronaviruses (CoVs) in captive birds placed inside a zoological park in Brazil. The role of captive birds in the epidemiology of CoVs in the tropics is poorly understood. A total of 25 (n=25) different species were tested for viral RNA using individual fecal samples collected from healthy birds. Reverse transcription-polymerase chain reaction targeting the 3' untranslated region was used to detect CoV RNA, and positive samples were submitted for sequence analysis. The phylogenetic search revealed nine mutations in the black shouldered peafowl (Pavus cristatus) CoV sequence, which clustered separately from samples previously described in England. This is the first report on the detection of the CoV genome in captive birds in Brazil.

  17. USE OF CITIZEN BIRD POPULATION MONITORING DATA FOR ECOLOGICAL RISK ASSESSMENT

    EPA Science Inventory

    Birds are among the most conspicuous and easily monitored indicators of environmental health and change. Although volunteer avian monitoring ('citizen science') programs provide unique opportunities to gather data at fine and broad geographic scales simultaneously, and over long...

  18. [Strategy on control of births by population trend (author's transl)].

    PubMed

    Kong, S K; Jang, Y S

    1982-12-01

    The birth control program was based on the idea that an individual should want a small family and pregnancy should be prevented if a child is not wanted. Birth control program goals were, therefore, conducted through an educational enlightenment of family planning programs and contraceptive services provided to the targetted groups. The service delivery system has been modified to reflect the socio-situational changes over the last 20 years. These programs have, however, faced difficulties because of unlimited contraceptive service delivery systems and a lack of diversity in the services offered. The dynamic socioeconomic development achieved during the last 20 years (1962-81) and the steady implementation of birth control measures have apparently had an impact on the population structure and distribution. At the same time, the practice of abortion and present acceptance rates make us wonder whether or not present services are meeting actual needs. The objectives of this study were to analyze behavioral changes in births, and to examine how population dynamics have changed. Recommendations for future birth control policy were made. During the 1960s, the population maintained a high 3% increase rate while the death rate gradually decreased. However, during 1970-80, birthrate and death rate decreased by 50%. The population structure has changed with younger population ratios decreasing and the elder population increasing. The increase in total population and the change in the age structure will increase the reproductive population in spite of the concentrated family planning efforts for the reproductive age group. Reproductive women have been increasing and the population ratio of women between ages 15-49 was 23% in 1960 and will increase to 26% in 1980 and 27% in 1990. This increase in the ratio of eligible women will function inversely to population decline. The ratio of higher fertility age groups in the total population has increased since 1980 so they should be

  19. Quantitative assessment of the importance of phenotypic plasticity in adaptation to climate change in wild bird populations.

    PubMed

    Vedder, Oscar; Bouwhuis, Sandra; Sheldon, Ben C

    2013-07-01

    Predictions about the fate of species or populations under climate change scenarios typically neglect adaptive evolution and phenotypic plasticity, the two major mechanisms by which organisms can adapt to changing local conditions. As a consequence, we have little understanding of the scope for organisms to track changing environments by in situ adaptation. Here, we use a detailed individual-specific long-term population study of great tits (Parus major) breeding in Wytham Woods, Oxford, UK to parameterise a mechanistic model and thus directly estimate the rate of environmental change to which in situ adaptation is possible. Using the effect of changes in early spring temperature on temporal synchrony between birds and a critical food resource, we focus in particular on the contribution of phenotypic plasticity to population persistence. Despite using conservative estimates for evolutionary and reproductive potential, our results suggest little risk of population extinction under projected local temperature change; however, this conclusion relies heavily on the extent to which phenotypic plasticity tracks the changing environment. Extrapolating the model to a broad range of life histories in birds suggests that the importance of phenotypic plasticity for adjustment to projected rates of temperature change increases with slower life histories, owing to lower evolutionary potential. Understanding the determinants and constraints on phenotypic plasticity in natural populations is thus crucial for characterising the risks that rapidly changing environments pose for the persistence of such populations.

  20. Quantitative Assessment of the Importance of Phenotypic Plasticity in Adaptation to Climate Change in Wild Bird Populations

    PubMed Central

    Vedder, Oscar; Bouwhuis, Sandra; Sheldon, Ben C.

    2013-01-01

    Predictions about the fate of species or populations under climate change scenarios typically neglect adaptive evolution and phenotypic plasticity, the two major mechanisms by which organisms can adapt to changing local conditions. As a consequence, we have little understanding of the scope for organisms to track changing environments by in situ adaptation. Here, we use a detailed individual-specific long-term population study of great tits (Parus major) breeding in Wytham Woods, Oxford, UK to parameterise a mechanistic model and thus directly estimate the rate of environmental change to which in situ adaptation is possible. Using the effect of changes in early spring temperature on temporal synchrony between birds and a critical food resource, we focus in particular on the contribution of phenotypic plasticity to population persistence. Despite using conservative estimates for evolutionary and reproductive potential, our results suggest little risk of population extinction under projected local temperature change; however, this conclusion relies heavily on the extent to which phenotypic plasticity tracks the changing environment. Extrapolating the model to a broad range of life histories in birds suggests that the importance of phenotypic plasticity for adjustment to projected rates of temperature change increases with slower life histories, owing to lower evolutionary potential. Understanding the determinants and constraints on phenotypic plasticity in natural populations is thus crucial for characterising the risks that rapidly changing environments pose for the persistence of such populations. PMID:23874152

  1. A Method for Investigating Population Declines of Migratory Birds Using Stable Isotopes: Origins of Harvested Lesser Scaup in North America

    PubMed Central

    Hobson, Keith A.; Wunder, Michael B.; Van Wilgenburg, Steven L.; Clark, Robert G.; Wassenaar, Leonard I.

    2009-01-01

    Background Elucidating geographic locations from where migratory birds are recruited into adult breeding populations is a fundamental but largely elusive goal in conservation biology. This is especially true for species that breed in remote northern areas where field-based demographic assessments are logistically challenging. Methodology/Findings Here we used hydrogen isotopes (δD) to determine natal origins of migrating hatch-year lesser scaup (Aythya affinis) harvested by hunters in the United States from all North American flyways during the hunting seasons of 1999–2000 (n = 412) and 2000–2001 (n = 455). We combined geospatial, observational, and analytical data sources, including known scaup breeding range, δD values of feathers from juveniles at natal sites, models of δD for growing-season precipitation, and scaup band-recovery data to generate probabilistic natal origin landscapes for individual scaup. We then used Monte Carlo integration to model assignment uncertainty from among individual δD variance estimates from birds of known molt origin and also from band-return data summarized at the flyway level. We compared the distribution of scaup natal origin with the distribution of breeding population counts obtained from systematic long-term surveys. Conclusions/Significance Our analysis revealed that the proportion of young scaup produced in the northern (above 60°N) versus the southern boreal and Prairie-Parkland region was inversely related to the proportions of breeding adults using these regions, suggesting that despite having a higher relative abundance of breeding adults, the northern boreal region was less productive for scaup recruitment into the harvest than more southern biomes. Our approach for evaluating population declines of migratory birds (particularly game birds) synthesizes all available distributional data and exploits the advantages of intrinsic isotopic markers that link individuals to geography. PMID:19946360

  2. Effects of land use on bird populations and pest control services on coffee farms.

    PubMed

    Railsback, Steven F; Johnson, Matthew D

    2014-04-22

    Global increases in both agriculture and biodiversity awareness raise a key question: Should cropland and biodiversity habitat be separated, or integrated in mixed land uses? Ecosystem services by wildlife make this question more complex. For example, birds benefit agriculture by preying on pest insects, but other habitat is needed to maintain the birds. Resulting land use questions include what areas and arrangements of habitat support sufficient birds to control pests, whether this pest control offsets the reduced cropland, and the comparative benefits of "land sharing" (i.e., mixed cropland and habitat) vs. "land sparing" (i.e., separate areas of intensive agriculture and habitat). Such questions are difficult to answer using field studies alone, so we use a simulation model of Jamaican coffee farms, where songbirds suppress the coffee berry borer (CBB). Simulated birds select habitat and prey in five habitat types: intact forest, trees (including forest fragments), shade coffee, sun coffee, and unsuitable habitat. The trees habitat type appears to be especially important, providing efficient foraging and roosting sites near coffee plots. Small areas of trees (but not forest alone) could support a sufficient number of birds to suppress CBB in sun coffee; the degree to which trees are dispersed within coffee had little effect. In simulations without trees, shade coffee supported sufficient birds to offset its lower yield. High areas of both trees and shade coffee reduced pest control because CBB was less often profitable prey. Because of the pest control service provided by birds, land sharing was predicted to be more beneficial than land sparing in this system.

  3. Effects of land use on bird populations and pest control services on coffee farms

    PubMed Central

    Railsback, Steven F.; Johnson, Matthew D.

    2014-01-01

    Global increases in both agriculture and biodiversity awareness raise a key question: Should cropland and biodiversity habitat be separated, or integrated in mixed land uses? Ecosystem services by wildlife make this question more complex. For example, birds benefit agriculture by preying on pest insects, but other habitat is needed to maintain the birds. Resulting land use questions include what areas and arrangements of habitat support sufficient birds to control pests, whether this pest control offsets the reduced cropland, and the comparative benefits of “land sharing” (i.e., mixed cropland and habitat) vs. “land sparing” (i.e., separate areas of intensive agriculture and habitat). Such questions are difficult to answer using field studies alone, so we use a simulation model of Jamaican coffee farms, where songbirds suppress the coffee berry borer (CBB). Simulated birds select habitat and prey in five habitat types: intact forest, trees (including forest fragments), shade coffee, sun coffee, and unsuitable habitat. The trees habitat type appears to be especially important, providing efficient foraging and roosting sites near coffee plots. Small areas of trees (but not forest alone) could support a sufficient number of birds to suppress CBB in sun coffee; the degree to which trees are dispersed within coffee had little effect. In simulations without trees, shade coffee supported sufficient birds to offset its lower yield. High areas of both trees and shade coffee reduced pest control because CBB was less often profitable prey. Because of the pest control service provided by birds, land sharing was predicted to be more beneficial than land sparing in this system. PMID:24711377

  4. World population trends and their significance for contraceptive research.

    PubMed

    Kegan, L R

    1982-01-01

    The total population of the world has grown from 2.5 billion in 1930 to 4.5 billion in 1982 and despite the fertility declines in developing countries world population is expected to increase another 2 billion to over 6 billion by the year 2000. This growth has caused in many countries food scarcity, unemployment, social unrest, political instability, and mass migration as well as inflation and environmental problems. There is an international consensus that access to contraceptive services is a basic human right. In the case of Indonesia, Thailand, China, and Sri Lanka, there is increasing evidence that government intervention can change fertility levels within a relatively short time, but progress in other places has been slower. Thus the fertility reductions to be achieved during the next 2 decades will require more intensive and expensive efforts in terms of education, motivation, and extension of services in rural areas. Contraceptive methods must be improved in terms of safety, acceptability, and effectiveness.

  5. 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.

  6. Point counts of birds: what are we estimating?

    USGS Publications Warehouse

    Johnson, D.H.

    1995-01-01

    Point counts of birds are made for many reasons, including estimating local densities, determining population trends, assessing habitat preferences, and exploiting the activities of recreational birdwatchers. Problems arise unless there is a clear understanding of what point counts mean in terms of actual populations of birds. Criteria for conducting point counts depend strongly on the purposes to which they will be put. This paper provides a simple mathematical conceptualization of point counts and illustrates graphically some of the influences on them.

  7. Monitoring trends in bat populations of the United States and territories: Problems and prospects

    USGS Publications Warehouse

    O'Shea, T.J.; Bogan, M. A.

    2003-01-01

    Bats are ecologically and economically important mammals. The life histories of bats (particularly their low reproductive rates and the need for some species to gather in large aggregations at limited numbers of roosting sites) make their populations vulnerable to declines. Many of the species of bats in the United States (U.S.) and territories are categorized as endangered or threatened, have been candidates for such categories, or are considered species of concern. The importance and vulnerability of bat populations makes monitoring trends in their populations a goal for their future management. However, scientifically rigorous monitoring of bat populations requires well-planned, statistically defensible efforts. This volume reports findings of an expert workshop held to examine the topic of monitoring populations of bats. The workshop participants included leading experts in sampling and analysis of wildlife populations, as well as experts in the biology and conservation of bats. Findings are reported in this volume under two sections. Part I of the report presents contributed papers that provide overviews of past and current efforts at monitoring trends in populations of bats in the U.S. and territories. These papers consider current techniques and problems, and summarize what is known about the status and trends in populations of selected groups of bats. The contributed papers in Part I also include a description of the monitoring program developed for bat populations in the United Kingdom, a critique of monitoring programs in wildlife in general with recommendations for survey and sampling strategies, and a compilation and analysis of existing data on trends in bats of the U.S. and territories. Efforts directed at monitoring bat populations are piecemeal and have shortcomings. In Part II of the report, the workshop participants provide critical analyses of these problems and develop recommendations for improving methods, defining objectives and priorities

  8. Demographic Trends in the Republic of Zaire. Caltech Population Program Occasional Papers, Series 1, Number 5.

    ERIC Educational Resources Information Center

    Boute, Joseph

    This paper, one in a series of occasional publications, discusses population growth and trends in the African Republic of Zaire. The series is intended to increase understanding of the interrelationships between population growth and socioeconomic and cultural patterns throughout the world, and to communicate this understanding to scholars and…

  9. Population Change: Do You Know the Trends in Your Community? Coping with Growth.

    ERIC Educational Resources Information Center

    Butler, Lorna Michael

    To help government agency representatives and community leaders understand local population trends, particularly in rapid growth situations, this publication outlines a simple framework for analyzing population changes and provides useful criteria that can be applied when considering management and policy alternatives. It is noted that two…

  10. Abundance, distribution, and population trends of the iconic Hawaiian Honeycreeper, the ʻIʻiwi (Vestiaria coccinea) throughout the Hawaiian Islands

    USGS Publications Warehouse

    Paxton, Eben H.; Gorresen, P. Marcos; Camp, Richard J.

    2013-01-01

    Naturalists in the 1800s described the ʻIʻiwi (Vestiaria coccinea) as one of the most abundant forest birds, detected in forested areas from sea level to tree line across all the major Hawaiian Islands. However, in the late 1800s, ʻIʻiwi began to disappear from low elevation forests, and by the mid-1900s, the species was largely absent from low- and mid-elevation areas. Today, ʻIʻiwi are restricted to high-elevation forests on the islands of Hawaiʻi, east Maui, and Kauaʻi, with a few birds apparently persisting on Oʻahu, Molokaʻi, and west Maui. ʻIʻiwi are highly vulnerable to introduced disease, and the prevalence of avian malaria in low and mid-elevations is believed to be the cause of ʻIʻiwi being restricted to high elevations where temperatures are too cold for the development of the disease and its mosquito vector. With global warming, it is feared that the disease will move quickly into the high-elevation forests where the last ʻIʻiwi reside, threatening their viability. The U.S. Fish and Wildlife Service was petitioned to list the ʻIʻiwi as an Endangered Species in 2010, and this report provides a comprehensive review of the abundance, distribution, and trends using historical survey data as well as the most recently available survey information (up to 2012). We estimate the total population size of ‘I‘iwi at 550,972–659,864 (mean = 605,418) individuals. Of these, 90 percent are on the island of Hawaiʻi, followed by east Maui (about 10 percent), with less than 1 percent on Kauaʻi. ʻIʻiwi population trends vary across the islands. ʻIʻiwi population in Kauaʻi has experienced sharp declines, with a projected trend of 92 percent decline over a 25 year period based on the 2000–2012 surveys. On East Maui, the northeastern region has experienced declines (34 percent over a 25 year period), while the southeastern region has been stable to moderately increasing. On the island of Hawaiʻi, population trends are mixed. On the windward

  11. Ecological Consequences of Island Colonization by Southwest Pacific Birds, II. The Effect of Species Diversity on Total Population Density

    PubMed Central

    Diamond, Jared M.

    1970-01-01

    Among southwest Pacific birds colonizing a species-poor island from a species-rich island, spatial expansion of the niche to include a wider range of altitudes, habitats, or vertical strata is often an immediate response, while changes in foraging techniques and diet usually occur more slowly and require genotypic change. Despite occupation of spatially broader niches by some colonizing species and increases in abundance by others, the total population density of the whole avifauna is up to nine times lower on a species-poor island than in a comparable habitat on a species-rich island. Total population density varies among islands approximately linearly with the number of species in the lowlands, supralinearly at higher elevations. Part of the explanation is that many birds on small islands expand into niche space which is suboptimal for them and from which they would be excluded by species utilizing this niche space optimally on a species-rich island. The other suggested explanation is an intrinsic inefficiency or loss of fitness among populations on small Pacific islands compared to large-island populations, due to impoverished gene pools, reduced selection pressure, and low degree of endemism. PMID:5275372

  12. Phenotype-associated inbreeding biases estimates of inbreeding depression in a wild bird population.

    PubMed

    Becker, P J J; Hegelbach, J; Keller, L F; Postma, E

    2016-01-01

    Inbreeding depression is usually quantified by regressing individual phenotypic values on inbreeding coefficients, implicitly assuming there is no correlation between an individual's phenotype and the kinship coefficient to its mate. If such an association between parental phenotype and parental kinship exists, and if the trait of interest is heritable, estimates of inbreeding depression can be biased. Here we first derive the expected bias as a function of the covariance between mean parental breeding value and parental kinship. Subsequently, we use simulated data to confirm the existence of this bias, and show that it can be accounted for in a quantitative genetic animal model. Finally, we use long-term individual-based data for white-throated dippers (Cinclus cinclus), a bird species in which inbreeding is relatively common, to obtain an empirical estimate of this bias. We show that during part of the study period, parents of inbred birds had shorter wings than those of outbred birds, and as wing length is heritable, inbred individuals were smaller, independent of any inbreeding effects. This resulted in the overestimation of inbreeding effects. Similarly, during a period when parents of inbred birds had longer wings, we found that inbreeding effects were underestimated. We discuss how such associations may have arisen in this system, and why they are likely to occur in others, too. Overall, we demonstrate how less biased estimates of inbreeding depression can be obtained within a quantitative genetic framework, and suggest that inbreeding and additive genetic effects should be accounted for simultaneously whenever possible.

  13. MULTIDRUG RESISTANCE IN WILD BIRD POPULATIONS: IMPORTANCE OF THE FOOD CHAIN.

    PubMed

    Pinto, Andreia; Simões, Romeo; Oliveira, Manuela; Vaz-Pires, Paulo; Brandão, Ricardo; da Costa, Paulo Martins

    2015-12-01

    The presence of multidrug-resistant (MDR) Escherichia coli has recently been reported in wild birds (gulls and birds of prey) that had no apparent exposure to antimicrobials. Little work has been done to assess the role of the food chain in the emergence and spread of MDR E. coli . In this study, we evaluated the presence of MDR E. coli in 29 fecal samples collected from wild birds living in a rehabilitation center (the center receives injured animals found in their natural habitat) and in eight feed samples. In total, 166 E. coli isolates were obtained: 129 from cloacal swabs and 37 from raw feed samples. The antimicrobial resistance profile of these isolates was determined, and we found that 75 isolates showed resistance to five or more drugs, resulting in a total of 38 different antimicrobial resistance patterns. Subsequently, the molecular characterization of 36 isolates, performed by pulsed-field gel electrophoresis, revealed a great similarity between isolates collected from various species of birds and also between these last ones and the ones found in their feed samples.

  14. Effect of air and noise pollution on species diversity and population density of forest birds at Lalpahari, West Bengal, India.

    PubMed

    Saha, Dulal C; Padhy, Pratap K

    2011-11-15

    The Rajmahal-type quality stones for building purposes are found abundantly in Birbhum district, West Bengal, India, where stone mining and crushing have become the main industrial activity. Although crusher dust is injurious to health, demand for crushed stone is ever-increasing as a result of rapid infrastructural growth in the country. Most of the crusher units at Rampurhat are situated along the roadways adjacent to forest under Tumboni Beat of Rampurhat Range of Birbhum Forest Division. Excessive load of air pollution in this area has led to degradation of this forest. The status of the ambient air and noise level was evaluated. The effect of air and noise pollution on abundance and variability of birds in this forest have been compared to an almost non-polluted forest of the same bio-geographic zone. Both species diversity and population density of birds were found to decrease in the polluted forest, especially in the areas adjacent to crushers. For comparing the pollution status of two different forest sites and for establishing whether the density of birds have any correlation between the sites, the Student's t-test and the chi-square test were applied respectively. Most of the results proved to be significant.

  15. Genetic signature of population fragmentation varies with mobility in seven bird species of a fragmented Kenyan cloud forest.

    PubMed

    Callens, Tom; Galbusera, Peter; Matthysen, Erik; Durand, Eric Y; Githiru, Mwangi; Huyghe, Jeroen R; Lens, Luc

    2011-05-01

    Habitat fragmentation can restrict geneflow, reduce neighbourhood effective population size, and increase genetic drift and inbreeding in small, isolated habitat remnants. The extent to which habitat fragmentation leads to population fragmentation, however, differs among landscapes and taxa. Commonly, researchers use information on the current status of a species to predict population effects of habitat fragmentation. Such methods, however, do not convey information on species-specific responses to fragmentation. Here, we compare levels of past population differentiation, estimated from microsatellite genotypes, with contemporary dispersal rates, estimated from multi-strata capture-recapture models, to infer changes in mobility over time in seven sympatric, forest-dependent bird species of a Kenyan cloud forest archipelago. Overall, populations of sedentary species were more strongly differentiated and clustered compared to those of vagile ones, while geographical patterning suggested an important role of landscape structure in shaping genetic variation. However, five of seven species with broadly similar levels of genetic differentiation nevertheless differed substantially in their current dispersal rates. We conclude that post-fragmentation levels of vagility, without reference to past population connectivity, may not be the best predictor of how forest fragmentation affects the life history of forest-dependent species. As effective conservation strategies often hinge on accurate prediction of shifts in ecological and genetic relationships among populations, conservation practices based solely upon current population abundances or movements may, in the long term, prove to be inadequate.

  16. Interpreting population estimates of birds following pesticide applications--behavior of male starlings exposed to an organophosphate pesticide

    USGS Publications Warehouse

    Grue, C.E.; Shipley, B.J.; Ralph, C. John; Scott, J. Michael

    1981-01-01

    We determined activity budgets for 10 pairs of captive male Starlings between 7 May and 18 July 1980. Our objective was to quantify changes in behavior after exposure to an organophosphate (OP) pesticide and to assess the impact of changes in behavior on the interpretation of population estimates of birds following pesticide applications. We observed each pair of males for an hour at 07:30 and 09:30 for four days and classified their behavior into one of four categories: flying, perching, foraging, or singing and displaying. At 06:30 on day 2, one male received a single oral dose of 2.5 mg dicrotophos (3-hydroxy-N, N-dimethyl-cis-crotonamide dimethyl phosphate) per kg of body weight; the other male received an equivalent exposure of corn oil. Changes in the activity budgets of OP-dosed and control males were compared using t-tests. Activity of OP-dosed males was significantly (P _ 0.05) reduced within the 2-4 h following exposure. OP-dosed males spent more time perching (46.1%) than controls and less time flying (-96.6%), foraging (-28.5%), and singing and displaying (-49.5%). The frequency of perching (-75.3%), flying (-83.8%), foraging (-54.1%), and singing and displaying (- 59.2%) was significantly reduced. Activity in OP-dosed males returned to normal by 26-28 h posttreatment. Results suggest that movement and vocalization may be significantly reduced in birds exposed to organophosphate and carbamate pesticides. Conventional censusing techniques and population estimating procedures may, therefore, be inadequate to assess changes in bird populations after pesticide applications because of the difficulty in separating decreases in density due to mortality or emigration from reductions in activity.

  17. Recent population trends of mountain goats in the Olympic Mountains, Washington

    USGS Publications Warehouse

    Jenkins, Kurt J.; Happe, Patricia J.; Beirne, Katherine F.; Hoffman, Roger A.; Griffin, Paul C.; Baccus, William T.; Fieberg, John

    2012-01-01

    Mountain goats (Oreamnos americanus) were introduced in Washington's Olympic Mountains during the 1920s. The population subsequently increased in numbers and expanded in range, leading to concerns by the 1970s over the potential effects of non-native mountain goats on high-elevation plant communities in Olympic National Park. The National Park Service (NPS) transplanted mountain goats from the Olympic Mountains to other ranges between 1981 and 1989 as a means to manage overabundant populations, and began monitoring population trends of mountain goats in 1983. We estimated population abundance of mountain goats during 18–25 July 2011, the sixth survey of the time series, to assess current population status and responses of the population to past management. We surveyed 39 sample units, comprising 39% of the 59,615-ha survey area. We estimated a population of 344 ± 72 (90% confidence interval [CI]) mountain goats in the survey area. Retrospective analysis of the 2004 survey, accounting for differences in survey area boundaries and methods of estimating aerial detection biases, indicated that the population increased at an average annual rate of 4.9% since the last survey. That is the first population growth observed since the cessation of population control measures in 1990. We postulate that differences in population trends observed in western, eastern, and southern sections of the survey zone reflected, in part, a variable influence of climate change across the precipitation gradient in the Olympic Mountains.

  18. Anthropogenic landscape change promotes asymmetric dispersal and limits regional patch occupancy in a spatially structured bird population.

    PubMed

    Pavlacky, David C; Possingham, Hugh P; Lowe, Andrew J; Prentis, Peter J; Green, David J; Goldizen, Anne W

    2012-09-01

    1. Local extinctions in habitat patches and asymmetric dispersal between patches are key processes structuring animal populations in heterogeneous environments. Effective landscape conservation requires an understanding of how habitat loss and fragmentation influence demographic processes within populations and movement between populations. 2. We used patch occupancy surveys and molecular data for a rainforest bird, the logrunner (Orthonyx temminckii), to determine (i) the effects of landscape change and patch structure on local extinction; (ii) the asymmetry of emigration and immigration rates; (iii) the relative influence of local and between-population landscapes on asymmetric emigration and immigration; and (iv) the relative contributions of habitat loss and habitat fragmentation to asymmetric emigration and immigration. 3. Whether or not a patch was occupied by logrunners was primarily determined by the isolation of that patch. After controlling for patch isolation, patch occupancy declined in landscapes experiencing high levels of rainforest loss over the last 100 years. Habitat loss and fragmentation over the last century was more important than the current pattern of patch isolation alone, which suggested that immigration from neighbouring patches was unable to prevent local extinction in highly modified landscapes. 4. We discovered that dispersal between logrunner populations is highly asymmetric. Emigration rates were 39% lower when local landscapes were fragmented, but emigration was not limited by the structure of the between-population landscapes. In contrast, immigration was 37% greater when local landscapes were fragmented and was lower when the between-population landscapes were fragmented. Rainforest fragmentation influenced asymmetric dispersal to a greater extent than did rainforest loss, and a 60% reduction in mean patch area was capable of switching a population from being a net exporter to a net importer of dispersing logrunners. 5. The

  19. Combining waterfowl and breeding bird survey data to estimate wood duck breeding population size in the Atlantic Flyway

    USGS Publications Warehouse

    Guthrie Zimmerman,; Sauer, John; Fleming, Kathy; Link, William; Pamela R. Garrettson,

    2015-01-01

    We combined data from the Atlantic Flyway Breeding Waterfowl Survey (AFBWS) and the North American Breeding Bird Survey (BBS) to estimate the number of wood ducks (Aix sponsa) in the United States portion of the Atlantic Flyway from 1993 to 2013. The AFBWS is a plot-based survey that covers most of the northern and central portions of the Flyway; when analyzed with adjustments for survey time of day effects, these data can be used to estimate population size. The BBS provides an index of wood duck abundance along roadside routes. Although factors influencing change in BBS counts over time can be controlled in BBS analysis, BBS indices alone cannot be used to derive population size estimates. We used AFBWS data to scale BBS indices for Bird Conservation Regions (BCR), basing the scaling factors on the ratio of estimated AFBWS population sizes to regional BBS indices for portions of BCRs that were common to both surveys. We summed scaled BBS results for portions of the Flyway not covered by the AFBWS with AFBWS population estimates to estimate a mean yearly total of 1,295,875 (mean 95% CI: 1,013,940–1,727,922) wood ducks. Scaling factors varied among BCRs from 16.7 to 148.0; the mean scaling factor was 68.9 (mean 95% CI: 53.5–90.9). Flyway-wide, population estimates from the combined analysis were consistent with alternative estimates derived from harvest data, and also provide population estimates within states and BCRs. We recommend their use in harvest and habitat management within the Atlantic Flyway.

  20. A statistical assessment of population trends for data deficient Mexican amphibians

    PubMed Central

    Thessen, Anne E.; Arias-Caballero, Paulina; Ayala-Orozco, Bárbara

    2014-01-01

    Background. Mexico has the world’s fifth largest population of amphibians and the second country with the highest quantity of threatened amphibian species. About 10% of Mexican amphibians lack enough data to be assigned to a risk category by the IUCN, so in this paper we want to test a statistical tool that, in the absence of specific demographic data, can assess a species’ risk of extinction, population trend, and to better understand which variables increase their vulnerability. Recent studies have demonstrated that the risk of species decline depends on extrinsic and intrinsic traits, thus including both of them for assessing extinction might render more accurate assessment of threats. Methods. We harvested data from the Encyclopedia of Life (EOL) and the published literature for Mexican amphibians, and used these data to assess the population trend of some of the Mexican species that have been assigned to the Data Deficient category of the IUCN using Random Forests, a Machine Learning method that gives a prediction of complex processes and identifies the most important variables that account for the predictions. Results. Our results show that most of the data deficient Mexican amphibians that we used have decreasing population trends. We found that Random Forests is a solid way to identify species with decreasing population trends when no demographic data is available. Moreover, we point to the most important variables that make species more vulnerable for extinction. This exercise is a very valuable first step in assigning conservation priorities for poorly known species. PMID:25548736

  1. A Study of the Effects of Gas Well Compressor Noise on Breeding Bird Populations of the Rattlesnake Canyon Habitat Management Area, San Juan County, New Mexico

    SciTech Connect

    LaGory, K.E.; Chang, Young-Soo; Chun, K.C.; Reeves, T.; Liebich, R.; Smith, K.

    2001-06-04

    This report, conducted from May through July 2000, addressed the potential effect of compressor noise on breeding birds in gas-production areas administered by the FFO, specifically in the Rattlesnake Canyon Habitat Management Area northeast of Farmington, New Mexico. The study was designed to quantify and characterize noise output from these compressors and to determine if compressor noise affected bird populations in adjacent habitat during the breeding season.

  2. Large-scale control site selection for population monitoring: an example assessing Sage-grouse trends

    USGS Publications Warehouse

    Fedy, Bradley C.; O'Donnell, Michael; Bowen, Zachary H.

    2015-01-01

    Human impacts on wildlife populations are widespread and prolific and understanding wildlife responses to human impacts is a fundamental component of wildlife management. The first step to understanding wildlife responses is the documentation of changes in wildlife population parameters, such as population size. Meaningful assessment of population changes in potentially impacted sites requires the establishment of monitoring at similar, nonimpacted, control sites. However, it is often difficult to identify appropriate control sites in wildlife populations. We demonstrated use of Geographic Information System (GIS) data across large spatial scales to select biologically relevant control sites for population monitoring. Greater sage-grouse (Centrocercus urophasianus; hearafter, sage-grouse) are negatively affected by energy development, and monitoring of sage-grouse population within energy development areas is necessary to detect population-level responses. Weused population data (1995–2012) from an energy development area in Wyoming, USA, the Atlantic Rim Project Area (ARPA), and GIS data to identify control sites that were not impacted by energy development for population monitoring. Control sites were surrounded by similar habitat and were within similar climate areas to the ARPA. We developed nonlinear trend models for both the ARPA and control sites and compared long-term trends from the 2 areas. We found little difference between the ARPA and control sites trends over time. This research demonstrated an approach for control site selection across large landscapes and can be used as a template for similar impact-monitoring studies. It is important to note that identification of changes in population parameters between control and treatment sites is only the first step in understanding the mechanisms that underlie those changes. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  3. Developing indicators for European birds

    PubMed Central

    Gregory, Richard D; van Strien, Arco; Vorisek, Petr; Gmelig Meyling, Adriaan W; Noble, David G; Foppen, Ruud P.B; Gibbons, David W

    2005-01-01

    The global pledge to deliver ‘a significant reduction in the current rate of biodiversity loss by 2010’ is echoed in a number of regional and national level targets. There is broad consensus, however, that in the absence of conservation action, biodiversity will continue to be lost at a rate unprecedented in the recent era. Remarkably, we lack a basic system to measure progress towards these targets and, in particular, we lack standard measures of biodiversity and procedures to construct and assess summary statistics. Here, we develop a simple classification of biodiversity indicators to assist their development and clarify purpose. We use European birds, as example taxa, to show how robust indicators can be constructed and how they can be interpreted. We have developed statistical methods to calculate supranational, multi-species indices using population data from national annual breeding bird surveys in Europe. Skilled volunteers using standardized field methods undertake data collection where methods and survey designs differ slightly across countries. Survey plots tend to be widely distributed at a national level, covering many bird species and habitats with reasonable representation. National species' indices are calculated using log-linear regression, which allows for plot turnover. Supranational species' indices are constructed by combining the national species' indices weighted by national population sizes of each species. Supranational, multi-species indicators are calculated by averaging the resulting indices. We show that common farmland birds in Europe have declined steeply over the last two decades, whereas woodland birds have not. Evidence elsewhere shows that the main driver of farmland bird declines is increased agricultural intensification. We argue that the farmland bird indicator is a useful surrogate for trends in other elements of biodiversity in this habitat. PMID:15814345

  4. Recent population size, trends, and limiting factors for the double-crested Cormorant in Western North America

    USGS Publications Warehouse

    Adkins, Jessica Y.; Roby, Daniel D.; Lyons, Donald E.; Courtot, Karen N.; Collis, Ken; Carter, Harry R.; Shuford, W. David; Capitolo, Phillip J.

    2014-01-01

    The status of the double-crested cormorant (Phalacrocorax auritus) in western North America was last evaluated during 1987–2003. In the interim, concern has grown over the potential impact of predation by double-crested cormorants on juvenile salmonids (Oncorhynchusspp.), particularly in the Columbia Basin and along the Pacific coast where some salmonids are listed for protection under the United States Endangered Species Act. Recent re-evaluations of double-crested cormorant management at the local, flyway, and federal level warrant further examination of the current population size and trends in western North America. We collected colony size data for the western population (British Columbia, Washington, Oregon, Idaho, California, Nevada, Utah, Arizona, and the portions of Montana, Wyoming, Colorado and New Mexico west of the Continental Divide) by conducting aircraft-, boat-, or ground-based surveys and by cooperating with government agencies, universities, and non-profit organizations. In 2009, we estimated approximately 31,200 breeding pairs in the western population. We estimated that cormorant numbers in the Pacific Region (British Columbia, Washington, Oregon, and California) increased 72% from 1987–1992 to circa 2009. Based on the best available data for this period, the average annual growth rate (λ) of the number of breeding birds in the Pacific Region was 1.03, versus 1.07 for the population east of the Continental Divide during recent decades. Most of the increase in the Pacific Region can be attributed to an increase in the size of the nesting colony on East Sand Island in the Columbia River estuary, which accounts for about 39% of all breeding pairs in the western population and is the largest known breeding colony for the species (12,087 breeding pairs estimated in 2009). In contrast, numbers of breeding pairs estimated in coastal British Columbia and Washington have declined by approximately 66% during this same period. Disturbance at breeding

  5. Effects of lek count protocols on greater sage-grouse population trend estimates

    USGS Publications Warehouse

    Monroe, Adrian; Edmunds, David; Aldridge, Cameron L.

    2016-01-01

    Annual counts of males displaying at lek sites are an important tool for monitoring greater sage-grouse populations (Centrocercus urophasianus), but seasonal and diurnal variation in lek attendance may increase variance and bias of trend analyses. Recommendations for protocols to reduce observation error have called for restricting lek counts to within 30 minutes of sunrise, but this may limit the number of lek counts available for analysis, particularly from years before monitoring was widely standardized. Reducing the temporal window for conducting lek counts also may constrain the ability of agencies to monitor leks efficiently. We used lek count data collected across Wyoming during 1995−2014 to investigate the effect of lek counts conducted between 30 minutes before and 30, 60, or 90 minutes after sunrise on population trend estimates. We also evaluated trends across scales relevant to management, including statewide, within Working Group Areas and Core Areas, and for individual leks. To further evaluate accuracy and precision of trend estimates from lek count protocols, we used simulations based on a lek attendance model and compared simulated and estimated values of annual rate of change in population size (λ) from scenarios of varying numbers of leks, lek count timing, and count frequency (counts/lek/year). We found that restricting analyses to counts conducted within 30 minutes of sunrise generally did not improve precision of population trend estimates, although differences among timings increased as the number of leks and count frequency decreased. Lek attendance declined >30 minutes after sunrise, but simulations indicated that including lek counts conducted up to 90 minutes after sunrise can increase the number of leks monitored compared to trend estimates based on counts conducted within 30 minutes of sunrise. This increase in leks monitored resulted in greater precision of estimates without reducing accuracy. Increasing count

  6. Long-Term Trends and Role of Climate in the Population Dynamics of Eurasian Reindeer

    PubMed Central

    Horstkotte, Tim; Kaarlejärvi, Elina; Sévêque, Anthony; Stammler, Florian; Olofsson, Johan; Forbes, Bruce C.; Moen, Jon

    2016-01-01

    Temperature is increasing in Arctic and sub-Arctic regions at a higher rate than anywhere else in the world. The frequency and nature of precipitation events are also predicted to change in the future. These changes in climate are expected, together with increasing human pressures, to have significant impacts on Arctic and sub-Arctic species and ecosystems. Due to the key role that reindeer play in those ecosystems, it is essential to understand how climate will affect the region’s most important species. Our study assesses the role of climate on the dynamics of fourteen Eurasian reindeer (Rangifer tarandus) populations, using for the first time data on reindeer abundance collected over a 70-year period, including both wild and semi-domesticated reindeer, and covering more than half of the species’ total range. We analyzed trends in population dynamics, investigated synchrony among population growth rates, and assessed the effects of climate on population growth rates. Trends in the population dynamics were remarkably heterogeneous. Synchrony was apparent only among some populations and was not correlated with distance among population ranges. Proxies of climate variability mostly failed to explain population growth rates and synchrony. For both wild and semi-domesticated populations, local weather, biotic pressures, loss of habitat and human disturbances appear to have been more important drivers of reindeer population dynamics than climate. In semi-domesticated populations, management strategies may have masked the effects of climate. Conservation efforts should aim to mitigate human disturbances, which could exacerbate the potentially negative effects of climate change on reindeer populations in the future. Special protection and support should be granted to those semi-domesticated populations that suffered the most because of the collapse of the Soviet Union, in order to protect the livelihood of indigenous peoples that depend on the species, and the multi

  7. Long-Term Trends and Role of Climate in the Population Dynamics of Eurasian Reindeer.

    PubMed

    Uboni, Alessia; Horstkotte, Tim; Kaarlejärvi, Elina; Sévêque, Anthony; Stammler, Florian; Olofsson, Johan; Forbes, Bruce C; Moen, Jon

    2016-01-01

    Temperature is increasing in Arctic and sub-Arctic regions at a higher rate than anywhere else in the world. The frequency and nature of precipitation events are also predicted to change in the future. These changes in climate are expected, together with increasing human pressures, to have significant impacts on Arctic and sub-Arctic species and ecosystems. Due to the key role that reindeer play in those ecosystems, it is essential to understand how climate will affect the region's most important species. Our study assesses the role of climate on the dynamics of fourteen Eurasian reindeer (Rangifer tarandus) populations, using for the first time data on reindeer abundance collected over a 70-year period, including both wild and semi-domesticated reindeer, and covering more than half of the species' total range. We analyzed trends in population dynamics, investigated synchrony among population growth rates, and assessed the effects of climate on population growth rates. Trends in the population dynamics were remarkably heterogeneous. Synchrony was apparent only among some populations and was not correlated with distance among population ranges. Proxies of climate variability mostly failed to explain population growth rates and synchrony. For both wild and semi-domesticated populations, local weather, biotic pressures, loss of habitat and human disturbances appear to have been more important drivers of reindeer population dynamics than climate. In semi-domesticated populations, management strategies may have masked the effects of climate. Conservation efforts should aim to mitigate human disturbances, which could exacerbate the potentially negative effects of climate change on reindeer populations in the future. Special protection and support should be granted to those semi-domesticated populations that suffered the most because of the collapse of the Soviet Union, in order to protect the livelihood of indigenous peoples that depend on the species, and the multi

  8. Long-term trends in first arrival and first egg laying dates of some migrant and resident bird species in northern Italy

    NASA Astrophysics Data System (ADS)

    Rubolini, Diego; Ambrosini, Roberto; Caffi, Mario; Brichetti, Pierandrea; Armiraglio, Stefano; Saino, Nicola

    2007-08-01

    Climate change is affecting the phenology of seasonal events in Europe and the Northern Hemisphere, as shown by several studies of birds’ timing of migration and reproduction. Here, we analyse the long-term (1982-2006) trends of first arrival dates of four long-distance migratory birds [swift ( Apus apus), nightingale ( Luscinia megarhynchos), barn swallow ( Hirundo rustica), and house martin ( Delichon urbicum)] and first egg laying dates of two migrant (swift, barn swallow) and two resident species [starling ( Sturnus vulgaris), Italian sparrow ( Passer italiae)] at a study site in northern Italy. We also addressed the effects of local weather (temperature and precipitation) and a climate index (the North Atlantic Oscillation, NAO) on the interannual variability of phenological events. We found that the swift and the barn swallow significantly advanced both arrival and laying dates, whereas all other species did not show any significant temporal trend in either arrival or laying date. The earlier arrival of swifts was explained by increasing local temperatures in April, whereas this was not the case for arrival dates of swallows and first egg laying dates of both species. In addition, arrival dates of house martins were earlier following high NAO winters, while nightingale arrival was earlier when local spring rainfall was greater. Finally, Italian sparrow onset of reproduction was anticipated by greater spring rainfall, but delayed by high spring NAO anomalies, and swift’s onset of reproduction was anticipated by abundant rainfall prior to reproduction. There were no significant temporal trends in the interval between onset of laying and arrival in either the swift or the barn swallow. Our findings therefore indicate that birds may show idiosyncratic responses to climate variability at different spatial scales, though some species may be adjusting their calendar to rapidly changing climatic conditions.

  9. [Spatial distribution characteristics of urban potential population in Shenyang City based on QuickBird image and GIS].

    PubMed

    Li, Jun-Ying; Hu, Yuan-Man; Chen, Wei; Liu, Miao; Hu, Jian-Bo; Zhong, Qiao-Lin; Lu, Ning

    2012-06-01

    Population is the most active factor affecting city development. To understand the distribution characteristics of urban population is of significance for making city policy decisions and for optimizing the layout of various urban infrastructures. In this paper, the information of the residential buildings in Shenyang urban area was extracted from the QuickBird remote sensing images, and the spatial distribution characteristics of the population within the Third-Ring Road of the City were analyzed, according to the social and economic statistics data. In 2010, the population density in different types of residential buildings within the Third-Ring Road of the City decreased in the order of high-storey block, mixed block, mixed garden, old multi-storey building, high-storey garden, multi-storey block, multi-storey garden, villa block, shanty, and villa garden. The vacancy rate of the buildings within the Third-Ring Road was more than 30%, meaning that the real estate market was seriously overstocked. Among the five Districts of Shenyang City, Shenhe District had the highest potential population density, while Tiexi District and Dadong District had a lower one. The gravity center of the City and its five Districts was also analyzed, which could provide basic information for locating commercial facilities and planning city infrastructure.

  10. Population structure and demographic trends of the registered Sahiwal cattle in Kenya.

    PubMed

    Kamiti, Duncan; Ilatsia, Evans; Bett, Rawlynce; Kahi, Alexander

    2016-06-01

    Sahiwal cattle breed is an important genetic resource that supports livelihoods of pastoralists in Kenya. However, information about its population structure, demographic trends, and genetic diversity is scarce. The objective of this study was to characterize the population structure, explore demographic trends, and evaluate genetic diversity parameters of the breed through pedigree analysis. Pedigree data from National Sahiwal Stud and Kenya Stud Book were combined and analyzed using POPREP software package. The number of registered breeding animals indicated a downward trend over time. Generation interval was longer by 3 years in males than in females. Average inbreeding coefficient was 0.58 % for all animals and 2.23 % for inbred animals. Average inbreeding between 1960 and 2008 for inbred animals decreased at -0.0012 % per year while for the entire breed increased at 0.025 % per year. Additive genetic relationship in the whole population was 0.87 %. The effective population size declined over time and was lower than that recommended to maintain genetic diversity in the long term. The breed was found to be losing genetic diversity over time, and therefore a strategy to reduce inbreeding rate and increase effective population size is recommended.

  11. A new method of projecting populations based on trends in life expectancy and survival.

    PubMed

    Mayhew, Les; Smith, David

    2013-07-01

    There is increasing concern about the lack of accuracy in population projections at national levels. A common problem has been the systematic underestimation of improvements in mortality, especially at older ages, resulting in projections that are too low. In this paper, we present a method that is based on projecting survivorship rather than mortality, which uses the same data but differs technically. In particular, rather than extrapolating trends in mortality, we use trends in life expectancy to establish a robust statistical relation between changes in life expectancy and survivorship using period life tables. We test the approach on data for England and Wales for the population aged 50 and over, and show that it gives more accurate projections than official projections using the same base data. Using the model to project the population aged 50 and over to 2020, our method suggests nearly 0.6 million more people in this age group than official projections.

  12. Population size and trend of Yellow-billed Loons in northern Alaska

    USGS Publications Warehouse

    Earnst, Susan L.; Stehn, R.A.; Platte, Robert; Larned, W.W.; Mallek, E.J.

    2005-01-01

    The Yellow-billed Loon (Gavia adamsii) is of conservation concern due to its restricted range, small population size, specific habitat requirements, and perceived threats to its breeding and wintering habitat. Within the U.S., this species breeds almost entirely within the National Petroleum Reserve-Alaska, nearly all of which is open, or proposed to be opened, for oil development. Rigorous estimates of Yellow-billed Loon population size and trend are lacking but essential for informed conservation. We used two annual aerial waterfowl surveys, conducted 1986a??2003 and 1992a??2003, to estimate population size and trend on northern Alaskan breeding grounds. In estimating population trend, we used mixed-effects regression models to reduce bias and sampling error associated with improvement in observer skill and annual effects of spring phenology. The estimated population trend on Alaskan breeding grounds since 1986 was near 0 with an estimated annual change of a??0.9% (95% CI of a??3.6% to +1.8%). The estimated population size, averaged over the past 12 years and adjusted by a correction factor based on an intensive, lake-circling, aerial survey method, was 2221 individuals (95% CI of 1206a??3235) in early June and 3369 individuals (95% CI of 1910a??4828) in late June. Based on estimates from other studies of the proportion of loons nesting in a given year, it is likely that <1000 nesting pairs inhabit northern Alaska in most years. The highest concentration of Yellow-billed Loons occurred between the Meade and Ikpikpuk Rivers; and across all of northern Alaska, 53% of recorded sightings occurred within 12% of the area.

  13. Trends in world population: how will the millenium compare with the past?

    PubMed

    Raleigh, V S

    1999-01-01

    This paper reviews historical and projected trends in world population numbers, and the underlying determinants of those trends. Whereas the world's population has shown little change over most of its one million-year history, the past 200 years have witnessed dramatic changes in fertility, mortality and population growth rates. Recent decades, in particular, have seen unprecedented demographic events, with more people added to the world's population in the past 50 years than in the preceding million. The demographic impact of HIV/AIDS, selective as it is to young adults and infants, is also unprecedented, with life expectancy among some populations reduced by almost 20 years. As we approach the end of the 20th century, further demographic changes are underway with, for the first time in recent human history, a slowing down of world population growth. Nonetheless, world population is projected to grow from 6 billion currently to about 9.4 billion by 2050 (medium fertility assumption), with ageing emerging as the most pressing demographic issue facing humanity in the millenium.

  14. Age trends in prevalence of cardiovascular risk factors in Roma minority population of Croatia.

    PubMed

    Zeljko, Hrvojka Marija; Skarić-Jurić, Tatjana; Narančić, Nina Smolej; Barešić, Ana; Tomas, Zeljka; Petranović, Matea Zajc; Miličić, Jasna; Salihović, Marijana Peričić; Janićijević, Branka

    2013-07-01

    The Roma (Gypsy) are the largest European minority population characterized by poverty, social exclusion as well as by numerous life-style and cultural specificities, which all could have an adverse impact on their cardiovascular health. This study assesses the prevalence of cardiovascular diseases (CVD) risk factors in community-based sample of 430 adult Roma, living in rural area of Croatia, by providing the actual and age-adjusted estimates using the European standard population. The most prominent classical CVD risk phenotypes (blood pressure, obesity, smoking, glucose and lipid profile) were selected, and the standard risk cut-offs were applied. The study has shown that compared to general population of Croatia, the Roma population bears a high CVD risk factors load related to smoking and high glucose level. The CVD risk factors prevalence in Roma also showed important sex and age patterns, the most imposing of which are the findings of higher prevalence of CVD risks in women (especially obesity and triglyceride levels) and the trend of higher body mass index (BMI) level in younger age group (18-34 years) which both stand in contrast to the trends characterizing the general population of Croatia. These findings are complemented by the trend of decreased risk in the oldest age group (65+ years) for all investigated CVD risk factors (with exception of triglycerides level) compared to the 50-64 age group. We conclude that the age and sex CVD risks pattern point to the health transition of this rural Roma population. As we expect the proportion of CVD in the Roma minority of Croatia to increase in the future along with further modernization of their lifestyle, the CVD prevention measures in this population are urgent and should be primarily targeted at women and at the younger segment of this population.

  15. A test of the variable circular-plot method where exact density of a bird population was known

    USGS Publications Warehouse

    Nelson, Jay T.; Fancy, Steven G.

    1999-01-01

    Variable circular-plot (VCP) counts are statistically more sound than point counts because they are adjusted for the probability of detecting birds at different distances and under different conditions. However, many ornithologists use point counts rather than VCP counts because they believe that assumptions of the VCP method are almost always violated, leading to poor results, and because earlier field tests using ad hoc analysis methods gave variable and relatively poor results. We conducted the first field test of the VCP method where the exact density of a forest bird was known as part of re-establishing the 'Oma'o Myadestes obscurus in former range. All 'Oma'o in the new population were intensively monitored by radio telemetry so that the number present during four VCP censuses was known. Excluding the first census, when three of the four detections were of the same individual, differences in VCP density estimates ranged from -34% to +24% (mean 0%) even though =18 'Oma'o were detected per survey. We review critical assumptions of the VCP method and make recommendations for data analysis based on our experience with the method on Pacific islands.

  16. Free-living Waterfowl as a Source of Zoonotic Bacteria in a Dense Wild Bird Population Area in Northeastern Spain.

    PubMed

    Antilles, N; Sanglas, A; Cerdà-Cuéllar, M

    2015-10-01

    Salmonella spp. and Campylobacter spp. are zoonotic bacteria that represent an economic and public health concern worldwide. Due to the difficulty to collect samples from free-living waterfowl, little is known on their importance as a reservoir of zoonotic agents. Thus, a study was conducted to determine the prevalence, genotypic diversity and antimicrobial susceptibility of Salmonella and Campylobacter from waterfowl in Ebro Delta (northeastern Spain), a geographical area with a dense wild bird population. Samples were collected from 318 adult waterfowl belonging to nine fowl species. All the samples were taken during the hunting season from 2008 to 2010. None of the birds were positive for Salmonella, while the overall Campylobacter prevalence was 12.58% (40/318). A much higher Campylobacter coli prevalence than Campylobacter jejuni was found (11.64% versus 0.94%). The species Fulica atra showed the highest Campylobacter prevalence (78.05%). ERIC-PCR of the isolates showed a high diversity of strains. Antimicrobial susceptibility testing of Campylobacter isolates showed that all the isolates were susceptible to the seven antibiotics tested.

  17. Beyond climate envelopes: effects of weather on regional population trends in butterflies.

    PubMed

    WallisDeVries, Michiel F; Baxter, Wendy; Van Vliet, Arnold J H

    2011-10-01

    Although the effects of climate change on biodiversity are increasingly evident by the shifts in species ranges across taxonomical groups, the underlying mechanisms affecting individual species are still poorly understood. The power of climate envelopes to predict future ranges has been seriously questioned in recent studies. Amongst others, an improved understanding of the effects of current weather on population trends is required. We analysed the relation between butterfly abundance and the weather experienced during the life cycle for successive years using data collected within the framework of the Dutch Butterfly Monitoring Scheme for 40 species over a 15-year period and corresponding climate data. Both average and extreme temperature and precipitation events were identified, and multiple regression was applied to explain annual changes in population indices. Significant weather effects were obtained for 39 species, with the most frequent effects associated with temperature. However, positive density-dependence suggested climatic independent trends in at least 12 species. Validation of the short-term predictions revealed a good potential for climate-based predictions of population trends in 20 species. Nevertheless, data from the warm and dry year of 2003 indicate that negative effects of climatic extremes are generally underestimated for habitat specialists in drought-susceptible habitats, whereas generalists remain unaffected. Further climatic warming is expected to influence the trends of 13 species, leading to an improvement for nine species, but a continued decline in the majority of species. Expectations from climate envelope models overestimate the positive effects of climate change in northwestern Europe. Our results underline the challenge to include population trends in predicting range shifts in response to climate change.

  18. The New Population Debate: Two Views on Population Growth and Economic Development. Population Trends and Public Policy, Number 7.

    ERIC Educational Resources Information Center

    King, Timothy; Kelley, Allen C.

    Articles representing two views on the issue of rapid population growth and economic development are presented. Although the authors present different perspectives, they agree on many of the fundamentals. For example, both reject alarmism about impending "population explosions" and the use of population as a scapegoat for all Third World…

  19. Mast and weather influences on population trends of a species of concern: The allegheny woodrat

    USGS Publications Warehouse

    Manjerovic, M.B.; Wood, P.B.; Edwards, J.W.

    2009-01-01

    Over the past 20-30 y. northern and western populations of the Allegheny woodrat (Neotoma magister) have experienced large declines. whereas populations in the core of the range are assumed to be stable. We examined population trends at two study areas in northcentral West Virginia along the western ridge of the central Appalachian Mountains. Temperature and precipitation parameters along with mast production were examined to determine if these environmental variables impacted the population. Based on a 5 y dataset. our results indicate a yearly decrease in the overall population. with adult females most affected. Hard and soft mast availability related to adult female capture rates. whereas temperatures significantly affected juvenile. adult female and overall capture rates. Juvenile summer capture rates increased with warmer temperatures the preceding winter. Female summer capture rates decreased with warmer temperatures the preceding spring suggesting that effects of warming should be added as a potential threat to the Allegheny woodrat.

  20. Signature of a pre-human population decline in the critically endangered Reunion Island endemic forest bird Coracina newtoni.

    PubMed

    Salmona, Jordi; Salamolard, Marc; Fouillot, Damien; Ghestemme, Thomas; Larose, Jerry; Centon, Jean-François; Sousa, Vitor; Dawson, Deborah A; Thebaud, Christophe; Chikhi, Lounès

    2012-01-01

    The exceptional biodiversity of Reunion Island is threatened by anthropogenic landscape changes that took place during the 350 years of human colonization. During this period the human population size increased dramatically from 250 to 800,000. The arrival of humans together with the development of agriculture, invasive species such as rats and cats, and deforestation has lead to the extinction of more than half of the original vertebrate species of the island. For the remaining species, significant work is being carried out to identify threats and conservation status, but little genetic work has been carried on some of the most endangered species. In the last decade theoretical studies have shown the ability of neutral genetic markers to infer the demographic history of endangered species and identify and date past population size changes (expansions or bottlenecks). In this study we provide the first genetic data on the critically endangered species the Reunion cuckoo-shrike Coracina newtoni. The Reunion cuckoo-shrike is a rare endemic forest bird surviving in a restricted 12-km(2) area of forested uplands and mountains. The total known population consists of less than one hundred individuals out of which 45 were genotyped using seventeen polymorphic microsatellite loci. We found a limited level of genetic variability and weak population structure, probably due to the limited geographic distribution. Using Bayesian methods, we identified a strong decline in population size during the Holocene, most likely caused by an ancient climatic or volcanic event around 5000 years ago. This result was surprising as it appeared in apparent contradiction with the accepted theory of recent population collapse due to deforestation and predator introduction. These results suggest that new methods allowing for more complex demographic models are necessary to reconstruct the demographic history of populations.

  1. Influence of habitat amount, arrangement, and use on population trend estimates of male Kirtland's warblers

    USGS Publications Warehouse

    Donner, D.M.; Probst, J.R.; Ribic, C.A.

    2008-01-01

    Kirtland's warblers (Dendroica kirtlandii) persist in a naturally patchy environment of young, regenerating jack pine forests (i.e., 5-23 years old) created after wildfires and human logging activities. We examined how changing landscape structure from 26 years of forest management and wildfire disturbances influenced population size and spatial dispersion of male Kirtland's warblers within their restricted breeding range in northern Lower Michigan, USA. The male Kirtland's warbler population was six times larger in 2004 (1,322) compared to 1979 (205); the change was nonlinear with 1987 and 1994 identified as significant points of change. In 1987, the population trend began increasing after a slowly declining trend prior to 1987, and the rate of increase appeared to slow after 1994. Total amount of suitable habitat and the relative area of wildfire-regenerated habitat were the most important factors explaining population trend. Suitable habitat increased 149% primarily due to increasing plantations from forest management. The relative amount and location of wildfire-regenerated habitat modified the distribution of males among various habitat types, and the spatial variation in their abundance across the primary breeding range. These findings indicate that the Kirtland's warbler male population shifted its use of habitat types temporally and spatially as the population increased and as the relative availability of habitats changed through time. We demonstrate that researchers and managers need to consider not only habitat quality, but the temporal and the spatial context of habitat availability and population levels when making habitat restoration decisions. ?? 2008 Springer Science+Business Media B.V.

  2. Population Change, Resources, and the Environment. Population Trends and Public Policy No. 4.

    ERIC Educational Resources Information Center

    Jacobsen, Judith, Ed.

    Intended for policymakers, this document focuses on environmental factors limiting the expansion of the world's food supply, the dilemma of fostering third world economic development, and prospects for energy development. The first of five parts gives an overview of a 1983 Population Reference Bureau conference which focused on current thinking…

  3. US Hemophilia Treatment Center population trends 1990-2010: patient diagnoses, demographics, health services utilization.

    PubMed

    Baker, J R; Riske, B; Drake, J H; Forsberg, A D; Atwood, R; Voutsis, M; Shearer, R

    2013-01-01

    For several decades, US government agencies have partially supported regional networks of Hemophilia Treatment Centers (HTC). HTC multidisciplinary teams provide comprehensive and coordinated diagnosis, treatment, prevention, education, outreach and surveillance services to improve the health of people with genetic bleeding disorders. However, national data are scarce on HTC-patient population trends and services. The aim of the study was to examine national trends over the past 20 years in patient diagnoses, demographics and health services utilization among the Health Resources and Services Administration (HRSA) and Centers for Disease Control and Prevention (CDC)-supported HTC network. Diagnoses, demographics and health services utilization data from 1990 to 2010 were aggregated from all HTCs using the Hemophilia Data Set (HDS). From 1990 to 2010, the HTC population grew 90% from 17 177 to 32 612. HTC patients with von Willebrand's disease increased by 148%, females by 346%, Hispanic patients by 236% and African Americans by 104%. Four thousand and seventy-five deaths were reported. From 2002 to 2010, annual comprehensive evaluations grew 38%, and persons with severe haemophilia on a home intravenous therapy programme rose 37%. In 2010, 46% of patients were less than 18 years vs. 24% for the general US population. The Hemophilia Data Set documents the growth and diversity of the US Hemophilia Treatment Center Network's patient population and services. Despite disproportionate deaths due to HIV, the HTC patient base grew faster than the general US population. The HDS is a vital national public health registry for this rare-disorder population.

  4. 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)

  5. Epidemiological and mortality trends in infective endocarditis, a 17-year population-based prospective study

    PubMed Central

    Chiavarelli, Mario; Scalese, Marco; Nencioni, Cesira; Valentini, Silvia; Guerrini, Francesco; D’Aiello, Incoronata; Picchi, Andrea; De Sensi, Francesco; Habib, Gilbert

    2017-01-01

    Background The population at risk, the clinical and microbiological features of infective endocarditis (IE) have changed. Aim of our study was to evaluate the contemporary epidemiological trends, over a 17-year period in a definite region of Tuscany, Italy, to analyze the clinical outcomes and associated prognostic factors. Methods From 1 January 1998 to 31 December 2014, all patients with a definite diagnosis of IE were prospectively entered in a data-base. The Health-Care system data-base was interrogated to capture patients who could have been missed. The final dataset derived by the merging of the two data-bases. Results Incidence rate of IE was 4.6/100,000/y with a significant linear incidence increase. In hospitalized patients the incidence was 1.27/1,000 admissions. Over age 65 incidence rate was 11.7/100,000/y. Male/female ratio was 1.54:1. A temporal trend towards an increase in the mean population age was found (P=0.033). There was an increase in the incidence of Health-care associated IE, P=0.016. The most common microorganisms were staphylococcus aureus (25%) and coagulase-negative staphylococci (22%). In-hospital mortality was 24%. A trend towards an increase in mortality rate was found (P=0.055). Independent predictors of mortality were older age, S. aureus infection, heart failure, septic shock and persistent bacteremia. Conclusions Our study confirms an increasing mortality trend in IE, although with a borderline significance. Elderly forms are associated with poor prognosis and higher than 1-year mortality rate even in the multivariate analysis. Ageing population, increase in healthcare-associated and staphylococcal infections, may explain the rise of IE incidence and of the mortality trend. PMID:28164010

  6. An animal breeding approach to the estimation of genetic and environmental trends from field populations.

    PubMed

    Garrick, D J

    2010-04-01

    Observed or phenotypic trends in animal performance can be readily quantified from information collected from research or field populations. Phenotypic performance is determined by the collective impact of systematic effects that vary by trait, but may include herd, year, sex, and age; additive genetic effects; and a remainder that is referred to as the lack-of-fit or unexplained residual. It is of interest to partition observed performance into these respective components to determine the extent to which genetic or environmental trends or both are responsible for any observed phenotypic trends. An animal breeding approach to separate these components from field data involves the use of a linear model that includes fixed effects for systematic terms and random effects for genetic and residual contributions. The fitted random effects are predicted using a shrinkage estimator known as BLUP that relies only on a translation invariant subset of the field data that does not involve the unknown fixed effects. Fixed effects can then be estimated by adjusting observations for estimates of the random effects. Reliable estimation of trends using this approach requires that relevant fixed effects are recorded, cohorts representing different fixed effects classes are genetically related or connected, and that any records used as the basis for selection in the population are included in the data set.

  7. The European and Japanese outbreaks of H5N8 derive from a single source population providing evidence for the dispersal along the long distance bird migratory flyways

    PubMed Central

    Iqbal, Munir

    2015-01-01

    The origin of recent parallel outbreaks of the high pathogenicity H5N8 avian flu virus in Europe and in Japan can be traced to a single source population, which has most likely been spread by migratory birds. By using Bayesian coalescent methods to analyze the DNA sequences of the virus to find the times for divergence and combining this sequence data with bird migration data we can show the most likely locations and migratory pathways involved in the origin of the current outbreak. This population was most likely located in the Siberian summer breeding grounds of long-range migratory birds. These breeding grounds provide a connection between different migratory flyways and explain the current outbreaks in remote locations. By combining genetic methods and epidemiological data we can rapidly identify the sources and the dispersion pathways for novel avian influenza outbreaks. PMID:25945320

  8. The relative roles of cultural drift and acoustic adaptation in shaping syllable repertoires of island bird populations change with time since colonization.

    PubMed

    Potvin, Dominique A; Clegg, Sonya M

    2015-02-01

    In birds, song divergence often precedes and facilitates divergence of other traits. We assessed the relative roles of cultural drift, innovation, and acoustic adaptation in divergence of island bird dialects, using silvereyes (Zosterops lateralis). In recently colonized populations, syllable diversity was not significantly lower than source populations, shared syllables between populations decreased with increasing number of founder events, and dialect variation displayed contributions from both habitat features and drift. The breadth of multivariate space occupied by recently colonized Z. l. lateralis populations was comparable to evolutionarily old forms that have diverged over thousands to hundreds of thousands of years. In evolutionarily old subspecies, syllable diversity was comparable to the mainland and the amount of variation in syllable composition explained by habitat features increased by two- to threefold compared to recently colonized populations. Together these results suggest that cultural drift influences syllable repertoires in recently colonized populations, but innovation likely counters syllable loss from colonization. In evolutionarily older populations, the influence of acoustic adaptation increases, possibly favoring a high diversity of syllables. These results suggest that the relative importance of cultural drift and acoustic adaptation changes with time since colonization in island bird populations, highlighting the value of considering multiple mechanisms and timescale of divergence when investigating island song divergence.

  9. Impact of secular trends on sex assessment evaluated through femoral dimensions of the Czech population.

    PubMed

    Guyomarc'h, Pierre; Velemínská, Jana; Sedlak, Petr; Dobisíková, Miluše; Švenkrtová, Iva; Brůžek, Jaroslav

    2016-05-01

    Human skeletal variability is influenced by several factors, including genetics, environment, and socio-cultural background. Forensic methods being traditionally based on targeted reference groups, it is recognized that they are population-specific. Additionally, secular trends highly impact on the skeletal morphology, but the effect of outdated methods on forensic cases is not yet well documented. This paper compares the sexual dimorphism of femoral dimensions in two samples from the Czech population separated by 60 years in time (Pachner and the Prague National Museum Collections). Significant secular trends are present within this short span in both sexes and for most of the seven tested linear variables. The consequence of secular trends on sex determination is tested with logistic regression, and a decrease in reliability is systematically observed when using the older Czech sample on the 20th century sample, whichever the set of variables included. A model based on a recent Croatian sample provides a higher reliability on contemporaneous Czech individuals. These results imply that above population specificity, temporal consistency may be a major criterion to fulfil when applying forensic anthropology identification methods.

  10. Spatial analysis of cattle and shoat population in Ethiopia: growth trend, distribution and market access.

    PubMed

    Leta, Samson; Mesele, Frehiwot

    2014-01-01

    The livestock subsector has an enormous contribution to Ethiopia's national economy and livelihoods of many Ethiopians. The subsector contributes about 16.5% of the national Gross Domestic Product (GDP) and 35.6% of the agricultural GDP. It also contributes 15% of export earnings and 30% of agricultural employment. The livestock subsector currently support and sustain livelihoods for 80% of all rural population. The GDP of livestock related activities valued at 59 billion birr. Ethiopian livestock population trends, distribution and marketing vary considerably across space and time due to a variety of reasons. This study was aimed to assess cattle and shoat population growth trend, distribution and their access to market. Regression analysis was used to assess the cattle and shoat population growth trend and Geographic Information Systems (GIS) techniques were used to determine the spatial distribution of cattle and shoats, and their relative access to market. The data sets used are agricultural census (2001/02) and annual CSA agricultural sample survey (1995/96 to 2012/13). In the past eighteen years, the livestock population namely cattle, sheep and goat grew from 54.5 million to over 103.5 million with average annual increment of 3.4 million. The current average national cattle, sheep and goat population per km(2) are estimated to be 71, 33 and 29 respectively (excluding Addis Ababa, Afar and Somali regions). From the total livestock population the country owns about 46% cattle, 43% sheep and 40% goats are reared within 10 km radius from major livestock market centres and all-weather roads. On the other hand, three fourth of the country's land mass which comprises 15% of the cattle, 20% of the sheep and 21% of goat population is not accessible to market (greater than 30 km from major livestock market centres). It is found that the central highland regions account for the largest share of livestock population and also more accessible to market. Defining the

  11. Restricted dispersal reduces the strength of spatial density dependence in a tropical bird population

    PubMed Central

    Burgess, Malcolm D; Nicoll, Malcolm A.C; Jones, Carl G; Norris, Ken

    2008-01-01

    Spatial processes could play an important role in density-dependent population regulation because the disproportionate use of poor quality habitats as population size increases is widespread in animal populations—the so-called buffer effect. While the buffer effect patterns and their demographic consequences have been described in a number of wild populations, much less is known about how dispersal affects distribution patterns and ultimately density dependence. Here, we investigated the role of dispersal in spatial density dependence using an extraordinarily detailed dataset from a reintroduced Mauritius kestrel (Falco punctatus) population with a territorial (despotic) breeding system. We show that recruitment rates varied significantly between territories, and that territory occupancy was related to its recruitment rate, both of which are consistent with the buffer effect theory. However, we also show that restricted dispersal affects the patterns of territory occupancy with the territories close to release sites being occupied sooner and for longer as the population has grown than the territories further away. As a result of these dispersal patterns, the strength of spatial density dependence is significantly reduced. We conclude that restricted dispersal can modify spatial density dependence in the wild, which has implications for the way population dynamics are likely to be impacted by environmental change. PMID:18285284

  12. Hierarchical models and Bayesian analysis of bird survey information

    USGS Publications Warehouse

    Sauer, J.R.; Link, W.A.; Royle, J. Andrew; Ralph, C. John; Rich, Terrell D.

    2005-01-01

    Summary of bird survey information is a critical component of conservation activities, but often our summaries rely on statistical methods that do not accommodate the limitations of the information. Prioritization of species requires ranking and analysis of species by magnitude of population trend, but often magnitude of trend is a misleading measure of actual decline when trend is poorly estimated. Aggregation of population information among regions is also complicated by varying quality of estimates among regions. Hierarchical models provide a reasonable means of accommodating concerns about aggregation and ranking of quantities of varying precision. In these models the need to consider multiple scales is accommodated by placing distributional assumptions on collections of parameters. For collections of species trends, this allows probability statements to be made about the collections of species-specific parameters, rather than about the estimates. We define and illustrate hierarchical models for two commonly encountered situations in bird conservation: (1) Estimating attributes of collections of species estimates, including ranking of trends, estimating number of species with increasing populations, and assessing population stability with regard to predefined trend magnitudes; and (2) estimation of regional population change, aggregating information from bird surveys over strata. User-friendly computer software makes hierarchical models readily accessible to scientists.

  13. Environmental and genetic determinants of innovativeness in a natural population of birds

    PubMed Central

    Quinn, John L.; Cole, Ella F.; Reed, Thomas E.

    2016-01-01

    Much of the evidence for the idea that individuals differ in their propensity to innovate and solve new problems has come from studies on captive primates. Increasingly, behavioural ecologists are studying innovativeness in wild populations, and uncovering links with functional behaviour and fitness-related traits. The relative importance of genetic and environmental factors in driving this variation, however, remains unknown. Here, we present the results of the first large-scale study to examine a range of causal factors underlying innovative problem-solving performance (PSP) among 831 great tits (Parus major) temporarily taken into captivity. Analyses show that PSP in this population: (i) was linked to a variety of individual factors, including age, personality and natal origin (immigrant or local-born); (ii) was influenced by natal environment, because individuals had a lower PSP when born in poor-quality habitat, or where local population density was high, leading to cohort effects. Links with many of the individual and environmental factors were present only in some years. In addition, PSP (iii) had little or no measurable heritability, as estimated by a Bayesian animal model; and (iv) was not influenced by maternal effects. Despite previous reports of links between PSP and a range of functional traits in this population, the analyses here suggest that innovativeness had weak if any evolutionary potential. Instead most individual variation was caused by phenotypic plasticity driven by links with other behavioural traits and by environmentally mediated developmental stress. Heritability estimates are population, time and context specific, however, and more studies are needed to determine the generality of these effects. Our results shed light on the causes of innovativeness within populations, and add to the debate on the relative importance of genetic and environmental factors in driving phenotypic variation within populations. PMID:26926275

  14. Environmental and genetic determinants of innovativeness in a natural population of birds.

    PubMed

    Quinn, John L; Cole, Ella F; Reed, Thomas E; Morand-Ferron, Julie

    2016-03-19

    Much of the evidence for the idea that individuals differ in their propensity to innovate and solve new problems has come from studies on captive primates. Increasingly, behavioural ecologists are studying innovativeness in wild populations, and uncovering links with functional behaviour and fitness-related traits. The relative importance of genetic and environmental factors in driving this variation, however, remains unknown. Here, we present the results of the first large-scale study to examine a range of causal factors underlying innovative problem-solving performance (PSP) among 831 great tits (Parus major) temporarily taken into captivity. Analyses show that PSP in this population: (i) was linked to a variety of individual factors, including age, personality and natal origin (immigrant or local-born); (ii) was influenced by natal environment, because individuals had a lower PSP when born in poor-quality habitat, or where local population density was high, leading to cohort effects. Links with many of the individual and environmental factors were present only in some years. In addition, PSP (iii) had little or no measurable heritability, as estimated by a Bayesian animal model; and (iv) was not influenced by maternal effects. Despite previous reports of links between PSP and a range of functional traits in this population, the analyses here suggest that innovativeness had weak if any evolutionary potential. Instead most individual variation was caused by phenotypic plasticity driven by links with other behavioural traits and by environmentally mediated developmental stress. Heritability estimates are population, time and context specific, however, and more studies are needed to determine the generality of these effects. Our results shed light on the causes of innovativeness within populations, and add to the debate on the relative importance of genetic and environmental factors in driving phenotypic variation within populations.

  15. Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana

    USGS Publications Warehouse

    Mace, R.D.; Carney, D.W.; Chilton-Radandt, T.; Courville, S.A.; Haroldson, M.A.; Harris, R.B.; Jonkel, J.; McLellan, B.; Madel, M.; Manley, T.L.; Schwartz, C.C.; Servheen, C.; Stenhouse, G.; Waller, J.S.; Wenum, E.

    2012-01-01

    We estimated grizzly bear (Ursus arctos) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio-collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892–0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters in spring, our adjusted mean litter size was 2.27 cubs/litter. We estimated the probabilities of females transitioning from one reproductive state to another between years. Using the stable state probability of 0.322 (95% CI = 0.262–0.382) for females with cub litters, our adjusted fecundity estimate (mx) was 0.367 (95% CI = 0.273–0.461). Using our derived rates, we estimated that the population grew at a mean annual rate of approximately 3% (λ = 1.0306, 95% CI = 0.928–1.102), and 71.5% of 10,000 Monte Carlo simulations produced estimates of λ > 1.0. Our results indicate an increasing population trend of grizzly bears in the NCDE. Coupled with concurrent studies of population size, we estimate that over 1,000 grizzly bears reside in and adjacent to this recovery area. We suggest that monitoring of population trend and other vital rates using radioed females be continued.

  16. The ornament-condition relationship varies with parasite abundance at population level in a female bird

    NASA Astrophysics Data System (ADS)

    Vergara, Pablo; Martínez-Padilla, Jesús; Redpath, Stephen M.; Mougeot, Francois

    2011-10-01

    Environmental heterogeneity is expected to create variation in the ornament-condition relationship. This topic has been studied in males with less attention being given to females. Here, we explore inter-population variation in the relationship between the size of a male-like trait, supra-orbital combs, and body mass in female red grouse Lagopus lagopus scoticus. We used the abundance of the nematode Trichostrongylus tenuis, a parasite with strong negative effects on this species, as a proxy of environmental conditions. We studied six populations over 5 years and showed that the comb size-body mass relationship varied with mean parasite abundance, with stronger ornament-condition relationships in populations with higher parasite infection levels. Our study supports the idea that environmental conditions, and in particular parasite infection levels, may affect the reliability of female ornaments as condition indicators.

  17. State-space modeling of population sizes and trends in Nihoa Finch and Millerbird

    USGS Publications Warehouse

    Gorresen, P. Marcos; Brinck, Kevin W.; Camp, Richard J.; Farmer, Chris; Plentovich, Sheldon M.; Banko, Paul C.

    2016-01-01

    Both of the 2 passerines endemic to Nihoa Island, Hawai‘i, USA—the Nihoa Millerbird (Acrocephalus familiaris kingi) and Nihoa Finch (Telespiza ultima)—are listed as endangered by federal and state agencies. Their abundances have been estimated by irregularly implemented fixed-width strip-transect sampling from 1967 to 2012, from which area-based extrapolation of the raw counts produced highly variable abundance estimates for both species. To evaluate an alternative survey method and improve abundance estimates, we conducted variable-distance point-transect sampling between 2010 and 2014. We compared our results to those obtained from strip-transect samples. In addition, we applied state-space models to derive improved estimates of population size and trends from the legacy time series of strip-transect counts. Both species were fairly evenly distributed across Nihoa and occurred in all or nearly all available habitat. Population trends for Nihoa Millerbird were inconclusive because of high within-year variance. Trends for Nihoa Finch were positive, particularly since the early 1990s. Distance-based analysis of point-transect counts produced mean estimates of abundance similar to those from strip-transects but was generally more precise. However, both survey methods produced biologically unrealistic variability between years. State-space modeling of the long-term time series of abundances obtained from strip-transect counts effectively reduced uncertainty in both within- and between-year estimates of population size, and allowed short-term changes in abundance trajectories to be smoothed into a long-term trend.

  18. Temporal trends of perfluoroalkyl substances (PFAS) in eggs of coastal and offshore birds: Increasing PFAS levels associated with offshore bird species breeding on the Pacific coast of Canada and wintering near Asia.

    PubMed

    Miller, Aroha; Elliott, John E; Elliott, Kyle H; Lee, Sandi; Cyr, Francois

    2015-08-01

    Perfluoroalkyl substances (PFAS) such as perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) have become virtually ubiquitous throughout the environment, and, based on laboratory studies, have known toxicological consequences. Various national and international voluntary phase-outs and restrictions on these compounds have been implemented over the last 10 to 15 years. In the present study, we examine trends (1990/1991-2010/2011) in aquatic birds (ancient murrelet, Synthliboramphus antiquus [2009 only]; Leach's storm-petrels, Oceanodroma leucorhoa; rhinoceros auklets, Cerorhinca monocerata; double-crested cormorants, Phalacrocorax auritus; and great blue herons, Ardea herodias). The PFCA, PFSA, and stable isotope (δ(15) N and δ(13) C) data collected from these species from the Pacific coast of Canada, ranging over 20 to 30 years, were used to investigate temporal changes in PFAS coupled to dietary changes. Perfluorooctane sulfonic acid (PFOS), the dominant PFSA compound in all 4 species, increased and subsequently decreased in auklet and cormorant eggs in line with the manufacturing phase-out of PFOS and perfluorooctanoic acid (PFOA), but concentrations continuously increased in petrel eggs and remained largely unchanged in heron eggs. Dominant PFCA compounds varied between the offshore and coastal species, with increases seen in the offshore species and little or variable changes seen in the coastal species. Little temporal change was seen in stable isotope values, indicating that diet alone is not driving observed PFAS concentrations.

  19. Candidate gene–environment interactions and their relationships with timing of breeding in a wild bird population

    PubMed Central

    Bourret, Audrey; Garant, Dany

    2015-01-01

    Monitoring and predicting evolutionary changes underlying current environmental modifications are complex challenges. Recent approaches to achieve these objectives include assessing the genetic variation and effects of candidate genes on traits indicating adaptive potential. In birds, for example, short tandem repeat polymorphism at four candidate genes (CLOCK, NPAS2, ADCYAP1, and CREB1) has been linked to variation in phenological traits such as laying date and timing of migration. However, our understanding of their importance as evolutionary predictors is still limited, mainly because the extent of genotype–environment interactions (GxE) related to these genes has yet to be assessed. Here, we studied a population of Tree swallow (Tachycineta bicolor) over 4 years in southern Québec (Canada) to assess the relationships between those four candidate genes and two phenological traits related to reproduction (laying date and incubation duration) and also determine the importance of GxE in this system. Our results showed that NPAS2 female genotypes were nonrandomly distributed across the study system and formed a longitudinal cline with longer genotypes located to the east. We observed relationships between length polymorphism at all candidate genes and laying date and/or incubation duration, and most of these relationships were affected by environmental variables (breeding density, latitude, or temperature). In particular, the positive relationships detected between laying date and both CLOCK and NPAS2 female genotypes were variable depending on breeding density. Our results suggest that all four candidate genes potentially affect timing of breeding in birds and that GxE are more prevalent and important than previously reported in this context. PMID:26380692

  20. A spatial genetic structure and effects of relatedness on mate choice in a wild bird population.

    PubMed

    Foerster, K; Valcu, M; Johnsen, A; Kempenaers, B

    2006-12-01

    Inbreeding depression, as commonly found in natural populations, should favour the evolution of inbreeding avoidance mechanisms. If natal dispersal, the first and probably most effective mechanism, does not lead to a complete separation of males and females from a common origin, a small-scale genetic population structure may result and other mechanisms to avoid inbreeding may exist. We studied the genetic population structure and individual mating patterns in blue tits (Parus caeruleus). The population showed a local genetic structure in two out of four years: genetic relatedness between individuals (estimated from microsatellite markers) decreased with distance. This pattern was mainly caused by immigrants to the study area; these, if paired with fellow immigrants, were more related than expected by chance. Since blue tits did not avoid inbreeding with their social partner, we examined if individuals preferred less related partners at later stages of the mate choice process. We found no evidence that females or males avoided inbreeding through extra-pair copulations or through mate desertion and postbreeding dispersal. Although the small-scale genetic population structure suggests that blue tits could use a simple rule of thumb to select less related mates, females did not generally prefer more distantly breeding extra-pair partners. However, the proportion of young fathered by an extra-pair male in mixed paternity broods depended on the genetic relatedness with the female. This suggests that there is a fertilization bias towards less related copulation partners and that blue tits are able to reduce the costs of inbreeding through a postcopulatory process.

  1. Partitioning of genetic variation across the genome using multimarker methods in a wild bird population.

    PubMed

    Robinson, Matthew R; Santure, Anna W; Decauwer, Isabelle; Sheldon, Ben C; Slate, Jon

    2013-08-01

    The underlying basis of genetic variation in quantitative traits, in terms of the number of causal variants and the size of their effects, is largely unknown in natural populations. The expectation is that complex quantitative trait variation is attributable to many, possibly interacting, causal variants, whose effects may depend upon the sex, age and the environment in which they are expressed. A recently developed methodology in animal breeding derives a value of relatedness among individuals from high-density genomic marker data, to estimate additive genetic variance within livestock populations. Here, we adapt and test the effectiveness of these methods to partition genetic variation for complex traits across genomic regions within ecological study populations where individuals have varying degrees of relatedness. We then apply this approach for the first time to a natural population and demonstrate that genetic variation in wing length in the great tit (Parus major) reflects contributions from multiple genomic regions. We show that a polygenic additive mode of gene action best describes the patterns observed, and we find no evidence of dosage compensation for the sex chromosome. Our results suggest that most of the genomic regions that influence wing length have the same effects in both sexes. We found a limited amount of genetic variance in males that is attributed to regions that have no effects in females, which could facilitate the sexual dimorphism observed for this trait. Although this exploratory work focuses on one complex trait, the methodology is generally applicable to any trait for any laboratory or wild population, paving the way for investigating sex-, age- and environment-specific genetic effects and thus the underlying genetic architecture of phenotype in biological study systems.

  2. Ten-year trends in overweight and obesity in the adult Portuguese population, 1995 to 2005

    PubMed Central

    2011-01-01

    Background There is little information regarding the trends in body mass index (BMI) and obesity in the overall Portuguese population, namely if these trends are similar according to educational level. In this study, we assessed the trends in the prevalence of overweight and obesity in the Portuguese population, overall and by educational level. Methods Cross-sectional national health interview surveys conducted in 1995-6 (n = 38,504), 1998-9 (n = 38,688) and 2005-6 (n = 25,348). Data were derived from the population and housing census of 1991 and two geographically-based strata were defined. The sampling unit was the house, and all subjects living in the sampling unit were surveyed. Height and weight were self-reported; the effects of gender, age group and educational level were also assessed by self-reported structured questionnaires. Bivariate comparisons were performed using Chi-square or analysis of variance (ANOVA). Trends in BMI levels were assessed by linear regression analysis, while trends in the prevalence of obesity were assessed by logistic regression. Results Mean (±standard deviation) BMI increased from 25.2 ± 4.0 in 1995-6 to 25.7 ± 4.5 kg/m2 in 2005-6. Prevalence of overweight remained stable (36.1% in 1995-6 and 36.4% in 2005) while prevalence of obesity increased (11.5% in 1995-6 and 15.1% in 2005-6). Similar findings were observed according to age group. Mean age-adjusted BMI increase (expressed in kg/m2/year and 95% confidence interval) was 0.073 (0.062, 0.084), 0.016 (0.000, 0.031) and 0.073 (0.049, 0.098) in men with primary, secondary and university levels, respectively; the corresponding values in women were 0.085 (0.073, 0.097), 0.052 (0.035, 0.069) and 0.062 (0.038, 0.084). Relative to 1995-6, obesity rates increased by 48%, 41% and 59% in men and by 40%, 75% and 177% in women with primary, secondary and university levels, respectively. The corresponding values for overweight were 6%, 1% and 23% in men and 5%, 7% and 65% in women

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

    PubMed

    Wright, Kyle R

    2016-01-01

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

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

    PubMed Central

    2016-01-01

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

  5. Combined Influences of Model Choice, Data Quality, and Data Quantity When Estimating Population Trends

    PubMed Central

    Rueda-Cediel, Pamela; Anderson, Kurt E.; Regan, Tracey J.; Franklin, Janet; Regan, Helen M.

    2015-01-01

    Estimating and projecting population trends using population viability analysis (PVA) are central to identifying species at risk of extinction and for informing conservation management strategies. Models for PVA generally fall within two categories, scalar (count-based) or matrix (demographic). Model structure, process error, measurement error, and time series length all have known impacts in population risk assessments, but their combined impact has not been thoroughly investigated. We tested the ability of scalar and matrix PVA models to predict percent decline over a ten-year interval, selected to coincide with the IUCN Red List criterion A.3, using data simulated for a hypothetical, short-lived organism with a simple life-history and for a threatened snail, Tasmaphena lamproides. PVA performance was assessed across different time series lengths, population growth rates, and levels of process and measurement error. We found that the magnitude of effects of measurement error, process error, and time series length, and interactions between these, depended on context. We found that high process and measurement error reduced the reliability of both models in predicted percent decline. Both sources of error contributed strongly to biased predictions, with process error tending to contribute to the spread of predictions more than measurement error. Increasing time series length improved precision and reduced bias of predicted population trends, but gains substantially diminished for time series lengths greater than 10–15 years. The simple parameterization scheme we employed contributed strongly to bias in matrix model predictions when both process and measurement error were high, causing scalar models to exhibit similar or greater precision and lower bias than matrix models. Our study provides evidence that, for short-lived species with structured but simple life histories, short time series and simple models can be sufficient for reasonably reliable conservation

  6. Environment-dependent selection on mate choice in a natural population of birds.

    PubMed

    Robinson, Matthew R; van Doorn, G Sander; Gustafsson, Lars; Qvarnström, Anna

    2012-06-01

    Female mate choice acts as an important evolutionary force, yet the influence of the environment on both its expression and the selective pressures acting upon it remains unknown. We found consistent heritable differences between females in their choice of mate based on ornament size during a 25-year study of a population of collared flycatchers. However, the fitness consequences of mate choice were dependent on environmental conditions experienced whilst breeding. Females breeding with highly ornamented males experienced high relative fitness during dry summer conditions, but low relative fitness during wetter years. Our results imply that sexual selection within a population can be highly variable and dependent upon the prevailing weather conditions experienced by individuals.

  7. Heritability of fear of humans in urban and rural populations of a bird species.

    PubMed

    Carrete, Martina; Martínez-Padilla, Jesús; Rodríguez-Martínez, Sol; Rebolo-Ifrán, Natalia; Palma, Antonio; Tella, José L

    2016-08-08

    Flight initiation distance (FID), a measure of an animal's tolerance to human disturbance and a descriptor of its fear of humans, is increasingly employed for conservation purposes and to predict the response of species to urbanization. However, most work devoted to understanding variability in FID has been conducted at the population level and little is still known about inter-individual variability in this behaviour. We estimated the heritability of FID, a factor fundamental to understanding the strength and evolutionary consequences of selection of particular phenotypes associated with human disturbances. We used a population of burrowing owls (Athene cunicularia) monitored long-term and for which FID was previously shown to be highly consistent across an individual's lifespan. Heritability estimates varied between 0.37 and 0.80, depending on the habitat considered (urban-rural) and method used (parent-offspring regressions or animal models). These values are unusually high compared with those previously reported for other behavioural traits. Although more research is needed to fully understand the underlying causes of this resemblance between relatives, selection pressures acting on this behaviour should be seriously considered as an important evolutionary force in animal populations increasingly exposed to human disturbance worldwide.

  8. Long-term population dynamics of breeding bird species in the German Wadden Sea area

    NASA Astrophysics Data System (ADS)

    Vauk, Gottfried; Prüter, Johannes; Hartwig, Eike

    1989-09-01

    For no other group of organisms in coastal areas are there so exact and long-term data available as there are for seabirds. Since the beginning of the 20th century, documentation of population size, especially for species breeding in colonies from the groups gulls, terns and auks, is almost complete. These species act as bio-indicators, and data on fluctuations in their population size are useful as they reflect changes in the state of the marine ecosystem. The population development of some of these seabird species (Herring Gull, Guillemot, Common, Arctic and Sandwich Tern) from the German North Sea coast, which primarily feed on fish, is given. Common to all these species is an exponential increase in numbers in recent years (1970 1985). Possible causes for this development, e.g. pressure from enemies or competitors, availability of breeding places, anthropogenic stress and mortality factors, as well as the direct and indirect anthropogenic-influenced changes in the trophic system due to the increasing eutrophication of coastal waters, are evaluated. Signs of a collapse in the stocks of seabrids resulting from environmental pollution are discussed. Consequences resulting from the ecosystem changes, such as reduction of nutrient discharge into the North Sea and the expansion of biological monitoring, are described.

  9. Heritability of fear of humans in urban and rural populations of a bird species

    PubMed Central

    Carrete, Martina; Martínez-Padilla, Jesús; Rodríguez-Martínez, Sol; Rebolo-Ifrán, Natalia; Palma, Antonio; Tella, José L.

    2016-01-01

    Flight initiation distance (FID), a measure of an animal’s tolerance to human disturbance and a descriptor of its fear of humans, is increasingly employed for conservation purposes and to predict the response of species to urbanization. However, most work devoted to understanding variability in FID has been conducted at the population level and little is still known about inter-individual variability in this behaviour. We estimated the heritability of FID, a factor fundamental to understanding the strength and evolutionary consequences of selection of particular phenotypes associated with human disturbances. We used a population of burrowing owls (Athene cunicularia) monitored long-term and for which FID was previously shown to be highly consistent across an individual’s lifespan. Heritability estimates varied between 0.37 and 0.80, depending on the habitat considered (urban-rural) and method used (parent-offspring regressions or animal models). These values are unusually high compared with those previously reported for other behavioural traits. Although more research is needed to fully understand the underlying causes of this resemblance between relatives, selection pressures acting on this behaviour should be seriously considered as an important evolutionary force in animal populations increasingly exposed to human disturbance worldwide. PMID:27499420

  10. Population trends of Mariana Crow Corvus kubaryi on Rota, Commonwealth of the Northern Mariana Islands

    USGS Publications Warehouse

    Plentovich, S.; Morton, J.M.; Bart, J.; Camp, R.J.; Lusk, M.; Johnson, N.; VanderWerf, E.

    2005-01-01

    Endemic to the islands of Guam and Rota in the Mariana Islands, Mariana Crow Corvus kubaryi is the only corvid in Micronesia. Currently, it survives on Guam only because of translocation of individuals from Rota (1999-2003). Island-wide surveys in 1982 and 1995 on Rota yielded population estimates of 1,348 and 592 respectively, indicating a 56% decrease in only 13 years. A sharp decline in the only viable Mariana Crow population has serious implications for conservation efforts on Rota and for efforts to re-establish the Guam population. However, the validity of the apparent decline has been debated among scientists and government management agencies. We augmented the 1982 and 1995 island-wide VCP surveys with (1) an additional island-wide survey conducted in 1998, and (2) roadside surveys conducted during 1991-1993 and again during 1999-2002. We also outline historical changes in Rota's limestone forest based on aerial photographs and historical information. Data from all surveys indicate a significant decline in the Mariana Crow population. Declines occurred especially along the north-central coast and in the area east of the airport known as As Dudo in the 1990s, but the data indicate an island-wide decline over the entire span of the surveys. introduced predators, human persecution, and habitat loss and degradation by anthropogenic and natural causes have all contributed to the decline. Long-term preservation of this species will require effective brown treesnake Boiga irregularis control, habitat protection, continued monitoring and research, and increased public education and awareness of Rota's rare and endangered species. ?? BirdLife International 2005.

  11. Agriculture modifies the seasonal decline of breeding success in a tropical wild bird population.

    PubMed

    Cartwright, Samantha J; Nicoll, Malcolm A C; Jones, Carl G; Tatayah, Vikash; Norris, Ken

    2014-10-01

    Habitat conversion for agriculture is a major driver of biodiversity loss, but our understanding of the demographic processes involved remains poor. We typically investigate the impacts of agriculture in isolation even though populations are likely to experience multiple, concurrent changes in the environment (e.g. land and climate change). Drivers of environmental change may interact to affect demography, but the mechanisms have yet to be explored fully in wild populations.Here, we investigate the mechanisms linking agricultural land use with breeding success using long-term data for the formerly Critically Endangered Mauritius kestrel Falco punctatus, a tropical forest specialist that also occupies agricultural habitats. We specifically focused on the relationship between breeding success, agriculture and the timing of breeding because the latter is sensitive to changes in climatic conditions (spring rainfall) and enables us to explore the interactive effects of different (land and climate) drivers of environmental change.Breeding success, measured as egg survival to fledging, declines seasonally in this population, but we found that the rate of this decline became increasingly rapid as the area of agriculture around a nest site increased. If the relationship between breeding success and agriculture was used in isolation to estimate the demographic impact of agriculture, it would significantly under-estimate breeding success in dry (early) springs and over-estimate breeding success in wet (late) springs.Analysis of prey delivered to nests suggests that the relationship between breeding success and agriculture might be due, in part, to spatial variation in the availability of native, arboreal geckos.Synthesis and applications. Agriculture modifies the seasonal decline in breeding success in this population. As springs are becoming wetter in our study area and since the kestrels breed later in wetter springs, the impact of agriculture on breeding success will

  12. Demographic Ageing of the South African Population: Past (1945-1985) and Expected Trends (1985-2035). Report S-190.

    ERIC Educational Resources Information Center

    Hofmeyr, B. E.; Mostert, W. P.

    This report presents demographic data for four racial populations in South Africa (Blacks, Whites, Coloureds, and Asians) and examines trends in the aging of each of these populations. The age structure of a population is determined most directly by fertility and mortality. The findings of this report support a general theory to the effect that…

  13. On the decline of the Rusty Blackbird and the use of ornithological literature to document long-term population trends

    USGS Publications Warehouse

    Greenberg, R.; Droege, S.

    1999-01-01

    Unlike most North American blackbirds, Rusty Blackbirds (Euphagus carolensis) have shown steep population declines. Declines of approximately 90% are indicated for three recent decades from the Breeding Bird Survey, Christmas Bird Counts, and Quebec Checklist Program. Analyses of abundance classifications in bird distribution books and annotated checklists reveal an overlooked but long-term decline dating back to at least the early part of this century. Rusty Blackbirds were described as very common to abundant in 5656 of the pre-192O published accounts, 19% of the 1921-1950 accounts, and only 7% of the post-1950 accounts. Rusty Blackbirds were described as uncommon in none of the pre-1950 accounts, 18% of the 1951-1980 accounts, and 43% of the post-1980 accounts. A similar pattern was found for analyses based on local checklists. Destruction of wooded wetlands on wintering grounds, acid precipitation, and the conversion of boreal forest wetlands could have contributed to these declines. Systematic analysis of regional guides and checklists provides a valuable tool for examining large-scale and long-term population changes in birds.

  14. Site-occupancy distribution modeling to correct population-trend estimates derived from opportunistic observations

    USGS Publications Warehouse

    Kery, M.; Royle, J. Andrew; Schmid, Hans; Schaub, M.; Volet, B.; Hafliger, G.; Zbinden, N.

    2010-01-01

    Species' assessments must frequently be derived from opportunistic observations made by volunteers (i.e., citizen scientists). Interpretation of the resulting data to estimate population trends is plagued with problems, including teasing apart genuine population trends from variations in observation effort. We devised a way to correct for annual variation in effort when estimating trends in occupancy (species distribution) from faunal or floral databases of opportunistic observations. First, for all surveyed sites, detection histories (i.e., strings of detection-nondetection records) are generated. Within-season replicate surveys provide information on the detectability of an occupied site. Detectability directly represents observation effort; hence, estimating detectablity means correcting for observation effort. Second, site-occupancy models are applied directly to the detection-history data set (i.e., without aggregation by site and year) to estimate detectability and species distribution (occupancy, i.e., the true proportion of sites where a species occurs). Site-occupancy models also provide unbiased estimators of components of distributional change (i.e., colonization and extinction rates). We illustrate our method with data from a large citizen-science project in Switzerland in which field ornithologists record opportunistic observations. We analyzed data collected on four species: the widespread Kingfisher (Alcedo atthis. ) and Sparrowhawk (Accipiter nisus. ) and the scarce Rock Thrush (Monticola saxatilis. ) and Wallcreeper (Tichodroma muraria. ). Our method requires that all observed species are recorded. Detectability was <1 and varied over the years. Simulations suggested some robustness, but we advocate recording complete species lists (checklists), rather than recording individual records of single species. The representation of observation effort with its effect on detectability provides a solution to the problem of differences in effort encountered

  15. Reconstructing the Phylogenetic History of Long-Term Effective Population Size and Life-History Traits Using Patterns of Amino Acid Replacement in Mitochondrial Genomes of Mammals and Birds

    PubMed Central

    Nabholz, Benoit; Lartillot, Nicolas

    2013-01-01

    The nearly neutral theory, which proposes that most mutations are deleterious or close to neutral, predicts that the ratio of nonsynonymous over synonymous substitution rates (dN/dS), and potentially also the ratio of radical over conservative amino acid replacement rates (Kr/Kc), are negatively correlated with effective population size. Previous empirical tests, using life-history traits (LHT) such as body-size or generation-time as proxies for population size, have been consistent with these predictions. This suggests that large-scale phylogenetic reconstructions of dN/dS or Kr/Kc might reveal interesting macroevolutionary patterns in the variation in effective population size among lineages. In this work, we further develop an integrative probabilistic framework for phylogenetic covariance analysis introduced previously, so as to estimate the correlation patterns between dN/dS, Kr/Kc, and three LHT, in mitochondrial genomes of birds and mammals. Kr/Kc displays stronger and more stable correlations with LHT than does dN/dS, which we interpret as a greater robustness of Kr/Kc, compared with dN/dS, the latter being confounded by the high saturation of the synonymous substitution rate in mitochondrial genomes. The correlation of Kr/Kc with LHT was robust when controlling for the potentially confounding effects of nucleotide compositional variation between taxa. The positive correlation of the mitochondrial Kr/Kc with LHT is compatible with previous reports, and with a nearly neutral interpretation, although alternative explanations are also possible. The Kr/Kc model was finally used for reconstructing life-history evolution in birds and mammals. This analysis suggests a fairly large-bodied ancestor in both groups. In birds, life-history evolution seems to have occurred mainly through size reduction in Neoavian birds, whereas in placental mammals, body mass evolution shows disparate trends across subclades. Altogether, our work represents a further step toward a more

  16. Stability of genetic variance and covariance for reproductive characters in the face of climate change in a wild bird population.

    PubMed

    Garant, Dany; Hadfield, Jarrod D; Kruuk, Loeske E B; Sheldon, Ben C

    2008-01-01

    Global warming has had numerous effects on populations of animals and plants, with many species in temperate regions experiencing environmental change at unprecedented rates. Populations with low potential for adaptive evolutionary change and plasticity will have little chance of persistence in the face of environmental change. Assessment of the potential for adaptive evolution requires the estimation of quantitative genetic parameters, but it is as yet unclear what impact, if any, global warming will have on the expression of genetic variances and covariances. Here we assess the impact of a changing climate on the genetic architecture underlying three reproductive traits in a wild bird population. We use a large, long-term, data set collected on great tits (Parus major) in Wytham Woods, Oxford, and an 'animal model' approach to quantify the heritability of, and genetic correlations among, laying date, clutch size and egg mass during two periods with contrasting temperature conditions over a 40-year period (1965-1988 [cooler] vs. 1989-2004 [warmer]). We found significant additive genetic variance and heritability for all traits under both temperature regimes. We also found significant negative genetic covariances and correlations between clutch size and egg weight during both periods, and among laying date and clutch size in the colder years only. The overall G matrix comparison among periods, however, showed only a minor difference among periods, thus suggesting that genotype by environment interactions are negligible in this context. Our results therefore suggest that despite substantial changes in temperature and in mean laying date phenotype over the last decades, and despite the large sample sizes available, we are unable to detect any significant change in the genetic architecture of the reproductive traits studied.

  17. Trends in health inequalities by educational level in a Norwegian total population study

    PubMed Central

    Krokstad, S; Kunst, A; Westin, S

    2002-01-01

    Objective: To describe levels of inequality and trends in self reported morbidity by educational level in a total Norwegian county population in the mid-1980s and mid-1990s. Design: Two cross sectional health surveys at an interval of 10 years in the Nord-Trøndelag Health Study, HUNT I (1984–86) and HUNT II (1995–97). Setting: Primary health care, total county population study. Participants: Men and women, 25–69 years. Main results: There was a consistent pattern of increasing self reported health problems with decreasing educational level for three health variables: perceived health, any longstanding health problem, and having a chronic condition. A stable or slight decrease in inequalities over time was found. The prevalence odds ratio for perceived health less than good were 2.71 for men (95% confidence intervals (CI): 2.39 to 3.09) and 2.13 for women (95% CI: 1.85 to 2.46) in the first survey, 2.51 for men (95% CI: 2.27 to 2.78) and 2.06 for women (95% CI: 1.88 to 2.26) 10 years later. Conclusions: The magnitude of the socioeconomic gradients in health in this population seemed somewhat lower than in Norway as a whole and close to the average in studies from other European countries. There was a slight trend towards smaller differences despite rapid structural changes in working life, turbulence in economy, and more people experiencing unemployment. PMID:11964436

  18. Consequences of habitat change and resource selection specialization for population limitation in cavity-nesting birds

    USGS Publications Warehouse

    Martin, Thomas E.

    2015-01-01

    Synthesis and applications. Management should target species that specialize in resource selection on a declining resource. Species with greater resource selection generalization can reduce population impacts of environmental change. Resource generalization can allow a species like the wren to take advantage of habitat refuges, such as those provided by the elk exclosures. Yet, resource generalization cannot offset the negative impacts of broad-scale declines in habitat quality on the landscape, as demonstrated by the general decline of wrens. Ultimately, aspen is an important habitat for biodiversity, and land management programmes that protect and aid recovery of aspen habitats may be critical.

  19. Seroprevalence of avian paramyxovirus 1, 2, and 3 in captive and free-living birds of prey in Spain (preliminary results): implications for management of wild and captive populations.

    PubMed

    Höfle, Ursula; Blanco, J M; Kaleta, E F

    2002-10-01

    Since December 1997, 700 blood plasma samples from 31 different species of captive and free-living birds of prey from Spain were analyzed by hemagglutination inhibition (HI) test for the presence of antibodies to avian paramyxovirus (aPMV) 1,2, and 3. Out of 700 birds, 120 tested positive for aPMV-1, 10 birds had antibodies to aPMV-2, and 4 birds tested positive against aPMV-3. Prevalence of antibodies against aPMV-1 was significantly higher in captive than in free-living birds of prey and in Falconiformes than in Strigidae and Accipitridae. Infection or exposure in captive birds may be due to the use of avian-derived food in rehabilitation and captive-breeding centers. This may be of concern at the time of reintroduction of these birds into free-living populations.

  20. Determinants and Time Trends for Ischaemic and Haemorrhagic Stroke in a Large Chinese Population

    PubMed Central

    Guo, Yutao; Wang, Hao; Tao, Tao; Tian, Yingchun; Wang, Yutang; Chen, Yundai; Lip, Gregory Y. H.

    2016-01-01

    Background The clinical epidemiology of stroke has been widely investigated in Caucasian populations, but the changes over time in the proportion of ischaemic to haemorrhagic strokes is less clear, especially in the Chinese population. Aims Our objective was to study the determinants and time trends for ischaemic and haemorrhagic stroke, in relation to age, in a large Chinese population cohort. Methods Using a medical insurance database in the southwest of China from 2001 to 2012, time trends in age-adjusted ischaemic and haemorrhagic stroke incidence and the contributing risk factors associated with age were investigated. Results Among 425,901 individuals without prior stroke (52.4% male, median age 54), the rate of ischaemic stroke (per 1000 patient-years) decreased between 2002–2007, then remained broadly similar between 2008–2012. The rate of haemorrhagic stroke showed a similar trend, being approximately 1.3–1.9 from 2008–2012. Compared to patients age<65, ischaemic and haemorrhagic stroke incidences (rate, 95% confidential interval, CI) were higher in the elderly population (age <65 versus age ≥65: ischaemic: 3.64, 3.33–4.00, vs 14.33, 14.01–14.60; haemorrhagic: 1.09, 1.00–1.10 vs 2.52,2.40–2.70, respectively, both p<0.001). There were no significant differences in haemorrhagic stroke rates between the elderly and the very elderly population. Ischaemic and haemorrhagic stroke shared similar risk factors (age, hypertension, coronary artery disease (CAD), vascular disease, and diabetes mellitus) (all p<0.05). In subjects age<75 years, CAD (7.17, 4.14–12.37) and diabetes mellitus (3.27, 2.42–4.42) contributed most to the developing of haemorrhagic stroke (all p<0.001). Amongst the very elderly, vascular disease (2.24, 1.49–3.37) was an additional major risk factor for haemorrhagic stroke, together with CAD and diabetes mellitus (all p<0.001). Conclusion In this large Chinese cohort, there was an increased risk of ischaemic stroke compared

  1. Social carry-over effects underpin trans-seasonally linked structure in a wild bird population.

    PubMed

    Firth, Josh A; Sheldon, Ben C

    2016-11-01

    Spatial structure underpins numerous population processes by determining the environment individuals' experience and which other individuals they encounter. Yet, how the social landscape influences individuals' spatial decisions remains largely unexplored. Wild great tits (Parus major) form freely moving winter flocks, but choose a single location to establish a breeding territory over the spring. We demonstrate that individuals' winter social associations carry-over into their subsequent spatial decisions, as individuals breed nearer to those they were most associated with during winter. Further, they also form territory boundaries with their closest winter associates, irrespective of breeding distance. These findings were consistent across years, and among all demographic classes, suggesting that such social carry-over effects may be general. Thus, prior social structure can shape the spatial proximity, and fine-scale arrangement, of breeding individuals. In this way, social networks can influence a wide range of processes linked to individuals' breeding locations, including other social interactions themselves.

  2. Disentangling the effect of genes, the environment and chance on sex ratio variation in a wild bird population

    PubMed Central

    Postma, Erik; Heinrich, Franziska; Koller, Ursina; Sardell, Rebecca J.; Reid, Jane M.; Arcese, Peter; Keller, Lukas F.

    2011-01-01

    Sex ratio theory proposes that the equal sex ratio typically observed in birds and mammals is the result of natural selection. However, in species with chromosomal sex determination, the same 1 : 1 sex ratio is expected under random Mendelian segregation. Here, we present an analysis of 14 years of sex ratio data for a population of song sparrows (Melospiza melodia) on Mandarte Island, at the nestling stage and at independence from parental care. We test for the presence of variance in sex ratio over and above the binomial variance expected under Mendelian segregation, and thereby quantify the potential for selection to shape sex ratio. Furthermore, if sex ratio variation is to be shaped by selection, we expect some of this extra-binomial variation to have a genetic basis. Despite ample statistical power, we find no evidence for the existence of either genetic or environmentally induced variation in sex ratio, in the nest or at independence. Instead, the sex ratio variation observed matches that expected under random Mendelian segregation. Using one of the best datasets of its kind, we conclude that female song sparrows do not, and perhaps cannot, adjust the sex of their offspring. We discuss the implications of this finding and make suggestions for future research. PMID:21345862

  3. Mhc supertypes confer both qualitative and quantitative resistance to avian malaria infections in a wild bird population

    PubMed Central

    Sepil, Irem; Lachish, Shelly; Hinks, Amy E.; Sheldon, Ben C.

    2013-01-01

    Major histocompatibility complex (Mhc) genes are believed to play a key role in the genetic basis of disease control. Although numerous studies have sought links between Mhc and disease prevalence, many have ignored the ecological and epidemiological aspects of the host–parasite interaction. Consequently, interpreting associations between prevalence and Mhc has been difficult, whereas discriminating alleles for qualitative resistance, quantitative resistance and susceptibility remains challenging. Moreover, most studies to date have quantified associations between genotypes and disease status, overlooking the complex relationship between genotype and the properties of the Mhc molecule that interacts with parasites. Here, we address these problems and demonstrate avian malaria (Plasmodium) parasite species-specific associations with functional properties of Mhc molecules (Mhc supertypes) in a wild great tit (Parus major) population. We further show that correctly interpreting these associations depends crucially on understanding the spatial variation in risk of infection and the fitness effects of infection. We report that a single Mhc supertype confers qualitative resistance to Plasmodium relictum, whereas a different Mhc supertype confers quantitative resistance to Plasmodium circumflexum infections. Furthermore, we demonstrate common functional properties of Plasmodium-resistance alleles in passerine birds, suggesting this is a model system for parasite–Mhc associations in the wild. PMID:23516242

  4. [Recent trends in the spatial mobility of the population of Paraiba].

    PubMed

    Targino, I; Monte, F F

    1989-01-01

    Recent trends in migration affecting the Brazilian state of Paraiba are analyzed. "Three dimensions of the state's migrations are analysed here: inter-state mobility, the growth of urban population, and the rural exodus. The central thesis of this study is that the migration of Paraiba's population is an element which is determined by and at the same time determines the process of production and the conformity of space to the logic of profit at the present stage of Brazilian capitalist development. The intensity of emigration from Paraiba cannot be understood when it is divorced from the process of the organization of the socio-economic space of the nation. The greater the imbalance between the economy of the state and that of Brazil's metropolises, the more frequent are the fluxes of migrants. On the [other] hand conservative modernization of agriculture has largely contributed to strengthen the causes of the ousting of peasants inherent to the state's economic framework." (SUMMARY IN ENG)

  5. Data depth, data completeness, and their influence on quantitative genetic estimation in two contrasting bird populations.

    PubMed

    Quinn, J L; Charmantier, A; Garant, D; Sheldon, B C

    2006-05-01

    Evolutionary biologists increasingly use pedigree-based quantitative genetic methods to address questions about the evolutionary dynamics of traits in wild populations. In many cases, phenotypic data may have been collected only for recent parts of the study. How does this influence the performance of the models used to analyse these data? Here we explore how data depth (number of years) and completeness (number of observations) influence estimates of genetic variance and covariance within the context of an existing pedigree. Using long-term data from the great tit Parus major and the mute swan Cygnus olor, species with different life-histories, we examined the effect of manipulating the amount of data included on quantitative genetic parameter estimates. Manipulating data depth and completeness had little influence on estimated genetic variances, heritabilities, or genetic correlations, but (as expected) did influence confidence in these estimates. Estimated breeding values in the great tit were not influenced by data depth but were in the mute swan, probably because of differences in pedigree structure. Our analyses suggest the 'rule of thumb' that data from 3 years and a minimum of 100 individuals per year are needed to estimate genetic parameters with acceptable confidence, and that using pedigree data is worthwhile, even if phenotypes are only available toward the tips of the pedigree.

  6. Genetic parameters and trends in the Chilean multibreed dairy cattle population.

    PubMed

    Elzo, M A; Jara, A; Barria, N

    2004-05-01

    Estimates of additive and nonadditive multibreed co-variance components, genetic parameters, and predicted genetic values for first lactation 305-d mature equivalent (ME) milk yield, fat yield, and protein yield were computed using data from a sample of 3316 cows from the Chilean Holstein-other breeds multibreed population. Variances and covariances were estimated by 2-trait REML analyses using a Generalized Expectation-Maximization algorithm applied to multibreed populations. Multiple estimates of additive genetic, nonadditive genetic, and environmental variances from 2-trait analyses were averaged to yield a single variance estimate for each trait and effect. Heritabilities were moderate for all traits in Holstein, other, and Holstein x other crossbred groups. Interbreed interactibilities (ratio of nonadditive genetic to phenotypic variances) were all near zero. Multibreed additive, nonadditive, and total genetic trends were estimated using the complete dataset (56,277 cows). Upward trends between 1990 and 2000 existed for all traits, genetic effects, and breed groups, except for 305-d ME protein yield in 1/4 Holstein, indicating that Chilean dairy producers were successful in choosing progressively better semen and sires from imported and local sources over time.

  7. Measuring trends and signals of sustainability in oyster population and production data

    NASA Astrophysics Data System (ADS)

    Wouters, N.; Valayer, P. J.; Pickerel, T.; Vanstaen, K. R.; Palmer, D. W.; Mills, G.; Cabral, H. N.

    2013-09-01

    Resilience research often includes time series analysis in search of trend shifts. Recently statistical signals including changes in variance and autocorrelation, were proven to be universal indicators of stability. In this paper the suitability of those early warning signals was tested on two case studies: oysters production of France (case study 1) and catch rates of the native oyster in the Solent, UK (case study 2). First, trend analyses were performed and their association to the evolution of the North Atlantic Oscillation (NAO) index was assessed. For the French oyster production, two sinusoidal waves were found in the first and second order residuals with periods of 33 and 8 years. In the Solent, the trend depiction showed after an initial increase, the catch rates of oysters declined over time from West to East. A positive relationship was apparent between NAO and both the production and population data, with a significant correlation in case study 2. Furthermore, a high and significant spectral coherency in the 8 year period of case study 1 revealed a near phase opposition between the influence of NAO and the French oyster production. For the first and second case study, the early warning signals calculated were lag-1 autocorrelation and variance, respectively. In case study 1, the stability of the low frequency wave of the first order residuals could not be assed, the trend of lag 1 autocorrelation was thus not conclusive. However the high but stable lag-1 autocorrelation of the second residuals, revealed a probable underlying stability. In case study 2 significant increase in variance reflected the instability prior to the decline. It is discussed that in periodic signals the number of residual fluctuations needs to be sufficient to allow the generation of an autocorrelation trend within the limits of the sliding window, used for its calculation. The importance of time scale and appropriate de-trending is also questioned when calculating and interpreting

  8. Effect of Energy Under-Reporting on Secular Trends of Dietary Patterns in a Mediterranean Population

    PubMed Central

    Funtikova, Anna N.; Gomez, Santiago F.; Fitó, Montserrat; Elosua, Roberto; Benítez-Arciniega, Alejandra A.; Schröder, Helmut

    2015-01-01

    Background Diet is an important factor in the prevention of chronic diseases. Analysis of secular trends of dietary patterns can be biased by energy under-reporting. Therefore, the objective of the present study was to analyse the impact of energy under-reporting on dietary patterns and secular trends in dietary patterns defined by cluster analysis. Design and methods Two cross-sectional population-based surveys were conducted in Spain, in 2000 and 2005, with 3058 and 6352 participants, respectively, aged 25 to 74 years. Validated questionnaire was used to collect dietary data. Cluster analysis was run separately for all participants, plausible energy reporters (PER), and energy under-reporters (EUR) to define dietary patterns. Results Three clusters, “healthy”, “mixed” and “western”, were identified for both surveys. The “mixed” cluster was the predominant cluster in both surveys. Excluding EUR reduced the proportion of the “mixed” cluster up to 6.40% in the 2000 survey; this caused secular trend increase in the prevalence of the “mixed” pattern. Cross-classification analysis of all participants and PER’ data showed substantial agreement in cluster assignments: 68.7% in 2000 and 84.4% in 2005. Excluding EUR did not cause meaningful (≥15%) changes in the “healthy” pattern. It provoked changes in consumption of some food groups in the “mixed” and “western” patterns: mainly decreases of unhealthy foods within the 2000 and increases of unhealthy foods within the 2005 surveys. Secular trend effects of EUR were similar to those within the 2005 survey. Excluding EUR reversed the direction of secular trends in consumption of several food groups in PER in the “mixed” and “western” patterns. Conclusions EUR affected distribution of participants between dietary patterns within and between surveys, secular trends in food group consumption and amount of food consumed in all, but not in the “healthy” pattern. Our findings

  9. Trends in Notifiable Infectious Diseases in China: Implications for Surveillance and Population Health Policy

    PubMed Central

    Zhang, Lei; Wilson, David P.

    2012-01-01

    This study aimed to analyse trends in notifiable infectious diseases in China, in their historical context. Both English and Chinese literature was searched and diseases were categorised according to the type of disease or transmission route. Temporal trends of morbidity and mortality rates were calculated for eight major infectious diseases types. Strong government commitment to public health responses and improvements in quality of life has led to the eradication or containment of a wide range of infectious diseases in China. The overall infectious diseases burden experienced a dramatic drop during 1975–1995, but since then, it reverted and maintained a gradual upward trend to date. Most notifiable diseases are contained at a low endemic level; however, local small-scale outbreaks remain common. Tuberculosis, as a bacterial infection, has re-emerged since the 1990s and has become prevalent in the country. Sexually transmitted infections are in a rapid, exponential growth phase, spreading from core groups to the general population. Together human immunodeficiency virus (HIV), they account for 39% of all death cases due to infectious diseases in China in 2008. Zoonotic infections, such as severe acute respiratory syndrome (SARS), rabies and influenza, pose constant threats to Chinese residents and remain the most deadly disease type among the infected individuals. Therefore, second-generation surveillance of behavioural risks or vectors associated with pathogen transmission should be scaled up. It is necessary to implement public health interventions that target HIV and relevant coinfections, address transmission associated with highly mobile populations, and reduce the risk of cross-species transmission of zoonotic pathogens. PMID:22359565

  10. Trend analysis of cancer incidence in Japan using data from selected population-based cancer registries.

    PubMed

    Katanoda, Kota; Ajiki, Wakiko; Matsuda, Tomohiro; Nishino, Yoshikazu; Shibata, Akiko; Fujita, Manabu; Tsukuma, Hideaki; Ioka, Akiko; Soda, Midori; Sobue, Tomotaka

    2012-02-01

    Population-based cancer registries are operated by over 80% of prefectures in Japan. However, only a limited proportion of the registries can provide long-term incidence data. Here, we aimed to establish a method for monitoring cancer incidence trends in Japan using data from selected prefectures. Based on the availability of long-term (≥ 20 years) high-quality data, we collected incidence data from five prefectures (Miyagi, Yamagata, Fukui, Osaka, and Nagasaki), which included an annual average of 54,539 primary cancer cases diagnosed between 1985 and 2004. Cancer mortality data for 1995-2004 were obtained from the vital statistics. Representativeness and homogeneity of the trends were examined by funnel plot analysis of log-linear regression coefficients calculated for the most recent 10 years of data (1995-2004) of age-standardized rates (ASR). The ASR of incidence for five prefectures in total (5-pref total) showed a significant decrease, with an annual percent change (APC) of -1.0 (95% confidence interval [CI] -1.4: -0.6) for males and -0.4 (95% CI -0.8: -0.1) for females. Excluding data from Osaka (4-pref total) reversed the decreasing trend; the corresponding APC was +0.4 (95% CI -0.2: +1.0) for males and +0.7 (95% CI +0.5: +0.9) for females. The APCs for the ASR of mortality for the 4-pref total (males, -1.5; females, -1.3) were more representative of nationwide data (males, -1.4 [95% CI -1.7: -1.2]; females, -1.1 [95% CI -1.4: -0.9]) than those for the 5-pref total (males, -1.7; females, -1.4). We conclude that using data from Miyagi, Yamagata, Fukui, and Nagasaki prefectures, with continuous monitoring of the representativeness of the data, is a provisionally relevant way to evaluate cancer incidence trends in Japan.

  11. Do HIV Prevalence Trends in ANC Surveillance Represent Trends in the General Population in the ART Era? The Case of Manicaland, East Zimbabwe

    PubMed Central

    Gregson, Simon; Dharmayat, Kanika; Pereboom, Monique; Takaruza, Albert; Mugurungi, Owen; Schur, Nadine; Nyamukapa, Constance A.

    2016-01-01

    Objective National estimates of HIV trends in generalised epidemics rely on HIV prevalence data from antenatal clinic (ANC) surveillance. We investigate whether HIV prevalence trends in ANC data reflect trends in men and women in the general population during the scale-up of anti-retroviral treatment (ART) in Manicaland, Zimbabwe. Methods Trends in HIV prevalence in local ANC attendees and adults aged 15-49yrs in towns, agricultural estates, and villages were compared using five rounds of parallel ANC (N≈1,200) and general-population surveys (N≈10,000) and multi-variable log-linear regression. Changes in the age-pattern of HIV prevalence and the age-distribution of ANC attendees were compared with those in the general population. Age-specific pregnancy prevalence rates were compared by HIV infection and ART status. Results Cumulatively, from 1998-2000 to 2009-2011, HIV prevalence fell by 60.0% (95% CI, 51.1%-67.3%) in ANC surveillance data and by 34.3% (30.8%-37.7%) in the general population. Most of the difference arose following the introduction of ART (2006-2011). The estates and villages reflected this overall pattern but HIV prevalence in the towns was lower at local ANCs than in the general population, largely due to attendance by pregnant women from outlying (lower prevalence) areas. The ageing of people living with HIV in the general population (52.4% aged >35yrs, 2009-2011) was under-represented in the ANC data (12.6%) due to lower fertility in older and HIV-infected women. Conclusion After the introduction of ART in Manicaland, HIV prevalence declined more steeply in ANC surveillance data than in the general population. Models used for HIV estimates must reflect this change in bias. PMID:26372390

  12. Advanced long-term bird banding and climate data mining in spring confirm passerine population declines for the Northeast Chinese-Russian flyway

    NASA Astrophysics Data System (ADS)

    Jiao, Shengwu; Huettmann, Falk; Guo, Yumin; Li, Xianda; Ouyang, Yanlan

    2016-09-01

    The migration of birds is fascinating for humans but it's also a serious environmental monitoring and management issue on a global level. Bird banding using mistnets has been the method of choice for decades worldwide; linking these data with climate data allows to infer on global warming and outlier events. However, good methods to achieve this effectively in time and space for many species are still missing; data for Asia are specifically sparse and often 'messy'. Here we present a data mining summary information for data from two bird banding stations (Gaofeng and Qingfeng) along the vast Northeast Chinese-Russian flyway. Bird data were collected during spring 2002-2011 with standardized techniques and then linked with related climate data in the banding as well as the wintering sites. This creates a complex data set which is based on a decade and which includes many predictors. This first-time data mining analysis with 'data cloning' and machine learning methods (boosted regression trees) shows how to extract the major signals in this unique dataset from highly correlated and interacting predictors. Our results indicate a large-scale warming trend for the flyway, with a start in 2003, and a freezing rain outlier event in 2008; the last years remained on a rather warm level. All evidence along this vast flyway supports major changes, warming trends, habitat losses and consequently strong passerine declines. Presumably human pressures are a major factor either way and we propose to address these problems immediately for betterment if meaningful conservation targets are to be met.

  13. Mountain goat abundance and population trends in the Olympic Mountains, Washington, 2011

    USGS Publications Warehouse

    Jenkins, Kurt; Happe, Patricia; Griffin, Paul C.; Beirne, Katherine; Hoffman, Roger; Baccus, William

    2011-01-01

    We conducted an aerial helicopter survey between July 18 and July 25, 2011, to estimate abundance and trends of introduced mountain goats (Oreamnos americanus) in the Olympic Mountains. The survey was the first since we developed a sightability correction model in 2008, which provided the means to estimate the number of mountain goats present in the surveyed areas and not seen during the aerial surveys, and to adjust for undercounting biases. Additionally, the count was the first since recent telemetry studies revealed that the previously defined survey zone, which was delineated at lower elevations by the 1,520-meter elevation contour, did not encompass all lands used by mountain goats during summer. We redefined the lower elevation boundary of survey units before conducting the 2011 surveys in an effort to more accurately estimate the entire mountain goat population. We surveyed 39 survey units, comprising 39 percent of the 59,615-hectare survey area. We estimated a mountain goat population of 344±44 (standard error, SE) in the expanded survey area. Based on this level of estimation uncertainty, the 95-percent confidence interval ranged from 258 to 430 mountain goats at the time of the survey. To permit comparisons of mountain goat populations between the 2004 and 2011 surveys, we recomputed population estimates derived from the 2004 survey using the newly developed bias correction methods, and we computed the 2004 and 2011 surveys based on comparable survey zone definitions (for example, using the boundaries of the 2004 survey). The recomputed estimates of mountain goat populations were 217±19 (SE) in 2004 and 303±41(SE) in 2011. The difference between the current 2011 population estimate (344±44[SE]) and the recomputed 2011 estimate (303±41[SE]) reflects the number of mountain goats counted in the expanded lower elevation portions of the survey zone added in 2011. We conclude that the population of mountain goats has increased in the Olympic Mountains at

  14. Trends in mortality rates of cutaneous melanoma in East Asian populations

    PubMed Central

    2016-01-01

    The incidence of cutaneous melanoma (CM) has rapidly increased over the past four decades. CM is often overlooked in East Asian populations due to its low incidence, despite East Asia making up 22% of the world’s population. Since the 1990s, Caucasian populations have seen a plateau in CM mortality rates; however, there is little data investigating the mortality rates of CM in East Asian populations. In this study, the World Health Organization Mortality Database with the joinpoint regression method, and a generalized additive model were used to investigate trends in age standardized mortality rates (ASMRs) of CM in four East Asia regions (Japan, Republic of Korea (Korea), China: Hong Kong (Hong Kong), and Singapore) over the past six decades. In addition, mortality rate ratios by different variables (i.e., sex, age group, and region) were analyzed. Our results showed ASMRs of CM in East Asia significantly increased non-linearly over the past six decades. The joinpoint regression method indicated women had greater annual percentage changes than men in Japan, Korea, and Hong Kong. Men had significantly greater mortality rate ratio (1.51, 95% CI [1.48–1.54]) than women. Mortality rate ratios in 30−59 and 60+ years were significant greater than in the 0−29 years. Compared to Hong Kong, mortality rate ratio was 0.72 (95% CI [0.70–0.74]) times, 0.73 (95% CI [0.70–0.75]) times, and 1.02 (95% CI [1.00–1.05]) times greater in Japan, Korea, and Singapore, respectively. Although there is limited research investigating CM mortality rates in East Asia, results from the present study indicate that there is a significant growth in the ASMRs of CM in East Asian populations, highlighting a need to raise awareness of CM in the general population. PMID:28028475

  15. Trends in mortality rates of cutaneous melanoma in East Asian populations.

    PubMed

    Chen, Ling; Jin, Shaofei

    2016-01-01

    The incidence of cutaneous melanoma (CM) has rapidly increased over the past four decades. CM is often overlooked in East Asian populations due to its low incidence, despite East Asia making up 22% of the world's population. Since the 1990s, Caucasian populations have seen a plateau in CM mortality rates; however, there is little data investigating the mortality rates of CM in East Asian populations. In this study, the World Health Organization Mortality Database with the joinpoint regression method, and a generalized additive model were used to investigate trends in age standardized mortality rates (ASMRs) of CM in four East Asia regions (Japan, Republic of Korea (Korea), China: Hong Kong (Hong Kong), and Singapore) over the past six decades. In addition, mortality rate ratios by different variables (i.e., sex, age group, and region) were analyzed. Our results showed ASMRs of CM in East Asia significantly increased non-linearly over the past six decades. The joinpoint regression method indicated women had greater annual percentage changes than men in Japan, Korea, and Hong Kong. Men had significantly greater mortality rate ratio (1.51, 95% CI [1.48-1.54]) than women. Mortality rate ratios in 30-59 and 60+ years were significant greater than in the 0-29 years. Compared to Hong Kong, mortality rate ratio was 0.72 (95% CI [0.70-0.74]) times, 0.73 (95% CI [0.70-0.75]) times, and 1.02 (95% CI [1.00-1.05]) times greater in Japan, Korea, and Singapore, respectively. Although there is limited research investigating CM mortality rates in East Asia, results from the present study indicate that there is a significant growth in the ASMRs of CM in East Asian populations, highlighting a need to raise awareness of CM in the general population.

  16. Understanding the contribution of habitats and regional variation to long-term population trends in tricolored blackbirds

    PubMed Central

    Graves, Emily E; Holyoak, Marcel; Rodd Kelsey, T; Meese, Robert J

    2013-01-01

    Population trends represent a minimum amount of information required to assess the conservation status of a species. However, understanding and detecting trends can be complicated by variation among habitats and regions, and by dispersal connecting habitats through source-sink dynamics. We analyzed trends in breeding populations between habitats and regions to better understand the overall dynamics of a species' decline. Specifically, we analyzed historical trends in breeding populations of tricolored blackbirds (Agelaius tricolor) using breeding records from 1907 to 2009. The species breeds itinerantly and ephemerally uses multiple habitat types and breeding areas, which make interpretation of trends complex. We found overall abundance declines of 63% between 1935 and 1975. Since 1980 overall declines became nonsignificant and obscure despite large amounts of data from 1980 to 2009. Temporal trends differed between breeding habitat types and were associated with regional differences in population declines. A new habitat, triticale crops (a wheat-rye hybrid grain) produced colonies 40× larger, on average, than other breeding habitats, and contributed to a change in regional distribution since it primarily occurred in a single region. The mechanism for such an effect is not clear, but could represent the local availability of foodstuffs in the landscape rather than something specific to triticale crops. While variation in trends among habitats clearly occurred, they could not easily be ascribed to source-sink dynamics, ecological traps, habitat selection or other detailed ecological mechanisms. Nonetheless, such exchanges provide valuable information to guide management of dynamic systems. PMID:24101977

  17. Understanding the contribution of habitats and regional variation to long-term population trends in tricolored blackbirds.

    PubMed

    Graves, Emily E; Holyoak, Marcel; Rodd Kelsey, T; Meese, Robert J

    2013-09-01

    Population trends represent a minimum amount of information required to assess the conservation status of a species. However, understanding and detecting trends can be complicated by variation among habitats and regions, and by dispersal connecting habitats through source-sink dynamics. We analyzed trends in breeding populations between habitats and regions to better understand the overall dynamics of a species' decline. Specifically, we analyzed historical trends in breeding populations of tricolored blackbirds (Agelaius tricolor) using breeding records from 1907 to 2009. The species breeds itinerantly and ephemerally uses multiple habitat types and breeding areas, which make interpretation of trends complex. We found overall abundance declines of 63% between 1935 and 1975. Since 1980 overall declines became nonsignificant and obscure despite large amounts of data from 1980 to 2009. Temporal trends differed between breeding habitat types and were associated with regional differences in population declines. A new habitat, triticale crops (a wheat-rye hybrid grain) produced colonies 40× larger, on average, than other breeding habitats, and contributed to a change in regional distribution since it primarily occurred in a single region. The mechanism for such an effect is not clear, but could represent the local availability of foodstuffs in the landscape rather than something specific to triticale crops. While variation in trends among habitats clearly occurred, they could not easily be ascribed to source-sink dynamics, ecological traps, habitat selection or other detailed ecological mechanisms. Nonetheless, such exchanges provide valuable information to guide management of dynamic systems.

  18. Proceedings of the 2015 international summit on fibropapillomatosis: Global status, trends, and population impacts

    USGS Publications Warehouse

    Hargrove, Stacy A.; Work, Thierry M.; Brunson, Shandell; Foley, Allen M.; Balazs, George H.

    2016-01-01

    The 2015 International Summit on Fibropapillomatosis (FP) was convened in Honolulu, Hawaii June 11-14, 2015. Scientists from around the world were invited to present results from sea turtle monitoring and research programs as they relate to the global status, trends, and population impacts of FP on green turtles. The participants engaged in discussions that resulted in the following conclusions: 1.Globally, FP has long been present in wild sea turtle populations the earliest mention was in the late 1800s in the Florida Keys. 2.FP primarily affects medium-sized immature turtles in coastal foraging pastures. 3.Expression of FP differs across ocean basins and to some degree within basins. Turtles in the Southeast US, Caribbean, Brazil, and Australia rarely have oral tumors (inside the mouth cavity), whereas they are common and often severe in Hawaii. Internal tumors (on vital organs) occur in the Atlantic and Hawaii, but only rarely in Australia. Liver tumors are common in Florida but not in Hawaii. 4.Recovery from FP through natural processes, when the affliction is not severe, has been documented in wild populations globally. 5.FP causes reduced survivorship, but documented mortality rates in Australia and Hawaii are low. The mortality impact of FP is not currently exceeding population growth rates in some intensively monitored populations (e.g., Florida, Hawaii) as evidenced by increasing nesting trends despite the incidence of FP in immature foraging populations. 6.Pathogens, hosts, and potential disease and environmental cofactors have the capacity to change; while we are having success now, there needs to be continued monitoring to detect changes in the distribution, occurrence, and severity of the disease. 7.While we do not have clear evidence to provide the direct link, globally, the preponderance of sites with a high frequency of FP tumors are areas with some degree of degradation resulting from altered watersheds. Watershed management and responsible coastal

  19. Trends in suicidal behaviour and use of mental health services in Canadian military and civilian populations

    PubMed Central

    Sareen, Jitender; Afifi, Tracie O.; Taillieu, Tamara; Cheung, Kristene; Turner, Sarah; Bolton, Shay-Lee; Erickson, Julie; Stein, Murray B.; Fikretoglu, Deniz; Zamorski, Mark A.

    2016-01-01

    Background: In the context of the Canadian mission in Afghanistan, substantial media attention has been placed on mental health and lack of access to treatment among Canadian Forces personnel. We compared trends in the prevalence of suicidal behaviour and the use of mental health services between Canadian military personnel and the general population from 2002 to 2012/13. Methods: We obtained data for respondents aged 18–60 years who participated in 4 nationally representative surveys by Statistics Canada designed to permit comparisons between populations and trends over time. Surveys of the general population were conducted in 2002 (n = 25 643) and 2012 (n = 15 981); those of military personnel were conducted in 2002 (n = 5153) and 2013 (n = 6700). We assessed the lifetime and past-year prevalence of suicidal ideation, plans and attempts, as well as use of mental health services. Results: In 2012/13, but not in 2002, military personnel had significantly higher odds of both lifetime and past-year suicidal ideation than the civilian population (lifetime: adjusted odds ratio [OR] 1.32, 95% confidence interval [CI] 1.17–1.50; past year: adjusted OR 1.34, 95% CI 1.09–1.66). The same was true for suicidal plans (lifetime: adjusted OR 1.64, 95% CI 1.35–1.99; past year: adjusted OR 1.66, 95% CI 1.18–2.33). Among respondents who reported past-year suicidal ideation, those in the military had a significantly higher past-year utilization rate of mental health services than those in the civilian population in both 2002 (adjusted OR 2.02, 95% CI 1.31–3.13) and 2012/13 (adjusted OR 3.14, 95% CI 1.86–5.28). Interpretation: Canadian Forces personnel had a higher prevalence of suicidal ideation and plans in 2012/13 and a higher use of mental health services in 2002 and 2012/13 than the civilian population. PMID:27221270

  20. Temporal trends in vascular trauma in Ontario, 1991-2009: a population-based study

    PubMed Central

    Altoijry, Abdulmajeed; Al-Omran, Mohammed; Johnston, K. Wayne; Mamdani, Muhammad; Lindsay, Thomas F.

    2016-01-01

    Background: Vascular injuries add substantial complexity to trauma care, yet Canadian epidemiologic data on such injuries are not readily available. We conducted a retrospective cross-sectional study to examine temporal trends in the rate of hospital admissions for vascular injuries from 1991 to 2009 in Ontario. Methods: Individuals of any age admitted to hospital because of vascular trauma in Ontario were included. Details of vascular injury and patient demographic characteristics were recorded, hospital admission rates estimated and analyses stratified by sex, age, mechanism of injury, economic status and geographic location. Time-series analysis was used to examine trends in hospital admission rates. Results: Of the 8252 hospital admissions for vascular trauma, 4287 (52.0%) involved injuries to the upper limb and 1819 (22.0%) were due to transport-related causes. Overall, the annual rate declined significantly over time, from 3.3 per 100 000 in 1991 to 2.7 per 100 000 in 2009 (p < 0.01). The subgroups with the highest rates were young men, patients with a low economic status and those living in a rural location. Declines occurred in both sexes and in all age groups except those 65 years and older. The rates of vascular injury to the neck, thorax, upper limbs and lower limbs declined over time, but not the rate of abdominal vascular injury. Although the rate of non-transport-related vascular injuries declined, the rate of transport-related vascular injuries did not change significantly over time. Decreases in annual rates occurred in both low- and high-economic status groups and in urban populations but not in rural populations. Interpretation: Overall, the annual rate of hospital admissions for vascular trauma declined significantly in Ontario over the study period. Our findings have important implications for public health and the development of injury-prevention strategies, particularly for population subgroups at high risk of vascular injury. PMID

  1. Trends in stimulant use in Australia: A comparison of wastewater analysis and population surveys.

    PubMed

    Tscharke, Benjamin J; Chen, Chang; Gerber, Jacobus P; White, Jason M

    2015-12-01

    Levels of community drug use are usually described by national surveys; data relied upon by decision makers in health and law enforcement. In recent years the analysis of wastewater for drugs and their metabolites has become prominent. Both methods convey unique drug use information. This paper demonstrates differences arising from the two approaches, using methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and cocaine data from the state of South Australia. The proportion of people using each drug, obtained from three prominent drug surveys, was compared with estimates of total community drug use derived by wastewater analysis. Temporal trends were compared for available years of the surveys and wastewater analysis from 2010 to 2013. Wastewater results showed methamphetamine to be the most prevalent stimulant in Adelaide, South Australia, with an average of 24.4±1.7 doses per day per 1000 inhabitants for 2013, while consumption of MDMA and cocaine were much lower at 0.52±0.12 and 0.42±0.06 doses per day per 1000 inhabitants, respectively. Survey data typically had MDMA as the most used stimulant on a proportion of the population basis. The difference in magnitude of drug use between MDMA and methamphetamine was also less apparent. Temporal trends of the proportion of the population using a drug by surveys did not generally reflect total use within the community which was observed by wastewater analysis. Survey data are excellent for describing users demographically. However, discrepancies between the proportion of the population who are users and the magnitude of drug use can lead to misrepresentation of the overall scale of use. The results from this study indicate methamphetamine was used to a much greater extent than suggested by the surveys. Together, wastewater analysis and survey data give a comprehensive view of the drug problem enabling more informed decisions on drug policy.

  2. Long Term Population, City Size and Climate Trends in the Fertile Crescent: A First Approximation

    PubMed Central

    Lawrence, Dan; Philip, Graham; Hunt, Hannah; Snape-Kennedy, Lisa; Wilkinson, T. J.

    2016-01-01

    Over the last 8000 years the Fertile Crescent of the Near East has seen the emergence of urban agglomerations, small scale polities and large territorial empires, all of which had profound effects on settlement patterns. Computational approaches, including the use of remote sensing data, allow us to analyse these changes at unprecedented geographical and temporal scales. Here we employ these techniques to examine and compare long term trends in urbanisation, population and climate records. Maximum city size is used as a proxy for the intensity of urbanisation, whilst population trends are modelled from settlement densities in nine archaeological surveys conducted over the last 30 years across the region. These two measures are then compared with atmospheric moisture levels derived from multiple proxy analyses from two locations close to the study area, Soreq Cave in Israel and Lake Van in south-eastern Turkey, as well as wider literature. The earliest urban sites emerged during a period of relatively high atmospheric moisture levels and conform to a series of size thresholds. However, after the Early Bronze Age maximum urban size and population levels increase rapidly whilst atmospheric moisture declines. We argue that although the initial phase of urbanization may have been linked to climate conditions, we can see a definitive decoupling of climate and settlement patterns after 2000 BC. We relate this phenomenon to changes in socio-economic organisation and integration in large territorial empires. The complex relationships sustaining urban growth during this later period resulted in an increase in system fragility and ultimately impacted on the sustainability of cities in the long term. PMID:27018998

  3. Decline of birds in a human modified coastal dune forest landscape in South Africa.

    PubMed

    Trimble, Morgan J; van Aarde, Rudi J

    2011-01-13

    Previous studies demonstrate that old-growth forest remnants and vegetation regenerating after anthropogenic disturbance provide habitat for birds in a human modified coastal dune forest landscape in northern KwaZulu-Natal, South Africa. However, occurrence does not ensure persistence. Based on a 13-year monitoring database we calculated population trends for 37 bird species and general trends in overall bird density in different vegetation types. We evaluated species' characteristics as covariates of population trend and assessed changes in rainfall and proportional area and survey coverage per vegetation type. 76% of species assessed have declined, 57% significantly so at an average rate of 13.9% per year. Overall, bird density has fallen at 12.2% per year across old-growth forest and woody regenerating vegetation types. Changes in proportional area and coverage per vegetation type may partly explain trends for a few species but are unlikely to account for most. Below average rainfall may have contributed to bird declines. However, other possibilities warrant further investigation. Species with larger range extents tended to decline more sharply than did others, and these species may be responding to environmental changes on a broader geographical scale. Our results cast doubt on the future persistence of birds in this human modified landscape. More research is needed to elucidate the mechanisms driving population decline in the study area and to investigate whether the declines identified here are more widespread across the region and perhaps the continent.

  4. Population risk factors and trends in health care and public policy.

    PubMed

    Haughton, Betsy; Stang, Jamie

    2012-03-01

    Many factors affect the current and future practice of dietetics in the United States. This article provides an overview of the most important population risk factors and trends in health care and public policy that are anticipated to affect the current dietetics workforce and future of dietetics training and practice. It concludes with an overview of the state of the current workforce, highlighting the opportunities and challenges it will face in the future. Demographic shifts in the age and racial/ethnic composition of the US population will be a major determinant of future the dietetics profession because a growing population of older adults with chronic health conditions will require additional medical nutrition therapy services. Dietetics practitioners will work with an increasingly diverse population, which will require the ability to adapt existing programs and services to culturally diverse individuals and communities. Economic factors will affect not only the type, quantity, and quality of food available in homes, but also how health care is delivered, influencing future roles of registered dietitians (RDs) and dietetic technicians, registered (DTRs). As health care services consume a larger percentage of federal and corporate expenditures, health care agencies will continue to look for ways to reduce costs. Health promotion and disease prevention efforts will likely play a larger role in health care services, thus creating many opportunities for RDs and DTRs in preventive care and wellness. Increasingly, dietetics services will be provided in more diverse settings, such as worksites, community health centers, and home-care agencies. To address population-based health care and nutrition priorities effectively, dietetics practice will need to focus on appropriate evidence-based intervention approaches and targets. The workforce needs to be skilled in the delivery of culturally competent interventions across the lifespan, for all population groups, and

  5. Census of Population and Housing: 1970. General Demographic Trends for Metropolitan Areas, 1960 to 1970. United States Summary. Final Report.

    ERIC Educational Resources Information Center

    Bureau of the Census (DOC), Suitland, MD.

    This publication is one of a series of 1970 census reports concerned mainly with population and housing trends in metropolitan areas from 1960 to 1970. The analytical text discusses changes in population growth and distribution and housing in the nation as a whole and by regions. Following the detailed tables are included definitions,…

  6. IVC filters—Trends in placement and indications, a study of 2 populations

    PubMed Central

    Shah, Mahek; Alnabelsi, Talal; Patil, Shantanu; Reddy, Shilpa; Patel, Brijesh; Lu, Marvin; Chandorkar, Aditya; Perelas, Apostholos; Arora, Shilpkumar; Patel, Nilay; Jacobs, Larry; Eiger, Glenn G.

    2017-01-01

    Abstract Inferior vena cava filter (IVCF) placement appears to be expanding over time despite absence of clear directing evidence. Two populations were studied. The first population included patients who received an IVCF between January 2005 and August 2013 at our community hospital center. Demographic information, indications for placement, and retrieval rate was recorded among other variables. The second population comprised of patients receiving an IVCF from 2005 to 2012 according to the Nationwide Inpatient Sample (NIS) using ICD-9CM coding. Patients were divided into 2 groups based on the year of admission for comparison, that is, first group from 2005 to 2008 and the second from 2009 to 2012. In addition, we analyzed annual trends in filter placement, acute venothromboembolic events (VTE) and several underlying comorbidities within this population. At our center, 802 IVCFs were placed (55.2% retrievable); 34% for absolute, 61% for relative, and 5% for prophylactic indications. Major bleeding (27.5%), minor self-limited bleeding (13.7%), and fall history (11.2%) were the commonest indications. Periprocedural complication rate was 0.7%, and filter retrieval rate was 7%. The NIS population (811,487 filters) saw a decline in IVCF placement after year 2009, following an initial uptrend (Ptrend < 0.01). IVCF use among patients with neither acute VTE nor bleeding among prior VTE saw a 3-fold absolute reduction from 2005 to 2012 (33,075–11,655; Ptrend < 0.01). Patients from 2009 to 2012 were more likely to be male and had higher rates of acute VTE, thrombolytic use, cancer, bleeding, hypotension, acute cardiorespiratory failure, shock, prior falls, blood product transfusion, hospital mortality including higher Charlson comorbidity scores. The patients were younger, had shorter length of stay, and were less likely to be associated with strokes including hemorrhagic or require ventilator support. Prior falls (adjusted odds ratio—aOR 2.8), thrombolytic use

  7. River dolphins can act as population trend indicators in degraded freshwater systems.

    PubMed

    Turvey, Samuel T; Risley, Claire L; Barrett, Leigh A; Yujiang, Hao; Ding, Wang

    2012-01-01

    Conservation attention on charismatic large vertebrates such as dolphins is often supported by the suggestion that these species represent surrogates for wider biodiversity, or act as indicators of ecosystem health. However, their capacity to act as indicators of patterns or trends in regional biodiversity has rarely been tested. An extensive new dataset of >300 last-sighting records for the Yangtze River dolphin or baiji and two formerly economically important fishes, the Yangtze paddlefish and Reeves' shad, all of which are probably now extinct in the Yangtze, was collected during an interview survey of fishing communities across the middle-lower Yangtze drainage. Untransformed last-sighting date frequency distributions for these species show similar decline curves over time, and the linear gradients of transformed last-sighting date series are not significantly different from each other, demonstrating that these species experienced correlated population declines in both timing and rate of decline. Whereas species may be expected to respond differently at the population level even in highly degraded ecosystems, highly vulnerable (e.g. migratory) species can therefore display very similar responses to extrinsic threats, even if they represent otherwise very different taxonomic, biological and ecological groupings. Monitoring the status of river dolphins or other megafauna therefore has the potential to provide wider information on the status of other threatened components of sympatric freshwater biotas, and so represents a potentially important monitoring tool for conservation management. We also show that interview surveys can provide robust quantitative data on relative population dynamics of different species.

  8. Red-shouldered hawk broadcast surveys: Factors affecting detection of responses and population trends

    USGS Publications Warehouse

    McLeod, M.A.; Andersen, D.E.

    1998-01-01

    Forest-nesting raptors are often difficult to detect and monitor because they can be secretive, and their nests can be difficult to locate. Some species, however, respond to broadcasts of taped calls, and these responses may be useful both in monitoring population trends and in locating nests. We conducted broadcast surveys on roads and at active red-shouldered hawk (Buteo lineatus) nests in northcentral Minnesota to determine effects of type of call (conspecific or great horned owl [Bubo virginianus]), time of day, and phase of the breeding cycle on red-shouldered hawk response behavior and to evaluate usefulness of broadcasts as a population monitoring tool using area occupied-probability-of-detection techniques. During the breeding seasons of 1994 and 1995, we surveyed 4 10-station road transects 59 times and conducted 76 surveys at 24 active nests. Results of these surveys indicated conspecific calls broadcast prior to hatch and early in the day were the most effective method of detecting red-shouldered hawks. Probability of detection via conspecific calls averaged 0.25, and area occupied was 100%. Computer simulations using these field data indicated broadcast surveys have the potential to be used as a population monitoring tool.

  9. Global dimming and urbanization: did stronger negative SSR trends collocate with regions of population growth?

    NASA Astrophysics Data System (ADS)

    Imamovic, Adel; Tanaka, Katsumasa; Folini, Doris; Wild, Martin

    2016-04-01

    Global dimming refers to the decrease in surface solar radiation (SSR) observed from the 1960s to the 1980s at different measurement sites all around the world. It is under debate whether anthropogenic aerosols emitted from urban areas close to the measurement sites are mainly responsible for the dimming. In order to assess this urbanization impact on SSR, we use spatially explicit population density data of 0.08° resolution to construct population indices (PI) at 157 high data quality sites. Our study extends previous population-based studies by incorporating distance-weighting as a simple aerosol diffusion model. We measured urbanization in the surrounding of a site as the PI change form 1960 to 1990 and found no negative correlation with the corresponding SSR trends from 1964 to 1989 for the 92 sites in Europe and Japan. For the 39 sites in China the correlation coefficients are significant at the 5 % level and reach around -0.35, while for the 26 remaining Asian, mostly Russian sites the correlation coefficients reach around -0.55 at the 1 % significance level. Results are similar, when the absolute levels of PIs are taken as an indicator for urbanization. Our findings call into question the existence of an urbanization effect for the sites in Europe and Japan, while such an effect cannot be ruled out for the sites in Asia, especially in Russia.

  10. Global dimming and urbanization: did stronger negative SSR trends collocate with regions of population growth?

    NASA Astrophysics Data System (ADS)

    Imamovic, Adel; Tanaka, Katsumasa; Folini, Doris; Wild, Martin

    2016-03-01

    Global dimming refers to the decrease in surface solar radiation (SSR) observed from the 1960s to the 1980s at different measurement sites all around the world. It is under debate whether anthropogenic aerosols emitted from urban areas close to the measurement sites are mainly responsible for the dimming. In order to assess this urbanization impact on SSR, we use spatially explicit population density data of 0.08° resolution to construct population indices (PI) at 157 high data quality sites. Our study extends previous population-based studies by incorporating distance-weighting as a simple aerosol diffusion model. We measured urbanization in the surrounding of a site as the PI change from 1960 to 1990 and found no negative correlation with the corresponding SSR trends from 1964 to 1989 for the 92 sites in Europe and Japan. For the 39 sites in China the correlation coefficients are significant at the 5 % level and reach around -0.35, while for the 26 remaining Asian, mostly Russian sites the correlation coefficients reach around -0.55 at the 1 % significance level. Results are similar, when the absolute levels of PIs are taken as an indicator for urbanization. Our findings call into question the existence of an urbanization effect for the sites in Europe and Japan, while such an effect cannot be ruled out for the sites in Asia, especially in Russia.

  11. Global dimming and urbanization: did stronger negative SSR trends collocate with regions of population growth?

    NASA Astrophysics Data System (ADS)

    Imamovic, A.; Tanaka, K.; Folini, D.; Wild, M.

    2015-11-01

    Global dimming refers to the decrease in surface solar radiation (SSR) observed from the 1960s to the 1980s at different measurement sites all around the world. It is under debate whether anthropogenic aerosols emitted from urban areas close to the measurement sites are mainly responsible for the dimming. In order to assess this urbanization impact on SSR, we use spatially explicit population density data of 0.08° resolution to construct population indices (PI) at 157 high data quality sites. Our study extends previous population-based studies by incorporating distance-weighting as a simple aerosol diffusion model. We measured urbanization in the surrounding of a site as the PI change form 1960 to 1990 and found no negative correlation with the corresponding SSR trends from 1964 to 1989 for the 92 sites in Europe and Japan. For the 39 sites in China the correlation coefficients are significant at the 5 % level and reach around -0.35, while for the 26 remaining Asian, mostly Russian sites the correlation coefficients reach around -0.55 at the 1 % significance level. Results are similar, when the absolute levels of PIs are taken as an indicator for urbanization. Our findings call into question the existence of an urbanization effect for the sites in Europe and Japan, while such an effect cannot be ruled out for the sites in Asia, especially in Russia.

  12. Impact of forestry practices on fitness correlates and population productivity in an open-nesting bird species.

    PubMed

    Griesser, Michael; Nystrand, Magdalena; Eggers, Sönke; Ekman, Jan

    2007-06-01

    In the boreal forests of Fennoscandia, over 99% of forest area has been altered by forestry practices, which has created forest with age structures and stand characteristics that differ from primary forest stands. Although many researchers have investigated how forestry affects species abundance, few have assessed how forestry practices affect fitness correlates of species living in altered habitats, and this has negatively affected management efforts. We experimentally addressed the effect of standard forestry practices on fitness correlates of an open-nesting, long-lived bird species typical to boreal forests of Eurasia, the Siberian Jay (Perisoreus infaustus). We used a before-after comparison of reproductive data on the level of territories and found that standard forestry practices had a strong negative effect on the breeding success of jays. Both partial thinning of territories and partial clearcutting of territories reduced future breeding success by a factor of 0.35. Forestry practices reduced territory occupancy. Thus, over the 15 years of the study, productivity of the affected population declined over 50% as a result of territory abandonment and reduced breeding success. Results of previous studies on Siberian Jays suggest that the strong effect of forest thinning on fitness is explained by the fact that most common predators of nests and adults are visually oriented and thus thinning makes prey and nests more visible to predators. The consequences of thinning we observed are likely to apply to a wide range of species that rely on understory to provide visual protection from predators. Thus, our results are important for the development of effective conservation management protocols and for the refinement of thinning practices.

  13. Population genetic structure and direct observations reveal sex-reversed patterns of dispersal in a cooperative bird

    PubMed Central

    Harrison, Xavier A; York, Jennifer E; Young, Andrew J

    2014-01-01

    Sex-biased dispersal is pervasive and has diverse evolutionary implications, but the fundamental drivers of dispersal sex biases remain unresolved. This is due in part to limited diversity within taxonomic groups in the direction of dispersal sex biases, which leaves hypothesis testing critically dependent upon identifying rare reversals of taxonomic norms. Here, we use a combination of observational and genetic data to demonstrate a rare reversal of the avian sex bias in dispersal in the cooperatively breeding white-browed sparrow weaver (Plocepasser mahali). Direct observations revealed that (i) natal philopatry was rare, with both sexes typically dispersing locally to breed, and (ii), unusually for birds, males bred at significantly greater distances from their natal group than females. Population genetic analyses confirmed these patterns, as (i) corrected Assignment index (AIc), FST tests and isolation-by-distance metrics were all indicative of longer dispersal distances among males than females, and (ii) spatial autocorrelation analysis indicated stronger within-group genetic structure among females than males. Examining the spatial scale of extra-group mating highlighted that the resulting ‘sperm dispersal’ could have acted in concert with individual dispersal to generate these genetic patterns, but gamete dispersal alone cannot account entirely for the sex differences in genetic structure observed. That leading hypotheses for the evolution of dispersal sex biases cannot readily account for these sex-reversed patterns of dispersal in white-browed sparrow weavers highlights the continued need for attention to alternative explanations for this enigmatic phenomenon. We highlight the potential importance of sex differences in the distances over which dispersal opportunities can be detected. PMID:25346189

  14. Habitat availability is a more plausible explanation than insecticide acute toxicity for U.S. grassland bird species declines.

    PubMed

    Hill, Jason M; Egan, J Franklin; Stauffer, Glenn E; Diefenbach, Duane R

    2014-01-01

    Grassland bird species have experienced substantial declines in North America. These declines have been largely attributed to habitat loss and degradation, especially from agricultural practices and intensification (the habitat-availability hypothesis). A recent analysis of North American Breeding Bird Survey (BBS) "grassland breeding" bird trends reported the surprising conclusion that insecticide acute toxicity was a better correlate of grassland bird declines in North America from 1980-2003 (the insecticide-acute-toxicity hypothesis) than was habitat loss through agricultural intensification. In this paper we reached the opposite conclusion. We used an alternative statistical approach with additional habitat covariates to analyze the same grassland bird trends over the same time frame. Grassland bird trends were positively associated with increases in area of Conservation Reserve Program (CRP) lands and cropland used as pasture, whereas the effect of insecticide acute toxicity on bird trends was uncertain. Our models suggested that acute insecticide risk potentially has a detrimental effect on grassland bird trends, but models representing the habitat-availability hypothesis were 1.3-21.0 times better supported than models representing the insecticide-acute-toxicity hypothesis. Based on point estimates of effect sizes, CRP area and agricultural intensification had approximately 3.6 and 1.6 times more effect on grassland bird trends than lethal insecticide risk, respectively. Our findings suggest that preserving remaining grasslands is crucial to conserving grassland bird populations. The amount of grassland that has been lost in North America since 1980 is well documented, continuing, and staggering whereas insecticide use greatly declined prior to the 1990s. Grassland birds will likely benefit from the de-intensification of agricultural practices and the interspersion of pastures, Conservation Reserve Program lands, rangelands and other grassland habitats into

  15. Mountain goat abundance and population trends in the Olympic Mountains, northwestern Washington, 2016

    USGS Publications Warehouse

    Jenkins, Kurt J.; Happe, Patricia J.; Beirne, Katherine F.; Baccus, William T.

    2016-11-30

    Executive SummaryWe estimated abundance and trends of non-native mountain goats (Oreamnos americanus) in the Olympic Mountains of northwestern Washington, based on aerial surveys conducted during July 13–24, 2016. The surveys produced the seventh population estimate since the first formal aerial surveys were conducted in 1983. This was the second population estimate since we adjusted survey area boundaries and adopted new estimation procedures in 2011. Before 2011, surveys encompassed all areas free of glacial ice at elevations above 1,520 meters (m), but in 2011 we expanded survey unit boundaries to include suitable mountain goat habitats at elevations between 1,425 and 1,520 m. In 2011, we also began applying a sightability correction model allowing us to estimate undercounting bias associated with aerial surveys and to adjust survey results accordingly. The 2016 surveys were carried out by National Park Service (NPS) personnel in Olympic National Park and by Washington Department of Fish and Wildlife (WDFW) biologists in Olympic National Forest and in the southeastern part of Olympic National Park. We surveyed a total of 59 survey units, comprising 55 percent of the 60,218-hectare survey area. We estimated a mountain goat population of 623 ±43 (standard error, SE). Based on this level of estimation uncertainty, the 95-percent confidence interval ranged from 561 to 741 mountain goats at the time of the survey.We examined the rate of increase of the mountain goat population by comparing the current population estimate to previous estimates from 2004 and 2011. Because aerial survey boundaries changed between 2004 and 2016, we recomputed population estimates for 2011 and 2016 surveys based on the revised survey boundaries as well as the previously defined boundaries so that estimates were directly comparable across years. Additionally, because the Mount Washington survey unit was not surveyed in 2011, we used results from an independent survey of the Mount

  16. Precipitation Trends and Water Consumption Related to Population in the Southwestern United States: A Reassessment

    NASA Astrophysics Data System (ADS)

    Diaz, Henry F.; Anderson, Craig A.

    1995-03-01

    Water consumption figures for the southwest United States are compared for the last four decades. Past trends in consumption are evaluated in the context of precipitation variability in the region and with regard to Colorado River streamflow changes. The study represents a follow-up look at a previous assessment of water consumption, regional precipitation, and demographic trends in Arizona, California, Colorado, Nevada, New Mexico, and Utah, which account for much of the annual depletions of Colorado River water. The previous study was completed during a wet spell in the West, and trends in all major categories of water consumption were consistently upward. This study indicates that a decline or reversal has taken place in water use in many of the western states. The greater water efficiency (reduced per capita water use) is particularly noteworthy in California, which alone accounts for the lion's share of water depletions from the Colorado River Basin. The years since the mid-1980's have been predominantly dry in much of the West. At the same time, population in the six-state region has ncreased at about the same pace it had grown during prior decades. A shift from irrigation-related uses to civil consumption is evident in the 1980's. Taking into consideration a situation where multiyear dry spells are a normal part of the climate of the region, it appears that irrigation depletions may have peaked in the West. In the future, allocations for civil supply, recreation, and other in-stream uses as well as for hydropower generation may heighten the competition for available water supplies, put pressure on existing pricing policies, and force users toward greater conservation efforts and improved efficiencies.

  17. The power to detect trends in Missouri River fish populations within the Pallid Sturgeon Population Assessment Program

    USGS Publications Warehouse

    Bryan, Janice L.; Wildhaber, Mark L.; Gladish, Dan; Holan, Scott; Ellerseick, Mark

    2010-01-01

    pallid sturgeon models was not as high as other species at the current level of sampling, but an increase in the sampling effort to 16 subsamples for each of 24 bends for 20 years would generate adequate power for the pallid sturgeon in all Zones. Since gear types are selective in their species efficiency, the strength of the Pallid Sturgeon Population Assessment Program approach is using multiple gears that have statistical power to detect population trends at the same time in different fish species within the Missouri River. As often is the case with monitoring studies involving endangered species, the data used to conduct the analyses exhibit some departures from the parametric model assumptions; however, preliminary simulations indicate that the results of this study are appropriate.

  18. Assessing the status and trend of bat populations across broad geographic regions with dynamic distribution models

    USGS Publications Warehouse

    Rodhouse, Thomas J.; Ormsbee, Patricia C.; Irvine, Kathryn M.; Vierling, Lee A.; Szewczak, Joseph M.; Vierling, Kerri T.

    2012-01-01

    Despite its common status, M. lucifugus was only detected during ∼50% of the surveys in occupied sample units. The overall naïve estimate for the proportion of the study region occupied by the species was 0.69, but after accounting for imperfect detection, this increased to ∼0.90. Our models provide evidence of an association between NPP and forest cover and M. lucifugus distribution, with implications for the projected effects of accelerated climate change in the region, which include net aridification as snowpack and stream flows decline. Annual turnover, the probability that an occupied sample unit was a newly occupied one, was estimated to be low (∼0.04–0.14), resulting in flat trend estimated with relatively high precision (SD = 0.04). We mapped the variation in predicted occurrence probabilities and corresponding prediction uncertainty along the productivity gradient. Our results provide a much needed baseline against which future anticipated declines in M. lucifugus occurrence can be measured. The dynamic distribution modeling approach has broad applicability to regional bat monitoring efforts now underway in several countries and we suggest ways to improve and expand our grid-based monitoring program to gain robust insights into bat population status and trend across large portions of North America.

  19. [Population ageing and health implication. Thinking time trends in Emilia-Romagna Region].

    PubMed

    Mazzocchetti, Angelina; Caranci, Nicola; Addis, Antonio

    2014-05-01

    Ageing is doubtless a factor characterizing population in Europe, and particularly in Emilia-Romagna, a north-east Italian region of about 4,5 million people. From 1990 to 2010 life expectancy in Emilia-Romagna has grown by about 6 years for men and 5 for women. At the same time good health life expectancy has grown even more rapidly, particularly among women. While it is expected that in 2030 the number of over-65s will have exceeded one million people, the trends in good health life expectancy is not granted. Strengthen actions aimed at increasing good health conditions promotes ageing sustainability and can feed the positive trend observed for the life expectancy in good health. The Emilia-Romagna Region takes up the demographic challenge of the coming years in the European context and promotes strategies for active and healthy ageing, working on prevention in its broadest sense and for the entire life span, with the aim of actively contribute to the achievement of the EU2020 target of an increase of two years in life expectancy in good health of European citizens.

  20. A brief report on the illegal cage-bird trade in southern Florida: a potentially serious negative impact on the eastern population of Painted Bunting (Passerina ciris)

    USGS Publications Warehouse

    Sykes, P.W.; Manfredi, L.; Padura, M.

    2006-01-01

    Populations of Painted Bunting (Passerina ciris) have been declining annually over the past 35 years. A cursory survey indicates that illegal trapping of Painted Buntings for a black market cage-bird trade is widespread in southeastern Florida. Coupled with other negative factors confronting the eastern population, the trapping of buntings for the cagebird trade may, in time, produce dire results for this native songbird. Law enforcement personnel need to continue to monitor the illegal activity of trapping native passerines for the local songbird market and to continue to arrest those who support it.

  1. Secretarybird Sagittarius serpentarius population trends and ecology: insights from South African citizen science data.

    PubMed

    Hofmeyr, Sally D; Symes, Craig T; Underhill, Leslie G

    2014-01-01

    Data from two long-term citizen science projects were used to examine the status and ecology of a Red List species, the Secretarybird Sagittarius serpentarius (Vulnerable), in South Africa. The first phase of the Southern African Bird Atlas Project operated from 1987 until 1992, and the second phase began in 2007. The Coordinated Avifaunal Roadcounts (CAR) project began in 1993 and by 1998 had expanded to cover much of the south-eastern half of the country. Data submitted up until April 2013 were used. A new method of comparing reporting rates between atlas projects was developed. Changing reporting rates are likely to reflect changes in abundance; in this instance the data suggest that the Secretarybird population decreased across much of South Africa between the two atlas projects, with a widespread important decrease in the Kruger National Park. Habitat data from the CAR project were analysed to gain insight into the ecology of the species. Secretarybirds tended to avoid transformed habitats across much of the area covered by the CAR project. In the winter rainfall region of the Western Cape, which is characterised by heavily transformed fynbos vegetation, at least 50% of Secretarybirds recorded were in transformed environments. This implies that in the Fynbos biome, at least, Secretarybirds have adapted to transformed environments to some degree. However, in the rest of the country it is likely that habitat loss, largely through widespread bush encroachment but also through agriculture, afforestation, and urbanisation, is a major threat to the species. The methods developed here represent a new approach to analysing data from long-term citizen science projects, which can provide important insights into a species' conservation status and ecology.

  2. Book review: Bird census techniques, Second edition

    USGS Publications Warehouse

    Sauer, John R.

    2002-01-01

    Conservation concerns, federal mandates to monitor birds, and citizen science programs have spawned a variety of surveys that collect information on bird populations. Unfortunately, all too frequently these surveys are poorly designed and use inappropriate counting methods. Some of the flawed approaches reflect a lack of understanding of statistical design; many ornithologists simply are not aware that many of our most entrenched counting methods (such as point counts) cannot appropriately be used in studies that compare densities of birds over space and time. It is likely that most of the readers of The Condor have participated in a bird population survey that has been criticized for poor sampling methods. For example, North American readers may be surprised to read in Bird Census Techniques that the North American Breeding Bird Survey 'is seriously flawed in its design,' and that 'Analysis of trends is impossible from points that are positioned along roads' (p. 109). Our conservation efforts are at risk if we do not acknowledge these concerns and improve our survey designs. Other surveys suffer from a lack of focus. In Bird Census Techniques, the authors emphasize that all surveys require clear statements of objectives and an understanding of appropriate survey designs to meet their objectives. Too often, we view survey design as the realm of ornithologists who know the life histories and logistical issues relevant to counting birds. This view reflects pure hubris: survey design is a collaboration between ornithologists, statisticians, and managers, in which goals based on management needs are met by applying statistical principles for design to the biological context of the species of interest. Poor survey design is often due to exclusion of some of these partners from survey development. Because ornithologists are too frequently unaware of these issues, books such as Bird Census Techniques take on added importance as manuals for educating ornithologists about

  3. North American Breeding Bird Survey Annual Summary, 1988

    USGS Publications Warehouse

    Droege, S.; Sauer, J.R.

    1989-01-01

    Introduction: The North American Breeding Bird Survey (BBS) is run by approximately 2,000 skilled amateur ornithologists, and is coordinated cooperatively by the U.S. Fish and Wildlife Service and the Canadian Wildlife Service. Beginning in 1966, BBS cooperators have been collecting standardized information on North American bird populations. The BBS is a roadside survey, comprised of permanent routes that are surveyed yearly. Each route is 39.4 km (24.5 miles) long and consists of 50 stops spaced 0.8 km (0.5 mile) apart. All birds heard or seen during a 3-min observation period at each stop are recorded, and the sum of the individual stops for each species is used as an index of species density on the route. In this report, we present the population changes of the 222 bird species reported on > 50 BBS routes during 1987 and 1988. Population trends for 1966-87 are presented for comparison. Owing to space constraints, trends are not reported for States, Provinces, or physiographic regions. Instead, we present maps illustrating patterns of population change for selected species, and summarize State and physiographic strata patterns of population change as the proportion of species that increased in each region. Detailed State, Provincial, and physiographic strata changes arc available to interested readers.

  4. Trends and predicted trends in presentations of older people to Australian emergency departments: effects of demand growth, population aging and climate change.

    PubMed

    Burkett, Ellen; Martin-Khan, Melinda G; Scott, Justin; Samanta, Mayukh; Gray, Leonard C

    2016-07-29

    Objectives The aim of the present study was to describe trends in and age and gender distributions of presentations of older people to Australian emergency departments (EDs) from July 2006 to June 2011, and to develop ED utilisation projections to 2050.Methods A retrospective analysis of data collected in the National Non-admitted Patient Emergency Department Care Database was undertaken to assess trends in ED presentations. Three standard Australian Bureau of Statistics population growth models, with and without adjustment for current trends in ED presentation growth and effects of climate change, were examined with projections of ED presentations across three age groups (0-64, 65-84 and ≥85 years) to 2050.Results From 2006-07 to 2010-11, ED presentations increased by 12.63%, whereas the Australian population over this time increased by only 7.26%. Rates of presentation per head of population were greatest among those aged ≥85 years. Projections of ED presentations to 2050 revealed that overall ED presentations are forecast to increase markedly, with the rate of increase being most marked for older people.Conclusion Growth in Australian ED presentations from 2006-07 to 2010-11 was greater than that expected from population growth alone. The predicted changes in demand for ED care will only be able to be optimally managed if Australian health policy, ED funding instruments and ED models of care are adjusted to take into account the specific care and resource needs of older people.What is known about the topic? Rapid population aging is anticipated over coming decades. International studies and specific local-level Australian studies have demonstrated significant growth in ED presentations. There have been no prior national-level Australian studies of ED presentation trends by age group.What does this paper add? The present study examined national ED presentation trends from July 2006 to June 2011, with specific emphasis on trends in presentation by age group

  5. The Climate-Population Nexus in the East African Horn: Emerging Degradation Trends in Rangeland and Pastoral Livelihood Zones

    NASA Astrophysics Data System (ADS)

    Pricope, N. G.; Husak, G. J.; Funk, C. C.; Lopez-Carr, D.

    2014-12-01

    Increasing climate variability and extreme weather conditions along with declining trends in both rainfall and temperature represent major risk factors affecting agricultural production and food security in many regions of the world. We identify regions where significant rainfall decrease from 1979-2011 over the entire continent of Africa couples with significant human population density increase. The rangelands of Ethiopia, Kenya, and Somalia in the East African Horn remain one of the world's most food insecure regions, yet have significantly increasing human populations predominantly dependent on pastoralist and agro-pastoralist livelihoods. Vegetation in this region is characterized by a variable mosaic of land covers, generally dominated by grasslands necessary for agro-pastoralism, interspersed by woody vegetation. Recent assessments indicate that widespread degradation is occurring, adversely impacting fragile ecosystems and human livelihoods. Using two underutilized MODIS products, we observe significant changes in vegetation patterns and productivity over the last decade all across the East African Horn. We observe significant vegetation browning trends in areas experiencing drying precipitation trends in addition to increasing population pressures. We also found that the drying precipitation trends only partially statistically explain the vegetation browning trends, further indicating that other factors such as population pressures and land use changes are responsible for the observed declining vegetation health. Furthermore, we show that the general vegetation browning trends persist even during years with normal rainfall conditions such as 2012, indicating potential long-term degradation of rangelands on which approximately 10 million people depend. These findings have serious implications for current and future regional food security monitoring and forecasting as well as for mitigation and adaptation strategies in a region where population is expected

  6. Global Population Trends and Human Use Patterns of Manta and Mobula Rays

    PubMed Central

    Ward-Paige, Christine A.; Davis, Brendal; Worm, Boris

    2013-01-01

    Despite being the world’s largest rays and providing significant revenue through dive tourism, little is known about the population status, exploitation and trade volume of the Mobulidae (mobulids; Manta and Mobula spp.). There is anecdotal evidence, however, that mobulid populations are declining, largely due to the recent emergence of a widespread trade for their gill rakers, which is reflected in increasing Food and Agriculture Organization landings trends. Here, we present results from two dedicated diver surveys, one from the eManta project, which includes summary observations from ninety 10°x10° regions with ∼200–62,000 dives per region, and the other from the Reef Environmental Education Foundation, which includes spatially more detailed observations from 3 regions with ∼4,000–118,000 dives per region. We show that mobulids as a group, which includes eleven species, have globally and regionally restricted distributions, typically have low sighting frequency (<1% of dives) and aggregate in only a few locations. Of the regions surveyed by divers, almost half (47%) report declining mobulid sightings over the last decade. Divers indicate that although mobulid ecotourism occurs in many regions (45% of those reported, n = 41) they are considered protected in only 32% of the regions. Mobulids being fished or sold in local markets were reported from 16% and 12% of regions, respectively, with most being adjacent to mobulid abundance hotspot and ecotourism regions (e.g. Sri Lanka, Indonesia, east Africa). Identification of regions where ecotourism and exploitation are at odds could help prioritize conservation efforts. Vulnerability analysis, using life history characteristics, indicates that Manta spp. are vulnerable to exploitation, tolerating only low fishing mortality rates; data limitations prohibited such analysis for Mobula spp. Our analyses support previous studies in showing the need for improved conservation and monitoring efforts, and

  7. Global population trends and human use patterns of Manta and Mobula rays.

    PubMed

    Ward-Paige, Christine A; Davis, Brendal; Worm, Boris

    2013-01-01

    Despite being the world's largest rays and providing significant revenue through dive tourism, little is known about the population status, exploitation and trade volume of the Mobulidae (mobulids; Manta and Mobula spp.). There is anecdotal evidence, however, that mobulid populations are declining, largely due to the recent emergence of a widespread trade for their gill rakers, which is reflected in increasing Food and Agriculture Organization landings trends. Here, we present results from two dedicated diver surveys, one from the eManta project, which includes summary observations from ninety 10°x10° regions with ∼200-62,000 dives per region, and the other from the Reef Environmental Education Foundation, which includes spatially more detailed observations from 3 regions with ∼4,000-118,000 dives per region. We show that mobulids as a group, which includes eleven species, have globally and regionally restricted distributions, typically have low sighting frequency (<1% of dives) and aggregate in only a few locations. Of the regions surveyed by divers, almost half (47%) report declining mobulid sightings over the last decade. Divers indicate that although mobulid ecotourism occurs in many regions (45% of those reported, n = 41) they are considered protected in only 32% of the regions. Mobulids being fished or sold in local markets were reported from 16% and 12% of regions, respectively, with most being adjacent to mobulid abundance hotspot and ecotourism regions (e.g. Sri Lanka, Indonesia, east Africa). Identification of regions where ecotourism and exploitation are at odds could help prioritize conservation efforts. Vulnerability analysis, using life history characteristics, indicates that Manta spp. are vulnerable to exploitation, tolerating only low fishing mortality rates; data limitations prohibited such analysis for Mobula spp. Our analyses support previous studies in showing the need for improved conservation and monitoring efforts, and suggest that

  8. Incidence and time trends of Herpes zoster in rheumatoid arthritis: a population-based cohort study

    PubMed Central

    Veetil, Bharath Manu Akkara; Myasoedova, Elena; Matteson, Eric L.; Gabriel, Sherine E.; Green, Abigail B.; Crowson, Cynthia S.

    2012-01-01

    Objective To determine the incidence, time trends, risk factors and severity of herpes zoster (HZ) in a population-based incidence cohort of patients with rheumatoid arthritis (RA) compared to a group of individuals without RA from the same population. Methods All residents of Olmsted County, MN who first fulfilled 1987 American College of Rheumatology criteria for RA between 1/1/1980 and 12/31/2007 and a cohort of similar residents without RA were assembled and followed by retrospective chart review until death, migration, or 12/31/2008. Results There was no difference in the presence of HZ prior to RA incidence/index date between the cohorts (p=0.85). During follow-up 84 patients with RA (rate: 12.1 per 1000 person-years) and 44 subjects without RA (rate: 5.4 per 1000 person-years) developed HZ. Patients with RA were more likely to develop HZ than those without RA (hazard ratio: 2.4; 95% confidence interval: 1.7, 3.5). Patients diagnosed with RA in 1995–2007 had a higher likelihood of developing HZ than those diagnosed in 1980–1994. Erosive disease, previous joint surgery, use of hydroxychloroquine and corticosteroids were significantly associated with the development of HZ in RA, while the use of methotrexate or biologic agents was not. Complications of HZ occurred at a similar rate in both cohorts. Conclusion The incidence of HZ is increased in RA and has risen in recent years. The increasing incidence of HZ in more recent years is also noted in the general population. RA disease severity is associated with development of HZ. PMID:23281295

  9. Prevalence and Trends of the Abdominal Aortic Aneurysms Epidemic in General Population - A Meta-Analysis

    PubMed Central

    Li, Xi; Zhao, Ge; Zhang, Jian; Duan, Zhiquan; Xin, Shijie

    2013-01-01

    Objective To conduct a meta-analysis assessing the prevalence and trends of the abdominal aortic aneurysms (AAA) epidemic in general population. Method Studies that reported prevalence rates of AAA from the general population were identified through MEDLINE, EMBASE, Web of Science, and reference lists for the period between 1988 and 2013. Studies were included if they reported prevalence rates of AAA in general population from the community. In stratified analyses possible sources of bias, including areas difference, age, gender and diameter of aneurysms were examined. Publication bias was assessed with Egger's test method. Results 56 studies were identified. The overall pooled prevalence of AAA was 4.8% (4.3%, 5.3%). Stratified analyses showed the following results, areas difference: America 2.2% (2.2%, 2.2%), Europe 2.5% (2.4%, 2.5%), Australia 6.7% (6.5%, 7.0%), Asia 0.5% (0.3%, 0.7%); gender difference: male 6.0% (5.3%, 6.7%), female 1.6% (1.2%, 1.9%); age difference: 55–64years 1.3% (1.2%, 1.5%), 65–74 years 2.8% (2.7%, 2.9%), 75–84 years1.2%(1.1%, 1.3%), ≥85years0.6% (0.4%, 0.7%); aortic diameters difference: 30–39 mm, 3.3% (2.8%, 3.9%), 40–49 mm,0.7% (0.4%,1.0%), ≥50 mm, 0.4% (0.3%, 0.5%). The prevalence of AAA has decreased in Europe from 1988 to 2013. Hypertension, smoking, coronary artery disease, dyslipidemia, respiratory disease, cerebrovascular disease, claudication and renal insufficiency were risk factors for AAA in Europe. Conclusion AAA is common in general population. The prevalence of AAA is higher in Australia than America and Europe. The pooled prevalence in western countries is higher than the Asia. Future research requires a larger database on the epidemiology of AAA in general population. PMID:24312543

  10. Time trends in burdens of cadmium, lead, and mercury in the population of northern Sweden

    SciTech Connect

    Wennberg, Maria . E-mail: miawennberg@skehus19.ac; Lundh, Thomas; Bergdahl, Ingvar A.; Hallmans, Goeran; Jansson, Jan-Hakan; Stegmayr, Birgitta; Custodio, Hipolito M.; Skerfving, Staffan

    2006-03-15

    The time trends of exposure to heavy metals are not adequately known. This is a worldwide problem with regard to the basis for preventive actions and evaluation of their effects. This study addresses time trends for the three toxic elements cadmium (Cd), mercury (Hg), and lead (Pb). Concentrations in erythrocytes (Ery) were determined in a subsample of the population-based MONICA surveys from 1990, 1994, and 1999 in a total of 600 men and women aged 25-74 years. The study took place in the two northernmost counties in Sweden. To assess the effect of changes in the environment, adjustments were made for life-style factors that are determinants of exposure. Annual decreases of 5-6% were seen for Ery-Pb levels (adjusted for age and changes in alcohol intake) and Ery-Hg levels (adjusted for age and changes in fish intake). Ery-Cd levels (adjusted for age) showed a similar significant decrease in smoking men. It is concluded that for Pb and maybe also Hg the actions against pollution during recent decades have caused a rapid decrease of exposure; for Hg the decreased use of dental amalgam may also have had an influence. For Cd, the decline in Ery-Cd was seen only in smokers, indicating that Cd exposure from tobacco has decreased, while other environmental sources of Cd have not changed significantly. To further improve the health status in Sweden, it is important to decrease the pollution of Cd, and actions against smoking in the community are important.

  11. Trends in amenable mortality rate in the Mongolian population, 2007–2014

    PubMed Central

    Surenjav, Enkhjin; Sovd, Tugsdelger; Yoshida, Yoshitoku; Yamamoto, Eiko; Reyer, Joshua A.; Hamajima, Nobuyuki

    2016-01-01

    ABSTRACT Amenable mortality (AM) is an indicator of medical care quality. This study aimed to assess the trend and magnitude of AM in Mongolia, with the purpose of providing evidence for decisions on resource allocation. This is the first study on AM trends in Mongolia. Retrospective analysis was done on mortality statistics for the period 2007–2014. Causes of death were coded according to the 10th revision of the International Classification of Diseases (ICD-10). Nolte & McKee’s classification of AM was used for the estimation of amenable mortality rates (AMRs) in Mongolia. During the study period, a total of 130,402 deaths were registered in Mongolia, of which 44,800 (34.4%) deaths were classified as being amenable. The age-standardized AMR per 100,000 population was highest in 2007 (226.6), and declined continuously until the level of 169.2 in 2014. The rate remained consistently higher in males than in females. Cerebrovascular diseases, ischemic heart diseases, perinatal deaths, influenza/pneumonia/asthma and tuberculosis were the leading causes of AM in the past eight years in Mongolia. The AMR was higher in remote western provinces with harsh weather conditions, high poverty rates, lack of human resources for health, and poor infrastructure. In addition, the provinces where Mongolia’s ethnic minorities live tended to have a higher AMR. The government of Mongolia needs to critically look at the regional differences in AM in order to allocate health resources, including human resources, effectively. Further studies are needed to look into the causes of regional disparities in AM, individual-level risk factors to amenable deaths, and validity of death coding in health sector. PMID:27019528

  12. Age specific survival rates of Steller sea lions at rookeries with divergent population trends in the Russian Far East.

    PubMed

    Altukhov, Alexey V; Andrews, Russel D; Calkins, Donald G; Gelatt, Thomas S; Gurarie, Eliezer D; Loughlin, Thomas R; Mamaev, Evgeny G; Nikulin, Victor S; Permyakov, Peter A; Ryazanov, Sergey D; Vertyankin, Vladimir V; Burkanov, Vladimir N

    2015-01-01

    After a dramatic population decline, Steller sea lions have begun to recover throughout most of their range. However, Steller sea lions in the Western Aleutians and Commander Islands are continuing to decline. Comparing survival rates between regions with different population trends may provide insights into the factors driving the dynamics, but published data on vital rates have been extremely scarce, especially in regions where the populations are still declining. Fortunately, an unprecedented dataset of marked Steller sea lions at rookeries in the Russian Far East is available, allowing us to determine age and sex specific survival in sea lions up to 22 years old. We focused on survival rates in three areas in the Russian range with differing population trends: the Commander Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery) and the Kuril Islands (four rookeries). Survival rates differed between these three regions, though not necessarily as predicted by population trends. Pup survival was higher where the populations were declining (Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island rookeries. The lowest adult (> 3 years old) female survival was found on Medny Island and this may be responsible for the continued population decline there. However, the highest adult survival was found at Kozlov Cape, not in the Kuril Islands where the population is increasing, so we suggest that differences in birth rates might be an important driver of these divergent population trends. High pup survival on the Commander Islands and Kamchatka Coast may be a consequence of less frequent (e.g. biennial) reproduction there, which may permit females that skip birth years to invest more in their offspring, leading to higher pup survival, but this hypothesis awaits measurement of birth rates in these areas.

  13. Age Specific Survival Rates of Steller Sea Lions at Rookeries with Divergent Population Trends in the Russian Far East

    PubMed Central

    Altukhov, Alexey V.; Andrews, Russel D.; Calkins, Donald G.; Gelatt, Thomas S.; Gurarie, Eliezer D.; Loughlin, Thomas R.; Mamaev, Evgeny G.; Nikulin, Victor S.; Permyakov, Peter A.; Ryazanov, Sergey D.; Vertyankin, Vladimir V.; Burkanov, Vladimir N.

    2015-01-01

    After a dramatic population decline, Steller sea lions have begun to recover throughout most of their range. However, Steller sea lions in the Western Aleutians and Commander Islands are continuing to decline. Comparing survival rates between regions with different population trends may provide insights into the factors driving the dynamics, but published data on vital rates have been extremely scarce, especially in regions where the populations are still declining. Fortunately, an unprecedented dataset of marked Steller sea lions at rookeries in the Russian Far East is available, allowing us to determine age and sex specific survival in sea lions up to 22 years old. We focused on survival rates in three areas in the Russian range with differing population trends: the Commander Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery) and the Kuril Islands (four rookeries). Survival rates differed between these three regions, though not necessarily as predicted by population trends. Pup survival was higher where the populations were declining (Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island rookeries. The lowest adult (> 3 years old) female survival was found on Medny Island and this may be responsible for the continued population decline there. However, the highest adult survival was found at Kozlov Cape, not in the Kuril Islands where the population is increasing, so we suggest that differences in birth rates might be an important driver of these divergent population trends. High pup survival on the Commander Islands and Kamchatka Coast may be a consequence of less frequent (e.g. biennial) reproduction there, which may permit females that skip birth years to invest more in their offspring, leading to higher pup survival, but this hypothesis awaits measurement of birth rates in these areas. PMID:26016772

  14. Conservation Action Based on Threatened Species Capture Taxonomic and Phylogenetic Richness in Breeding and Wintering Populations of Central Asian Birds

    PubMed Central

    Schweizer, Manuel; Ayé, Raffael; Kashkarov, Roman; Roth, Tobias

    2014-01-01

    Although phylogenetic diversity has been suggested to be relevant from a conservation point of view, its role is still limited in applied nature conservation. Recently, the practice of investing conservation resources based on threatened species was identified as a reason for the slow integration of phylogenetic diversity in nature conservation planning. One of the main arguments is based on the observation that threatened species are not evenly distributed over the phylogenetic tree. However this argument seems to dismiss the fact that conservation action is a spatially explicit process, and even if threatened species are not evenly distributed over the phylogenetic tree, the occurrence of threatened species could still indicate areas with above average phylogenetic diversity and consequently could protect phylogenetic diversity. Here we aim to study the selection of important bird areas in Central Asia, which were nominated largely based on the presence of threatened bird species. We show that although threatened species occurring in Central Asia do not capture phylogenetically more distinct species than expected by chance, the current spatially explicit conservation approach of selecting important bird areas covers above average taxonomic and phylogenetic diversity of breeding and wintering birds. We conclude that the spatially explicit processes of conservation actions need to be considered in the current discussion of whether new prioritization methods are needed to complement conservation action based on threatened species. PMID:25337861

  15. Population.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    In an effort to help meet the growing interest and concern about the problems created by the rapid growth of population, The International Planned Parenthood Federation has prepared this booklet with the aim of assisting the study of the history and future trends of population growth and its impact on individual and family welfare, national,…

  16. Population trends of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site, California

    SciTech Connect

    Berry, W.H.; Standley, W.G.

    1992-10-01

    Population trends of a San Joaquin kit fox population (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training Site, California, from November 1989 through August 1991. Six semiannual livetrapping sessions and eight scent-station survey sessions were conducted. Livetrapping results and radiotelemetry data were used to calculate minimum population size, density, and distribution. A total of 175 individual foxes were trapped 463 times. The number of individuals trapped and minimum population size calculations showed a decline over time. The highest minimum population (109) was observed in winter 1988. Summer 1991 had the lowest minimum population size (45). No evidence was found to indicate that the apparent population decline was a result of military-authorized activities.

  17. Hierarchical models and the analysis of bird survey information

    USGS Publications Warehouse

    Sauer, J.R.; Link, W.A.

    2003-01-01

    Management of birds often requires analysis of collections of estimates. We describe a hierarchical modeling approach to the analysis of these data, in which parameters associated with the individual species estimates are treated as random variables, and probability statements are made about the species parameters conditioned on the data. A Markov-Chain Monte Carlo (MCMC) procedure is used to fit the hierarchical model. This approach is computer intensive, and is based upon simulation. MCMC allows for estimation both of parameters and of derived statistics. To illustrate the application of this method, we use the case in which we are interested in attributes of a collection of estimates of population change. Using data for 28 species of grassland-breeding birds from the North American Breeding Bird Survey, we estimate the number of species with increasing populations, provide precision-adjusted rankings of species trends, and describe a measure of population stability as the probability that the trend for a species is within a certain interval. Hierarchical models can be applied to a variety of bird survey applications, and we are investigating their use in estimation of population change from survey data.

  18. Contrasting population trends of piscivorous seabirds in the Pribilof Islands: A 30-year perspective

    USGS Publications Warehouse

    Byrd, G.V.; Schmutz, J.A.; Renner, H.M.

    2008-01-01

    The Pribilof Islands provide nesting habitat for one of the largest concentrations of piscivorous seabirds in the North Pacific region. Pribilof breeding populations of black-legged and red-legged kittiwakes (Rissa tridactyla and Rissa brevirostris), and common and thick-billed murres (Uria aalge and Uria lomvia) are supported by a highly productive marine food web. Productivity and temperature in this area are influenced by winter sea ice that frequently reaches its maximum extent near the Pribilofs. Although St. George and St. Paul islands, the two largest of the Pribilof group, are situated only 60 km apart, St. George is within 25 km of the shelf break, but St. Paul is approximately 90 km away. In contrast, the local contribution of sea ice-edge productivity in the spring is frequently closer to St. Paul than to St. George. Central place foraging piscivorous seabirds nesting at St. Paul and St. George are likely differentially affected by the relative contributions of the shelf break and ice-edge environments based on juxtaposition. Within the past decade or so, sea ice in the Bering Sea has failed to reach the vicinity of the Pribilofs in some years, and predictions of warming in the future suggest the possibility that direct effects of the ice on the immediate Pribilof environment will be reduced. To evaluate the response of kittiwakes and murres on the two islands to conditions in their foraging environments, we examined population trends over the past 30 years based on data from the seabird monitoring program conducted by the Alaska Maritime National Wildlife Refuge and others. Spatial differences in trends have been more consistent than differences among species, with populations at St. Paul having more enduring declines than those at St. George. At St. George, black-legged kittiwakes and common murres have remained stable. Red-legged kittiwakes and thick-billed murres both declined, but began to rebound in the late 1980s, such that in 2005 population

  19. eHealth Trends in Europe 2005-2007: A Population-Based Survey

    PubMed Central

    Chronaki, Catherine E; Lausen, Berthold; Prokosch, Hans-Ulrich; Rasmussen, Janne; Santana, Silvina; Staniszewski, Andrzej; Wangberg, Silje Camilla

    2008-01-01

    Background In the last decade, the number of Internet users worldwide has dramatically increased. People are using the Internet for various health-related purposes. It is important to monitor such use as it may have an impact on the individual’s health and behavior, patient-practitioner roles, and on general health care provision. Objectives This study investigates trends and patterns of European health-related Internet use over a period of 18 months. The main study objective was to estimate the change in the proportion of the population using the Internet for health purposes, and the importance of the Internet as a source of health information compared to more traditional sources. Methods The survey data were collected through computer-assisted telephone interviews. A representative sample (N = 14,956) from seven European countries has been used: Denmark, Germany, Greece, Latvia, Norway, Poland, and Portugal. The European eHealth Consumer Trends Survey was first conducted in October-November 2005 and repeated in April-May 2007. In addition to providing background information, respondents were asked to rate the importance of various sources of health information. They were also queried as to the frequency of different online activities related to health and illness and the effects of such use on their disposition. Results The percentage of the population that has used the Internet for health purposes increased from an estimated 42.3% (95% CI [Confidence Interval] 41.3 - 43.3) in 2005 to an estimated 52.2% (95% CI 51.3 - 53.2) in 2007. Significant growth in the use of the Internet for health purposes was found in all the seven countries. Young women are the most active Internet health users. The importance of the Internet as a source of health information has increased. In 2007, the Internet was perceived as an important source of health information by an estimated 46.8% (95% CI 45.7 - 47.9) of the population, a significant increase of 6.5 % (95% CI 4.9 - 8

  20. Trends in primary care antidepressant prescribing 1995-2007: a longitudinal population database analysis

    PubMed Central

    Lockhart, Pauline; Guthrie, Bruce

    2011-01-01

    Background Antidepressant prescribing is increasing worldwide, prompting policy interventions and targets to halt the rise. Aim To examine time trends in GP antidepressant prescribing using patient-level data. Design and setting Longitudinal population database of all community pharmacy dispensed prescriptions for all 325 000 residents of theTayside region of Scotland. Method In each of 3 study years (1995/1996, 2000/2001 and 2006/2007), the volume of antidepressants prescribed was calculated, and numbers of patients prescribed antidepressants in each year, mean treatment duration, and mean dose per patient in that year examined using descriptive statistics. Results Total drug volume increased threefold between 1995/1996 and 2006/2007, largely driven by increases in selective serotonin reuptake inhibitor (SSRI) prescribing, and laterally also in ‘other’ antidepressant prescribing. Tricyclic prescribing is static, but low-dose amitriptyline increasingly dominates this drug class. Increased drug volume was initially driven by increasing patient numbers (from 8.0% of the population prescribed at least once in 1995/1996 to 11.9% in 2000/2001) and increased treatment duration (from 170 days in the measurement year to 200). Latterly, drug volume increases are increasingly attributable to longer duration of treatment and higher mean daily dose. Conclusion The large rise in antidepressant volumes is caused by a complex mixture of more patients being prescribed SSRI and ‘other’ antidepressants, the use of higher doses, and longer durations of treatment, with the balance changing overtime. Tricyclic prescribing is now largely low dose, and probably for conditions otherthan depression. Interventions to improve the quality of antidepressant prescribing need to be more subtle than blanket targets to reduce the total volume of antidepressants prescribed. PMID:22152736

  1. Trends in emergent inguinal hernia surgery in Olmsted County, MN: a population-based study

    PubMed Central

    Hernández-Irizarry, R.; Zendejas, B.; Ramirez, T.; Moreno, M.; Ali, S. M.; Lohse, C. M.

    2013-01-01

    Background Evidence suggests that watchful waiting of inguinal hernias (IH) is safe because the risk of acute strangulation requiring an emergent repair is low. However, population-based incidence rates are lacking, and it is unknown whether the incidence of emergent inguinal hernia repairs (IHR) has changed over time. Study design A retrospective review of all IHR performed on adult residents of Olmsted County, Minnesota from 1989 to 2008 was performed using the Rochester epidemiology project, a record-linkage system that covers more than 97 % of the population (2010 US Census = 146,466). Incidence rates/100,000 person-years were calculated, and trends over time were evaluated using Poisson regression. Results A total of 4,026 IHR were performed on 3,599 patients; 136 repairs (3.8 %) were emergent. Of these, 19 patients (14 %) had bowel resection and three (2 %) died within 30 days of the repair. Rates/100,000 person-years yielded an overall incidence of 7.6 for emergent IHR and 200.0 for elective IHR. Emergent IHR rates increased with age. Overall emergent IHR rates declined from 18.2 to 12.4 in men and from 6.4 to 2.4 in women from 1989 to 2008 (p > 0.05). Older age, obesity, a high ASA risk score, a femoral and/or a recurrent hernia were more likely to be associated with an emergent IHR (all p ≤ 0.05). Conclusion The incidence of emergent IHR is low. This risk has decreased over the past 20 years. However, patients who are either ≥70 years old, obese, with a high ASA score, or with a femoral or recurrent hernias are more likely to require an emergent IHR and could benefit from elective operative intervention if deemed adequate surgical candidates. PMID:22695978

  2. Study on the Trend and Disease Burden of Injury Deaths in Chinese Population, 2004–2010

    PubMed Central

    Zhang, Lijuan; Li, Zhiqiang; Li, Xucheng; Zhang, Jie; Zheng, Liang; Jiang, Chenghua; Li, Jue

    2014-01-01

    Injuries are a growing public health concern in China, accounting for more than 30% of all Person Years of Life Lost (PYLL) due to premature mortality. This study analyzes the trend and disease burden of injury deaths in Chinese population from 2004 to 2010, using data from the National Disease Surveillance Points (DSPs) system, as injury deaths are classified based on the International Classification of Disease-10th Revision (ICD-10). We observed that injury death accounted for nearly 10% of all deaths in China throughout the period 2004–2010, and the injury mortality rates were higher in males than those in females, and higher in rural areas than in urban areas. Traffic crashes (33.79–38.47% of all injury deaths) and suicides (16.20–22.01%) were the two leading causes of injury deaths. Alarmingly, suicide surpassed traffic crashes as the leading cause of injury mortality in rural females, yet adults aged 65 and older suffered the greatest number of fatal falls (20,701 deaths, 2004–2010). The burden of injury among men (72.11%) was about three times more than that of women's (28.89%). This study provides indispensible evidence that China Authority needs to improve the surveillance and deterrence of three major types of injuries: Traffic-related injury deaths should be targeted for injury prevention activities in all population, people aged 65+ should be encouraged to take individual fall precautions, and prevention of suicidal behavior in rural females should be another key priority for the government of China. PMID:24465534

  3. Bird Study

    ERIC Educational Resources Information Center

    Katz, Margaret

    1978-01-01

    Excerpts from a first grade teacher's diary describe bird study activities done by the class over a two week period. Each student studied a bird of their choice in detail and made a papier-mache model of the bird. These models were exhibited at a student initiated program for visitors. (MA)

  4. Christmas Island birds returning

    NASA Astrophysics Data System (ADS)

    Six months after their mass exodus, birds are beginning to return to Christmas Island. Roughly 17 million birds, almost the entire adult bird population, either perished or fled their mid-Pacific atoll home last autumn, leaving behind thousands of nestlings to starve (Eos, April 5, 1983, p. 131). It is believed that the strong El Niño altered the ecology of the surrounding waters and forced the birds to flee. Christmas Island is the world's largest coral atoll.“Ocean and atmosphere scientists are unsure of future directions for the El Niño conditions and cannot now predict what will happen to the birds in the coming months,” said Ralph W. Schreiber, curator of ornithology at the Natural History Museum of Los Angeles County in California. Heisthe ornithologist who discovered the disappearance. “The recovery of the bird populations depends on the food supply in the waters surrounding the island.” The island's birds feed exclusively on small fish and squid.

  5. The SLUGGS survey: globular cluster stellar population trends from weak absorption lines in stacked spectra

    NASA Astrophysics Data System (ADS)

    Usher, Christopher; Forbes, Duncan A.; Brodie, Jean P.; Romanowsky, Aaron J.; Strader, Jay; Conroy, Charlie; Foster, Caroline; Pastorello, Nicola; Pota, Vincenzo; Arnold, Jacob A.

    2015-01-01

    As part of the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey, we stack 1137 Keck DEIMOS (Deep Imaging Multi-Object Spectrograph) spectra of globular clusters from 10 galaxies to study their stellar populations in detail. The stacked spectra have median signal-to-noise ratios of ˜90 Å-1. Besides the calcium triplet, we study weaker sodium, magnesium, titanium and iron lines as well as the Hα and higher order Paschen hydrogen lines. In general, the stacked spectra are consistent with old ages and a Milky Way-like initial mass function. However, we see different metal line index strengths at fixed colour and magnitude, and differences in the calcium triplet-colour relation from galaxy to galaxy. We interpret this as strong evidence for variations in the globular cluster colour-metallicity relation between galaxies. Two possible explanations for the colour-metallicity relation variations are that the average ages of globular clusters vary from galaxy to galaxy or that the average abundances of light elements (i.e. He, C, N and O) differ between galaxies. Stacking spectra by magnitude, we see that the colours become redder and metal line indices stronger with brighter magnitudes. These trends are consistent with the previously reported `blue tilts' being mass-metallicity relations.

  6. Testicular cancer trends as 'whistle blowers' of testicular developmental problems in populations.

    PubMed

    Skakkebaek, N E; Rajpert-De Meyts, E; Jørgensen, N; Main, K M; Leffers, H; Andersson, A-M; Juul, A; Jensen, T K; Toppari, J

    2007-08-01

    Recently a worldwide rise in the incidence of testicular germ cell cancer (TGCC) has been repeatedly reported. The changing disease pattern may signal that other testicular problems may also be increasing. We have reviewed recent research progress, in particular evidence gathered in the Nordic countries, which shows strong associations between testicular cancer, undescended testis, hypospadias, poor testicular development and function, and male infertility. These studies have led us to suggest the existence of a testicular dysgenesis syndrome (TDS), of which TGCC, undescended testis, hypospadias/disorders of sex differentiation and male fertility problems may be symptoms with varying penetration. In spite of their fetal origin, most of the TDS symptoms, including TGCC and poor semen quality, can only be diagnosed in adulthood. Data from a Danish-Finnish research collaboration strongly suggest that trends in TGCC rates of a population may be 'whistle blowers' of other reproductive health problems. As cancer registries are often of excellent quality - in contrast to registries for congenital abnormalities - health authorities should consider an increase in TGCC as a warning that other reproductive health problems may also be rising.

  7. Use of pellet-group plots to measure trends in deer and elk populations

    SciTech Connect

    Rowland, M.M.; White, G.C.; Karlen, E.M.

    1984-01-01

    Distribution and abundance of mule deer and elk were studied from 1976 to 1981 near Los Alamos, New Mexico, using pellet-group counts. Pellet-group data were shown to fit the negative binomial distribution. Counts for mule deer varied among years in all vegetation types; the population trend was generally downward. Pellet-group counts for elk (winter only) increased in ponderosa pine, but remained unchanged in other areas. Deer pellet groups were distributed similarly from year to year and were nonrandom (i.e., clumped). Elk pellet groups also were clumped, but were clumped less in mixed conifer during the latter part of the study. In ponderosa pine, where deer were most abundant, pellet groups were clumped less than in other habitats. Similarly, in mixed conifer, where elk numbers were highest, pellet groups were clumped least. Neither weather nor fire appeared to affect greatly counts of deer or elk pellet groups, although fire may have influenced distribution of elk. 37 references, 5 tables.

  8. Data for calculating population, collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure

    USGS Publications Warehouse

    Adams, Josh; Kelsey, Emily; Felis, Jonathan J.; Pereksta, David M.

    2016-01-01

    The U.S. Geological Survey, Western Ecological Research Center (USGS-WERC) was requested by the Bureau of Ocean Energy Management (BOEM) to create a database for marine birds of the California Current System (CCS) that would allow quantification and species ranking regarding vulnerability to offshore wind energy infrastructure (OWEI). This was needed so that resource managers could evaluate potential impacts associated with siting and construction of OWEI within the California Current System section of the Pacific Offshore Continental Shelf, including California, Oregon, and Washington. Along with its accompanying Open File Report (OFR), this comprehensive database can be used (and modified or updated) to quantify marine bird vulnerability to OWEIs in the CCS at the population level. For 81 marine bird species present in the CCS, we generated numeric scores to represent three vulnerability indices associated with potential OWEI: population vulnerability, collision vulnerability, and displacement vulnerability. The metrics used to produce these scores includes global population size, proportion of the population in the CCS, threat status, adult survival, breeding score, annual occurrence in the CCS, nocturnal and diurnal flight activity, macro-avoidance behavior, flight height, and habitat flexibility; values for these metrics can be updated and adjusted as new data become available. The scoring methodology was peer-reviewed to evaluate if the metrics identified and the values generated were appropriate for each species considered. The numeric vulnerability scores in this database can readily be applied to areas in the CCS with known species distributions and where offshore renewable energy development is being considered. We hope that this information can be used to assist meaningful planning decisions that will impact seabird conservation. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016

  9. Top-down and bottom-up factors affecting seabird population trends in the California current system (1985-2006)

    NASA Astrophysics Data System (ADS)

    Ainley, David G.; David Hyrenbach, K.

    2010-03-01

    To characterize the environmental factors affecting seabird population trends in the central portion of the California current system (CCS), we analyzed standardized vessel-based surveys collected during the late spring (May-June) upwelling season over 22 yr (1985-2006). We tested the working hypothesis that population trends are related to species-specific foraging ecology, and predicted that temporal variation in population size should be most extreme in diving species with higher energy expenditure during foraging. We related variation in individual species abundance (number km -2) to seasonally lagged (late winter, early spring, late spring) and concurrent ocean conditions, and to long-term trends (using a proxy variable: year) during a multi-decadal period of major fluctuations in the El Niño-Southern oscillation (ENSO) and the Pacific decadal oscillation (PDO). We considered both remote (Multivariate ENSO Index, PDO) and local (coastal upwelling indices and sea-surface temperature) environmental variables as proxies for ocean productivity and prey availability. We also related seabird trends to those of potentially major trophic competitors, humpback ( Megaptera novaeangliae) and blue ( Balaenoptera musculus) whales, which increased in number 4-5-fold midway during our study. Cyclical oscillations in seabird abundance were apparent in the black-footed albatross ( Phoebastria nigripes), and decreasing trends were documented for ashy storm-petrel ( Oceanodroma homochroa), pigeon guillemot ( Cepphus columbus), rhinoceros auklet ( Cerorhinca monocerata), Cassin’s auklet ( Ptychoramphus aleuticus), and western gull ( Larus occidentalis); the sooty shearwater ( Puffinus griseus), exhibited a marked decline before signs of recovery at the end of the study period. The abundance of nine other focal species varied with ocean conditions, but without decadal or long-term trends. Six of these species have the largest global populations in the CCS, and four are highly

  10. Differential trends in mercury concentrations in double-crested cormorant populations of the Canadian Prairies.

    PubMed

    Hall, Britt D; Doucette, Jennifer L; Bates, Lara M; Bugajski, Aleksandra; Niyogi, Som; Somers, Christopher M

    2014-04-01

    Mercury and selenium concentrations were measured in double-crested cormorants (Phalacrocorax auritus), piscivorous fish, and common prey items in five lakes in two ecoregions in Saskatchewan, Canada. Hg and Se concentrations in cormorants were within the natural ranges of birds living in un-impacted sites. Site explained a significant proportion of the variation in total Hg (THg) and methylmercury (MeHg) concentrations in both cormorant breast muscle and livers. Birds nesting on more northern lakes in the Boreal Plain ecoregion (THg range 0.11-1.06 and 0.26-9.27 μg g(-1) wet weight, for breast and liver respectively) had lower THg concentrations compared to those from lakes in the Prairie ecoregion (THg range 0.60-4.26 μg g(-1) ww and 1.59-25.11 μg g(-1), for breast and liver respectively). Concentrations of MeHg in livers was also lower in birds from northern sites (0.06-1.15 μg g(-1) ww) compared to those from prairie sites (0.22-4.06 μg g(-1) ww). We documented a wide range of %MeHg in livers (4.5-52 %), indicative of detoxifying MeHg via demethylation to inorganic Hg. Our data suggest that the threshold value where demethylation rates increase substantially appears to be ~10 μg g(-1) ww MeHg, similar to thresholds in other wildlife. Molar ratios of Hg:Se suggests that some birds from highly saline Reed Lake in the prairie region had insufficient Se available to bind to Hg, thereby removing Se binding as a mitigative strategy for high Hg levels for these birds.

  11. Trends in heat-related mortality in urban populations of the Czech Republic over 1994-2013

    NASA Astrophysics Data System (ADS)

    Urban, Aleš; Kyselý, Jan

    2016-04-01

    The study resumes previous research that found significant effects of hot spells on increased mortality in highly urbanized regions of the Czech Republic, and declining trends in heat-related mortality in the Czech population as a whole. We analyze severe hot spells during 1994-2013 and temporal changes of their effects on total and cardiovascular mortality in several urban regions with a different overall socioeconomic level (city of Prague, city of Brno, Ostrava region, NW Bohemia). Mortality data were standardized to account for different population structure and its changes over time. The mortality baseline for each region was determined using a generalized additive model. Although declining trends in the mortality impacts of hot spells prevail in most regions in spite of rising temperature trends, the magnitude of the mortality decline was different with respect to the overall socioeconomic level and development of the regions. The results suggest that trends in heat-related mortality depend on the level of socioeconomic deprivation of population. It is essential to better understand the risks of climate change in different parts of population with respect to their adaptability.

  12. Estimating temporal trend in the presence of spatial complexity: A Bayesian hierarchical model for a wetland plant population undergoing restoration

    USGS Publications Warehouse

    Rodhouse, T.J.; Irvine, K.M.; Vierling, K.T.; Vierling, L.A.

    2011-01-01

    Monitoring programs that evaluate restoration and inform adaptive management are important for addressing environmental degradation. These efforts may be well served by spatially explicit hierarchical approaches to modeling because of unavoidable spatial structure inherited from past land use patterns and other factors. We developed Bayesian hierarchical models to estimate trends from annual density counts observed in a spatially structured wetland forb (Camassia quamash [camas]) population following the cessation of grazing and mowing on the study area, and in a separate reference population of camas. The restoration site was bisected by roads and drainage ditches, resulting in distinct subpopulations ("zones") with different land use histories. We modeled this spatial structure by fitting zone-specific intercepts and slopes. We allowed spatial covariance parameters in the model to vary by zone, as in stratified kriging, accommodating anisotropy and improving computation and biological interpretation. Trend estimates provided evidence of a positive effect of passive restoration, and the strength of evidence was influenced by the amount of spatial structure in the model. Allowing trends to vary among zones and accounting for topographic heterogeneity increased precision of trend estimates. Accounting for spatial autocorrelation shifted parameter coefficients in ways that varied among zones depending on strength of statistical shrinkage, autocorrelation and topographic heterogeneity-a phenomenon not widely described. Spatially explicit estimates of trend from hierarchical models will generally be more useful to land managers than pooled regional estimates and provide more realistic assessments of uncertainty. The ability to grapple with historical contingency is an appealing benefit of this approach.

  13. Seasonal metabolic variation over two years in an Afrotropical passerine bird.

    PubMed

    Thompson, Lindy J; Brown, Mark; Downs, Colleen T

    2015-08-01

    Seasonal trends in metabolic parameters are well established in avian populations from highly seasonal environments, however, seasonal trends in metabolism of birds from lower latitudes (and of Afrotropical birds in particular) are not well understood. We investigated seasonal trends in metabolism for a small (10-12g) Afrotropical bird, the Cape White-eye (Zosterops virens), using flow-through respirometry in two summers and two winters. There was no seasonal difference in body mass between consecutive seasons. The lower critical limit of thermoneutrality was lower in winter (23°C) than in summer (28°C), as expected for a small Afrotropical bird. In the first year of the study, mean whole animal basal metabolic rate (BMR) of Cape White-eyes was significantly lower in winter than in summer, while in the second year of the study this trend was reversed, and in the middle two seasons there was no significant difference in BMR. Differences in mean temperature and mean rainfall between seasons could not account for the seasonal trends in BMR. We conclude that seasonal trends in avian BMR may vary between years, within a population.

  14. Electrical burns: The trend and risk factors in the Ghanaian population

    PubMed Central

    Agbenorku, P.; Agbenorku, E.; Akpaloo, J.; Obeng, G.; Agbley, D.

    2014-01-01

    Summary The usefulness of electricity in daily life offers several advantages which cannot be underestimated. Electricity is needed by industries for manufacturing and also in homes for lighting, cooking, washing, etc. However, electricity can cause severe life-threatening complications. This study investigates the trend and mortality risk factors of electrical burn injuries at the Burns Intensive Care Unit (BICU) of the Komfo Anokye Teaching Hospital (KATH), Ghana. The Burns Registry at KATH BICU containing information on patients who were admitted for electrical burns was used. Data on the sex, age, occupation, cause of injury, Total Body Surface Area burned (TBSA) and outcome of admissions was obtained. GraphPad version 5 was used for the analysis. There were 13 (2.7%) electrical burns, suffered by 11 males (84.6%) and 2 females (15.4%) out of a total 487 BICU admissions over a 4-year period (July 1, 2009 – June 30, 2013); the mean age of the electrical burn victims was 37.8 years (range = 22–56); the TBSA ranged from 5.0% - 98.0%. Mortality risk factors identified were high voltage electrical burns, older age (P=0.0250) and TBSA>20% (P=0.048). Four cases (30.8%) were transferred to the Main Burns Ward (Ward D2C); 6 cases (46.1%) were discharged home; 3 patients (23.1%) died; all deaths were recorded in persons who had high voltage electrical burns. Electrical burns can be severe and can cause death. Even though the current study showed that a small population was affected by electrical burns, society has to be continually conscious of the detrimental effects of electrical energy and take the necessary precautions to minimize this type of accident. PMID:26336364

  15. Electrical burns: The trend and risk factors in the Ghanaian population.

    PubMed

    Agbenorku, P; Agbenorku, E; Akpaloo, J; Obeng, G; Agbley, D

    2014-12-31

    The usefulness of electricity in daily life offers several advantages which cannot be underestimated. Electricity is needed by industries for manufacturing and also in homes for lighting, cooking, washing, etc. However, electricity can cause severe life-threatening complications. This study investigates the trend and mortality risk factors of electrical burn injuries at the Burns Intensive Care Unit (BICU) of the Komfo Anokye Teaching Hospital (KATH), Ghana. The Burns Registry at KATH BICU containing information on patients who were admitted for electrical burns was used. Data on the sex, age, occupation, cause of injury, Total Body Surface Area burned (TBSA) and outcome of admissions was obtained. GraphPad version 5 was used for the analysis. There were 13 (2.7%) electrical burns, suffered by 11 males (84.6%) and 2 females (15.4%) out of a total 487 BICU admissions over a 4-year period (July 1, 2009 - June 30, 2013); the mean age of the electrical burn victims was 37.8 years (range = 22-56); the TBSA ranged from 5.0% - 98.0%. Mortality risk factors identified were high voltage electrical burns, older age (P=0.0250) and TBSA>20% (P=0.048). Four cases (30.8%) were transferred to the Main Burns Ward (Ward D2C); 6 cases (46.1%) were discharged home; 3 patients (23.1%) died; all deaths were recorded in persons who had high voltage electrical burns. Electrical burns can be severe and can cause death. Even though the current study showed that a small population was affected by electrical burns, society has to be continually conscious of the detrimental effects of electrical energy and take the necessary precautions to minimize this type of accident.

  16. Population trends of binary near-Earth asteroids based on radar and lightcurves observations

    NASA Astrophysics Data System (ADS)

    Brozovic, Marina; Benner, Lance A. M.; Naidu, Shantanu P.; Taylor, Patrick A.; Busch, Michael W.; Margot, Jean-Luc; Nolan, Michael C.; Howell, Ellen S.; Springmann, Alessondra; Giorgini, Jon D.; Shepard, Michael K.; Magri, Christopher; Richardson, James E.; Rivera-Valentin, Edgard G.; Rodriguez-Ford, Linda A.; Zambrano Marin, Luisa Fernanda

    2016-10-01

    The Arecibo and Goldstone planetary radars are invaluable instruments for the discovery and characterization of binary and triple asteroids in the near-Earth asteroid (NEA) population. To date, 41 out of 56 known binaries and triples (~73% of the objects) have been discovered by radar and 49 of these multiple systems have been detected by radar. Their absolute magnitudes range from 12.4 for (1866) Sisyphus to 22.6 for 2015 TD144 and have a mean and rms dispersion of 18.1+-2.0. There is a pronounced decrease in the abundance of binaries for absolute magnitudes H>20. One of the smallest binaries, 1994 CJ1, with an absolute magnitude H=21.4, is also the most accessible binary for a spacecraft rendezvous. Among 365 NEAs with H<22 (corresponding to diameters larger than ~ 140 m) detected by radar since 1999, ~13% have at least one companion. Two triple systems are known, (15391) 2001 SN263 and (136617) 1994 CC, but this is probably an underestimate due to low signal to noise ratios (SNRs) for many of the binary radar detections. Taxonomic classes have been reported for 41 out of 56 currently known multiple systems and some trends are starting to emerge: at least 50% of multiple asteroid systems are S, Sq, Q, or Sk, and at least 20% are optically dark (C, B, P, or U). Thirteen V-class NEAs have been observed by radar and six of them are binaries. Curiously, a comparable number of E-class objects have been detected by radar, but none is known to be a binary.

  17. Time Trend in Psychotropic Medication Use in Spain: A Nationwide Population-Based Study

    PubMed Central

    Carrasco-Garrido, Pilar; Hernández-Barrera, Valentín; Jiménez-Trujillo, Isabel; Esteban-Hernández, Jesús; Álvaro-Meca, Alejandro; López-de Andrés, Ana; DelBarrio-Fernández, José Luis; Jiménez-García, Rodrigo

    2016-01-01

    Background: We performed an epidemiologic study to analyze nationwide time trends in adult psychotropic drug use over a period from 2006 to 2012, and to identify those factors associated with the likelihood of consumption of these drugs during the study period; Methods: Cross-sectional study on psychotropic medication in the Spanish adult population. We used secondary individualized data drawn from the 2006 and 2012 Spanish National Health Surveys (SNHS). The dependent variable was the use of psychotropic drugs in the previous two weeks. Independent variables included socio-demographic characteristics, comorbidity, lifestyles and healthcare resource utilization. Using logistic multivariate regression models, we analyzed the temporal evolution of psychotropic medication consumption between 2006 and 2012 in both sexes; Results: The prevalence of psychotropic drug use was significantly greater in women (18.14% vs. 8.08% in 2012 (p < 0.05). In Spanish women, the variables associated with a greater probability of psychotropic use were, age, unemployment (adjusted odds ratio (AOR), 1.60; 95% CI, 1.24–2.07), negative perception of health or taking non-psychotropic drugs. Among men, psychotropic use is associated with presence of chronic disease, negative perception of health (AOR, 3.27; 95% CI, 2.62–4.07 in 2012) or inactive status; Conclusions: Between 2006 and 2012, the probability of having taken psychotropic drugs increased by 16% among women. Unemployed women aged ≥45 years with a negative perception of their health constitute a clear risk profile in terms of psychotropic drug use. Inactive men who have a negative perception of their health are the group most likely to consume psychotropic drugs. PMID:27886138

  18. Trends in vegetation degradation in relation to land tenure, rainfall, and population changes in Peddie district, Eastern Cape, South Africa.

    PubMed

    Kakembo, V

    2001-07-01

    Spatial and temporal variations in vegetation are examined in relation to land tenure, population increase, and rainfall variation in a part of Peddie district, Eastern Cape. Sequential aerial photographs between 1938 and 1988 are analyzed to determine trends in vegetation and population change in three different land-tenure units. The areal extent at each date of four distinct vegetation categories is determined using PC ARC/INFO GIS. Long-term annual rainfall trends for the area are analyzed and juxtaposed with vegetation changes. Extensive ground-truthing exercises are carried out to verify the present condition of vegetation condition in terms of cover and species composition. Differences in land-tenure systems are discerned as the dominant factor controlling variations in vegetation degradation. The study also reveals that neither population changes nor rainfall variations can explain the observed trends in vegetation degradation. Earlier injudicious land-use practices, sustained since the turn of the last century, may provide plausible explanations for the trends and present status of vegetation degradation in the area.

  19. Population trends in Pacific Oceanic sharks and the utility of regulations on shark finning.

    PubMed

    Clarke, Shelley C; Harley, Shelton J; Hoyle, Simon D; Rice, Joel S

    2013-02-01

    Accurate assessment of shark population status is essential for conservation but is often constrained by limited and unreliable data. To provide a basis for improved management of shark resources, we analyzed a long-term record of species-specific catches, sizes, and sexes of sharks collected by onboard observers in the western and central Pacific Ocean from 1995 to 2010. Using generalized linear models, we estimated population-status indicators on the basis of catch rate and biological indicators of fishing pressure on the basis of median size to identify trends for blue (Prionace glauca), mako (Isurus spp.), oceanic whitetip (Carcharhinus longimanus), and silky (Carcharhinus falciformis) sharks. Standardized catch rates of longline fleets declined significantly for blue sharks in the North Pacific (by 5% per year [CI 2% to 8%]), for mako sharks in the North Pacific (by 7% per year [CI 3% to 11%]), and for oceanic whitetip sharks in tropical waters (by 17% per year [CI 14% to 20%]). Median lengths of silky and oceanic whitetip sharks decreased significantly in their core habitat, and almost all sampled silky sharks were immature. Our results are consistent with results of analyses of similar data sets. Combined, these results and evidence of targeted fishing for sharks in some regional fisheries heighten concerns for sustainable utilization, particularly for oceanic whitetip and North Pacific blue sharks. Regional regulations that prohibit shark finning (removal of fins and discarding of the carcass) were enacted in 2007 and are in many cases the only form of control on shark catches. However, there is little evidence of a reduction of finning in longline fisheries. In addition, silky and oceanic whitetip sharks are more frequently retained than finned, which suggests that even full implementation of and adherence to a finning prohibition may not substantially reduce mortality rates for these species. We argue that finning prohibitions divert attention from

  20. The forms and fitness cost of senescence: age-specific recapture, survival, reproduction, and reproductive value in a wild bird population.

    PubMed

    Bouwhuis, Sandra; Choquet, Rémi; Sheldon, Ben C; Verhulst, Simon

    2012-01-01

    Longitudinal studies of senescence accumulate rapidly from natural populations. However, it is largely unknown whether different fitness components senesce in parallel, how reproductive and survival senescence contribute to declines in reproductive value, and how large the fitness cost of senescence is (the difference between the observed reproductive value and the hypothetical reproductive value, if senescence would not occur). We analyzed age-specific survival in great tits Parus major and combined our results with analyses of reproductive senescence to address these issues. Recapture probability of breeding females declined with age, suggesting age-specific increases in skipped or failed breeding and highlighting an important bias that studies of senescence in wild populations should incorporate. Survival probability also declined with age and in parallel with recruit production. Reproductive value decreased 87% between age 1 and age 9 but at a fitness cost of only 4%; the proportion of the contribution of reproductive senescence versus survival senescence to this cost was 0.7. For 11 other species, we estimated fitness costs of senescence of 6%-63% (average: birds, 9%; mammals, 42%), with relative contributions of reproductive senescence of 0.0-0.7 (average: birds, 0.4; mammals, 0.3). We suggest that understanding when and why reproductive and survival senescence differ will help in the identification of proximate mechanisms underlying variation in rates of senescence and its evolution.

  1. Biology and Conservation of the Common Murre in California, Oregon, Washington, and British Columbia: Vol. 1, Natural History and Population Trends

    USGS Publications Warehouse

    Manuwal, David Allen; Carter, Harry R.; Zimmerman, Tara S.; Orthmeyer, Dennis L.

    2001-01-01

    EXECUTIVE SUMMARY Over the past 30 years, the common murre (Uria aalge californica) has been recognized as a prominent indicator of marine conservation issues in California, Oregon, Washington, and British Columbia, especially regarding oil pollution, certain fisheries, and human disturbance. To assist the effective management of the common murre and the marine environments in which they live, this summary of available information on the biology and regional status of the common murre has been sponsored by the U.S. Fish and Wildlife Service (Division of Migratory Bird Management). In Volume 1 (Chapter 1), the natural history of the common murre is summarized, drawing heavily on breeding studies from the South Farallon Islands, California, plus a host of detailed breeding studies from the North Atlantic Ocean. Population trends of the common murre are summarized in Volume 1 (Chapter 2), focusing on changes in whole-colony counts determined from aerial photographs between the late 1970s and 1995 in California, Oregon and Washington. Historical data and human impacts to murre colonies since the early nineteenth century are also summarized. Volume 2 will summarize population threats, conservation, and management. Information presented in Volume 1 has been obtained and recorded by a large number of researchers and natural historians over two centuries. From the 1960s to 1995, most work in California, Oregon, and Washington was sponsored by the U.S. Fish and Wildlife Service, Minerals Management Service, and California Department of Fish and Game. Important breeding biology studies were conducted at the South Farallon Islands (Farallon National Wildlife Refuge) by the Point Reyes Bird Observatory, in coordination with the U.S. Fish and Wildlife Service (San Francisco Bay National Wildlife Refuge). Colony surveys in California were conducted mainly by the U.S. Fish and Wildlife Service (San Francisco Bay National Wildlife Refuge), U.S. Geological Survey (Western

  2. Education for All: Status and Trends, 1994. Basic Education Population and Development.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Education for All Forum Secretariat.

    This second issue of "Education for All: Status and Trends" focuses on the interactions between basic education and certain demographic and socioeconomic phenomena. It examines significant correlations between selected indicators and the trends in those indicators over a decade or more. It also presents projections of certain indicators to the…

  3. Analyzing NEXRAD doppler radar images to assess nightly dispersal patterns and population trends in Brazilian free-tailed bats (Tadarida brasiliensis).

    PubMed

    Horn, Jason W; Kunz, Thomas H

    2008-07-01

    Operators of early weather-surveillance radars often observed echoes on their displays that did not behave like weather pattern, including expanding ring-like shapes they called angels. These echoes were caused by high-flying insects, migrating birds, and large colonies of bats emerging from roosts to feed. Modern weather-surveillance radar stations in the United States (NEXt-generation RADar or NEXRAD) provide detailed images that clearly show evening bat emergences from large colonies. These images can be used to investigate the flight behavior of groups of bats and population trends in large colonies of Brazilian free-tailed bats (Tadarida brasiliensis) in south-central Texas which are clearly imaged by local NEXRAD radar stations. In this study, we used radar reflectivity data from the New Braunfels, Texas NEXRAD station to examine relative colony size, direction of movement, speed of dispersion, and altitude gradients of bats from these colonies following evening emergence. Base reflectivity clear-air-mode Level-II images were geo-referenced and compiled in a GIS along with locations of colonies and features on the landscape. Temporal sequences of images were filtered for the activity of bats, and from this, the relative size of bat colonies, and the speed and heading of bat emergences were calculated. Our results indicate cyclical changes in colony size from year to year and that initial headings taken by bats during emergence flights are highly directional. We found that NEXRAD data can be an effective tool for monitoring the nightly behavior and seasonal changes in these large colonies. Understanding the distribution of a large regional bat population on a landscape scale has important implications for agricultural pest management and conservation efforts.

  4. North American Breeding Bird Survey Annual Summary, 1989

    USGS Publications Warehouse

    Droege, S.; Sauer, J.R.

    1990-01-01

    The North American Breeding Bird Survey (BBS) is run by approximately 2,000 skilled amateur ornithologists and is coordinated cooperatively by the U.S. Fish and Wildlife Service and the Canadian Wildlife Service. Since 1966, BBS cooperators have been collecting standardized information on North American bird populations. The BBS is a roadside survey, comprised of permanent routes that are surveyed yearly. Each route is 39.4 km (24.5 miles) long and consists of 50 stops spaced 0.8 km (0.5 mile) apart. All birds heard or seen during a 3-min observation period at each stop are recorded, and, for each species, the sum of the counts on individual stops is used as an index of species density on the route. Survey routes occur throughout the continental United States and most of Canada. Here, we present the population changes of the 251 bird species reported on the 50 or more BBS routes in the survey region during 1988 and 1989. Population trends for 1966-89 are presented for comparison. The direction and significance of population changes between the years for the 306 species occurring on 10 or more routes within States and Provinces are summarized in Appendix B. The pattern of population changes for selected species is graphically summarized on maps by physiographic stratum.

  5. Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird.

    PubMed

    Habel, J C; Mulwa, R K; Gassert, F; Rödder, D; Ulrich, W; Borghesio, L; Husemann, M; Lens, L

    2014-09-01

    The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distributions and predict potential future range shifts under a scenario of climate warming. We found well-supported genetic and morphologic clusters corresponding to the mountain ranges where populations were sampled, with 43% of all alleles being restricted to single mountains. Our data suggest that large-scale and long-term geographic isolation on mountain islands caused genetically and morphologically distinct population clusters in Z. poliogaster. However, major genetic and biometric splits were not correlated to the geographic distances among populations. This heterogeneous pattern can be explained by past climatic shifts, as highlighted by our SDM projections. Anthropogenically fragmented populations showed lower genetic diversity and a lower mean body mass, possibly in response to suboptimal habitat conditions. On the basis of these findings and the results from our SDM analysis we predict further loss of genotypic and phenotypic uniqueness in the wake of climate change, due to the contraction of the species' climatic niche and subsequent decline in population size.

  6. Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

    PubMed Central

    Habel, J C; Mulwa, R K; Gassert, F; Rödder, D; Ulrich, W; Borghesio, L; Husemann, M; Lens, L

    2014-01-01

    The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distributions and predict potential future range shifts under a scenario of climate warming. We found well-supported genetic and morphologic clusters corresponding to the mountain ranges where populations were sampled, with 43% of all alleles being restricted to single mountains. Our data suggest that large-scale and long-term geographic isolation on mountain islands caused genetically and morphologically distinct population clusters in Z. poliogaster. However, major genetic and biometric splits were not correlated to the geographic distances among populations. This heterogeneous pattern can be explained by past climatic shifts, as highlighted by our SDM projections. Anthropogenically fragmented populations showed lower genetic diversity and a lower mean body mass, possibly in response to suboptimal habitat conditions. On the basis of these findings and the results from our SDM analysis we predict further loss of genotypic and phenotypic uniqueness in the wake of climate change, due to the contraction of the species' climatic niche and subsequent decline in population size. PMID:24713824

  7. Model-Based Predictions of the Effects of Harvest Mortality on Population Size and Trend of Yellow-Billed Loons

    USGS Publications Warehouse

    Schmutz, Joel A.

    2009-01-01

    Yellow-billed loons (Gavia adamsii) breed in low densities in northern tundra habitats in Alaska, Canada, and Russia. They migrate to coastal marine habitats at mid to high latitudes where they spend their winters. Harvest may occur throughout the annual cycle, but of particular concern are recent reports of harvest from the Bering Strait region, which lies between Alaska and Russia and is an area used by yellow-billed loons during migration. Annual harvest for this region was reported to be 317, 45, and 1,077 during 2004, 2005, and 2007, respectively. I developed a population model to assess the effect of this reported harvest on population size and trend of yellow-billed loons. Because of the uncertainty regarding actual harvest and definition of the breeding population(s) affected by this harvest, I considered 25 different scenarios. Predicted trends across these 25 scenarios ranged from stability to rapid decline (24 percent per year) with halving of the population in 3 years. Through an assessment of literature and unpublished satellite tracking data, I suggest that the most likely of these 25 scenarios is one where the migrant population subjected to harvest in the Bering Strait includes individuals from breeding populations in Alaska (Arctic coastal plain and the Kotzebue region) and eastern Russia, and for which the magnitude of harvest varies among years and emulates the annual variation of reported harvest during 2004-07 (317, 45, and 1,077 yellow-billed loons). This scenario, which assumes no movement of Canadian breeders through the Bering Strait, predicts a 4.6 percent rate of annual population decline, which would halve the populations in 15 years. Although these model outputs reflect the best available information, confidence in these predictions and applicable scenarios would be greatly enhanced by more information on harvest, rates of survival and reproduction, and migratory pathways.

  8. Osteoporotic hip fractures: bisphosphonates sales and observed turning point in trend. A population-based retrospective study.

    PubMed

    Alves, Sandra Maria; Economou, Theodoros; Oliveira, Carla; Ribeiro, Ana Isabel; Neves, Nuno; Goméz-Barrena, Enrique; Pina, Maria Fátima

    2013-04-01

    The aim is to examine the temporal trends of hip fracture incidence in Portugal by sex and age groups, and explore the relation with anti-osteoporotic medication. From the National Hospital Discharge Database, we selected from 1st January 2000 to 31st December 2008, 77,083 hospital admissions (77.4% women) caused by osteoporotic hip fractures (low energy, patients over 49years-age), with diagnosis codes 820.x of ICD 9-CM. The 2001 Portuguese population was used as standard to calculate direct age-standardized incidence rates (ASIR) (100,000 inhabitants). Generalized additive and linear models were used to evaluate and quantify temporal trends of age specific rates (AR), by sex. We identified 2003 as a turning point in the trend of ASIR of hip fractures in women. After 2003, the ASIR in women decreased on average by 10.3 cases/100,000 inhabitants, 95% CI (-15.7 to -4.8), per 100,000 anti-osteoporotic medication packages sold. For women aged 65-69 and 75-79 we identified the same turning point. However, for women aged over 80, the year 2004 marked a change in the trend, from an increase to a decrease. Among the population aged 70-74 a linear decrease of incidence rate (95% CI) was observed in both sexes, higher for women: -28.0% (-36.2 to -19.5) change vs -18.8%, (-32.6 to -2.3). The abrupt turning point in the trend of ASIR of hip fractures in women is compatible with an intervention, such as a medication. The trends were different according to gender and age group, but compatible with the pattern of bisphosphonates sales.

  9. Trends in incidence of cutaneous malignant melanoma in a Swedish population 1976-1994.

    PubMed

    Månsson-Brahme, Eva; Johansson, Hemming; Larsson, Olle; Rutqvist, Lars E; Ringborg, Ulrik

    2002-01-01

    The incidence of cutaneous malignant melanoma has been increasing in Sweden for several decades. In the Stockholm-Gotland area educational activities for healthcare professionals were started in the late 1970s and public primary and secondary prevention campaigns were initiated in the mid-1980s. Melanoma incidence trends have been studied in Sweden, with special reference to trends in the Stockholm-Gotland area where these prevention campaigns were first started. During 1976-1994 the average annual increase of age-standardized incidence in the Stockholm-Gotland area was about 5%, the increase being associated mainly with thin tumors and melanoma in situ. During the 1990s, the incidence among males leveled off. In contrast, no such shift in trend was observed among females, or among males or females residing outside the Stockholm-Gotland area. The campaigns may have contributed to a trend towards earlier diagnosis but there is still no clear effect of the primary prevention efforts.

  10. Explaining Disability Trends in the U.S. Elderly and Near-Elderly Population

    PubMed Central

    Chen, Yiqun; Sloan, Frank A

    2015-01-01

    Objective To examine disability trends among U.S. near-elderly and elderly persons and explain observed trends. Data Source 1996–2010 waves of the Health and Retirement Study. Study Design We first examined trends in Activities of Daily Living and Instrumental Activities of Daily Living limitations, and large muscle, mobility, gross motor, and fine motor indexes. Then we used decomposition analysis to estimate contributions of changes in sociodemographic composition, self-reported chronic disease prevalence and health behaviors, and changes in disabling effects of these factors to disability changes between 1996 and 2010. Principal Findings Disability generally increased or was unchanged. Increased trends were more apparent for near-elderly than elderly persons. Sociodemographic shifts tended to reduce disability, but their favorable effects were largely offset by increased self-reported chronic disease prevalence. Changes in smoking and heavy drinking prevalence had relatively minor effects on disability trends. Increased obesity rates generated sizable effects on lower-body functioning changes. Disabling effects of self-reported chronic diseases often declined, and educational attainment became a stronger influence in preventing disability. Conclusions Such unfavorable trends as increased chronic disease prevalence and higher obesity rates offset or outweighed the favorable effects with the result that disability remained unchanged or increased. PMID:25655273

  11. Cancer incidence, trends, and survival among immigrants to Sweden: a population-based study.

    PubMed

    Mousavi, Seyed Mohsen; Hemminki, Kari

    2015-03-01

    This review aimed at covering cancer risk trends by site and histology in first-generation and second-generation immigrants in Sweden compared with natives. In addition, we reviewed data on cancer survival in immigrants to explore factors explaining cancer survival in the entire population. The Swedish Family-Cancer Database was used to calculate standardized incidence ratios and hazard ratios (HRs) of death from cancer in 77,360 and 993,824 cases among first-generation, and 4356 and 263,485 cases among second-generation immigrants and Swedes, respectively. Ordinal logistic regression analyses were used to calculate odds ratio. To obtain the maximum number of cases, we classified the immigrants according to geographical setting, population, and/or cancer risk. Compared with native Swedes, the highest risk of cancer was observed for nasopharyngeal carcinoma in Southeast Asian men (standardized incidence ratio=35.6) and women (24.6), for hypopharyngeal carcinoma in Indian men (5.4), for squamous-cell carcinoma of the esophagus in Iranian women (3.8), for cardia of the stomach in East Asian women (4.2), for signet-ring cell carcinoma of the stomach in Southeast Asian women (6.7), for the liver in East Asian men (6.8), for the gall bladder in Indian women (3.8), for the pancreas in North African men (2.2), for large cell carcinoma of the lung in former Yugoslavian men (4.2), for pleural mesothelioma in Turkish women (23.8), for the cervix in Danes (1.6), for seminoma in Chileans (2.1), for transitional-cell carcinoma of the bladder in Asian Arab men (2.3), for meningioma in former Yugoslavians (1.3), and for papillary carcinoma of the thyroid in East and Southeast Asian men (3.6). No immigrant groups had an increased risk of breast, uterus, ovary, and prostate cancers or nervous system tumors. The HRs for all breast cancers were between 1.0 in low-risk Europeans and 1.2 in lowest-risk non-Europeans. Low-risk non-Europeans had an HR of 2.9 for lobular carcinoma. Low

  12. Coordinating across scales: Building a regional marsh bird monitoring program from national and state Initiatives

    USGS Publications Warehouse

    Shriver, G.W.; Sauer, J.R.

    2008-01-01

    Salt marsh breeding bird populations (rails, bitterns, sparrows, etc.) in eastern North America are high conservation priorities in need of site specific and regional monitoring designed to detect population changes over time. The present status and trends of these species are unknown but anecdotal evidence of declines in many of the species has raised conservation concerns. Most of these species are listed as conservation priorities on comprehensive wildlife plans throughout the eastern U.S. National Wildlife Refuges, National Park Service units, and other wildlife conservation areas provide important salt marsh habitat. To meet management needs for these areas, and to assist regional conservation planning, survey designs are being developed to estimate abundance and population trends for these breeding bird species. The primary purpose of this project is to develop a hierarchical sampling frame for salt marsh birds in Bird Conservation Region (BCR) 30 that will provide the ability to estimate species population abundances on 1) specific sites (i.e. National Parks and National Wildlife Refuges), 2) within states or regions, and 3) within BCR 30. The entire breeding range of Saltmarsh Sharp-tailed and Coastal Plain Swamp sparrows are within BCR 30, providing an opportunity to detect population trends within the entire breeding ranges of two priority species.

  13. Linking climate trends to population dynamics in the Baltic ringed seal: impacts of historical and future winter temperatures.

    PubMed

    Sundqvist, Lisa; Harkonen, Tero; Svensson, Carl Johan; Harding, Karin C

    2012-12-01

    A global trend of a warming climate may seriously affect species dependent on sea ice. We investigated the impact of climate on the Baltic ringed seals (Phoca hispida botnica), using historical and future climatological time series. Availability of suitable breeding ice is known to affect pup survival. We used detailed information on how winter temperatures affect the extent of breeding ice and a climatological model (RCA3) to project the expected effects on the Baltic ringed seal population. The population comprises of three sub-populations, and our simulations suggest that all of them will experience severely hampered growth rates during the coming 90 years. The projected 30, 730 seals at the end of the twenty-first century constitutes only 16 % of the historical population size, and thus reduced ice cover alone will severely limit their growth rate. This adds burden to a species already haunted by other anthropogenic impacts.

  14. DNA sampling from eggshell swabbing is widely applicable in wild bird populations as demonstrated in 23 species.

    PubMed

    Martín-Gálvez, David; Peralta-Sánchez, Juan M; Dawson, Deborah A; Martín-Platero, Antonio M; Martínez-Bueno, Manuel; Burke, Terry; Soler, Juan J

    2011-05-01

    There is increasing interest in noninvasive DNA sampling techniques. In birds, there are several methods proposed for sampling DNA, and of these, the use of eggshell swabbing is potentially applicable to a wide range of species. We estimated the effectiveness of this method in the wild by sampling the eggs of 23 bird species. Sampling of eggs was performed twice per nest, soon after the clutch was laid and again at the end of egg incubation. We genotyped DNA samples using a set of five conserved microsatellite markers, which included a Z-linked locus and a sex-typing marker. We successfully collected avian DNA from the eggs of all species tested and from 88.48% of the samples. In most of the cases, the DNA concentration was low (ca. 10 ng/μL). The number of microsatellite loci amplified per sample (0-5) was used as a measure of the genotyping success of the sample. On average, we genotyped 3.01 ± 0.12 loci per sample (mean ± SE), and time of sampling did not seem to have an effect; however, genotyping success differed among species and was greater in those species that used feather material for lining their nest cups. We also checked for the occurrence of possible genotyping errors derived from using samples with very low DNA quantities (i.e. allelic dropout or false alleles) and for DNA contamination from individuals other than the mother, which appeared at a moderate rate (in 44% of the PCR replicates and in 17.36% of samples, respectively). Additionally, we investigated whether the DNA on eggshells corresponded to maternal DNA by comparing the genotypes obtained from the eggshells to those obtained from blood samples of all the nestlings for six nests of magpies. In five of the six magpie nests, we found evidence that the swab genotypes were a mixture of genotypes from both parents and this finding was independent of the time of incubation. Thus, our results broadly confirm that the swabbing of eggshells can be used as a noninvasive method for obtaining DNA

  15. 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.

  16. Population of the United States, Trends and Prospects: 1950-1990. Series P-23, No. 49.

    ERIC Educational Resources Information Center

    Bureau of the Census (DOC), Suitland, MD. Population Div.

    This document, one of the series of United States Current Population Reports, is also a part of a series of "country statements," prepared as background material for the World Population Conference held in August 1974, which describe the demographic situations of approximately 57 cooperating countries. The population situation is…

  17. Massive Nest-Box Supplementation Boosts Fecundity, Survival and Even Immigration without Altering Mating and Reproductive Behaviour in a Rapidly Recovered Bird Population

    PubMed Central

    Berthier, Karine; Leippert, Fabio; Fumagalli, Luca; Arlettaz, Raphaël

    2012-01-01

    Habitat restoration measures may result in artificially high breeding density, for instance when nest-boxes saturate the environment, which can negatively impact species' demography. Potential risks include changes in mating and reproductive behaviour such as increased extra-pair paternity, conspecific brood parasitism, and polygyny. Under particular cicumstances, these mechanisms may disrupt reproduction, with populations dragged into an extinction vortex. With the use of nuclear microsatellite markers, we investigated the occurrence of these potentially negative effects in a recovered population of a rare secondary cavity-nesting farmland bird of Central Europe, the hoopoe (Upupa epops). High intensity farming in the study area has resulted in a total eradication of cavity trees, depriving hoopoes from breeding sites. An intensive nest-box campaign rectified this problem, resulting in a spectacular population recovery within a few years only. There was some concern, however, that the new, high artificially-induced breeding density might alter hoopoe mating and reproductive behaviour. As the species underwent a serious demographic bottleneck in the 1970–1990s, we also used the microsatellite markers to reconstitute the demo-genetic history of the population, looking in particular for signs of genetic erosion. We found i) a low occurrence of extra-pair paternity, polygyny and conspecific brood parasitism, ii) a high level of neutral genetic diversity (mean number of alleles and expected heterozygosity per locus: 13.8 and 83%, respectively) and, iii) evidence for genetic connectivity through recent immigration of individuals from well differentiated populations. The recent increase in breeding density did thus not induce so far any noticeable detrimental changes in mating and reproductive behaviour. The demographic bottleneck undergone by the population in the 1970s-1990s was furthermore not accompanied by any significant drop in neutral genetic diversity. Finally

  18. Massive nest-box supplementation boosts fecundity, survival and even immigration without altering mating and reproductive behaviour in a rapidly recovered bird population.

    PubMed

    Berthier, Karine; Leippert, Fabio; Fumagalli, Luca; Arlettaz, Raphaël

    2012-01-01

    Habitat restoration measures may result in artificially high breeding density, for instance when nest-boxes saturate the environment, which can negatively impact species' demography. Potential risks include changes in mating and reproductive behaviour such as increased extra-pair paternity, conspecific brood parasitism, and polygyny. Under particular cicumstances, these mechanisms may disrupt reproduction, with populations dragged into an extinction vortex. With the use of nuclear microsatellite markers, we investigated the occurrence of these potentially negative effects in a recovered population of a rare secondary cavity-nesting farmland bird of Central Europe, the hoopoe (Upupa epops). High intensity farming in the study area has resulted in a total eradication of cavity trees, depriving hoopoes from breeding sites. An intensive nest-box campaign rectified this problem, resulting in a spectacular population recovery within a few years only. There was some concern, however, that the new, high artificially-induced breeding density might alter hoopoe mating and reproductive behaviour. As the species underwent a serious demographic bottleneck in the 1970-1990s, we also used the microsatellite markers to reconstitute the demo-genetic history of the population, looking in particular for signs of genetic erosion. We found i) a low occurrence of extra-pair paternity, polygyny and conspecific brood parasitism, ii) a high level of neutral genetic diversity (mean number of alleles and expected heterozygosity per locus: 13.8 and 83%, respectively) and, iii) evidence for genetic connectivity through recent immigration of individuals from well differentiated populations. The recent increase in breeding density did thus not induce so far any noticeable detrimental changes in mating and reproductive behaviour. The demographic bottleneck undergone by the population in the 1970s-1990s was furthermore not accompanied by any significant drop in neutral genetic diversity. Finally

  19. The Summer Atlas of North American Birds

    USGS Publications Warehouse

    Price, J.; Droege, S.; Price, A.

    1995-01-01

    The North American Breeding Bird Survey comprises a network of regularly censussed, road-based survey routes and constitutes the most comprehensive set of data on the relative abundance and population trends of these birds during the summer months. Its value was highlighted in 1989, when the data were used to confirm suspected population declines in a number of species of neotropical migrants breeding in the northeastern United States and Canada. In this book Jeff and Amy Price and Sam Droege have used these data to create detailed, computer-generated maps showing the relative abundance of 450 species that summer in the contiguous United States and southern Canada. Tabular information on distribution hotspots for these, and a further 50 or so species too local in occurrence to map effectively, are also presented. As a data-based survey, the focus of the maps is on places where occurrence has been systematically confirmed over a number of years. As such, the maps provide a baseline for future and more regionally based studies. Supporting chapters provide details on the survey methodology, the mapping procedures used, and some current concerns in North American bird conservation.

  20. Estimating Temporal Trend in the Presence of Spatial Complexity: A Bayesian Hierarchical Model for a Wetland Plant Population Undergoing Restoration

    PubMed Central

    Rodhouse, Thomas J.; Irvine, Kathryn M.; Vierling, Kerri T.; Vierling, Lee A.

    2011-01-01

    Monitoring programs that evaluate restoration and inform adaptive management are important for addressing environmental degradation. These efforts may be well served by spatially explicit hierarchical approaches to modeling because of unavoidable spatial structure inherited from past land use patterns and other factors. We developed Bayesian hierarchical models to estimate trends from annual density counts observed in a spatially structured wetland forb (Camassia quamash [camas]) population following the cessation of grazing and mowing on the study area, and in a separate reference population of camas. The restoration site was bisected by roads and drainage ditches, resulting in distinct subpopulations (“zones”) with different land use histories. We modeled this spatial structure by fitting zone-specific intercepts and slopes. We allowed spatial covariance parameters in the model to vary by zone, as in stratified kriging, accommodating anisotropy and improving computation and biological interpretation. Trend estimates provided evidence of a positive effect of passive restoration, and the strength of evidence was influenced by the amount of spatial structure in the model. Allowing trends to vary among zones and accounting for topographic heterogeneity increased precision of trend estimates. Accounting for spatial autocorrelation shifted parameter coefficients in ways that varied among zones depending on strength of statistical shrinkage, autocorrelation and topographic heterogeneity—a phenomenon not widely described. Spatially explicit estimates of trend from hierarchical models will generally be more useful to land managers than pooled regional estimates and provide more realistic assessments of uncertainty. The ability to grapple with historical contingency is an appealing benefit of this approach. PMID:22163047

  1. Alcohol policy changes and 22-year trends in individual alcohol consumption in a Swiss adult population: a 1993–2014 cross-sectional population-based study

    PubMed Central

    Dumont, Shireen; Marques-Vidal, Pedro; Favrod-Coune, Thierry; Theler, Jean-Marc; Gaspoz, Jean-Michel; Broers, Barbara; Guessous, Idris

    2017-01-01

    Objective Evidence on the impact of legislative changes on individual alcohol consumption is limited. Using an observational study design, we assessed trends in individual alcohol consumption of a Swiss adult population following the public policy changes that took place between 1993 and 2014, while considering individual characteristics and secular trends. Design Cross-sectional study. Setting Swiss general adult population. Participants Data from 18 963 participants were collected between 1993 and 2014 (aged 18–75 years). Outcome measures We used data from the ‘Bus Santé’ study, an annual health survey conducted in random samples of the adult population in the State of Geneva, Switzerland. Individual alcohol intake was assessed using a validated food frequency questionnaire. Individual characteristics including education were self-reported. 7 policy changes (6 about alcohol and 1 about tobacco) that occurred between 1993 and 2014 defined 6 different periods. We predicted alcohol intake using quantile regression with multivariate analysis for each period adjusting for participants' characteristics and tested significance periods. Sensitivity analysis was performed including drinkers only, the 10th centile of highest drinkers and smoker's status. Results Between 1993 and 2014, participants' individual alcohol intake decreased from 7.1 to 5.4 g/day (24% reduction, p<0.001). Men decreased their alcohol intake by 34% compared with 22% for women (p<0.001). The decrease in alcohol intake remained significant when considering drinkers only (28% decrease, p<0.001) and the 10th centile highest drinkers (24% decrease, p<0.001). Consumption of all alcoholic beverages decreased between 1993 and 2014 except for the moderate consumption of beer, which increased. After adjustment for participants' characteristics and secular trends, no independent association between alcohol legislative changes and individual alcohol intake was found. Conclusions Between 1993 and

  2. Kit fox population trends at the Naval Petroleum Reserves in California

    SciTech Connect

    Kato, T.T.; Scrivner, J.H.; Warrick, G.; Cypher, B.

    1991-01-01

    The San Joaquin kit fox was listed as an endangered subspecies following passage of the Endangered Species Protection Act of 1966, and further classified as rare under the California Endangered Species Act of 1970. The San Joaquin kit fox occurs on the Naval Petroleum Reserves in California administered by the Department of Energy (DOE). A long term kit fox population monitoring program was initiated as part of DOE's mitigation strategy to comply with the Endangered Species Act. In addition to monitoring kit fox populations, the program includes assessments of kit fox prey density and assessments of predator abundance. The objectives of this study were to: describe the long term changes in the kit fox population on the Reserves and assess the roles of coyotes and lagomorphs in kit fox population dynamics. When the fox population on NPR-1 declined between 1980 and 1984, it appeared to have been negatively impacted by a declining prey base (lagomorphs) and an increasing coyote population. Declining lagomorph densities may have been a more important factor because as coyote numbers declined between 1985 and 1990, the kit fox population remained stable. The fox population on NPR-2 remained at a higher and more stable level than the population on NPR-1. The factors determining the higher densities and greater stability of the fox population on NPR-2 are unknown.

  3. Threatened Bird Valuation in Australia

    PubMed Central

    Zander, Kerstin K.; Ainsworth, Gillian B.; Meyerhoff, Jürgen; Garnett, Stephen T.

    2014-01-01

    Threatened species programs need a social license to justify public funding. A contingent valuation survey of a broadly representative sample of the Australian public found that almost two thirds (63%) supported funding of threatened bird conservation. These included 45% of a sample of 645 respondents willing to pay into a fund for threatened bird conservation, 3% who already supported bird conservation in another form, and 15% who could not afford to pay into a conservation fund but who nevertheless thought that humans have a moral obligation to protect threatened birds. Only 6% explicitly opposed such payments. Respondents were willing to pay about AUD 11 annually into a conservation fund (median value), including those who would pay nothing. Highest values were offered by young or middle aged men, and those with knowledge of birds and those with an emotional response to encountering an endangered bird. However, the prospect of a bird going extinct alarmed almost everybody, even most of those inclined to put the interests of people ahead of birds and those who resent the way threatened species sometimes hold up development. The results suggest that funding for threatened birds has widespread popular support among the Australian population. Conservatively they would be willing to pay about AUD 14 million per year, and realistically about AUD 70 million, which is substantially more than the AUD 10 million currently thought to be required to prevent Australian bird extinctions. PMID:24955957

  4. Threatened bird valuation in Australia.

    PubMed

    Zander, Kerstin K; Ainsworth, Gillian B; Meyerhoff, Jürgen; Garnett, Stephen T

    2014-01-01

    Threatened species programs need a social license to justify public funding. A contingent valuation survey of a broadly representative sample of the Australian public found that almost two thirds (63%) supported funding of threatened bird conservation. These included 45% of a sample of 645 respondents willing to pay into a fund for threatened bird conservation, 3% who already supported bird conservation in another form, and 15% who could not afford to pay into a conservation fund but who nevertheless thought that humans have a moral obligation to protect threatened birds. Only 6% explicitly opposed such payments. Respondents were willing to pay about AUD 11 annually into a conservation fund (median value), including those who would pay nothing. Highest values were offered by young or middle aged men, and those with knowledge of birds and those with an emotional response to encountering an endangered bird. However, the prospect of a bird going extinct alarmed almost everybody, even most of those inclined to put the interests of people ahead of birds and those who resent the way threatened species sometimes hold up development. The results suggest that funding for threatened birds has widespread popular support among the Australian population. Conservatively they would be willing to pay about AUD 14 million per year, and realistically about AUD 70 million, which is substantially more than the AUD 10 million currently thought to be required to prevent Australian bird extinctions.

  5. Limited population structure, genetic drift and bottlenecks characterise an endangered bird species in a dynamic, fire-prone ecosystem.

    PubMed

    Brown, Sarah M; Harrisson, Katherine A; Clarke, Rohan H; Bennett, Andrew F; Sunnucks, Paul

    2013-01-01

    Fire is a major disturbance process in many ecosystems world-wide, resulting in spatially and temporally dynamic landscapes. For populations occupying such environments, fire-induced landscape change is likely to influence population processes, and genetic patterns and structure among populations. The Mallee Emu-wren Stipiturus mallee is an endangered passerine whose global distribution is confined to fire-prone, semi-arid mallee shrublands in south-eastern Australia. This species, with poor capacity for dispersal, has undergone a precipitous reduction in distribution and numbers in recent decades. We used genetic analyses of 11 length-variable, nuclear loci to examine population structure and processes within this species, across its global range. Populations of the Mallee Emu-wren exhibited a low to moderate level of genetic diversity, and evidence of bottlenecks and genetic drift. Bayesian clustering methods revealed weak genetic population structure across the species' range. The direct effects of large fires, together with associated changes in the spatial and temporal patterns of suitable habitat, have the potential to cause population bottlenecks, serial local extinctions and subsequent recolonisation, all of which may interact to erode and homogenise genetic diversity in this species. Movement among temporally and spatially shifting habitat, appears to maintain long-term genetic connectivity. A plausible explanation for the observed genetic patterns is that, following extensive fires, recolonisation exceeds in-situ survival as the primary driver of population recovery in this species. These findings suggest that dynamic, fire-dominated landscapes can drive genetic homogenisation of populations of species with low-mobility and specialised habitat that otherwise would be expected to show strongly structured populations. Such effects must be considered when formulating management actions to conserve species in fire-prone systems.

  6. Estimating Size and Trend of the North Interlake Woodland Caribou Population Using Fecal-DNA and Capture–Recapture Models

    PubMed Central

    Hettinga, Peter N; Arnason, Arni Neil; Manseau, Micheline; Cross, Dale; Whaley, Kent; Wilson, Paul J

    2012-01-01

    A critical step in recovery efforts for endangered and threatened species is the monitoring of population demographic parameters. As part of these efforts, we evaluated the use of fecal-DNA based capture–recapture methods to estimate population sizes and population rate of change for the North Interlake woodland caribou herd (Rangifer tarandus caribou), Manitoba, Canada. This herd is part of the boreal population of woodland caribou, listed as threatened under the federal Species at Risk Act (2003) and the provincial Manitoba Endangered Species Act (2006). Between 2004 and 2009 (9 surveys), we collected 1,080 fecal samples and identified 180 unique genotypes (102 females and 78 males). We used a robust design survey plan with 2 surveys in most years and analysed the data with Program MARK to estimate encounter rates (p), apparent survival rates (ϕ), rates of population change (λ), and population sizes (N). We estimated these demographic parameters for males and females and for 2 genetic clusters within the North Interlake. The population size estimates were larger for the Lower than the Upper North Interlake area and the proportion of males was lower in the Lower (33%) than the Upper North Interlake (49%). Population rate of change for the entire North Interlake area (2005–2009) using the robust design Pradel model was significantly <1.0 (λ = 0.90, 95% CI: 0.82–0.99) and varied between sex and area with the highest being for males in Lower North Interlake (λ = 0.98, 95% CI: 0.83–1.13) and the lowest being for females in Upper North Interlake (λ = 0.83, 95% CI: 0.69–0.97). The additivity of λ between sex and area is supported on the log scale and translates into males having a λ that is 0.09 greater than females and independent of sex, Lower North Interlake having a λ that is 0.06 greater than Upper North Interlake. Population estimates paralleled these declining trends, which correspond to trends observed in other fragmented populations of

  7. Trends and Implications of Proposed Changes to the "DSM-5" for Vulnerable Populations

    ERIC Educational Resources Information Center

    Miller, Raissa; Prosek, Elizabeth A.

    2013-01-01

    The revision process for the "Diagnostic and Statistical Manual of Mental Disorders" (4th ed., text rev.; American Psychiatric Association, 2000) has increased consciousness for the role of diagnosis in counseling. In this article, the authors discuss 3 trends of the proposed changes: the influence of the medical model, the attention to…

  8. Clostridium difficile infection in the hospitalized pediatric population: increasing trend in disease incidence.

    PubMed

    Deshpande, Abhishek; Pant, Chaitanya; Anderson, Michael P; Donskey, Curtis J; Sferra, Thomas J

    2013-10-01

    To determine whether the incidence of Clostridium difficile infection continues to increase in hospitalized pediatric patients, we evaluated data from a United States national inpatient database. For the period of 2003 to 2009, we found an increasing trend in the incidence of C. difficile infection. These data suggest greater effort be given to prevent and treat this infection in children.

  9. Longevity Trends in the Older Population of Louisiana with Residence Comparisons.

    ERIC Educational Resources Information Center

    Kwan, Yui-Huen; Bertrand, Alvin L.

    Utilizing Louisiana State Bureau of Vital Statistics and U.S. Census data, longevity trends with residence comparisons were examined for all persons 65 or over who died between 1962 and 1974, who were Louisiana residents at the time of death, and whose death was not due to external violence. Every third year in the 12 year period was arbitrarily…

  10. The Changing Face of Poverty. Trends in New York City's Population in Poverty: 1960-1990.

    ERIC Educational Resources Information Center

    Tobier, Emanuel

    This report is the first product of the Community Service Society's Economic and Social Monitoring Unit which analyzes and forecasts the status of the poor in New York City (NYC). The report documents the following major findings: (1) nationwide, there are now fewer elderly and more minorities and women among the poor; the trends in New York City…

  11. Future Trends in San Diego: Population, Income, Employment, Post College Wages and Enrollment.

    ERIC Educational Resources Information Center

    Barnes, Randy; Armstrong, William B.; Bersentes, Gina; Turingan, Maria

    This report contains forecasted data for San Diego through the year 2015 and examines changes that have taken place over the past fifty years. Historically, San Diego population growth rates have been relatively high compared with the rest of the nation. Between 1998 and 2015, the population will not only become larger, it will become more…

  12. Resource Trends and Population Policy: A Time for Reassessment. Worldwatch Paper 29.

    ERIC Educational Resources Information Center

    Brown, Lester R.

    Population growth and resource depletion are discussed. The need is stressed for policy makers to understand how population projections relate to the carrying capacity of the earth's basic biological systems. Because the earth's resources are limited, it is essential that policy makers in developed and developing nations be able to analyze the…

  13. Population Aging at Cross-Roads: Diverging Secular Trends in Average Cognitive Functioning and Physical Health in the Older Population of Germany

    PubMed Central

    Steiber, Nadia

    2015-01-01

    This paper uses individual-level data from the German Socio-Economic Panel to model trends in population health in terms of cognition, physical fitness, and mental health between 2006 and 2012. The focus is on the population aged 50–90. We use a repeated population-based cross-sectional design. As outcome measures, we use SF-12 measures of physical and mental health and the Symbol-Digit Test (SDT) that captures cognitive processing speed. In line with previous research we find a highly significant Flynn effect on cognition; i.e., SDT scores are higher among those who were tested more recently (at the same age). This result holds for men and women, all age groups, and across all levels of education. While we observe a secular improvement in terms of cognitive functioning, at the same time, average physical and mental health has declined. The decline in average physical health is shown to be stronger for men than for women and found to be strongest for low-educated, young-old men aged 50–64: the decline over the 6-year interval in average physical health is estimated to amount to about 0.37 SD, whereas average fluid cognition improved by about 0.29 SD. This pattern of results at the population-level (trends in average population health) stands in interesting contrast to the positive association of physical health and cognitive functioning at the individual-level. The findings underscore the multi-dimensionality of health and the aging process. PMID:26323093

  14. Population Aging at Cross-Roads: Diverging Secular Trends in Average Cognitive Functioning and Physical Health in the Older Population of Germany.

    PubMed

    Steiber, Nadia

    2015-01-01

    This paper uses individual-level data from the German Socio-Economic Panel to model trends in population health in terms of cognition, physical fitness, and mental health between 2006 and 2012. The focus is on the population aged 50-90. We use a repeated population-based cross-sectional design. As outcome measures, we use SF-12 measures of physical and mental health and the Symbol-Digit Test (SDT) that captures cognitive processing speed. In line with previous research we find a highly significant Flynn effect on cognition; i.e., SDT scores are higher among those who were tested more recently (at the same age). This result holds for men and women, all age groups, and across all levels of education. While we observe a secular improvement in terms of cognitive functioning, at the same time, average physical and mental health has declined. The decline in average physical health is shown to be stronger for men than for women and found to be strongest for low-educated, young-old men aged 50-64: the decline over the 6-year interval in average physical health is estimated to amount to about 0.37 SD, whereas average fluid cognition improved by about 0.29 SD. This pattern of results at the population-level (trends in average population health) stands in interesting contrast to the positive association of physical health and cognitive functioning at the individual-level. The findings underscore the multi-dimensionality of health and the aging process.

  15. Population-based incidence trends of oropharyngeal and oral cavity cancers by sex among the poorest and underprivileged populations

    PubMed Central

    2014-01-01

    Background Oral cancer is an important health issue, with changing incidence in many countries. Oropharyngeal cancer (OPC, in tonsil and oropharygeal areas) is increasing, while oral cavity cancer (OCC, other sites in the mouth) is decreasing. There is the need to identify high risk groups and communities for further study and intervention. The objective of this study was to determine how the incidence of OPC and OCC varied by neighbourhood socioeconomic status (SES) in British Columbia (BC), including the magnitude of any inequalities and temporal trends. Methods ICDO-3 codes were used to identify OPC and OCC cases in the BC Cancer Reg