WorldWideScience

Sample records for bird migration theory

  1. Tracking migrating birds

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    Migratory movements of birds has always fascinated man and led to many questions concerning the ecological drivers behind, the necessary adaptations and the navigational abilities required. However, especially for the long-distance migrants, basic descriptions of their movements are still lacking...... and a forest reserve. In the degraded habitat all species used more space, although the consequence on bird density is less clear. Two manuscripts relate the migratory movements of a long-distance migrant with models of navigation. One compares model predictions obtained by simulation with actual movements......, and conclude that the currently believed theoretical framework is insufficient to explain the observed performance. The other study investigates the ability of a displaced experienced migrant to navigate back to the normal migration route. It documents the capability, but also finds interesting patterns...

  2. Migration in birds and fishes

    NARCIS (Netherlands)

    Verwey, J.

    1949-01-01

    Our knowledge concerning the periodical movements in animals called migrations is chiefly based on observations on birds. By and by, however, a number of facts concerning migration in other animal groups have been assembled and it seems worth while to compare them with those known for birds. There

  3. Long migration flights of birds

    International Nuclear Information System (INIS)

    Denny, Mark

    2014-01-01

    The extremely long migration flights of some birds are carried out in one hop, necessitating a substantial prior build-up of fat fuel. We summarize the basic elements of bird flight physics with a simple model, and show how the fat reserves influence flight distance, flight speed and the power expended by the bird during flight. (paper)

  4. Long migration flights of birds

    Science.gov (United States)

    Denny, Mark

    2014-05-01

    The extremely long migration flights of some birds are carried out in one hop, necessitating a substantial prior build-up of fat fuel. We summarize the basic elements of bird flight physics with a simple model, and show how the fat reserves influence flight distance, flight speed and the power expended by the bird during flight.

  5. Radar studies of bird migration

    Science.gov (United States)

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

    1974-01-01

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

  6. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans......-Saharan migrants than autumn migration. Information about the behavior and interactions of migrants during the nonbreeding season in sub-Saharan Africa is also scarce for many species. Furthermore, very little is known about intra-African migration. This thesis summarizes my research on the autumn migration...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...

  7. Tracking migrating birds

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    and many experiments are only becoming possible with the current development of tracking technologies. During this thesis work I have been tracking the poorly known movements of several species of long-distance migrants and document highly complex migration patterns. In three manuscripts these movements......, and conclude that the currently believed theoretical framework is insufficient to explain the observed performance. The other study investigates the ability of a displaced experienced migrant to navigate back to the normal migration route. It documents the capability, but also finds interesting patterns...... were related to the yearly progression of an environmental surrogate for food availability along the course of migration. In one species, with multiple, different non-breeding staging sites, environmental conditions explain movements well and also how yearly differences explain differences in timing...

  8. Bird Migration Echoes Observed by Polarimetric Radar

    OpenAIRE

    MINDA, Haruya; FURUZAWA, Fumie A.; SATOH, Shinsuke; NAKAMURA, Kenji

    2008-01-01

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

  9. A polar system of intercontinental bird migration

    OpenAIRE

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

    2007-01-01

    Studies of bird migration in the Beringia region of Alaska and eastern Siberia are of special interest for revealing the importance of bird migration between Eurasia and North America, for evaluating orientation principles used by the birds at polar latitudes and for understanding the evolutionary implications of intercontinental migratory connectivity among birds as well as their parasites. We used tracking radar placed onboard the ice-breaker Oden to register bird migratory flights from 30 ...

  10. Endogenous timing factors in bird migration

    Science.gov (United States)

    Gwinner, E. G.

    1972-01-01

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

  11. Factors influencing phototaxis in nocturnal migrating birds.

    Science.gov (United States)

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

    2014-12-01

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

  12. Green Light for Nocturnally Migrating Birds

    Directory of Open Access Journals (Sweden)

    Hanneke Poot

    2008-12-01

    Laboratory experiments have shown the magnetic compass to be wavelength dependent: migratory birds require light from the blue-green part of the spectrum for magnetic compass orientation, whereas red light (visible long-wavelength disrupts magnetic orientation. We designed a field study to test if and how changing light color influenced migrating birds under field conditions. We found that nocturnally migrating birds were disoriented and attracted by red and white light (containing visible long-wavelength radiation, whereas they were clearly less disoriented by blue and green light (containing less or no visible long-wavelength radiation. This was especially the case on overcast nights. Our results clearly open perspective for the development of bird-friendly artificial lighting by manipulating wavelength characteristics. Preliminary results with an experimentally developed bird-friendly light source on an offshore platform are promising. What needs to be investigated is the impact of bird-friendly light on other organisms than birds.

  13. The evolution of bird migration--a synthesis.

    Science.gov (United States)

    Salewski, Volker; Bruderer, Bruno

    2007-04-01

    We approach the problem of the evolution of bird migration by asking whether migration evolves towards new breeding areas or towards survival areas in the non-breeding season. Thus, we avoid the ambiguity of the usually discussed "southern-home-theory" or "northern-home-theory". We argue that migration evolved in birds that spread to seasonal habitats through gradual dispersal to enhance survival during the non-breeding season; this in contrast to the alternative idea suggesting that migration evolved towards new breeding areas to increase reproductive success. Our synthesis is based on the threshold model explaining how migratory traits can change rapidly through microevolutionary processes. Our model brings former theories together and explains how bird migration, with the appropriate direction and time program, evolves through selection after genetically non-directed events such as dispersal and colonization. The model does not need the former untested assumptions such as competition as a reason for migration and for the disappearance of sedentary populations or higher reproductive success in temperate breeding areas. Our theory offers answers to questions such as how birds with a southern origin may gradually reach northern latitudes, why migration routes may follow historical expansion routes and why birds leave an area for the non-breeding season and move back instead of breeding on their wintering grounds. The theory proposes gradual change through selection and not sudden changes such as long distance dispersal or mutations and can be applied to migration at all latitudes and in all directions. The scenario provides a reasonable concept to understand most of the existing migratory phenomena on the basis of the ecology and genetics of migratory behaviour.

  14. A polar system of intercontinental bird migration.

    Science.gov (United States)

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

    2007-10-22

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

  15. Nocturnal bird migration in opaque clouds

    Science.gov (United States)

    Griffin, D. R.

    1972-01-01

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

  16. ON CORRELATING BIRD MIGRATION TRAJECTORY WITH CLIMATE CHANGES

    OpenAIRE

    Oleinik, Janaina; de Macedo, Jose Antonio Fernandes; Yuanjian, Wang Zufferey

    2009-01-01

    Climate changes are expected to affect bird migration in several aspects including timing changes, breeding and migration orientation. The correlation analysis of several climate conditions (e.g. temperature, wind, humidity, etc) and bird migration trajectory is the key for explaining bird behavior during migration. Moreover, the resulting correlation can be used for predicting new bird behavior according to climate changes. In this paper we propose an integrated solution for correlating bird...

  17. Spring Bird Migration Phenology in Eilat, Israel

    Directory of Open Access Journals (Sweden)

    Reuven Yosef

    2009-12-01

    Full Text Available Analysis of the mean date of first captures and median arrival dates of spring migration for 34 species of birds at Eilat, Israel, revealed that the earlier a species migrates through Eilat, the greater is the inter-annual variation in the total time of its passage. Birds arrive during spring migration in Eilat in four structured and independent waves. The annual fluctuation in the initial arrival dates (initial capture dates and median dates (median date of all captures, not including recaptures, did not depend on the length of the migratory route. This implies that migrants crossing the Sahara desert depart from their winter quarters on different Julian days in different years. We suggest that negative correlations between the median date of the spring migration of early and late migrants depends upon the easterly (Hamsin wind period. Moreover, we believe that the phenology of all birds during spring migration in Eilat is possibly also determined by external factors such as weather conditions on the African continent or global climatic processes in the Northern hemisphere. Orphean Warblers (Sylvia hortensis show a strong positive correlation (rs=-0.502 of initial capture date with calendar years, whereas other species such as Barred Warbler (S. nisoria; rs = -0.391 and Spotted Flycatcher (Muscicapa striata; rs = -0.398 display an insignificant trend. The Dead Sea Sparrow (Passer moabiticus and Red-Backed Shrike (Lanius collurio are positively correlated regarding initial arrival date and medians of spring migration.

  18. Individuality in bird migration: routes and timing.

    Science.gov (United States)

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

    2011-08-23

    The exploration of animal migration has entered a new era with individual-based tracking during multiple years. Here, we investigated repeated migratory journeys of a long-distance migrating bird, the marsh harrier Circus aeruginosus, in order to analyse the variation within and between individuals with respect to routes and timing. We found that there was a stronger individual repeatability in time than in space. Thus, the annual timing of migration varied much less between repeated journeys of the same individual than between different individuals, while there was considerable variation in the routes of the same individual on repeated journeys. The overall contrast in repeatability between time and space was unexpected and may be owing to strong endogenous control of timing, while short-term variation in environmental conditions (weather and habitat) might promote route flexibility. The individual variation in migration routes indicates that the birds navigate mainly by other means than detailed route recapitulation based on landmark recognition. This journal is © 2011 The Royal Society

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

    Science.gov (United States)

    Watanabe, Yuuki Y

    2016-08-01

    Billions of birds migrate to exploit seasonally available resources. The ranges of migration vary greatly among species, but the underlying mechanisms are poorly understood. I hypothesise that flight mode (flapping or soaring) and body mass affect migration range through their influence on flight energetics. Here, I compiled the tracks of migratory birds (196 species, weighing 12-10 350 g) recorded by electronic tags in the last few decades. In flapping birds, migration ranges decreased with body mass, as predicted from rapidly increasing flight cost with increasing body mass. The species with higher aspect ratio and lower wing loading had larger migration ranges. In soaring birds, migration ranges were mass-independent and larger than those of flapping birds, reflecting their low flight costs irrespective of body mass. This study demonstrates that many animal-tracking studies are now available to explore the general patterns and the underlying mechanisms of animal migration. © 2016 John Wiley & Sons Ltd/CNRS.

  20. Metabolic constraints on long-distance migration in birds

    NARCIS (Netherlands)

    Klaassen, M.R.J.

    1996-01-01

    The flight range of migrating birds depends crucially on the amount of fuel stored by the bird prior to migration or taken up en route at stop-over sites. However, an increase in body mass is associated with an increase in energetic costs, counteracting the benefit of fuel stores. Water imbalance,

  1. Avian Alert - a bird migration early warning system

    NARCIS (Netherlands)

    van Gasteren, H.; Shamoun-Baranes, J.; Ginati, A.; Garofalo, G.

    2008-01-01

    Every year billions of birds migrate from breeding areas to their wintering ranges, some travelling over 10,000 km. Stakeholders interested in aviation flight safety, spread of disease, conservation, education, urban planning, meteorology, wind turbines and bird migration ecology are interested in

  2. Avian Alert - a bird migration early warning system

    OpenAIRE

    van Gasteren, H.; Shamoun-Baranes, J.; Ginati, A.; Garofalo, G.

    2008-01-01

    Every year billions of birds migrate from breeding areas to their wintering ranges, some travelling over 10,000 km. Stakeholders interested in aviation flight safety, spread of disease, conservation, education, urban planning, meteorology, wind turbines and bird migration ecology are interested in information on bird movements. Collecting and disseminating useful information about such mobile creatures exhibiting diverse behaviour is no simple task. However, ESA’s Integrated Application Promo...

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

    Science.gov (United States)

    Benson, Juliann

    2007-01-01

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

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

    Science.gov (United States)

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

    2015-09-01

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

  5. Quality assessment of weather radar wind profiles during bird migration

    NARCIS (Netherlands)

    Holleman, I.; van Gasteren, H.; Bouten, W.

    2008-01-01

    Wind profiles from an operational C-band Doppler radar have been combined with data from a bird tracking radar to assess the wind profile quality during bird migration. The weather radar wind profiles (WRWPs) are retrieved using the well-known volume velocity processing (VVP) technique. The X-band

  6. Atmospheric conditions create freeways, detours and tailbacks for migrating birds.

    Science.gov (United States)

    Shamoun-Baranes, Judy; Liechti, Felix; Vansteelant, Wouter M G

    2017-07-01

    The extraordinary adaptations of birds to contend with atmospheric conditions during their migratory flights have captivated ecologists for decades. During the 21st century technological advances have sparked a revival of research into the influence of weather on migrating birds. Using biologging technology, flight behaviour is measured across entire flyways, weather radar networks quantify large-scale migratory fluxes, citizen scientists gather observations of migrant birds and mechanistic models are used to simulate migration in dynamic aerial environments. In this review, we first introduce the most relevant microscale, mesoscale and synoptic scale atmospheric phenomena from the point of view of a migrating bird. We then provide an overview of the individual responses of migrant birds (when, where and how to fly) in relation to these phenomena. We explore the cumulative impact of individual responses to weather during migration, and the consequences thereof for populations and migratory systems. In general, individual birds seem to have a much more flexible response to weather than previously thought, but we also note similarities in migratory behaviour across taxa. We propose various avenues for future research through which we expect to derive more fundamental insights into the influence of weather on the evolution of migratory behaviour and the life-history, population dynamics and species distributions of migrant birds.

  7. Phenology and the changing pattern of bird migration in Britain

    Science.gov (United States)

    Sparks, T. H.

    Britain has a huge mass of data on the timing of bird migration, although much of this remains in a form that is inaccessible for immediate scientific study. In this paper, I undertake a preliminary examination of data from a number of historical and current sources. Among these are the Marsham family records from Norfolk, dating back to 1736, and post-World War II records from coastal bird observatories. The majority of the examined time series displayed a negative relationship to temperature indicating a tendency for the earlier arrival of the studied birds in warmer springs. In addition to temperature effects, trends through time and some sampling effects (through population size) have become apparent. Identification and curation of data sources and further analysis is still required to produce a clearer picture of climate effects on bird migration timing and on subsequent bird population dynamics.

  8. Aspects regarding the limicoline birds' migration in the IBA

    Directory of Open Access Journals (Sweden)

    MULLER Johanna Walle

    2006-09-01

    Full Text Available The IBA “Jijia and Miletin ponds” (code 014 is situated at 40 km north-west from Iaşi city, around the confluence point of Miletin and Jijia Rivers, forming Vlădeni wetland. During the migration periods – in spring and autumn – we can count in Vlădeni wetland territory large flocks of limicoline birds (thousands exemplars, being represented 28 species; some of them are very rare in this part of Romania: Pluvialis apricaria, Pluvialis squatarola, Gallinago media, Lymnocryptes minimus, Arenaria interpres or Limosa lapponica. During the spring migration, but also during the autumn migration, we recorded 25 species, three species being different from a season of migration to other. During whole migration period, there are two super-dominant species Vanellus vanellus and Limosa limosa. We notice the irregular presence autumn migration of Gallinago media. In December are still present 5 species of limicoline birds.

  9. Convergence of broad-scale migration strategies in terrestrial birds.

    Science.gov (United States)

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

    2016-01-27

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

  10. Tracking radar studies of bird migration

    Science.gov (United States)

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

    1972-01-01

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

  11. The Algorithm of Habitat Discovery in Bird Migration

    Directory of Open Access Journals (Sweden)

    Wei Zhengzheng

    2017-01-01

    Full Text Available Bird migration has attracted an increasing attention. The study of habitats has played a vital role in the birds migratory. Previous researches, however, have encountered many problems, such as great limitations on research methods, low data utilization rate, statistics-focused and ineffective data processing and analysis methods. In this paper, the algorithm of habitat discovery is put forward by using computer’s data-mining technology based on the spatio-temporal characteristics of bird-watching data. First the algorithm detects and eliminates duplicate data to guarantee data standardization. Then density-based clustering algorithms are used to identify habitats where birds gathered. Finally the habitats of birds migratory are discovered.

  12. Spring migration of birds in relation to North Atlantic Oscillation

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk

    2003-01-01

    Roč. 52, č. 3 (2003), s. 287-298 ISSN 0139-7893 Institutional research plan: CEZ:AV0Z6093917 Keywords : bird migration * phenology * climate Subject RIV: EG - Zoology Impact factor: 0.494, year: 2003 http://www.ivb.cz/folia/52/3/287-298.pdf

  13. Light pollution is greatest within migration passage areas for nocturnally-migrating birds around the world.

    Science.gov (United States)

    Cabrera-Cruz, Sergio A; Smolinsky, Jaclyn A; Buler, Jeffrey J

    2018-02-19

    Excessive or misdirected artificial light at night (ALAN) produces light pollution that influences several aspects of the biology and ecology of birds, including disruption of circadian rhythms and disorientation during flight. Many migrating birds traverse large expanses of land twice every year at night when ALAN illuminates the sky. Considering the extensive and increasing encroachment of light pollution around the world, we evaluated the association of the annual mean ALAN intensity over land within the geographic ranges of 298 nocturnally migrating bird species with five factors: phase of annual cycle, mean distance between breeding and non-breeding ranges, range size, global hemisphere of range, and IUCN category of conservation concern. Light pollution within geographic ranges was relatively greater during the migration season, for shorter-distance migrants, for species with smaller ranges, and for species in the western hemisphere. Our results suggest that migratory birds may be subject to the effects of light pollution particularly during migration, the most critical stage in their annual cycle. We hope these results will spur further research on how light pollution affects not only migrating birds, but also other highly mobile animals throughout their annual cycle.

  14. Contributions of endocrinology to the migration life history of birds.

    Science.gov (United States)

    Cornelius, J M; Boswell, T; Jenni-Eiermann, S; Breuner, C W; Ramenofsky, M

    2013-09-01

    Migration is a key life cycle stage in nearly 2000 species of birds and is a greatly appreciated phenomenon in both cultural and academic arenas. Despite a long research tradition concerning many aspects of migration, investigations of hormonal contributions to migratory physiology and behavior are more limited and represent a comparatively young research field. We review advances in our understanding of the hormonal mechanisms of migration with particular emphasis on the sub-stages of the migration life history: development, departure, flight and arrival. These sub-stages vary widely in their behavioral, ecological and physiological contexts and, as such, should be given appropriate individual consideration. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Light pollution is greatest within migration passage areas for nocturnally-migrating birds around the world

    OpenAIRE

    Cabrera-Cruz, Sergio A.; Smolinsky, Jaclyn A.; Buler, Jeffrey J.

    2018-01-01

    Excessive or misdirected artificial light at night (ALAN) produces light pollution that influences several aspects of the biology and ecology of birds, including disruption of circadian rhythms and disorientation during flight. Many migrating birds traverse large expanses of land twice every year at night when ALAN illuminates the sky. Considering the extensive and increasing encroachment of light pollution around the world, we evaluated the association of the annual mean ALAN intensity over ...

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

    Science.gov (United States)

    Bruderer, B.; Steidinger, P.

    1972-01-01

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

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

    Science.gov (United States)

    Smith, James A.

    2009-01-01

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

  18. Migration and parasitism : Habitat use, not migration distance, influences helminth species richness in Charadriiform birds

    NARCIS (Netherlands)

    Gutiérrez, Jorge S.; Rakhimberdiev, Eldar; Piersma, Theunis; Thieltges, David W.

    Aim: Habitat use and migration strategies of animals are often associated with spatial variation in parasite pressure, but how they relate to one another is not well understood. Here, we use a large dataset on helminth species richness of Charadriiform birds to test whether higher habitat diversity

  19. Migration and parasitism: habitat use, not migration distance, influences helminth species richness in Charadriiform birds

    NARCIS (Netherlands)

    Gutiérrez, J.S.; Rakhimberdiev, E.; Piersma, T.; Thieltges, D.W.

    2017-01-01

    Aim Habitat use and migration strategies of animals are often associated withspatial variation in parasite pressure, but how they relate to one another is notwell understood. Here, we use a large dataset on helminth species richness ofCharadriiform birds to test whether higher habitat diversity and

  20. Extracting bird migration information from C-band Doppler weather radars

    NARCIS (Netherlands)

    van Gasteren, H.; Holleman, I.; Bouten, W.; van Loon, E.; Shamoun-Baranes, J.

    2008-01-01

    Although radar has been used in studies of bird migration for 60 years, there is still no network in Europe for comprehensive monitoring of bird migration. Europe has a dense network of military air surveillance radars but most systems are not directly suitable for reliable bird monitoring. Since

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

    Science.gov (United States)

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

    2015-12-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

    Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel

  3. Migration Theories and Mental Health in Toni Morrison's Jazz

    OpenAIRE

    Leila Tafreshi Motalgh; Wan Roselezam Wan Yahya

    2015-01-01

    This article aims to elaborate the relationship between migration and mental health problems that are evident in migrant women in Toni Morrison's Jazz (1992). To this end, pre-migration, migration and post-migration stress factors are identified in the novel based on Danish Bhugra's theory of migration. It seems that pre-migration stress factors and traumas are associated with the push theory of migration, while post-migration stresses are associated with the pull theory of migration. Despite...

  4. Candidatus Neoehrlichia mikurensis in Ticks from Migrating Birds in Sweden.

    Science.gov (United States)

    Labbé Sandelin, Lisa; Tolf, Conny; Larsson, Sara; Wilhelmsson, Peter; Salaneck, Erik; Jaenson, Thomas G T; Lindgren, Per-Eric; Olsen, Björn; Waldenström, Jonas

    2015-01-01

    Candidatus Neoehrlichia mikurensis (CNM; family Anaplasmataceae) was recently recognized as a potential tick-borne human pathogen. The presence of CNM in mammals, in host-seeking Ixodes ticks and in ticks attached to mammals and birds has been reported recently. We investigated the presence of CNM in ornithophagous ticks from migrating birds. A total of 1,150 ticks (582 nymphs, 548 larvae, 18 undetermined ticks and two adult females) collected from 5,365 birds captured in south-eastern Sweden was screened for CNM by molecular methods. The birds represented 65 different species, of which 35 species were infested with one or more ticks. Based on a combination of morphological and molecular species identification, the majority of the ticks were identified as Ixodes ricinus. Samples were initially screened by real-time PCR targeting the CNM 16S rRNA gene, and confirmed by a second real-time PCR targeting the groEL gene. For positive samples, a 1260 base pair fragment of the 16S rRNA gene was sequenced. Based upon bacterial gene sequence identification, 2.1% (24/1150) of the analysed samples were CNM-positive. Twenty-two out of 24 CNM-positive ticks were molecularly identified as I. ricinus nymphs, and the remaining two were identified as I. ricinus based on morphology. The overall CNM prevalence in I. ricinus nymphs was 4.2%. None of the 548 tested larvae was positive. CNM-positive ticks were collected from 10 different bird species. The highest CNM-prevalences were recorded in nymphs collected from common redpoll (Carduelis flammea, 3/7), thrush nightingale (Luscinia luscinia, 2/29) and dunnock (Prunella modularis, 1/17). The 16S rRNA sequences obtained in this study were all identical to each other and to three previously reported European strains, two of which were obtained from humans. It is concluded that ornithophagous ticks may be infected with CNM and that birds most likely can disperse CNM-infected ticks over large geographical areas.

  5. Candidatus Neoehrlichia mikurensis in Ticks from Migrating Birds in Sweden.

    Directory of Open Access Journals (Sweden)

    Lisa Labbé Sandelin

    Full Text Available Candidatus Neoehrlichia mikurensis (CNM; family Anaplasmataceae was recently recognized as a potential tick-borne human pathogen. The presence of CNM in mammals, in host-seeking Ixodes ticks and in ticks attached to mammals and birds has been reported recently. We investigated the presence of CNM in ornithophagous ticks from migrating birds. A total of 1,150 ticks (582 nymphs, 548 larvae, 18 undetermined ticks and two adult females collected from 5,365 birds captured in south-eastern Sweden was screened for CNM by molecular methods. The birds represented 65 different species, of which 35 species were infested with one or more ticks. Based on a combination of morphological and molecular species identification, the majority of the ticks were identified as Ixodes ricinus. Samples were initially screened by real-time PCR targeting the CNM 16S rRNA gene, and confirmed by a second real-time PCR targeting the groEL gene. For positive samples, a 1260 base pair fragment of the 16S rRNA gene was sequenced. Based upon bacterial gene sequence identification, 2.1% (24/1150 of the analysed samples were CNM-positive. Twenty-two out of 24 CNM-positive ticks were molecularly identified as I. ricinus nymphs, and the remaining two were identified as I. ricinus based on morphology. The overall CNM prevalence in I. ricinus nymphs was 4.2%. None of the 548 tested larvae was positive. CNM-positive ticks were collected from 10 different bird species. The highest CNM-prevalences were recorded in nymphs collected from common redpoll (Carduelis flammea, 3/7, thrush nightingale (Luscinia luscinia, 2/29 and dunnock (Prunella modularis, 1/17. The 16S rRNA sequences obtained in this study were all identical to each other and to three previously reported European strains, two of which were obtained from humans. It is concluded that ornithophagous ticks may be infected with CNM and that birds most likely can disperse CNM-infected ticks over large geographical areas.

  6. Theories on migration processes of Cd in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Li, Haixia; Wang, Qi; Ding, Jun; Zhang, Longlei

    2018-03-01

    Understanding the migration progress is essential to pollution control, while developing theories for the migration progress is the scientific basis. This paper further developed five key theories on migration processes of Cd including homogeneous theory, environmental dynamic theory, horizontal loss theory, migration trend theory and vertical migration theory, respectively. The performance and practical values of these theories were demonstrated in the application of these on analyzing the migration process of Cd in Jiaozhou Bay. Results these theory helpful to better understand the migration progress of pollutants in marine bay.

  7. Bird migration through Middle Rio Grande riparian forests, 1994 to 1997

    Science.gov (United States)

    Michael D. Means; Deborah M. Finch

    1999-01-01

    Expanding human populations in the middle Rio Grande have increased demands on water, land, and other resources, potentially disrupting bird migration activities. From 1994 to 1997, a total of 26,350 birds of 157 species were banded and studied. Results include species composition, timing of migration, and habitat use. Recommendations for managers are included.

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

    Science.gov (United States)

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

  9. Historical diversification of migration patterns in a passerine bird.

    Science.gov (United States)

    Pérez-Tris, Javier; Bensch, Staffan; Carbonell, Roberto; Helbig, Andreas J; Tellería, José Luis

    2004-08-01

    Migratory strategies of birds require complex orientation mechanisms, morphological adaptations, and life-history adjustments. From an evolutionary perspective, it is important to know how fast this complex combination of traits can evolve. We analyzed mitochondrial control-region DNA sequences in 241 blackcaps (Sylvia atricapilla) from 12 populations with different migratory behaviors. The sample included sedentary populations in Europe and Atlantic archipelagos and migratory populations with different distances of migration, from regional to intercontinental migrations, and different heading directions (due to a migratory divide in central Europe). There was no genetic structure between migratory and sedentary populations, or among populations from different biogeographic areas (Atlantic islands, the Iberian Peninsula, or the continent), however we found evidence of a genetic structure when comparing populations located on either side of the migratory divide. These findings support an independent evolution of highly divergent migratory strategies in blackcaps, occurring after a postglacial colonization of the continent along western and eastern routes. Accordingly, mismatch-distribution analyses suggested an expansion of blackcaps from a very small population size, and time estimates dated such an expansion during the last postglacial period. However, the populations in Gibraltar, located in a putative Mediterranean refuge, appeared to be independent of these processes, showing evidence of restricted gene flow with other populations and demonstrating insignificant historical changes in effective population size. Our results show that the interruption of gene flow between migratory and sedentary populations is not necessary for the maintenance of such a polymorphism, and that even the most divergent migratory strategies of a bird species are susceptible to evolution in response to historical environmental changes.

  10. An application of queuing theory to waterfowl migration

    Science.gov (United States)

    Sojda, Richard S.; Cornely, John E.; Fredrickson, Leigh H.; Rizzoli, A.E.; Jakeman, A.J.

    2002-01-01

    There has always been great interest in the migration of waterfowl and other birds. We have applied queuing theory to modelling waterfowl migration, beginning with a prototype system for the Rocky Mountain Population of trumpeter swans (Cygnus buccinator) in Western North America. The queuing model can be classified as a D/BB/28 system, and we describe the input sources, service mechanism, and network configuration of queues and servers. The intrinsic nature of queuing theory is to represent the spatial and temporal characteristics of entities and how they move, are placed in queues, and are serviced. The service mechanism in our system is an algorithm representing how swans move through the flyway based on seasonal life cycle events. The system uses an observed number of swans at each of 27 areas for a breeding season as input and simulates their distribution through four seasonal steps. The result is a simulated distribution of birds for the subsequent year's breeding season. The model was built as a multiagent system with one agent handling movement algorithms, with one facilitating user interface, and with one to seven agents representing specific geographic areas for which swan management interventions can be implemented. The many parallels in queuing model servers and service mechanisms with waterfowl management areas and annual life cycle events made the transfer of the theory to practical application straightforward.

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

    Science.gov (United States)

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

    2011-01-06

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

  12. High-intensity urban light installation dramatically alters nocturnal bird migration.

    Science.gov (United States)

    Van Doren, Benjamin M; Horton, Kyle G; Dokter, Adriaan M; Klinck, Holger; Elbin, Susan B; Farnsworth, Andrew

    2017-10-17

    Billions of nocturnally migrating birds move through increasingly photopolluted skies, relying on cues for navigation and orientation that artificial light at night (ALAN) can impair. However, no studies have quantified avian responses to powerful ground-based light sources in urban areas. We studied effects of ALAN on migrating birds by monitoring the beams of the National September 11 Memorial & Museum's "Tribute in Light" in New York, quantifying behavioral responses with radar and acoustic sensors and modeling disorientation and attraction with simulations. This single light source induced significant behavioral alterations in birds, even in good visibility conditions, in this heavily photopolluted environment, and to altitudes up to 4 km. We estimate that the installation influenced ≈1.1 million birds during our study period of 7 d over 7 y. When the installation was illuminated, birds aggregated in high densities, decreased flight speeds, followed circular flight paths, and vocalized frequently. Simulations revealed a high probability of disorientation and subsequent attraction for nearby birds, and bird densities near the installation exceeded magnitudes 20 times greater than surrounding baseline densities during each year's observations. However, behavioral disruptions disappeared when lights were extinguished, suggesting that selective removal of light during nights with substantial bird migration is a viable strategy for minimizing potentially fatal interactions among ALAN, structures, and birds. Our results also highlight the value of additional studies describing behavioral patterns of nocturnally migrating birds in powerful lights in urban areas as well as conservation implications for such lighting installations.

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

    Science.gov (United States)

    Smith, James A.; Deppe, Jill L.

    2008-01-01

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

  14. The implications of migration theory for distributive justice

    OpenAIRE

    Sager, Alex

    2012-01-01

    This paper explores the implications of empirical theories of migration for normative accounts of migration and distributive justice. It examines neo-classical economics, world-systems theory, dual labor market theory, and feminist approaches to migration and contends that neo-classical economic theory in isolation provides an inadequate understanding of migration. Other theories provide a fuller account of how national and global economic, political, and social institutions cause and shape m...

  15. Annual spatiotemporal migration schedules in three larger insectivorous birds

    DEFF Research Database (Denmark)

    Jacobsen, Lars Bo; Jensen, Niels Odder; Willemoes, Mikkel

    2017-01-01

    Background: Knowledge of spatiotemporal migration patterns is important for our understanding of migration ecology and ultimately conservation of migratory species. We studied the annual migration schedules of European nightjar, a large nocturnal insectivore and compared it with two other larger ...

  16. Annual spatiotemporal migration schedules in three larger insectivorous birds

    DEFF Research Database (Denmark)

    Jacobsen, Lars Bo; Jensen, Niels Odder; Willemoes, Mikkel

    2017-01-01

    Background: Knowledge of spatiotemporal migration patterns is important for our understanding of migration ecology and ultimately conservation of migratory species. We studied the annual migration schedules of European nightjar, a large nocturnal insectivore and compared it with two other larger...

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

    Science.gov (United States)

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

    2013-08-01

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

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

    Science.gov (United States)

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

    2013-08-01

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

  19. Influence of offshore windmills on migration birds in southeast coast of Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, Jan [BirdWind, Faerjestaden (Sweden); Stalin, Thomas [GE Energy AB, Vaesteraas (Sweden)

    2003-06-01

    Up to 1,000,000 sea birds meets two offshore wind parks at Utgrunden and at Yttre Stengrund during their migration along the Swedish southeast coast. The sea birds reaction on these wind turbines are studied during spring and autumn migration since autumn 2000. The performed study shows that the sea birds recognise the wind turbines and change their flight route to either side of the wind park. Radar studies show that the sea birds have similar behaviour during night. In wintertime food-searching sea birds continue to be in the area with wind turbines. The results are promising and so far has no collision occurred during the observation of 800,000 sea birds.

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

    NARCIS (Netherlands)

    Dokter, A.M.; Shamoun-Baranes, J.; Kemp, M.U.; Tijm, S.; Holleman, I.

    2013-01-01

    At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher

  1. How birds weather the weather: avian migration in the mid-latitudes

    NARCIS (Netherlands)

    Kemp, M.U.

    2012-01-01

    The life cycle of many bird species involves the twice-annual movement between a breeding ground and a wintering ground that we refer to as `migration'. To complete these journeys, birds must successfully navigate many obstacles including a dynamic atmosphere. To make optimal use of this

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

    Science.gov (United States)

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

    2015-11-01

    Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration. © 2015 The Author(s).

  3. Seasonal associations with urban light pollution for nocturnally migrating bird populations.

    Science.gov (United States)

    La Sorte, Frank A; Fink, Daniel; Buler, Jeffrey J; Farnsworth, Andrew; Cabrera-Cruz, Sergio A

    2017-11-01

    The spatial extent and intensity of artificial light at night (ALAN) has increased worldwide through the growth of urban environments. There is evidence that nocturnally migrating birds are attracted to ALAN, and there is evidence that nocturnally migrating bird populations are more likely to occur in urban areas during migration, especially in the autumn. Here, we test if urban sources of ALAN are responsible, at least in part, for these observed urban associations. We use weekly estimates of diurnal occurrence and relative abundance for 40 nocturnally migrating bird species that breed in forested environments in North America to assess how associations with distance to urban areas and ALAN are defined across the annual cycle. Migratory bird populations presented stronger than expected associations with shorter distances to urban areas during migration, and stronger than expected association with higher levels of ALAN outside and especially within urban areas during migration. These patterns were more pronounced during autumn migration, especially within urban areas. Outside of the two migration periods, migratory bird populations presented stronger than expected associations with longer distances to urban areas, especially during the nonbreeding season, and weaker than expected associations with the highest levels of ALAN outside and especially within urban areas. These findings suggest that ALAN is associated with higher levels of diurnal abundance along the boundaries and within the interior of urban areas during migration, especially in the autumn when juveniles are undertaking their first migration journey. These findings support the conclusion that urban sources of ALAN can broadly effect migratory behavior, emphasizing the need to better understand the implications of ALAN for migratory bird populations. © 2017 John Wiley & Sons Ltd.

  4. Differences in speed and duration of bird migration between spring and autumn

    NARCIS (Netherlands)

    Nilsson, Cecilia; Klaassen, Raymond H. G.; Alerstam, Thomas

    It has been suggested that birds migrate faster in spring than in autumn because of competition for arrival order at breeding grounds and environmental factors such as increased daylight. Investigating spring and autumn migration performances is important for understanding ecological and

  5. Improving the quantification of waterfowl migration with remote sensing and bird tracking

    NARCIS (Netherlands)

    Si, Y.; Xin, Q.; Prins, H.H.T.; Boer, de W.F.; Gong, P.

    2015-01-01

    Accurately quantifying waterfowl migration patterns is pertinent to monitor ecosystem health and control bird-borne infectious diseases. In this review, we summarize the current understanding of the environmental mechanisms that drive waterfowl migration and then investigate the effect of intra- and

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

    Science.gov (United States)

    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.

  7. The role of the antioxidant system during intense endurance exercise: lessons from migrating birds.

    Science.gov (United States)

    Cooper-Mullin, Clara; McWilliams, Scott R

    2016-12-01

    During migration, birds substantially increase their metabolic rate and burn fats as fuel and yet somehow avoid succumbing to overwhelming oxidative damage. The physiological means by which vertebrates such as migrating birds can counteract an increased production of reactive species (RS) are rather limited: they can upregulate their endogenous antioxidant system and/or consume dietary antioxidants (prophylactically or therapeutically). Thus, birds can alter different components of their antioxidant system to respond to the demands of long-duration flights, but much remains to be discovered about the complexities of RS production and antioxidant protection throughout migration. Here, we use bird migration as an example to discuss how RS are produced during endurance exercise and how the complex antioxidant system can protect against cellular damage caused by RS. Understanding how a bird's antioxidant system responds during migration can lend insights into how antioxidants protect birds during other life-history stages when metabolic rate may be high, and how antioxidants protect other vertebrates from oxidative damage during endurance exercise. © 2016. Published by The Company of Biologists Ltd.

  8. Climate change leads to decreasing bird migration distances

    NARCIS (Netherlands)

    Visser, M.E.; Perdeck, A.C.; van Balen, J.H.; Both, C.

    2009-01-01

    Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

  9. Climate change leads to decreasing bird migration distances

    NARCIS (Netherlands)

    Visser, Marcel E.; Perdeck, Albert C.; van Balen, Johan H.; Both, Christiaan

    Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

  10. Causes and consequences of partial migration in a passerine bird

    NARCIS (Netherlands)

    Hegemann, Arne; Marra, Peter P.; Tieleman, B. Irene

    2015-01-01

    Many animal species have populations in which some individuals migrate and others remain on the breeding grounds. This phenomenon is called partial migration. Despite substantial theoretical work, empirical data on causes and consequences of partial migration remain scarce, mainly because of

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

    Science.gov (United States)

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

    2014-01-01

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

  12. Migration Theories and Mental Health in Toni Morrison's Jazz

    Directory of Open Access Journals (Sweden)

    Leila Tafreshi Motalgh

    2015-01-01

    Full Text Available This article aims to elaborate the relationship between migration and mental health problems that are evident in migrant women in Toni Morrison's Jazz (1992. To this end, pre-migration, migration and post-migration stress factors are identified in the novel based on Danish Bhugra's theory of migration. It seems that pre-migration stress factors and traumas are associated with the push theory of migration, while post-migration stresses are associated with the pull theory of migration. Despite post-migration stresses, the main female characters who encounter pre-migration stress factors and traumas are more likely to develop mental health problems like Post-traumatic Stress Disorder (PTSD. Although there is extensive literary criticism of Jazz (1992, no theoretical criticism exists that simultaneously covers migration theories and the mental health problems evident in Toni Morrison's female characters. It is worth highlighting that gender is a variable that correlates positively with migration and mental health. This article attempts to fill a gap in literary criticism and contribute to the body of research on mental health problems associated with gender and migration. Keywords: Push-Pull Theory, Great Migration, Black Studies, Gender, Trauma, PTSD

  13. Mathematical model for bird flu disease transmission with no bird ...

    African Journals Online (AJOL)

    In this paper a mathematical model for the transmission dynamics of bird flu among birds and humans is presented. The model assumes that there is no migration of birds in the susceptible bird population immediately the disease starts. The model formulated is analyzed using dynamical systems theory . The analysis of the ...

  14. mathematical model for bird flu disease transmission with no bird ...

    African Journals Online (AJOL)

    Admin

    In this paper a mathematical model for the transmission dynamics of bird flu among birds and humans is presented. The model assumes that there is no migration of birds in the susceptible bird population immediately the disease starts. The model formulated is analyzed using dynamical systems theory. The analysis of the ...

  15. Bird migration advances more strongly in urban environments.

    Science.gov (United States)

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

    2013-01-01

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

  16. Bird migration advances more strongly in urban environments.

    Directory of Open Access Journals (Sweden)

    Piotr Tryjanowski

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

  17. Artificial light at night confounds broad-scale habitat use by migrating birds

    Science.gov (United States)

    McLaren, James D.; Buler, Jeffrey J.; Schreckengost, Tim; Smolinsky, Jaclyn A.; Boone, Matthew; van Loon, E. Emiel; Dawson, Deanna K.; Walters, Eric L.

    2018-01-01

    With many of the world's migratory bird populations in alarming decline, broad-scale assessments of responses to migratory hazards may prove crucial to successful conservation efforts. Most birds migrate at night through increasingly light-polluted skies. Bright light sources can attract airborne migrants and lead to collisions with structures, but might also influence selection of migratory stopover habitat and thereby acquisition of food resources. We demonstrate, using multi-year weather radar measurements of nocturnal migrants across the northeastern U.S., that autumnal migrant stopover density increased at regional scales with proximity to the brightest areas, but decreased within a few kilometers of brightly-lit sources. This finding implies broad-scale attraction to artificial light while airborne, impeding selection for extensive forest habitat. Given that high-quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness, artificial lights present a potentially heightened conservation concern for migratory bird populations.

  18. Differences in speed and duration of bird migration between spring and autumn.

    Science.gov (United States)

    Nilsson, Cecilia; Klaassen, Raymond H G; Alerstam, Thomas

    2013-06-01

    It has been suggested that birds migrate faster in spring than in autumn because of competition for arrival order at breeding grounds and environmental factors such as increased daylight. Investigating spring and autumn migration performances is important for understanding ecological and evolutionary constraints in the timing and speed of migration. We compiled measurements from tracking studies and found a consistent predominance of cases showing higher speeds and shorter durations during spring compared to autumn, in terms of flight speeds (airspeed, ground speed, daily travel speed), stopover duration, and total speed and duration of migration. Seasonal differences in flight speeds were generally smaller than those in stopover durations and total speed/duration of migration, indicating that rates of foraging and fuel deposition were more important than flight speed in accounting for differences in overall migration performance. Still, the seasonal differences in flight speeds provide important support for time selection in spring migration.

  19. Nematode parasite diversity in birds: the role of host ecology, life history and migration.

    Science.gov (United States)

    Leung, Tommy L F; Koprivnikar, Janet

    2016-11-01

    Previous studies have found that migratory birds generally have a more diverse array of pathogens such as parasites, as well as higher intensities of infection. However, it is not clear whether this is driven by the metabolic and physiological demands of migration, differential selection on host life-history traits or basic ecological differences between migratory and non-migratory species. Parasitic helminths can cause significant pathology in their hosts, and many are trophically transmitted such that host diet and habitat use play key roles in the acquisition of infections. Given the concurrent changes in avian habitats and migratory behaviour, it is critical to understand the degree to which host ecology influences their parasite communities. We examined nematode parasite diversity in 153 species of Anseriformes (water birds) and Accipitriformes (predatory birds) in relation to their migratory behaviour, diet, habitat use, geographic distribution and life history using previously published data. Overall, migrators, host species with wide geographic distributions and those utilizing multiple aquatic habitats had greater nematode richness (number of species), and birds with large clutches harboured more diverse nematode fauna with respect to number of superfamilies. Separate analyses for each host order found similar results related to distribution, habitat use and migration; however, herbivorous water birds played host to a less diverse nematode community compared to those that consume some animals. Birds using multiple aquatic habitats have a more diverse nematode fauna relative to primarily terrestrial species, likely because there is greater opportunity for contact with parasite infectious stages and/or consumption of infected hosts. As such, omnivorous and carnivorous birds using aquatic habitats may be more affected by environmental changes that alter their diet and range. Even though there were no overall differences in their ecology and life history

  20. Flight by night or day? Optimal daily timing of bird migration.

    Science.gov (United States)

    Alerstam, Thomas

    2009-06-21

    Many migratory bird species fly mainly during the night (nocturnal migrants), others during daytime (diurnal migrants) and still others during both night and day. Need to forage during the day, atmospheric structure, predator avoidance and orientation conditions have been proposed as explanations for the widespread occurrence of nocturnal migration. However, the general principles that determine the basic nocturnal-diurnal variation in flight habits are poorly known. In the present study optimal timing of migratory flights, giving the minimum total duration of the migratory journey, is evaluated in a schematic way in relation to ecological conditions for energy gain in foraging and for energy costs in flight. There exists a strong and fundamental advantage of flying by night because foraging time is maximized and energy deposition can take place on days immediately after and prior to the nocturnal flights. The increase in migration speed by nocturnal compared with diurnal migration will be largest for birds with low flight costs and high energy deposition rates. Diurnal migration will be optimal if it is associated with efficient energy gain immediately after a migratory flight because suitable stopover/foraging places have been located during the flight or if energy losses during flight are substantially reduced by thermal soaring and/or by fly-and-forage migration. A strategy of combined diurnal and nocturnal migration may be optimal when birds migrate across regions with relatively poor conditions for energy deposition (not only severe but also soft barriers). Predictions about variable timing of migratory flights depending on changing foraging and environmental conditions along the migration route may be tested for individual birds by analysing satellite tracking results with respect to daily travel routines in different regions. Documenting and understanding the adaptive variability in daily travel schedules among migrating animals constitute a fascinating

  1. The migration and conservation of birds in a Southern African context

    Directory of Open Access Journals (Sweden)

    H. Bouwman

    1997-07-01

    Full Text Available The migration of birds is a phenomenon that has been studied for more than two thousand years. Almost half of the extant bird species undertake migration, covering distances of a few tens of kilometres, up to a calculated 50 000 km per year, sometimes at heights exceeding 9 000 m, at very low temperatures, during the day or night. Some species fly actively and continuously for more than a 100 hours, whilst making efficient use of energy. A variety of strategies and physiological mechanisms are used to perform such feats, but many remain to be studied.

  2. The Study of Bird Migration by Radar . Part 1: The Technical Basis*

    Science.gov (United States)

    Bruderer, Bruno

    Since the 1960s radar has been an established research tool in bird migration studies. Radar informs us about the actual course of migration under various environmental conditions: it covers wide distances, is independent of light and reasonably independent of weather, provides data on migratory intensity, flight paths and with special equipment the wing-beat pattern of birds. It thus fills an important gap left by other methods such as visual and auditory observations, laboratory research, trapping, and ringing studies. For an appropriate use of the sophisticated tool, however, it is important to know its capabilities and limitations.

  3. Co-fluctuation among bird species in their migration timing

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk

    2005-01-01

    Roč. 54, 1-2 (2005), s. 159-164 ISSN 0139-7893 Institutional research plan: CEZ:AV0Z60930519 Keywords : migratory birds * phenology * spring arrival Subject RIV: EG - Zoology Impact factor: 0.585, year: 2005 http://www.ivb.cz/folia/54/1-2/159-164.pdf

  4. Bird migration and risk for H5N1 transmission into Qinghai Lake, China.

    Science.gov (United States)

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

    2011-05-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    Smith, James A.

    2005-01-01

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

  7. Animal tracking meets migration genomics: transcriptomic analysis of a partially migratory bird species.

    Science.gov (United States)

    Franchini, Paolo; Irisarri, Iker; Fudickar, Adam; Schmidt, Andreas; Meyer, Axel; Wikelski, Martin; Partecke, Jesko

    2017-06-01

    Seasonal migration is a widespread phenomenon, which is found in many different lineages of animals. This spectacular behaviour allows animals to avoid seasonally adverse environmental conditions to exploit more favourable habitats. Migration has been intensively studied in birds, which display astonishing variation in migration strategies, thus providing a powerful system for studying the ecological and evolutionary processes that shape migratory behaviour. Despite intensive research, the genetic basis of migration remains largely unknown. Here, we used state-of-the-art radio-tracking technology to characterize the migratory behaviour of a partially migratory population of European blackbirds (Turdus merula) in southern Germany. We compared gene expression of resident and migrant individuals using high-throughput transcriptomics in blood samples. Analyses of sequence variation revealed a nonsignificant genetic structure between blackbirds differing by their migratory phenotype. We detected only four differentially expressed genes between migrants and residents, which might be associated with hyperphagia, moulting and enhanced DNA replication and transcription. The most pronounced changes in gene expression occurred between migratory birds depending on when, in relation to their date of departure, blood was collected. Overall, the differentially expressed genes detected in this analysis may play crucial roles in determining the decision to migrate, or in controlling the physiological processes required for the onset of migration. These results provide new insights into, and testable hypotheses for, the molecular mechanisms controlling the migratory phenotype and its underlying physiological mechanisms in blackbirds and other migratory bird species. © 2017 John Wiley & Sons Ltd.

  8. Why migrate during the day: a comparative analysis of North American birds.

    Science.gov (United States)

    Beauchamp, G

    2011-09-01

    Migration can take place primarily during the day or at night, or during both depending on the species. Why the timing of migration varies among species has been the object of much research but the underlying ecological processes are still unclear. Proximally, migration timing may be influenced by the timing of other activities or may be more prevalent in species that migrate over long distances. Adaptive scenarios emphasize the reduction in flight costs at night especially in smaller species and the advantages of travelling in groups during the day to locate staging sites more efficiently. I used phylogenetic independent contrasts to examine these hypotheses in all North American nesting birds. I uncovered 24 evolutionary transitions in migration timing, most of which involved a switch from nocturnal to diurnal migration. Few of these transitions involved a concomitant change in the timing of foraging habits or migration distance. However, species in diurnal clades were larger, travelled in larger flocks and were generally more sociable than their nocturnal counterparts. The results support the hypotheses that a reduction in flight costs and the ability to pool information from companions are associated with migration timing in North American bird species. © 2011 The Author. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

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

    Science.gov (United States)

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

    2016-11-01

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

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

    Science.gov (United States)

    Louchart, Antoine

    2008-12-01

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

  11. The paradox of Spoonbill migration : Most birds travel to where survival rates are lowest

    NARCIS (Netherlands)

    Lok, Tamar; Overdijk, Otto; Tinbergen, Joost M.; Piersma, Theunis

    2011-01-01

    Migrant birds face a choice where to spend the winter. Presumably there is a trade-off between migration distance (costs) and the quality of the wintering site (benefits). Wintering site fidelity is often high and increases with age. Hypotheses to explain such a pattern assume that wintering site

  12. Polymorphism at the Clock gene predicts phenology of long-distance migration in birds.

    Science.gov (United States)

    Saino, Nicola; Bazzi, Gaia; Gatti, Emanuele; Caprioli, Manuela; Cecere, Jacopo G; Possenti, Cristina D; Galimberti, Andrea; Orioli, Valerio; Bani, Luciano; Rubolini, Diego; Gianfranceschi, Luca; Spina, Fernando

    2015-04-01

    Dissecting phenotypic variance in life history traits into its genetic and environmental components is at the focus of evolutionary studies and of pivotal importance to identify the mechanisms and predict the consequences of human-driven environmental change. The timing of recurrent life history events (phenology) is under strong selection, but the study of the genes that control potential environmental canalization in phenological traits is at its infancy. Candidate genes for circadian behaviour entrained by photoperiod have been screened as potential controllers of phenological variation of breeding and moult in birds, with inconsistent results. Despite photoperiodic control of migration is well established, no study has reported on migration phenology in relation to polymorphism at candidate genes in birds. We analysed variation in spring migration dates within four trans-Saharan migratory species (Luscinia megarhynchos; Ficedula hypoleuca; Anthus trivialis; Saxicola rubetra) at a Mediterranean island in relation to Clock and Adcyap1 polymorphism. Individuals with larger number of glutamine residues in the poly-Q region of Clock gene migrated significantly later in one or, respectively, two species depending on sex and whether the within-individual mean length or the length of the longer Clock allele was considered. The results hinted at dominance of the longer Clock allele. No significant evidence for migration date to covary with Adcyap1 polymorphism emerged. This is the first evidence that migration phenology is associated with Clock in birds. This finding is important for evolutionary studies of migration and sheds light on the mechanisms that drive bird phenological changes and population trends in response to climate change. © 2015 John Wiley & Sons Ltd.

  13. A robust tool highlights the influence of bird migration on influenza A virus evolution.

    Science.gov (United States)

    Dugan, Vivien G

    2012-12-01

    One of the fundamental unknowns in the field of influenza biology is a panoramic understanding of the role wild birds play in the global maintenance and spread of influenza A viruses. Wild aquatic birds are considered a reservoir host for all lowly pathogenic avian influenza A viruses (AIV) and thus serve as a potential source of zoonotic AIV, such as Australasian-origin H5N1 responsible for morbidity and mortality in both poultry and humans, as well as genes that may contribute to the emergence of pandemic viruses. Years of broad, in-depth wild bird AIV surveillance have helped to decipher key observations and ideas regarding AIV evolution and viral ecology including the trending of viral lineages, patterns of gene flow within and between migratory flyways and the role of geographic boundaries in shaping viral evolution (Bahl et al. 2009; Lam et al. 2012). While these generally 'virus-centric' studies have ultimately advanced our broader understanding of AIV dynamics, recent studies have been more host-focused, directed at determining the potential impact of host behaviour on AIV, specifically, the influence of bird migration upon AIV maintenance and transmission. A large number of surveillance studies have taken place in Alaska, United States-a region where several global flyways overlap-with the aim of detecting the introduction of novel, Australasian-origin highly pathogenic H5N1 AIV into North America. By targeting bird species with known migration habits, long-distance migrators were determined to be involved in the intercontinental movement of individual AIV gene segments, but not entire viruses, between the Australasian and North American flyways (Koehler et al. 2008; Pearce et al. 2010). Yet, bird movement is not solely limited to long-distance migration, and the relationship of resident or nonmigratory and intermediate-distance migrant populations with AIV ecology has only recently been explored by Hill et al. (2012) in this issue of Molecular Ecology

  14. Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds

    Directory of Open Access Journals (Sweden)

    Røed Knut H

    2011-06-01

    Full Text Available Abstract Background Bovine babesiosis is regarded as a limited health problem for Norwegian cows, and the incidence has decreased markedly since the 1930s. Rare cases of babesiosis in splenectomised humans from infection with Babesia divergens and B.venatorum have been described. The objective of this study was to determine whether birds can introduce Babesia-infected ticks. There are between 30 and 85 million passerine birds that migrate to Norway every spring. Methods Passerine birds were examined for ticks at four bird observatories along the southern Norwegian coast during the spring migrations of 2003, 2004 and 2005. The presence of Babesia was detected in the nymphs of Ixodes ricinus by real-time PCR. Positive samples were confirmed using PCR, cloning and phylogenetic analyses. Results Of 512 ticks examined, real-time PCR revealed five to be positive (1.0%. Of these, four generated products that indicated the presence of Babesia spp.; each of these were confirmed to be from Babesia venatorum (EU1. Two of the four B. venatorum-positive ticks were caught from birds having an eastern migratory route (P Conclusions Birds transport millions of ticks across the North Sea, the Skagerrak and the Kattegat every year. Thus, even with the low prevalence of Babesia-infected ticks, a substantial number of infected ticks will be transported into Norway each year. Therefore, there is a continuous risk for introduction of new Babesia spp. into areas where I. ricinus can survive.

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

    Science.gov (United States)

    Smith, James A.; Deppe, Jill L.

    2008-01-01

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

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

    Science.gov (United States)

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

    2011-02-07

    Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel networks is still very limited. To start investigating these aspects we developed an individual-based simulation model that describes the local interactions between birds and their environment during their migratory flight, leading to emergent patterns at larger scales. The aim of our model is to identify likely decision rules with respect to thermal selection and navigation. After explaining the model, it is applied to analyse the migration of white storks (Ciconia ciconia) over part of its migration domain. A model base-run is accompanied by a sensitivity analysis. It appears that social interactions lead to the use of fewer thermals and slight increases in distance travelled. Possibilities for different model extensions and further model application are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Spatio-temporal dynamics of global H5N1 outbreaks match bird migration patterns.

    Science.gov (United States)

    Si, Yali; Skidmore, Andrew K; Wang, Tiejun; de Boer, Willem F; Debba, Pravesh; Toxopeus, Albert G; Li, Lin; Prins, Herbert H T

    2009-11-01

    The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant pandemic threat and a serious public health risk. An efficient surveillance and disease control system relies on the understanding of the dispersion patterns and spreading mechanisms of the virus. A space-time cluster analysis of H5N1 outbreaks was used to identify spatio-temporal patterns at a global scale and over an extended period of time. Potential mechanisms explaining the spread of the H5N1 virus, and the role of wild birds, were analyzed. Between December 2003 and December 2006, three global epidemic phases of H5N1 influenza were identified. These H5N1 outbreaks showed a clear seasonal pattern, with a high density of outbreaks in winter and early spring (i.e., October to March). In phase I and II only the East Asia Australian flyway was affected. During phase III, the H5N1 viruses started to appear in four other flyways: the Central Asian flyway, the Black Sea Mediterranean flyway, the East Atlantic flyway and the East Africa West Asian flyway. Six disease cluster patterns along these flyways were found to be associated with the seasonal migration of wild birds. The spread of the H5N1 virus, as demonstrated by the space-time clusters, was associated with the patterns of migration of wild birds. Wild birds may therefore play an important role in the spread of H5N1 over long distances. Disease clusters were also detected at sites where wild birds are known to overwinter and at times when migratory birds were present. This leads to the suggestion that wild birds may also be involved in spreading the H5N1 virus over short distances.

  18. Spatio-temporal dynamics of global H5N1 outbreaks match bird migration patterns

    Directory of Open Access Journals (Sweden)

    Yali Si

    2009-11-01

    Full Text Available The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant pandemic threat and a serious public health risk. An efficient surveillance and disease control system relies on the understanding of the dispersion patterns and spreading mechanisms of the virus. A space-time cluster analysis of H5N1 outbreaks was used to identify spatio-temporal patterns at a global scale and over an extended period of time. Potential mechanisms explaining the spread of the H5N1 virus, and the role of wild birds, were analyzed. Between December 2003 and December 2006, three global epidemic phases of H5N1 influenza were identified. These H5N1 outbreaks showed a clear seasonal pattern, with a high density of outbreaks in winter and early spring (i.e., October to March. In phase I and II only the East Asia Australian flyway was affected. During phase III, the H5N1 viruses started to appear in four other flyways: the Central Asian flyway, the Black Sea Mediterranean flyway, the East Atlantic flyway and the East Africa West Asian flyway. Six disease cluster patterns along these flyways were found to be associated with the seasonal migration of wild birds. The spread of the H5N1 virus, as demonstrated by the space-time clusters, was associated with the patterns of migration of wild birds. Wild birds may therefore play an important role in the spread of H5N1 over long distances. Disease clusters were also detected at sites where wild birds are known to overwinter and at times when migratory birds were present. This leads to the suggestion that wild birds may also be involved in spreading the H5N1 virus over short distances.

  19. Theoretical foundations of international migration process studies: analysis of key migration theories development

    Directory of Open Access Journals (Sweden)

    Shymanska K.V.

    2017-03-01

    Full Text Available The need for transformation of Ukraine's migration policy based on globalized world development trends and in response to the challenges of European integration transformations causes the need of researching the theoretical and methodological basis of migration studies, and the regulations of existing theories of international migration. The bibliometric analysis of scientific publications on international migration in cites indexes found that the recent researches on these problems acquire interdisciplinary character. It necessitates the transformation of migration study approaches basing on economic, social, institutional theories and concepts synthesis. The article is devoted to the study of theoretical regulations of existing international migration theories in the context of the evolution of scientists’ views on this phenomenon. The author found that the existing theories of international migration should be divided into three categories (microeconomic, macroeconomic, globalizational that contributes to their understanding in the context of implementation possibilities in migrational public administration practice. It allows to determine the theories which should be used for Ukrainian state migration policy constructing and eliminating or reducing the external migration negative effects.

  20. Spring Flyways of Migrating Soaring Birds in Akkar/Northern Lebanon

    International Nuclear Information System (INIS)

    Ramadan Jaradi, Gh.; Ramadan Jaradi, M.

    2015-01-01

    Beale and Ramadan Jaradi initiated in 2001 the first large scale survey in Lebanon to trace the main routes of migrating raptors and other soaring birds, aiming at contributing to the conservation of flyways and stopover sites through the identification of areas where protection is most needed. Nowadays, the study of the flyways and stopover sites at micro level becomes necessary following the development of the national wind atlas map that will assist among others in locating potential wind farms which on their turn may influence the migratory birds flyways, especially that the wind farms use winds for their function and the soaring birds use wind for their transportation. The present work starts from where the work of Beale and Ramadan-Jaradi ended but in an attempt toprovide policy makers, scientists and experts with a conceptual framework, as well as methodological and operational tools for dealing with wind farms impacts and to prevent collisions of birds with blades of wind urbines. The study is meant to be conducted during spring and autumn passage ofbirds. This paper concerns the spring migration as at the time of writing it the autumn migration didn't start yet. The present spring season study revealed among others that the migratory soaring birds that may use the wind ridge lifts for their soaring travel in windy areas are more influenced by two other main factors:1) presence of depressions perpendicular to mountains ridgesand 2) abundance of the thermals in these depressions, a matter that naturally reduce the impact of wind turbines by attracting the birds away from their blade. (author)

  1. The potential of fruit trees to enhance converted habitats for migrating birds in southern Mexico

    Science.gov (United States)

    Foster, M.S.

    2007-01-01

    Migration routes used by Nearctic migrant birds can cover great distances; they also differ among species, within species, and between years and seasons. As a result, migration routes for an entire migratory avifauna can encompass broad geographic areas, making it impossible to protect continuous stretches of habitat sufficient to connect the wintering and breeding grounds for most species. Consequently, ways to enhance habitats converted for human use (i.e. for pasture, crop cultivation, human settlement) as stopover sites for migrants are especially important. Shelterbelts around pastures and fields, if planted with species targeted to support migrant (and resident) bird species that naturally occupy mature forest habitats and that are at least partially frugivorous, could be a powerful enhancement tool for such species, if the birds will enter the converted areas to feed. I tested this approach for Nearctic migrant birds during the spring migration through an area in Chiapas, Mexico. Mature forest tree species whose fruits are eaten by birds were surveyed. Based on life form, crop size and fruit characteristics, I selected three tree species for study: Cymbopetalum mayanum (Annonaceae), Bursera simaruba (Burseraceae) and Trophis racemosa (Moraceae). I compared the use of fruits of these species by migrants and residents in forest with their use of the fruits of isolated individuals of the same species in pasture and cropland. All three plant species were useful for enhancing converted habitats for forest-occupying spring migrants, although species differed in the degree to which they entered disturbed areas to feed on the fruits. These tree species could probably enhance habitats for migrants at sites throughout the natural geographic ranges of the plants; in other geographic areas for other target bird groups, other tree species might be more appropriate.

  2. Changes in bird-migration patterns associated with human-induced mortality.

    Science.gov (United States)

    Palacín, Carlos; Alonso, Juan C; Martín, Carlos A; Alonso, Javier A

    2017-02-01

    Many bird populations have recently changed their migratory behavior in response to alterations of the environment. We collected data over 16 years on male Great Bustards (Otis tarda), a species showing a partial migratory pattern (sedentary and migratory birds coexisting in the same breeding groups). We conducted population counts and radio tracked 180 individuals to examine differences in survival rates between migratory and sedentary individuals and evaluate possible effects of these differences on the migratory pattern of the population. Overall, 65% of individuals migrated and 35% did not. The average distance between breeding and postbreeding areas of migrant individuals was 89.9 km, and the longest average movement of sedentary males was 3.8 km. Breeding group and migration distance had no effect on survival. However, mortality of migrants was 2.4 to 3.5 times higher than mortality of sedentary birds. For marked males, collision with power lines was the main cause of death from unnatural causes (37.6% of all deaths), and migratory birds died in collisions with power lines more frequently than sedentary birds (21.3% vs 6.3%). The percentage of sedentary individuals increased from 17% in 1997 to 45% in 2012. These results were consistent with data collected from radio-tracked individuals: The proportion of migratory individuals decreased from 86% in 1997-1999 to 44% in 2006-2010. The observed decrease in the migratory tendency was not related to climatic changes (temperatures did not change over the study period) or improvements in habitat quality (dry cereal farmland area decreased in the main study area). Our findings suggest that human-induced mortality during migration may be an important factor shaping the migration patterns of species inhabiting humanized landscapes. © 2016 Society for Conservation Biology.

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Return migration: theory and empirical evidence

    OpenAIRE

    Dustmann, C.; Weiss, Y.

    2007-01-01

    In this paper we discuss forms of migration that are non-permanent. We focus on temporary migrations where the decision to return is taken by the immigrant. These migrations are likely to be frequent, and we provide some evidence for the UK. We then develop a simple model which rationalizes the decision of a migrant to return to his home country, despite a persistently higher wage in the host country. We consider three motives for a temporary migration: Differences in relative prices in host-...

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

    Science.gov (United States)

    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.

  6. Repeatability of individual migration routes, wintering sites, and timing in a long-distance migrant bird.

    Science.gov (United States)

    van Wijk, Rien E; Bauer, Silke; Schaub, Michael

    2016-12-01

    Migratory birds are often faithful to wintering (nonbreeding) sites, and also migration timing is usually remarkably consistent, that is, highly repeatable. Spatiotemporal repeatability can be of advantage for multiple reasons, including familiarity with local resources and predators as well as avoiding the costs of finding a new place, for example, nesting grounds. However, when the environment is variable in space and time, variable site selection and timing might be more rewarding. To date, studies on spatial and temporal repeatability in short-lived long-distance migrants are scarce, most notably of first-time and subsequent migrations. Here, we investigated repeatability in autumn migration directions, wintering sites, and annual migration timing in Hoopoes ( Upupa epops ), a long-distance migrant, using repeated tracks of adult and first-time migrants. Even though autumn migration directions were mostly the same, individual wintering sites often changed from year to year with distances between wintering sites exceeding 1,000 km. The timing of migration was repeatable within an individual during autumn, but not during spring migration. We suggest that Hoopoes respond to variable environmental conditions such as north-south shifts in rainfall during winter and differing onset of the food availability during spring migration.

  7. PRELIMINARY RESULTS OF RADAR OBSERVATION OF NOCTURNAL BIRD MIGRATION IN ISRAEL

    Directory of Open Access Journals (Sweden)

    Matsyura A.V.

    2011-11-01

    Full Text Available The results of radar-tracking supervisions over the night migration in Israel are submitted. The determination of flight altitudes, flight speeds, heights of maximum birds’ concentration, and migratory directions was performed. The average flight altitudes of night migration were 985 m in autumn and 1465 m in spring of 1998-2000, maximum flight altitudes were 2068 m and 2655 m correspondingly. The mean track direction of the night bird migration is 183° in spring and 6° in autumn. The migration of waterfowl over the Mediterranean Sea in the low altitude band was registered. Their average headings differ from the general migratory path, averaging 135° in autumn and 315° in spring. The average birds’ groundspeed was 14 m/s (50 km/h in spring and 13 m/s (47 km/h in autumn.

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

    Science.gov (United States)

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

    2013-01-01

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

  9. Local temperature fine-tunes the timing of spring migration in birds

    DEFF Research Database (Denmark)

    Tøttrup, Anders P.; Rainio, Kalle; Coppack, Timothy

    2010-01-01

    Evidence for climate-driven phenological changes is rapidly increasing at all trophic levels. Our current poor knowledge of the detailed control of bird migration from the level of genes and hormonal control to direct physiological and behavioral responses hampers our ability to understand......-time climatic conditions: (1) vegetation "greenness" (NDVI) in Europe, (2) local spring temperatures in northern Europe, and (3) the North Atlantic Oscillation Index (NAO) as predictors of the phenology of avian migration as well as the strength of their effect on different subsets of populations...

  10. Quantifying the Risk of Introduction of West Nile Virus into Great Britain by Migrating Passerine Birds.

    Science.gov (United States)

    Bessell, P R; Robinson, R A; Golding, N; Searle, K R; Handel, I G; Boden, L A; Purse, B V; Bronsvoort, B M de C

    2016-10-01

    West Nile virus (WNV) is a mosquito borne arbovirus that circulates within avian reservoirs. WNV can spill over into humans and Equidae that are dead-end hosts for WNV but suffer fever, acute morbidity and sometimes death. Outbreaks of WNV are common across Africa and Eastern Europe, and there have also been sporadic outbreaks in Spain and the Camargue Regional Park in France, but never in Great Britain (GB). These areas all fall along a major bird migration route. In this study, we analyse a scenario in which WNV is circulating in the Camargue or in other wetland areas in France and we estimate the risk of northward migrating passerine birds stopping in a WNV hotspot, becoming infected and carrying active infection to GB. If the disease were circulating in the Camargue during a single migratory season, the probability that one or more migrating birds becomes infected and lands in GB whilst still infected is 0.881 with 0.384 birds arriving in areas of suitable vector habitat. However, if WNV became established in the Grand Brière National Park or La Brenne Regional Park wetland areas further to the north, the model predicts that at least one infected bird will continue to GB. Thus, GB is at risk of WNV introduction from the Camargue, but the risk is considerably greater if WNV were to circulate further north than its previous focus in France, but this is highly sensitive to the force of infection in the infected area. However, the risk of establishment and infection of humans in GB is dependent upon a number of additional factors, in particular the vector and epidemiological situation in GB. © 2014 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

  11. Influenza a virus migration and persistence in North American wild birds.

    Science.gov (United States)

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

    2013-01-01

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

  12. Influenza a virus migration and persistence in North American wild birds.

    Directory of Open Access Journals (Sweden)

    Justin Bahl

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

  13. Shifts in Bird Migration Timing in North American Long-Distance and Short-Distance Migrants Are Associated with Climate Change

    OpenAIRE

    Zaifman, Jay; Shan, Daoyang; Ay, Ahmet; Jimenez, Ana Gabriela

    2017-01-01

    Bird migration is a synchronized event that has evolved over thousands of years. Changing temperatures due to climate change threaten the intricacies of migration timing for birds; however, the extent of these changes has only recently begun to be addressed. Utilizing data from the citizen-science website eBird and historical temperature data, we analyzed bird migration timing in two states warming quickly (Alaska and Maine) and one warming gradually (South Carolina). Using linear regressions...

  14. Efficient Parallel Sorting for Migrating Birds Optimization When Solving Machine-Part Cell Formation Problems

    Directory of Open Access Journals (Sweden)

    Ricardo Soto

    2016-01-01

    Full Text Available The Machine-Part Cell Formation Problem (MPCFP is a NP-Hard optimization problem that consists in grouping machines and parts in a set of cells, so that each cell can operate independently and the intercell movements are minimized. This problem has largely been tackled in the literature by using different techniques ranging from classic methods such as linear programming to more modern nature-inspired metaheuristics. In this paper, we present an efficient parallel version of the Migrating Birds Optimization metaheuristic for solving the MPCFP. Migrating Birds Optimization is a population metaheuristic based on the V-Flight formation of the migrating birds, which is proven to be an effective formation in energy saving. This approach is enhanced by the smart incorporation of parallel procedures that notably improve performance of the several sorting processes performed by the metaheuristic. We perform computational experiments on 1080 benchmarks resulting from the combination of 90 well-known MPCFP instances with 12 sorting configurations with and without threads. We illustrate promising results where the proposal is able to reach the global optimum in all instances, while the solving time with respect to a nonparallel approach is notably reduced.

  15. Oxidative stress in endurance flight: an unconsidered factor in bird migration.

    Directory of Open Access Journals (Sweden)

    Susanne Jenni-Eiermann

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

  16. Bird migration in south-western Romania: an analysis of ringing recoveries from Dolj county

    Directory of Open Access Journals (Sweden)

    RIDICHE Mirela-Sabina

    2017-12-01

    Full Text Available The present study concerns the bird species marked with rings in 21 countries (from Europe, Africa and Asia and that were recaptured in the SouhWest of Romania, more precisely in Dol county. The most came from Hungary (1 specimens, Russia ( specimens, and Ukraine ( specimens. The birds taken into consideration ( specimens belong to 22 species from halacocoa elecanus cticoa Aea iconia leais latalea Anas Atha otuni ulica hiloachus aus issa Stena aus genera. Some of them are kept in the patrimony of Museum of Oltenia, Craiova. The purpose of this study is to inform about the transcontinental bird migration and about some aspects regarding the traveled distance, flight speed, and longevity. In general, the ringed birds turned up in wetland areas nearby water courses, most of them being registred in the Danube Floodplain. In this contet, we want to emphasie the importance of wetland habitats, especially of the ones in the green corridor of Danube, as benefic shelters for stopover of migratory birds.

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

    Science.gov (United States)

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

  18. Shifts in Bird Migration Timing in North American Long-Distance and Short-Distance Migrants Are Associated with Climate Change

    Directory of Open Access Journals (Sweden)

    Jay Zaifman

    2017-01-01

    Full Text Available Bird migration is a synchronized event that has evolved over thousands of years. Changing temperatures due to climate change threaten the intricacies of migration timing for birds; however, the extent of these changes has only recently begun to be addressed. Utilizing data from the citizen-science website eBird and historical temperature data, we analyzed bird migration timing in two states warming quickly (Alaska and Maine and one warming gradually (South Carolina. Using linear regressions, we looked at relationships between different temperature indices and year with bird migration timing from 2010 to 2016. Bird migration through all three states, regardless of warming rate, showed similar rates of alterations. Additionally, in every state over half of the birds that had altered migration timing were long-distance migrants. Furthermore, we performed feature selection to determine important factors for changing migration timing of birds. Changes to summer resident and transient bird migration were most influenced by state. In winter resident migration, departure date and length of stay were most influenced by maximum temperature, while arrival date was most associated with minimum temperature. Relationships between changing temperatures and migration timing suggest that global climate change may have consequential effects on all bird migration patterns throughout the United States.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-06

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

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

    Science.gov (United States)

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

    2011-10-22

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

  2. Obese super athletes: fat-fueled migration in birds and bats.

    Science.gov (United States)

    Guglielmo, Christopher G

    2018-03-07

    Migratory birds are physiologically specialized to accumulate massive fat stores (up to 50-60% of body mass), and to transport and oxidize fatty acids at very high rates to sustain flight for many hours or days. Target gene, protein and enzyme analyses and recent -omic studies of bird flight muscles confirm that high capacities for fatty acid uptake, cytosolic transport, and oxidation are consistent features that make fat-fueled migration possible. Augmented circulatory transport by lipoproteins is suggested by field data but has not been experimentally verified. Migratory bats have high aerobic capacity and fatty acid oxidation potential; however, endurance flight fueled by adipose-stored fat has not been demonstrated. Patterns of fattening and expression of muscle fatty acid transporters are inconsistent, and bats may partially fuel migratory flight with ingested nutrients. Changes in energy intake, digestive capacity, liver lipid metabolism and body temperature regulation may contribute to migratory fattening. Although control of appetite is similar in birds and mammals, neuroendocrine mechanisms regulating seasonal changes in fuel store set-points in migrants remain poorly understood. Triacylglycerol of birds and bats contains mostly 16 and 18 carbon fatty acids with variable amounts of 18:2n-6 and 18:3n-3 depending on diet. Unsaturation of fat converges near 70% during migration, and unsaturated fatty acids are preferentially mobilized and oxidized, making them good fuel. Twenty and 22 carbon n-3 and n-6 polyunsaturated fatty acids (PUFA) may affect membrane function and peroxisome proliferator-activated receptor signaling. However, evidence for dietary PUFA as doping agents in migratory birds is equivocal and requires further study. © 2018. Published by The Company of Biologists Ltd.

  3. Migrating Birds Optimization for the Seaside Problems at Maritime Container Terminals

    Directory of Open Access Journals (Sweden)

    Eduardo Lalla-Ruiz

    2015-01-01

    Full Text Available Sea freight transportation involves moving huge amounts of freights among maritime locations widely spaced by means of container vessels. The time required to serve container vessels is the most relevant indicator when assessing the competitiveness of a maritime container terminal. In this paper, two main logistic problems stemming from the transshipment of containers in the seaside of a maritime container terminal are addressed, namely, the Berth Allocation Problem aimed at allocating and scheduling incoming vessels into berthing positions along the quay and the Quay Crane Scheduling Problem, whose objective is to schedule the loading and unloading tasks associated with a container vessel. For solving them, two Migrating Birds Optimization (MBO approaches are proposed. The MBO is a recently proposed nature-inspired algorithm based on the V-formation flight of migrating birds. In this algorithm, a set of solutions of the problem at hand, called birds, cooperate among themselves during the search process by sharing information within a V-line formation. The computational experiments performed over well-known problem instances reported in the literature show that the performance of our proposed MBO approaches is highly competitive and presents a better performance in terms of running time than the best approximate approach proposed in the literature.

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

    Science.gov (United States)

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

    2011-06-01

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

  5. Thermal impact of migrating birds' wing color on their flight performance: Possibility of new generation of biologically inspired drones.

    Science.gov (United States)

    Hassanalian, M; Abdelmoula, H; Ben Ayed, S; Abdelkefi, A

    2017-05-01

    The thermal impact of the birds' color on their flight performance are investigated. In most of the large migrating birds, the top of their wings is black. Considering this natural phenomenon in the migrating birds, such as albatross, a thermal analysis of the boundary layer of their wings is performed during the year depending on the solar insulation. It is shown that the temperature difference between the bright and dark colored top wing surface is around 10°C. The dark color on the top of the wing increases the temperature of the boundary layer over the wing which consequently reduces the skin drag force over the wing. This reduction in the drag force can be considered as one of the effective factors for long endurance of these migrating birds. This research should lead to improved designs of the drones by applying the inspired colors which can help drones increase their endurance. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Science.gov (United States)

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

    2015-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Karl Hagman

    2014-01-01

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

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

    Science.gov (United States)

    Kellermann, Jherime L.; van Riper, Charles

    2015-01-01

    Small-bodied songbirds replenish fat reserves during migration at stopover sites where they continually encounter novel and often unpredictable environmental conditions. The ability to select and utilize high quality habitats is critical to survival and fitness. Vegetation phenology is closely linked with emergence of insect prey and may provide valid cues of food availability for stopover habitat selection. Climate change is disrupting phenological synchrony across trophic levels with negative impacts on bird populations. However, whether synchrony or mismatch indicates historic or disrupted systems remains unclear. Many Neotropical migratory songbirds of western North America must cross arid regions where drought conditions related to climate change and human water use are expected to increase. We studied migrant abundance and the diversity (niche breadth) and proportional use of vegetation species as foraging substrates and their synchrony with vegetation flowering during spring migration along the lower Colorado River in the Sonoran Desert of the U.S. and Mexico.

  10. Birds in New York State Have Altered Their Migration Timing and Are Experiencing Different Thermal Regimes While Breeding or on Stopover from 2010 to 2015

    OpenAIRE

    Pudalov, Natalie; Ziatek, Sydney; Jimenez, Ana Gabriela

    2017-01-01

    Migration represents a significant physiological challenge for birds, and increasing ambient temperatures due to global climate change may add to birds’ physiological burden during migration. We analyzed migration timing in a central New York county and two counties in the Adirondack region by using data from the citizen science network, eBird, and correlating it with historical temperature data. Species of birds sighted in Central NY (N=195) and the Adirondack region (N=199) were categorized...

  11. Milestones of the history of modern Western theory of migration

    Directory of Open Access Journals (Sweden)

    A M Adediran

    2015-12-01

    Full Text Available The article outlines the key stages in the development of modern theory of migration following the historical sequence and continuity of its basic conceptual constructs’ formation. Although the author refers to the twentieth century as a chronological framework of the text, the narrative begins from the works of E. Ravenstein published at the end of the XIX century, for they laid the foundation for future theoretical studies on migration issues. In particular, many well-known scientists still use concepts “laws of migration” and “attracting and push factors of migration” proposed by Ravenstein claiming their timeless validity or, on the contrary, criticizing them for the loss of relevance in the new social and cultural realities. The author considers as milestones of the modern theory of migration the works of the representatives of Chicago school of sociology that enriched the conceptual apparatus of the analysis of migration processes and the typology of driving causes of migration; the works of S. Stouffer, G. Zipf, E. Lee and W. Lewis, W. Zelinsky and D. Massey. Finally, the article summarizes the objective trends in today’s global development that force scientists to introduce new accents in the study of migration processes, although upon closer inspection it turns out that all “new” ideas had already been formulated in early migration studies and just got a new sound in another historical period.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2014-10-22

    Migration is a common strategy used by birds that breed in seasonal environments. The patterns and determinants of migration routes, however, remain poorly understood. Recent empirical analyses have demonstrated that the locations of two North America migration flyways (eastern and western) shift seasonally, reflecting the influence of looped migration strategies. For the eastern but not western flyway, seasonal variation in atmospheric circulation has been identified as an explanation. Here, we test an alternative explanation based on the phenology of ecological productivity, which may be of greater relevance in western North America, where phenology is more broadly dictated by elevation. Migrants in the western flyway selected lower-elevation spring routes that were wetter, greener and more productive, and higher-elevation autumn routes that were less green and less productive, but probably more direct. Migrants in the eastern flyway showed little season variation but maintained associations with maximum regional greenness. Our findings suggest the annual phenology of ecological productivity is associated with en route timing in both flyways, and the spring phenology of ecological productivity contributes to the use of looped strategies in the western flyway. This fine-tuned spatial synchronization may be disrupted when changing climate induces a mismatch between food availability and needs. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  14. Route simulations, compass mechanisms and long-distance migration flights in birds.

    Science.gov (United States)

    Åkesson, Susanne; Bianco, Giuseppe

    2017-07-01

    Bird migration has fascinated humans for centuries and routes crossing the globe are now starting to be revealed by advanced tracking technology. A central question is what compass mechanism, celestial or geomagnetic, is activated during these long flights. Different approaches based on the geometry of flight routes across the globe and route simulations based on predictions from compass mechanisms with or without including the effect of winds have been used to try to answer this question with varying results. A major focus has been use of orthodromic (great circle) and loxodromic (rhumbline) routes using celestial information, while geomagnetic information has been proposed for both a magnetic loxodromic route and a magnetoclinic route. Here, we review previous results and evaluate if one or several alternative compass mechanisms can explain migration routes in birds. We found that most cases could be explained by magnetoclinic routes (up to 73% of the cases), while the sun compas s could explain only 50%. Both magnetic and geographic loxodromes could explain <25% of the routes. The magnetoclinic route functioned across latitudes (1°S-74°N), while the sun compass only worked in the high Arctic (61-69°N). We discuss the results with respect to orientation challenges and availability of orientation cues.

  15. Migrating birds and carnivores introduce ticks and tick borne pathogens to Denmark – but are they also a public health risk?

    DEFF Research Database (Denmark)

    Bødker, Rene; Vrbová, Erika; Højgaard, Jesper

    Since the end of the ice age, spring migrating birds from Africa and Europe and autumn migrating birds from Northern Scandinavia have entered Denmark, and recently a small wave of long migrating carnivores have started arriving in Denmark from Central Europe. Theoretically, migrating birds could ...... pathogens. We show that the risk is not just theoretical and we suggest that these introductions may have a practical public health impact....... in Danish forest and nature areas can be expected to be of little practical importance. However, some of the infected ticks, introduced by migrating birds, may be deposited in private gardens and public parks that are otherwise not able to sustain a viable tick population. Migrating birds may therefore...

  16. Emerging practices of wind farm planning in a dense bird migration area

    DEFF Research Database (Denmark)

    Clausen, Niels-Erik; Mortensen, N.G.; Hansen, J.C.

    2003-01-01

    The objective of this paper is to present part of The Wind Atlas for Egypt project aiming at developing a firm basis for planning and utilization of the vast wind energy resources available in Egypt. The project should recommend a common planning framework for wind farm development in Egypt...... is briefly introduced. As a case study to illustrate the planning process a 60 MW wind farm located at the Gulf of El-Zayt at the Gulf of Suez in Egypt will be analysed. This area is chosen for its very high wind energy potential and the high concentration of migrating birds during spring and autumn. During...... the site selection and layout of a wind farm the balancing of interests and land use will be described....

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

    Science.gov (United States)

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

    2009-01-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Christine Nießner

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

  20. Migration distance and the effect of North Atlantic Oscillation on the spring arrival of birds in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Čapek, Miroslav

    2008-01-01

    Roč. 57, č. 3 (2008), s. 212-220 ISSN 0139-7893 Institutional research plan: CEZ:AV0Z60930519 Keywords : climate * NAO * phenology * temperature * weather * migration of bird s * wintering area Subject RIV: EH - Ecology, Behaviour Impact factor: 0.522, year: 2008 http://www.ivb.cz/folia/57/3/212_220.pdf

  1. Prevalence of Campylobacter jejuni, C.lari and C.coli in different ecological guilds and taxa of migrating birds

    NARCIS (Netherlands)

    Waldenstrom, J.; Broman, T.; Carlsson, I.; Hasselquist, D.; Achterberg, R.P.; Wagenaar, J.A.; Olsen, B.

    2002-01-01

    A total of 1,794 migrating birds trapped at a coastal site in southern Sweden were sampled for detection of Campylobacter spp. All isolates phenotypically identified as Campylobacter jejuni and a subset of those identified as non-C. jejuni were identified to the species level by PCR-based

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

    Science.gov (United States)

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

    2014-01-01

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

  3. Theory of endogenous and exogenous motivation in L2 migration

    Directory of Open Access Journals (Sweden)

    Kambon, Obadele Bakari

    2015-09-01

    Full Text Available Implied in theories of Second Language Acquisition (SLA is the notion that language learning is analogous to obtaining or acquiring a possession – thus the use of the term ‘acquisition.’ While this interpretation has gone relatively unchallenged in the literature, this article introduces a new analogy whereby language learning is seen as analogous to a process of permanent or semi-permanent migration towards a new socio-linguistic L2 space. As such, a theory of endogenous and exogenous motivation is delineated, entailing a dynamic interplay between internal (primarily psychological and external (primarily sociological push-pull factors. Endogenous and exogenous push-pull factors, together with various other personal factors, contribute to learner decisions to migrate towards, move away from or remain inert with regard to the target language. Further, motivation is framed in the larger theoretical context of causation.

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

    Science.gov (United States)

    Ramos-Robles, Michelle; Andresen, Ellen; Díaz-Castelazo, Cecilia

    2016-01-01

    Background. Ecological communities are dynamic collections whose composition and structure change over time, making up complex interspecific interaction networks. Mutualistic plant-animal networks can be approached through complex network analysis; these networks are characterized by a nested structure consisting of a core of generalist species, which endows the network with stability and robustness against disturbance. Those mutualistic network structures can vary as a consequence of seasonal fluctuations and food availability, as well as the arrival of new species into the system that might disorder the mutualistic network structure (e.g., a decrease in nested pattern). However, there is no assessment on how the arrival of migratory species into seasonal tropical systems can modify such patterns. Emergent and fine structural temporal patterns are adressed here for the first time for plant-frugivorous bird networks in a highly seasonal tropical environment. Methods. In a plant-frugivorous bird community, we analyzed the temporal turnover of bird species comprising the network core and periphery of ten temporal interaction networks resulting from different bird migration periods. Additionally, we evaluated how fruit abundance and richness, as well as the arrival of migratory birds into the system, explained the temporal changes in network parameters such as network size, connectance, nestedness, specialization, interaction strength asymmetry and niche overlap. The analysis included data from 10 quantitative plant-frugivorous bird networks registered from November 2013 to November 2014. Results. We registered a total of 319 interactions between 42 plant species and 44 frugivorous bird species; only ten bird species were part of the network core. We witnessed a noteworthy turnover of the species comprising the network periphery during migration periods, as opposed to the network core, which did not show significant temporal changes in species composition. Our results

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

    Science.gov (United States)

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

    2015-06-01

    Current knowledge of phenological shifts in Palearctic bird migration is largely based on data collected on migrants at their breeding grounds; little is known about the phenology of these birds at their nonbreeding grounds, and even less about that of intra-African migrants. Because climate change patterns are not uniform across the globe, we can expect regional disparities in bird phenological responses. It is also likely that they vary across species, as species show differences in the strength of affinities they have with particular habitats and environments. Here, we examine the arrival and departure of nine Palearctic and seven intra-African migratory species in the central Highveld of South Africa, where the former spend their nonbreeding season and the latter their breeding season. Using novel analytical methods based on bird atlas data, we show phenological shifts in migration of five species - red-backed shrike, spotted flycatcher, common sandpiper, white-winged tern (Palearctic migrants), and diederik cuckoo (intra-African migrant) - between two atlas periods: 1987-1991 and 2007-2012. During this time period, Palearctic migrants advanced their departure from their South African nonbreeding grounds. This trend was mainly driven by waterbirds. No consistent changes were observed for intra-African migrants. Our results suggest that the most consistent drivers of migration phenological shifts act in the northern hemisphere, probably at the breeding grounds. © 2015 John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2011-01-01

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

  7. Candidate genes for migration do not distinguish migratory and non-migratory birds.

    Science.gov (United States)

    Lugo Ramos, Juan S; Delmore, Kira E; Liedvogel, Miriam

    2017-07-01

    Migratory traits in birds have been shown to have a strong heritable component and several candidate genes have been suggested to control these migratory traits. To investigate if the genetic makeup of one or a set of these candidate genes can be used to identify a general pattern between migratory and non-migratory birds, we extracted genomic sequence data for 25 hypothesised candidate genes for migration from 70 available genomes across all orders of Aves and characterised sequence divergence between migratory and non-migratory phenotypes. When examining each gene separately across all species, we did not identify any genetic variants in candidate genes that distinguished migrants from non-migrants; any resulting pattern was driven by the phylogenetic signal. This was true for each gene analysed independently, but also for concatenated sequence alignments of all candidate genes combined. We also attempted to distinguish between migrant and non-migrants using structural features at four candidate genes that have previously been reported to show associated with migratory behaviour but did not pick up a signal for migratory phenotype here either. Finally, a screen for dN/dS ratio across all focal candidate genes to probe for putative features of selection did not uncover a pattern, though this might not be expected given the broad phylogenetic scale used here. Our study demonstrates the potential of public genomic data to test for general patterns of migratory gene candidates in a cross-species comparative context, and raise questions on the applicability of candidate gene approaches in a macro-evolutionary context to understand the genetic architecture of migratory behaviour.

  8. Birds in New York State Have Altered Their Migration Timing and Are Experiencing Different Thermal Regimes While Breeding or on Stopover from 2010 to 2015

    Directory of Open Access Journals (Sweden)

    Natalie Pudalov

    2017-01-01

    Full Text Available Migration represents a significant physiological challenge for birds, and increasing ambient temperatures due to global climate change may add to birds’ physiological burden during migration. We analyzed migration timing in a central New York county and two counties in the Adirondack region by using data from the citizen science network, eBird, and correlating it with historical temperature data. Species of birds sighted in Central NY (N=195 and the Adirondack region (N=199 were categorized into year-round residents and one- and two-stopover groupings based on eBird observations. Using linear regressions, we looked at various relationships between temperature and variables relating to birds’ migration across 2010–2015. Of the total 195 species used within this data in Central NY, 35 species showed some alteration in their migration timing or in the temperature regime they experienced while breeding or on migration stopover. In the Adirondack region, of the total 199 species used within this dataset, 43 species showed some alteration in their migration timing or experienced significantly colder or warmer temperatures while breeding or on migration stopover during 2010–2015. Additionally, many of the bird species affected by temperature changes in the state of New York and those that altered migration timing tended to be long-distance migrants.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Lisa C Davenport

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

  11. Limitations and mechanisms influencing the migratory performance of soaring birds

    Science.gov (United States)

    Tricia A. Miller; Brooks Robert P.; Michael J. Lanzone; David Brandes; Jeff Cooper; Junior A. Tremblay; Jay Wilhelm; Adam Duerr; Todd E. Katzner

    2016-01-01

    Migration is costly in terms of time, energy and safety. Optimal migration theory suggests that individual migratory birds will choose between these three costs depending on their motivation and available resources. To test hypotheses about use of migratory strategies by large soaring birds, we used GPS telemetry to track 18 adult, 13 sub-adult and 15 juvenile Golden...

  12. Seasonal patterns in δ2 H values of multiple tissues from Andean birds provide insights into elevational migration.

    Science.gov (United States)

    Villegas, Mariana; Newsome, Seth D; Blake, John G

    2016-12-01

    Elevational migration is a widespread phenomenon in tropical avifauna but it is difficult to identify using traditional approaches. Hydrogen isotope (δ 2 H) values of precipitation decrease with elevation so δ 2 H analysis of multiple bird tissues with different isotopic incorporation rates may be a reliable method for characterizing seasonal elevational migration. Here we compare δ 2 H values in metabolically inert (feathers and claws) and metabolically active (whole blood) tissues to examine whether an upslope migration occurs prior to the breeding season in the Yungas Manakin (Chiroxiphia boliviana). We compare results from C. boliviana with data from a known elevational migrant, the Streak-necked Flycatcher (Mionectes striaticollis). Opposite to our expectations, tissue δ 2 H values increased over time, largely reflecting seasonal patterns in precipitation δ 2 H rather than elevational effects; linear mixed-effects models with strongest support included ordinal date, tissue type, and elevation. This seasonal increase in precipitation δ 2 H is a general phenomenon in both tropical and temperate mountain ranges. We use these data to propose a hypothetical framework that predicts different patterns in tissue δ 2 H values collected in different seasons from residents and elevational migrants. This framework can serve as a reference for future studies that assess elevational migration in birds and other animals. © 2016 by the Ecological Society of America.

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

    Science.gov (United States)

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

    2017-10-01

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

  14. Interntional Migration with Heterogeneous Agents: Theory and Evidence

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Brücker, Herbert

    Two puzzling facts of international migration are that only a small share of a sending country's population emigrates and that net migration rates tend to cease over time. This paper addresses these issues in a migration model with heterogeneous agents that features temporary migration....... In equilibrium a positive relation exists between the stock of migrants and the income differential, while the net migration flow becomes zero. Consequently, empirical migration models, estimating net migration flows instead of stocks, may be misspecified. This suspicion appears to be confirmed by our empirical...... investigation of cointegration relationships of flow and stock migration models....

  15. Combining radar systems to get a 3D - picture of the bird migration

    OpenAIRE

    Liechti, F.; Dokter, A.; Shamoun, J.; van Gasteren, H.; Holleman, I.

    2008-01-01

    For military training flights bird strikes en route are still a severe problem. To reduce collisions an international project has been launched by the European Space agency (ESA), aiming 1) for a compilation of information on current bird movements by various sensors, 2) to combine them in a single model, and to finally 3) predict bird strike risks for different spatial and temporal scales. A potential sensor to achieve these aims is the already existing European network of weather radars, bu...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, P.

    2002-03-01

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

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

    Science.gov (United States)

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

    2015-07-01

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

  18. Combining radar systems to get a 3D - picture of the bird migration

    NARCIS (Netherlands)

    Liechti, F.; Dokter, A.; Shamoun, J.; van Gasteren, H.; Holleman, I.

    2008-01-01

    For military training flights bird strikes en route are still a severe problem. To reduce collisions an international project has been launched by the European Space agency (ESA), aiming 1) for a compilation of information on current bird movements by various sensors, 2) to combine them in a single

  19. MASS CHANGES IN MIGRATING BIRDS - THE EVIDENCE FOR FAT AND PROTEIN STORAGE REEXAMINED

    NARCIS (Netherlands)

    PIERSMA, T

    The fact that one cannot kill a bird twice makes it very difficult to determine the relative contributions of fat and non-fat components to increases in body mass before migratory flights in individual birds. Knowing the relative contributions of these components is of obvious energetic interest

  20. New perspective of migration research in the book “Migration theory. Talking across disciplines”

    OpenAIRE

    Kazlauskaitė, Asta

    2010-01-01

    XX a. pabaigoje – XXI a. pradžioje dinamiškai besiplėtojęs globalizacijos reiškinys, skatinęs sunkiai kontroliuojamų migrantų judėjimo srautų augimą, tapo didelio mokslininkų susidomėjimo vertu objektu. Itin reikšmingą šio reiškinio atžvilgiu įdirbį pademonstravo JAV tarptautinės ekonomikos politikos srities specialistas Jamesas F. Hollifieldas ir antropologijos mokslų profesorė Caroline B. Brettell. Šie mokslininkai iniciavo „Migration theory. Talking across disciplines“ leidinio publikavimą...

  1. International Migration with Heterogeneous Agents: Theory and Evidence

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Brücker, Herbert

    Temporary migration, though empirically relevant, is often ignored in formal models. This paper proposes a migration model with heterogeneous agents and persistent cross country income differentials that features temporary migration. In equilibrium there exists a positive relation between the stock...... of migrants and the income differential, while the net migration flow becomes zero. Consequently, existing empirical migration models, estimating net migration flows, instead of stocks, may be misspecified. This suspicion appears to be confirmed by our investigation of the cointegration relationships...... of German migration stocks and flows since 1967. We find that (i) panel-unit root tests reject the hypothesis that migration flows and the explanatory variables are integrated of the same order, while migration stocks and the explanatory variables are all I(1) variables, and (ii) the hypothesis...

  2. The next waves: migration theory for a changing world.

    Science.gov (United States)

    Zolberg, A R

    1989-01-01

    In the last quarter of a century, migration theory has undergone fundamental change, moving from the classic "individual relocation" genre initiated by Ravenstein a century ago, to a variety of new approaches which nevertheless share important elements: they tend to be historical, structural, globalist, and critical. Historicization implies a constant modification of theoretical concerns and emphases in the light of changing social realities, and a commitment to a critical approach entails a view of research as 1 element in a broader project concerned with the elucidation of social and political conditions. The article uses elements from 2 major theoretical traditions - a modified world-systems approach and state theory - to project current trends. Global inequality is considered as a structural given. The article then reviews major topics, including the persistence of restrictive immigration policies as barriers to movement, changing patterns of exploitation of foreign labor, liberalization of exit from the socialist world, and the refugee crisis in the developing world. It concludes with a brief consideration of the normative implications of these trends.

  3. Dissemination of spotted fever rickettsia agents in Europe by migrating birds.

    Science.gov (United States)

    Elfving, Karin; Olsen, Björn; Bergström, Sven; Waldenström, Jonas; Lundkvist, Ake; Sjöstedt, Anders; Mejlon, Hans; Nilsson, Kenneth

    2010-01-05

    Migratory birds are known to play a role as long-distance vectors for many microorganisms. To investigate whether this is true of rickettsial agents as well, we characterized tick infestation and gathered ticks from 13,260 migratory passerine birds in Sweden. A total of 1127 Ixodes spp. ticks were removed from these birds and the extracted DNA from 957 of them was available for analyses. The DNA was assayed for detection of Rickettsia spp. using real-time PCR, followed by DNA sequencing for species identification. Rickettsia spp. organisms were detected in 108 (11.3%) of the ticks. Rickettsia helvetica, a spotted fever rickettsia associated with human infections, was predominant among the PCR-positive samples. In 9 (0.8%) of the ticks, the partial sequences of 17kDa and ompB genes showed the greatest similarity to Rickettsia monacensis, an etiologic agent of Mediterranean spotted fever-like illness, previously described in southern Europe as well as to the Rickettsia sp.IrITA3 strain. For 15 (1.4%) of the ticks, the 17kDa, ompB, gltA and ompA genes showed the greatest similarity to Rickettsia sp. strain Davousti, Rickettsia japonica and Rickettsia heilongjiangensis, all closely phylogenetically related, the former previously found in Amblyomma tholloni ticks in Africa and previously not detected in Ixodes spp. ticks. The infestation prevalence of ticks infected with rickettsial organisms was four times higher among ground foraging birds than among other bird species, but the two groups were equally competent in transmitting Rickettsia species. The birds did not seem to serve as reservoir hosts for Rickettsia spp., but in one case it seems likely that the bird was rickettsiemic and that the ticks had acquired the bacteria from the blood of the bird. In conclusion, migratory passerine birds host epidemiologically important vector ticks and Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents and their diseases.

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

    Science.gov (United States)

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

    2015-11-06

    Large birds regularly use updrafts to subsidize flight. Although most research on soaring bird flight has focused on use of thermal updrafts, there is evidence suggesting that many species are likely to use multiple modes of subsidy. We tested the degree to which a large soaring species uses multiple modes of subsidy to provide insights into the decision-making that underlies flight behaviour. We statistically classified more than 22 000 global positioning satellite-global system for mobile communications telemetry points collected at 30-s intervals to identify the type of subsidized flight used by 32 migrating golden eagles during spring in eastern North America. Eagles used subsidized flight on 87% of their journey. They spent 41.9% ± 1.5 ([Formula: see text], range: 18-56%) of their subsidized northbound migration using thermal soaring, 45.2% ± 2.1 (12-65%) of time gliding between thermals, and 12.9% ± 2.2 (1-55%) of time using orographic updrafts. Golden eagles responded to the variable local-scale meteorological events they encountered by switching flight behaviour to take advantage of multiple modes of subsidy. Orographic soaring occurred more frequently in morning and evening, earlier in the migration season, and when crosswinds and tail winds were greatest. Switching between flight modes allowed migration for relatively longer periods each day and frequent switching behaviour has implications for a better understanding of avian flight behaviour and of the evolution of use of subsidy in flight. © 2015 The Author(s).

  5. Insights on the thermal impacts of wing colorization of migrating birds on their skin friction drag and the choice of their flight route.

    Science.gov (United States)

    Hassanalian, M; Ayed, S Ben; Ali, M; Houde, P; Hocut, C; Abdelkefi, A

    2018-02-01

    The thermal effects of wing color in flight is investigated in four species of birds with respect to their flight routes, migration time, and geometric and behavioral characteristics. Considering the marine and atmospheric characteristics of these flight routes, a thermal analysis of the birds' wings is performed during their migration. The surrounding fluxes including the ocean flux and the solar irradiance are considered in an energy balance in order to determine the skin temperature of both sides of the wing. Applying the Blasius solution for heated boundary layers, it is shown that the color configuration of these migrating birds, namely black on the top side of the wings and white on the bottom side of the wings ("countershading"), results in a skin drag reduction, if compared to some other configurations, when both day and night are taken into consideration. This drag reduction can be considered as one of the effective factors for long endurance of these migrating birds. This research can provide the evolutionary perspective behind the colorization of these migrating birds. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Wild bird migration across the Qinghai-Tibetan plateau: a transmission route for highly pathogenic H5N1.

    Science.gov (United States)

    Prosser, Diann J; Cui, Peng; Takekawa, John Y; Tang, Mingjie; Hou, Yuansheng; Collins, Bridget M; Yan, Baoping; Hill, Nichola J; Li, Tianxian; Li, Yongdong; Lei, Fumin; Guo, Shan; Xing, Zhi; He, Yubang; Zhou, Yuanchun; Douglas, David C; Perry, William M; Newman, Scott H

    2011-03-09

    Qinghai Lake in central China has been at the center of debate on whether wild birds play a role in circulation of highly pathogenic avian influenza virus H5N1. In 2005, an unprecedented epizootic at Qinghai Lake killed more than 6000 migratory birds including over 3000 bar-headed geese (Anser indicus). H5N1 subsequently spread to Europe and Africa, and in following years has re-emerged in wild birds along the Central Asia flyway several times. To better understand the potential involvement of wild birds in the spread of H5N1, we studied the movements of bar-headed geese marked with GPS satellite transmitters at Qinghai Lake in relation to virus outbreaks and disease risk factors. We discovered a previously undocumented migratory pathway between Qinghai Lake and the Lhasa Valley of Tibet where 93% of the 29 marked geese overwintered. From 2003-2009, sixteen outbreaks in poultry or wild birds were confirmed on the Qinghai-Tibet Plateau, and the majority were located within the migratory pathway of the geese. Spatial and temporal concordance between goose movements and three potential H5N1 virus sources (poultry farms, a captive bar-headed goose facility, and H5N1 outbreak locations) indicated ample opportunities existed for virus spillover and infection of migratory geese on the wintering grounds. Their potential as a vector of H5N1 was supported by rapid migration movements of some geese and genetic relatedness of H5N1 virus isolated from geese in Tibet and Qinghai Lake. This is the first study to compare phylogenetics of the virus with spatial ecology of its host, and the combined results suggest that wild birds play a role in the spread of H5N1 in this region. However, the strength of the evidence would be improved with additional sequences from both poultry and wild birds on the Qinghai-Tibet Plateau where H5N1 has a clear stronghold.

  7. Wild bird migration across the Qinghai-Tibetan plateau: a transmission route for highly pathogenic H5N1.

    Directory of Open Access Journals (Sweden)

    Diann J Prosser

    Full Text Available BACKGROUND: Qinghai Lake in central China has been at the center of debate on whether wild birds play a role in circulation of highly pathogenic avian influenza virus H5N1. In 2005, an unprecedented epizootic at Qinghai Lake killed more than 6000 migratory birds including over 3000 bar-headed geese (Anser indicus. H5N1 subsequently spread to Europe and Africa, and in following years has re-emerged in wild birds along the Central Asia flyway several times. METHODOLOGY/PRINCIPAL FINDINGS: To better understand the potential involvement of wild birds in the spread of H5N1, we studied the movements of bar-headed geese marked with GPS satellite transmitters at Qinghai Lake in relation to virus outbreaks and disease risk factors. We discovered a previously undocumented migratory pathway between Qinghai Lake and the Lhasa Valley of Tibet where 93% of the 29 marked geese overwintered. From 2003-2009, sixteen outbreaks in poultry or wild birds were confirmed on the Qinghai-Tibet Plateau, and the majority were located within the migratory pathway of the geese. Spatial and temporal concordance between goose movements and three potential H5N1 virus sources (poultry farms, a captive bar-headed goose facility, and H5N1 outbreak locations indicated ample opportunities existed for virus spillover and infection of migratory geese on the wintering grounds. Their potential as a vector of H5N1 was supported by rapid migration movements of some geese and genetic relatedness of H5N1 virus isolated from geese in Tibet and Qinghai Lake. CONCLUSIONS/SIGNIFICANCE: This is the first study to compare phylogenetics of the virus with spatial ecology of its host, and the combined results suggest that wild birds play a role in the spread of H5N1 in this region. However, the strength of the evidence would be improved with additional sequences from both poultry and wild birds on the Qinghai-Tibet Plateau where H5N1 has a clear stronghold.

  8. Variation of basal EROD activities in ten passerine bird species--relationships with diet and migration status.

    Science.gov (United States)

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

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2014-01-01

    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

  10. Radioactivity measurements on migrating birds (Turdus philomelos) captured in the Comunidad Valenciana (Spain)

    International Nuclear Information System (INIS)

    Navarro, E.; Roldan, C.; Cervera, J.; Ferrero, J.L.

    1998-01-01

    The radionuclides 137 Cs, 134 Cs and 90 Sr have been measured in edible tissues and bones of migratory birds (song-thrushes, Turdus philomelos) from central and northern Europe and captured in the Comunidad Valenciana, Spain in the 1994 autumn-winter season. Eight years after the Chernobyl accident, extensive agricultural lands in Europe are still contaminated and this study shows that there was a transfer of radioactive isotopes to the captured migratory song-thrushes. The whole-body dose commitment to humans consuming these birds is estimated

  11. The magnetic map sense and its use in fine-tuning the migration programme of birds.

    Science.gov (United States)

    Heyers, D; Elbers, D; Bulte, M; Bairlein, F; Mouritsen, H

    2017-07-01

    The Earth's magnetic field is one of several natural cues, which migratory birds can use to derive directional ("compass") information for orientation on their biannual migratory journeys. Moreover, magnetic field effects on prominent aspects of the migratory programme of birds, such as migratory restlessness behaviour, fuel deposition and directional orientation, implicate that geomagnetic information can also be used to derive positional ("map") information. While the magnetic "compass" in migratory birds is likely to be based on radical pair-forming molecules embedded in their visual system, the sensory correlates underlying a magnetic "map" sense currently remain elusive. Behavioural, physiological and neurobiological findings indicate that the sensor is most likely innervated by the ophthalmic branch of the trigeminal nerve and based on magnetic iron particles. Information from this unknown sensor is neither necessary nor sufficient for a functional magnetic compass, but instead could contribute important components of a multifactorial "map" for global positioning. Positional information could allow migratory birds to make vitally important dynamic adaptations of their migratory programme at any relevant point during their journeys.

  12. Monitoring bird migration in the Caribbean basin: multi-national cooperation can close the loop

    Science.gov (United States)

    Paul B. Hamel; Cecilia M. Riley; W. C. Hunter; Mark S. Woodrey

    2005-01-01

    The Gulf Coast Bird Observatory (GCBO) and the Southeastern Working Group of Partners in Flight have developed a protocol to monitor landbirds with volunteer observers performing avian censuses in the field. Field observations are compiled within a powerful internet database, and recording and summary capability is maintained by the GCBO. More than 100 observers have...

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

    Science.gov (United States)

    Sturner, Kelly; Lucci, Karen

    2015-01-01

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

  14. Flying, fasting, and feeding in birds during migration: a nutritional and physiological ecology perspective

    NARCIS (Netherlands)

    McWilliams, S.R.; Guglielmo, C.; Pierce, B.; Klaassen, M.R.J.

    2004-01-01

    Unlike exercising mammals, migratory birds fuel very high intensity exercise (e.g., flight) with fatty acids delivered from the adipose tissue to the working muscles by the circulatory system. Given the primary importance of fatty acids for fueling intense exercise, we discuss the likely limiting

  15. Heavy fall of migrating land-birds on board of a ship off Central America

    NARCIS (Netherlands)

    Roselaar, C.S.

    1976-01-01

    Between 4 and 7 October 1973, during a spell of unfavourable weather, 85 North American migratory birds were found dead on board a ship sailing between Costa Rica and Belize and in the roads of Belize. They were donated to the Institute of Taxonomic Zoology, University of Amsterdam, where they were

  16. Variation in energy intake and basal metabolic rate of a bird migrating in a wind tunnel

    NARCIS (Netherlands)

    Lindström, Å.; Klaassen, M.R.J.; Kvist, A.

    1999-01-01

    1. We studied the changes in body mass, metabolizable energy intake rate (ME) and basal metabolic rate (BMR) of a Thrush Nightingale, Luscinia luscinia, following repeated 12-h migratory flights in a wind tunnel. In total the bird flew for 176 h corresponding to 6300 km. This is the first study

  17. Consistency in long-distance bird migration: contrasting patterns in time and space for two raptors

    NARCIS (Netherlands)

    Vardanis, Yannis; Nilsson, Jan-Ake; Klaassen, Raymond H. G.; Strandberg, Roine; Alerstam, Thomas

    As the evolutionary responses to environmental change depend on selection acting on individual differences, disentangling within- and between-individual variation becomes imperative. In animal migration research, multiyear tracks are thus needed to estimate the individual consistency of phenotypic

  18. Migration, relationship capital and international travel : theory and evidence

    NARCIS (Netherlands)

    McCann, Philip; Poot, Jacques; Sanderson, Lynda

    In this article we consider how international migration is related to the frequency and duration of trips to the home country. For many migrants, international migration triggers a series of trips to visit the home country that allow for a replenishment of the depleted relationship capital with

  19. Inferring the potential risks of H7N9 infection by spatiotemporally characterizing bird migration and poultry distribution in eastern China.

    Science.gov (United States)

    Shi, Benyun; Xia, Shang; Yang, Guo-Jing; Zhou, Xiao-Nong; Liu, Jiming

    2013-05-03

    In view of the rapid geographic spread and the increasing number of confirmed cases of novel influenza A(H7N9) virus infections in eastern China, we developed a diffusion model to spatiotemporally characterize the impacts of bird migration and poultry distribution on the geographic spread of H7N9 infection. Three types of infection risks were estimated for 12 weeks, from February 4 to April 28, 2013, including (i) the risk caused by bird migration, (ii) the risk caused by poultry distribution, and (iii) the integrated risk caused by both bird migration and poultry distribution. To achieve this, we first developed a method for estimating the likelihood of bird migration based on available environmental and meteorological data. Then, we adopted a computational mobility model to estimate poultry distribution based on annual poultry production and consumption of each province/municipality. Finally, the spatiotemporal risk maps were created based on the integrated impacts of both bird migration and poultry distribution. In the study of risk estimation caused by bird migration, the likelihood matrix was estimated based on the 7-day temperature, from February 4 to April 28, 2013. It was found the estimated migrant birds mainly appear in the southeastern provinces of Zhejiang, Shanghai and Jiangsu during Weeks 1 to 4, and Week 6, followed by appearing in central eastern provinces of Shandong, Hebei, Beijing, and Tianjin during Weeks 7 to 9, and finally in northeastern provinces of Liaoning, Jilin, and Heilongjiang during Weeks 10 to 12.In the study of risk caused by poultry distribution, poultry distribution matrix was created to show the probability of poultry distribution. In spite of the fact that the majority of the initial infections were reported in Shanghai and Jiangsu, the relative risk of H7N9 infection estimated based on the poultry distribution model predicted that Jiangsu may have a slightly higher likelihood of H7N9 infection than those in Zhejiang and

  20. Birds of passage no more: migration decision making among Filipino immigrants in Hawaii.

    Science.gov (United States)

    Arnold, F

    1987-03-01

    Using data primarily from the Honolulu Destination Survey (HDS), which is part of the Philippine Migration Study (a study of a migration system that has its origins in Ilocos Norte, a largely rural province in the Philippines), the author examines migration decision making among Philippine immigrants in Hawaii. The HDS, conducted in 1981, interviewed 1484 residents of Honolulu who immigrated from the Ilocos Region after the US immigration law was liberalized in 1965. Results from the Philippine Migration Study (PMS) survey show that of those who did not have any intentions to move within 2 years in 1980, 88% did not move between 1980 and 1982. Of those who said they were certain to move within 2 years, 54% actually moved, while only 36% who were fairly certain and 31% who were uncertain moved. Virtually all of those who actually moved to Hawaii from 1980-1982 had intended to move to Hawaii in 1980. It thus appears that most migration is planned well in advance. For those who have already migrated, their behavior in the destination is influenced by their expectations about future migration. An estimated 20-38.7% of legal immigrants to the US from the Philippines in 1971 had emigrated as of January 1979. 49% of HDS respondents said that they did not intend to move out of Hawaii any time in the future. Among those who intend to move in the future, 69% want to return to Ilocos and 26% intend to move to the US mainland. 40% want to leave Hawaii for economic reasons and 27% for affiliation purposes. The value expectancy framework used in the PMS measures expectations of achieving one's most important goals in alternative locations. The analysis employs both binomial and multinomial logit analysis to identify significant determinants of future migration intentions. The 7 conceptual categories are: wealth, status, comfort, stimulation, autonomy, affiliation, and morality. 90% consider "having a peaceful life" followed by "getting ahead in the world" the most important

  1. Why is timing of bird migration advancing when individuals are not?

    Science.gov (United States)

    Gill, Jennifer A; Alves, José A; Sutherland, William J; Appleton, Graham F; Potts, Peter M; Gunnarsson, Tómas G

    2014-01-07

    Recent advances in spring arrival dates have been reported in many migratory species but the mechanism driving these advances is unknown. As population declines are most widely reported in species that are not advancing migration, there is an urgent need to identify the mechanisms facilitating and constraining these advances. Individual plasticity in timing of migration in response to changing climatic conditions is commonly proposed to drive these advances but plasticity in individual migratory timings is rarely observed. For a shorebird population that has significantly advanced migration in recent decades, we show that individual arrival dates are highly consistent between years, but that the arrival dates of new recruits to the population are significantly earlier now than in previous years. Several mechanisms could drive advances in recruit arrival, none of which require individual plasticity or rapid evolution of migration timings. In particular, advances in nest-laying dates could result in advanced recruit arrival, if benefits of early hatching facilitate early subsequent spring migration. This mechanism could also explain why arrival dates of short-distance migrants, which generally return to breeding sites earlier and have greater scope for advance laying, are advancing more rapidly than long-distance migrants.

  2. Using Human Capital Theory to Develop a Policy Approach towards College Student Migration in Illinois

    Science.gov (United States)

    Smith, Ryan Lee

    2006-01-01

    The purpose of this study was to use human capital theory to develop a policy approach towards college student migration in Illinois. A rate of return analysis revealed the social rate of return for college student migrants who return to Illinois and the private rate of return was 15.95%. It was estimated that due to college student migration in…

  3. Is long-distance bird flight equivalent to a high-energy fast? Body composition changes in freely migrating and captive fasting great knots

    NARCIS (Netherlands)

    Battley, PF; Dietz, MW; Piersma, T; Dekinga, A; Tang, SX; Hulsman, K; Battley, Phil F.; Tang, Sixian

    2001-01-01

    We studied changes in body composition in great knots, Calidris tenuirostris, before and after a migratory flight of 5,400 km from northwest Australia to eastern China. We also took premigratory birds into captivity and fasted them down to their equivalent arrival mass after migration to compare

  4. Integrating concepts and technologies to advance the study of bird migration

    NARCIS (Netherlands)

    Robinson, W.D.; Bowlin, M.S.; Bisson, I.; Shamoun-Baranes, J.; Thorup, K.; Diehl, R.H.; Kunz, T.H.; Mabey, S.; Winkler, D.W.

    2010-01-01

    Recent technological innovation has opened new avenues in migration research - for instance, by allowing individual migratory animals to be followed over great distances and long periods of time, as well as by recording physiological information. Here, we focus on how technology - specifically

  5. Migration distance is positively associated with sex-linked genetic diversity in passerine birds

    Czech Academy of Sciences Publication Activity Database

    Gohli, J.; Lifjeld, J. T.; Albrecht, Tomáš

    2016-01-01

    Roč. 28, č. 1 (2016), s. 42-52 ISSN 0394-9370 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : autosomes * female promiscuity * introns * seasonal migration * Z chromosome Subject RIV: EG - Zoology Impact factor: 1.582, year: 2016

  6. Radar analysis of fall bird migration stopover sites in the northeastern U.S.

    Science.gov (United States)

    Buler, Jeffrey J.; Dawson, Deanna K.

    2014-01-01

    The national network of weather surveillance radars (WSR-88D) detects flying birds and is a useful remote-sensing tool for ornithological study. We used data collected during fall 2008 and 2009 by 16 WSR-88D radars in the northeastern U.S. to quantify the spatial distribution of landbirds during migratory stopover. We geo-referenced estimates based on radar reflectivity, of the density of migrants aloft at their abrupt evening exodus from daytime stopover sites, to the approximate locations from which they emerged. We classified bird stopover use by the magnitude and variation of radar reflectivity across nights; areas were considered “important” stopover sites for conservation if bird density was consistently high. We developed statistical models that predict potentially important stopover sites across the region, based on land cover, ground elevation, and geographic location. Large areas of regionally important stopover sites were located along the coastlines of Long Island Sound, throughout the Delmarva Peninsula, in areas surrounding Baltimore and Washington, along the western edge of the Adirondack Mountains, and within the Appalachian Mountains of southwestern Virginia and West Virginia. Locally important stopover sites generally were associated with deciduous forests embedded within landscapes dominated by developed or agricultural lands, or near the shores of major water bodies. Preserving or enhancing patches of natural habitat, particularly deciduous forests, in developed or agricultural landscapes and along major coastlines could be a priority for conservation plans addressing the stopover requirements of migratory landbirds in the northeastern U.S. Our maps of important stopover sites can be used to focus conservation efforts and can serve as a sampling frame for fieldwork to validate radar observations or for ecological studies of landbirds on migratory stopover.

  7. Grounding a theory of African migration in recent data on Ghana.

    Science.gov (United States)

    Achanfuo-yeboah, D

    1993-06-01

    This article discusses the development of a single theory of migration in Africa, which accounts for social, economic, cultural, psychological, and demographic factors. Prior migration literature refers to many countries in Africa. The empirical test in this paper is based on Ghana and data for 1960, 1970, and 1984. Ghana is described as having rapid population growth and urbanization reaching 12.5 million in 1984. The economy is based on agriculture, mining, and manufacturing. Education is available for free through the secondary school level (since 1965). The general theory of migration holds that the nature, intensity, direction, and patterns of migration are shaped by social, cultural, economic, and political developments. Sociocultural developments, or nonagricultural occupations and educational resources, may influence the flow of migration to urban areas. The regression model shows that 70% of the variance in net migration is explained by education, economic activity, and population growth. Education determines the direction and intensity of migration. A unit value of education causes a change of 0.251952 in the value of net migration. Norms, values, and beliefs are affected by educational and employment opportunities and are influenced by factors such as kinship, clan, language, beliefs, and religion. Economic infrastructure, industrialization, employment opportunities, and increased wages and salaries exert a pull on migrants. During the 1960s, Ghana attracted migrants from Nigeria. During the 1970s and 1980s, the reverse occurred. Migrants tend to move based on expectations of higher wages and better employment. In a bivariate relationship, economic activity explains 62% of the variance in migration. A unit change in the value of economic activity leads to a change of 1.379382 in the value of net migration. The literature emphasizes rural-urban flows, but migration in Gwan state in Cameroon and Udo state in Nigeria reflects the prevalence of rural

  8. Relation between travel strategy and social organization of migrating birds with special consideration of formation flight in the northern bald ibis.

    Science.gov (United States)

    Voelkl, B; Fritz, J

    2017-08-19

    A considerable proportion of the world's bird species undertake seasonal long-distance migrations. These journeys are energetically demanding. Two major behavioural means to reduce energy expenditure have been suggested: the use of thermal uplifts for a soaring-gliding migration style and travelling in echelon or V-shaped formation. Both strategies have immediate consequences for the social organization of the birds as they either cause large aggregations or require travelling in small and stable groups. Here, we first discuss those consequences, and second present an analysis of formation flight in a flock of northern bald ibis on their first southbound migration. We observe clear correlations between leading and trailing on the dyadic level but only a weak correlation on the individual level during independent flight and no convincing correlation during the human guided part of the migration. This pattern is suggestive of direct reciprocation as a means for establishing cooperation during formation flight. In general, we conclude that behavioural adaptations for dealing with physiological constraints on long-distance migrations either necessitate or ultimately foster formation of social groups with different characteristics. Patterns and social organization of birds travelling in groups have been elusive to study; however, new tracking technology-foremost lightweight GPS units-will provide more insights in the near future.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'. © 2017 The Author(s).

  9. Dynamic optimal foraging theory explains vertical migrations of bigeye tuna

    DEFF Research Database (Denmark)

    Thygesen, Uffe Høgsbro; Sommer, Lene; Evans, Karen

    2016-01-01

    dynamic programming. With little calibration of model parameters, our results are consistent with observed data on vertical movement: we find that small tuna should display constant-depth strategies while large tuna should display vertical migrations. The analysis supports the hypothesis that the tuna...

  10. Is long-distance bird flight equivalent to a high-energy fast? Body composition changes in freely migrating and captive fasting great knots.

    Science.gov (United States)

    Battley, P F; Dietz, M W; Piersma, T; Dekinga, A; Tang, S; Hulsman, K

    2001-01-01

    We studied changes in body composition in great knots, Calidris tenuirostris, before and after a migratory flight of 5,400 km from northwest Australia to eastern China. We also took premigratory birds into captivity and fasted them down to their equivalent arrival mass after migration to compare organ changes and nutrient use in a low-energy-turnover fast with a high-energy-turnover fast (migratory flight). Migrated birds were as economical as any fasting animal measured yet at conserving protein: their estimated relative protein contribution (RPC) to the energy used was 4.0%. Fasted birds had an estimated RPC of 6.8% and, consequently, a much lower lean mass and higher fat content for an equivalent body mass than migrated birds. Lean tissue was catabolized from most organs in both groups, except the brain. Furthermore, a principal components biplot showed that individuals were grouped primarily on the basis of overall organ fat or lean tissue content rather than by the size of specific organs. This indicates that organ changes during migratory flight are similar to those of a low-energy fast, although the length of the fast in this study probably accentuated organ reductions in some functional groups. Whether the metabolic characteristics of a flying migratory fast follow the three-phase model described in many inactive fasting animals is unclear. We have some evidence for skeletal fat being catabolized without phase 3 of a fast having been reached.

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

    Science.gov (United States)

    Haest, Birgen; Hüppop, Ommo; Bairlein, Franz

    2018-04-01

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

  12. Smuggling Humans: A Theory of Debt-Financed Migration

    OpenAIRE

    Friebel, Guido; Guriev, Sergei

    2004-01-01

    We introduce financial constraints in a theoretical analysis of illegal immigration. Intermediaries finance the migration costs of wealth-constrained migrants, who enter temporary servitude contracts to repay the debt. These debt/labor contracts are easier to enforce in the illegal than in the legal sector of the host country. Hence, when moving from the illegal to the legal sector becomes more costly, for instance, because of stricter deportation policies, fewer immigrants default on debt. T...

  13. Rural-Urban Migration and Unemployment: Theory and Policy Implications

    OpenAIRE

    Zenou, Yves

    2010-01-01

    We develop a regional model where, in the city, unemployment prevails because of too high (efficiency) wages, while, in the rural area, workers are paid at their marginal productivity. We characterize the steady-state equilibrium and show that it is unique. We then consider two policies: decreasing urban unemployment benefits and subsidizing urban employment. We find that decreasing the unemployment benefit in the city creates urban jobs and reduces rural-urban migration since new migrants ha...

  14. Quantifying full phenological event distributions reveals simultaneous advances, temporal stability and delays in spring and autumn migration timing in long-distance migratory birds.

    Science.gov (United States)

    Miles, Will T S; Bolton, Mark; Davis, Peter; Dennis, Roy; Broad, Roger; Robertson, Iain; Riddiford, Nick J; Harvey, Paul V; Riddington, Roger; Shaw, Deryk N; Parnaby, David; Reid, Jane M

    2017-04-01

    Phenological changes in key seasonally expressed life-history traits occurring across periods of climatic and environmental change can cause temporal mismatches between interacting species, and thereby impact population and community dynamics. However, studies quantifying long-term phenological changes have commonly only measured variation occurring in spring, measured as the first or mean dates on which focal traits or events were observed. Few studies have considered seasonally paired events spanning spring and autumn or tested the key assumption that single convenient metrics accurately capture entire event distributions. We used 60 years (1955-2014) of daily bird migration census data from Fair Isle, Scotland, to comprehensively quantify the degree to which the full distributions of spring and autumn migration timing of 13 species of long-distance migratory bird changed across a period of substantial climatic and environmental change. In most species, mean spring and autumn migration dates changed little. However, the early migration phase (≤10th percentile date) commonly got earlier, while the late migration phase (≥90th percentile date) commonly got later. Consequently, species' total migration durations typically lengthened across years. Spring and autumn migration phenologies were not consistently correlated within or between years within species and hence were not tightly coupled. Furthermore, different metrics quantifying different aspects of migration phenology within seasons were not strongly cross-correlated, meaning that no single metric adequately described the full pattern of phenological change. These analyses therefore reveal complex patterns of simultaneous advancement, temporal stability and delay in spring and autumn migration phenologies, altering species' life-history structures. Additionally, they demonstrate that this complexity is only revealed if multiple metrics encompassing entire seasonal event distributions, rather than single

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

    International Nuclear Information System (INIS)

    Pekour, M. S.

    2002-01-01

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

  16. Coloniality and migration are related to selection on MHC genes in birds.

    Science.gov (United States)

    Minias, Piotr; Whittingham, Linda A; Dunn, Peter O

    2017-02-01

    The major histocompatibility complex (MHC) plays a key role in pathogen recognition as a part of the vertebrate adaptive immune system. The great diversity of MHC genes in natural populations is maintained by different forms of balancing selection and its strength should correlate with the diversity of pathogens to which a population is exposed and the rate of exposure. Despite this prediction, little is known about how life-history characteristics affect selection at the MHC. Here, we examined whether the strength of balancing selection on MHC class II genes in birds (as measured with nonsynonymous nucleotide substitutions, dN) was related to their social or migratory behavior, two life-history characteristics correlated with pathogen exposure. Our comparative analysis indicated that the rate of nonsynonymous substitutions was higher in colonial and migratory species than solitary and resident species, suggesting that the strength of balancing selection increases with coloniality and migratory status. These patterns could be attributed to: (1) elevated transmission rates of pathogens in species that breed in dense aggregations, or (2) exposure to a more diverse fauna of pathogens and parasites in migratory species. Our study suggests that differences in social structure and basic ecological traits influence MHC diversity in natural vertebrate populations. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  17. Status and distribution of migrating and breeding marine birds in north Lebanon

    International Nuclear Information System (INIS)

    Jarade, Gh.R.

    2017-01-01

    The study of marine birds in the northern part of Lebanon recorded 2681 individuals, distributed over 86 species. Among them 35 are foreshore species, 18 coastal, 6 maritime, 9 ducks, 6 herons, 9 various saltwater related species and 3 terrestrial. The highest density is shown by the yellow-legged Gull Larus michahellis and common blackheaded gull Chroicocephalus ridibundus. The globally vulnerable yelkouan shearwater Puffinus yelkouan, an endemic species to the Mediterranean, appears on the 9th rank in the classification of seabird species from the more to the least abundant, highlighting as such, beside other 6 globally near threatened species, the role that Lebanon can play in improving the conservation status of these species. Regarding the phenological status of species, 48 are passage migrant/winter visitors, 31 passage migrants, 5 winter visitors and 2 vagrant species. The surveys revealed that three coastal seabird species (Armenian gull Larus armenicus, slender-billed gull Chroicocephalus genei and sandwich tern Thalasseus sandvicensis) and one ubiquist species (Eurasian Golden Plover Pluvialis apricaria) are not rare as it was believed in previous papers but fairly common winter visitors. The study identified the yellow-legged gull breeding population to be 160 couples, and confirmed the second and third breeding records of the little ringed plover Charadrius dubius.(author)

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

    Science.gov (United States)

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

    2016-06-01

    Crimean-Congo haemorrhagic fever virus (CCHFV) is a zoonotic virus transmitted by Hyalomma ticks, the immature stages of which may be carried by migratory birds. In this study, a total of 12 Hyalomma ticks were recovered from five of 228 migratory birds trapped in Spring, 2012 in southern Spain along the East Atlantic flyway. All collected ticks tested negative for CCHFV. While most birds had zero Hyalomma ticks, two individuals had four and five ticks each and the statistical distribution of Hyalomma tick counts per bird is over-dispersed compared to the Poisson distribution, demonstrating the need for intensive sampling studies to avoid underestimating the total number of ticks. Rates of tick exchange on migratory birds during their northwards migration will affect the probability that a Hyalomma tick entering Great Britain is positive for CCHFV. Drawing on published data, evidence is presented that the latitude of a European country affects the probability of entry of Hyalomma ticks on wild birds. Further data on Hyalomma infestation rates and tick exchange rates are required along the East Atlantic flyway to further our understanding of the origin of Hyalomma ticks (i.e., Africa or southern Europe) and hence the probability of entry of CCHFV into GB. © 2016 The Society for Vector Ecology.

  19. Migration from the CIS Countries to Amur Oblast in the Context of the Synthetic Theory

    Directory of Open Access Journals (Sweden)

    Tatiana Nikolaevna Zhuravskaya

    2016-09-01

    Full Text Available The article considers international migration from the CIS countries to the Amur region in 2010- 2014 in the context of the synthetic theory of international migration by D. Massey. It is shown that separate economic theories of migration cannot explain the CIS migrants’ choice of the Amur region as a destination. In particular, socio-economic indicators characterize the region as unattractive both for permanent (high mortality, low life expectancy, relatively low standard of living and labor (low GRP, specialization in primary industries, high transport costs and pay for a patent migration. The attractiveness factors of the region fit the theory of a dual labor market: the Amur region has higher wages than the countries of origin and the growing shortage of personnel. However, it is also insufficient to explain increasing migration flows from the CIS countries, which were identified on the basis of statistical data of the Federal Migration Service of the Amur region. Based on the analysis of qualitative data the author reveals the motives (economic, educational, cultural, forced, non-self-moving and channels (social networks, intermediaries, enterprises, government programs of migration. In general, the motivation and channels of migration in the case of the Amur region look quite traditional within the framework of economic theories. However, only a comprehensive consideration of all the issues allows determining regional specificity and answering the question about the destination choice. Sources of empirical data include following: series of keynote expert and biographical interviews carried out in 2014-2015, official statistical data of FSSS and FMS, as well as data from Amurstat, the FMS of the Amur region and the insurance company ‘Kolymskaya’

  20. Astronomical Theory of Early Human Migration (Milutin Milankovic Medal Lecture)

    Science.gov (United States)

    Timmermann, Axel; Friedrich, Tobias

    2017-04-01

    Our climate system varies on a wide range of timescales, from seasons to several millions of years. A large part of this variability is internally generated as a result of instabilities of the coupled atmosphere-ocean-ice-carbon cycle system. Other modes of variability, such as glacial cycles, are caused by astronomical forcings with periods of 20, 40, 100 thousand years. These so-called Milankovitch Cycles are associated with earth's axis wobble, axis obliquity and shifts in the eccentricity of earth's orbit around the sun, respectively. When these cycles conspire, they can cause the climate system to plunge into an ice-age. This happened last time 110,000 years ago, when Northern Hemisphere summer radiation decreased substantially and ice-sheets started to form as a result. Around 100,000 years ago northern Hemisphere summer moved again closer to the sun and Homo sapiens started to leave Africa across vegetated corridors in Northeastern Africa and the Arabian Peninsula. This first migration wave must have been relatively weak, but it left unequivocal traces in the fossil and archaeological record. Why Homo sapiens embarked on its grand journey across our planet during glacial climate conditions has been subject of an intense debate in various scientific communities. Moreover, the archaeological records of an early exodus around 100 thousand years ago seem to be at odds with paleo-genetic evidences, that place the first dispersal out of Africa around 70-60 thousand years ago. To elucidate what role climate and environmental conditions played in the dispersal of Anatomically Modern Humans out of Africa, we have developed and applied one of the first integrated climate/human migration computer models. The model simulates ice-ages, abrupt climate change, the "peopling" of our planet and captures the arrival time of Homo sapiens in the Levant, Arabian Peninsula, Southern China and Australia in close agreement with paleo climate reconstructions, fossil and

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

    Science.gov (United States)

    Mead, Reginald; Paxton, John; Sojda, Richard S.; Swayne, David A.; Yang, Wanhong; Voinov, A.A.; Rizzoli, A.; Filatova, T.

    2010-01-01

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

  2. Population-level scaling of avian migration speed with body size and migration distance for powered fliers.

    Science.gov (United States)

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

    2013-08-01

    Optimal migration theory suggests specific scaling relationships between body size and migration speed for individual birds based on the minimization of time, energy, and risk. Here we test if the quantitative predictions originating from this theory can be detected when migration decisions are integrated across individuals. We estimated population-level migration trajectories and daily migration speeds for the combined period 2007-2011 using the eBird data set. We considered 102 North American bird species that use flapping or powered flight during migration. Many species, especially in eastern North America, had looped migration trajectories that traced a clockwise path with an eastward shift during autumn migration. Population-level migration speeds decelerated rapidly going into the breeding season, and accelerated more slowly during the transition to autumn migration. In accordance with time minimization predictions, spring migration speeds were faster than autumn migration speeds. In agreement with optimality predictions, migration speeds of powered flyers scaled negatively with body mass similarly during spring and autumn migration. Powered fliers with longer migration journeys also had faster migration speeds, a relationship that was more pronounced during spring migration. Our findings indicate that powered fliers employed a migration strategy that, when examined at the population level, was in compliance with optimality predictions. These results suggest that the integration of migration decisions across individuals does result in population-level patterns that agree with theoretical expectations developed at the individual level, indicating a role for optimal migration theory in describing the mechanisms underlying broadscale patterns of avian migration for species that use powered flight.

  3. THE DARWIN-FISHER THEORY OF SEXUAL SELECTION IN MONOGAMOUS BIRDS.

    Science.gov (United States)

    Kirkpatrick, Mark; Price, Trevor; Arnold, Stevan J

    1990-02-01

    Males of monogamous birds often show secondary sexual traits that are conspicuous but considerably less extreme than those of polygynous species. We develop a quantitative-genetic model for the joint evolution of a male secondary sexual trait, a female mating preference, and female breeding date, following a theory proposed by Darwin and Fisher. Good nutritional condition is postulated to cause females to breed early and to have high fecundity. The most-preferred males are mated by early-breeding females and receive a sexual-selection advantage from those females' greater reproductive success. Results show that conspicuous male traits that decrease survival can evolve but suggest that the extent of maladaptive evolution is greatly limited relative to what is possible in a polygynous mating system for two reasons. First, in the absence of direct fitness effects of mate choice on the female, the equilibria for the male trait and female preference form a curve whose shape shows that the maximum possible strength of sexual selection on males (and hence the potential for maladaptive evolution) is constrained. Under certain conditions, a segment of the equilibrium curve may become unstable, leading to two alternative stable states for the male trait. Second, male parental care will often favor the evolution of mating preferences for less conspicuous males. We also find that sexual selection can appear in the absence of the nutritional effects emphasized by Darwin and Fisher. A review of the literature suggests that the assumptions of the Darwin-Fisher mechanism may often be met in monogamous birds and that other mechanisms may often reinforce it by producing additional components of sexual selection. © 1990 The Society for the Study of Evolution.

  4. Do the ticks of birds at an important migratory hotspot reflect the seasonal dynamics of Ixodes ricinus at the migration initiation site? A case study in the Danube Delta.

    Science.gov (United States)

    Sándor, Attila D; Mărcuţan, Daniel I; D'Amico, Gianluca; Gherman, Călin M; Dumitrache, Mirabela O; Mihalca, Andrei D

    2014-01-01

    Migratory birds play important roles as distributors of ticks within and between continents. In the Old World, the most important migratory route of birds links Asia, Europe and Africa. During their migration, birds use various stopover sites, where they feed and rest and where ticks may attach or detach, creating new natural foci for vector-borne diseases. Danube Delta is one of the most important migration hotspots and so far no studies were focused on ticks of migratory birds herein. The aim of the present study was to assess the species diversity and seasonal dynamics of ticks parasitizing migratory birds in Danube Delta Biosphere Reserve. Migratory birds were trapped on Grindul Lupilor (44°41'N; 28°56'E) using mist nets during 4 migratory seasons (2 spring and 2 autumn) in 2011 and 2012. From each bird, all the ticks were collected and identified based on morphological features. Epidemiological parameters (prevalence, mean abundance, mean intensity) were calculated and all data were analysed statistically based on the season (spring and autumn), regional status of birds (migrants and breeding) and foraging behaviour (ground feeders, reed-bed feeders, foliage feeders). A total of 1434 birds (46 species) were captured. Ticks were found on 94 birds (10 species). Significantly more migratory birds hosted ticks, compared to resident birds. The 400 collected ticks belonged to four species: Ixodes ricinus (92.25%), I. arboricola (6.25%), I. redikorzevi (1.00%) and Haemaphysalis punctata (0.50%). A higher prevalence was found for I. ricinus in spring, with higher prevalence of nymphs in this season, while larvae occurred with the same prevalence in both seasons. Larval intensity was higher during spring and nymphs were more abundant during autumn. The seasonal differences in our study may be related not to the local seasonal dynamics of ticks, but on the seasonal dynamics at the site of migration initiation.

  5. Do the ticks of birds at an important migratory hotspot reflect the seasonal dynamics of Ixodes ricinus at the migration initiation site? A case study in the Danube Delta.

    Directory of Open Access Journals (Sweden)

    Attila D Sándor

    Full Text Available Migratory birds play important roles as distributors of ticks within and between continents. In the Old World, the most important migratory route of birds links Asia, Europe and Africa. During their migration, birds use various stopover sites, where they feed and rest and where ticks may attach or detach, creating new natural foci for vector-borne diseases. Danube Delta is one of the most important migration hotspots and so far no studies were focused on ticks of migratory birds herein. The aim of the present study was to assess the species diversity and seasonal dynamics of ticks parasitizing migratory birds in Danube Delta Biosphere Reserve. Migratory birds were trapped on Grindul Lupilor (44°41'N; 28°56'E using mist nets during 4 migratory seasons (2 spring and 2 autumn in 2011 and 2012. From each bird, all the ticks were collected and identified based on morphological features. Epidemiological parameters (prevalence, mean abundance, mean intensity were calculated and all data were analysed statistically based on the season (spring and autumn, regional status of birds (migrants and breeding and foraging behaviour (ground feeders, reed-bed feeders, foliage feeders. A total of 1434 birds (46 species were captured. Ticks were found on 94 birds (10 species. Significantly more migratory birds hosted ticks, compared to resident birds. The 400 collected ticks belonged to four species: Ixodes ricinus (92.25%, I. arboricola (6.25%, I. redikorzevi (1.00% and Haemaphysalis punctata (0.50%. A higher prevalence was found for I. ricinus in spring, with higher prevalence of nymphs in this season, while larvae occurred with the same prevalence in both seasons. Larval intensity was higher during spring and nymphs were more abundant during autumn. The seasonal differences in our study may be related not to the local seasonal dynamics of ticks, but on the seasonal dynamics at the site of migration initiation.

  6. Linking the Intercultural and Grounded Theory: Methodological Issues in Migration Research

    Directory of Open Access Journals (Sweden)

    Vera Sheridan

    2009-01-01

    Full Text Available Connecting intercultural research with Grounded Theory was advocated in the early history of intercultural theorising and includes the development of researchers' intercultural competencies. Such competency comes to the fore where intercultural theory places an equal emphasis on home and host cultures in migration research. In this context we have found a Grounded Theory approach particularly suitable for disentangling complex interlinkings within migration experiences and their individual outcomes. Grounded Theory allows for the exploration of various theories in different fields and the emergence of new or deeper interpretations of intercultural experiences, including where research has not engaged deeply with or avoided intercultural contexts. The use of software, based on Grounded Theory, provides the resource for systematically exploring the inter-related nature of data. In addition, engaging in intercultural research, in particular, raises questions around our practice as social science researchers: adherence to ethics guidelines, for instance, can be in some conflict with the relations we build with members of communities whose cultural values, for instance around friendship or trust, impact on the norms of both our own and institutional expectations. This leads to reflection on the relationship with research participants in terms of our own intercultural experiences and position. URN: urn:nbn:de:0114-fqs0901363

  7. Birds, magnets, soap, and sandblasting: surprising connections in the theory of incompressible flocks

    Science.gov (United States)

    Toner, John

    In this talk I'll describe the hydrodynamic theory of the motion of incompressible flocks: that is, collections of self-propelled entities (birds\\x9D) that are packed so tightly together that their density cannot change as they move. In two dimensions, this problem can be mapped onto an equilibrium magnet with a peculiar constraint. This problem, in turn, can be shown to be equivalent to a 2d smectic (soap\\x9D), with the flow lines of the flock playing the role of the smectic layers. Finally, this smectic problem can be mapped onto the 1+1 dimensional KPZ equation, which describes the growth or corrosion (sandblasting\\x9D) of a one dimensional interface. The scaling properties of this last system, which have been known exactly for a long time, can thereby be used to determine those of incompressible 2d flocks. One important implication of the resulting scaling laws is that such flocks can exhibit long-ranged order in two dimensions, unlike their equilibrium counterparts.

  8. The role of migration in the regional development and its appearance in the theories

    Directory of Open Access Journals (Sweden)

    Tünde Patay

    2017-10-01

    Full Text Available Phenomena relating to migration have a number of social, economic and political effects on both the sending and the host country. These impacts can vary depending on the reference period, region or sector as well as on the goals and aspects of our interpretation. Analysing the interference between immigration and regional development, we can rely on classic migration theories, however, a comparison of further models and concepts relating development and regional issues can be more useful for researchers. Another important question in connection with regional competitiveness is how decision makers act and react after perceiving migratory movements, thus this paper also aims to summarize the mainstream solutions and the controversies of migration policies that appear in the literature. Therefore it analyses the importance of integration and the main factors of inclusion as well. Besides, the aspects of methods and methodology also need appropriate attention. The paper finally presents these methodological issues of migration research exploring the typical questions and stumbling stones. These questions are relevant, since regional development and the strategies in the background have strong association with migratory phenomena. However, a well-structured perspective is needed to confront the theoretical background of the 4 main areas: regional development, regional policy, migration and issues from research methods.

  9. Empirical evidence for differential organ reductions during trans-oceanic bird flight

    NARCIS (Netherlands)

    Battley, PF; Piersma, T; Dietz, MW; Tang, SX; Dekinga, A; Hulsman, K

    2000-01-01

    Since the early 1960s it has been held that migrating birds deposit and use only fat as fuel during migratory flight, with the non-fat portion of the body remaining homeostatic. Recent evidence from field studies has shown large changes in organ sizes in fuelling birds, and theory on fuel use

  10. Understanding how birds navigate

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Schulten, Klaus

    2009-01-01

    A proposed model for migrating birds' magnetic sense can withstand moderate orientational disorder of a key protein in the eye.......A proposed model for migrating birds' magnetic sense can withstand moderate orientational disorder of a key protein in the eye....

  11. Migratory Birds. Issue Pac.

    Science.gov (United States)

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

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

  12. Melt migration in a silicate liquid-olivine system - An experimental test of compaction theory

    Science.gov (United States)

    Riley, G. N., Jr.; Kohlstedt, D. L.; Richter, F. M.

    1990-01-01

    An experimentally derived melt migration profile is compared with those obtained from compaction theory. A couple is prepared in which a source-for-melt (a disk composed of a silicate glass and olivine) was placed in contact with a sink-for-melt (a disk of polycrystalline olivine) in order to induce melt migration under laboratory conditions. It is noted that melt infiltrates into the sink disk along triple junctions driven by capillary forces. In order to analyze the melt migration profile in terms of compaction theory, the equations developed by McKenzie (1984) to describe porous flow of a liquid in a deformable matrix were modified. The bouyancy force term is replaced with a capillary force term and governing equations are then solved numerically with the initial boundary conditions specified by the experimental design. Also, it is determined that compaction theory provides a good description of the experimental results provided that the permeability of these solid-liquid materials increases linearly with increasing liquid fraction.

  13. Adaptive sex allocation in birds : The complexities of linking theory and practice

    NARCIS (Netherlands)

    Komdeur, Jan; Pen, Ido

    2002-01-01

    We review some recent theoretical and empirical developments in the study of sex allocation in birds. The advent of reliable molecular sexing techniques has led to a sharp increase in the number of studies that report biased offspring sex ratios in birds. However, compelling evidence for adaptive

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

    Science.gov (United States)

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

    2017-10-01

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

  15. 75 FR 52873 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2010-08-30

    ... resources including migratory birds and their habitats. Large-scale efforts to influence bird migration and... timing and speed of bird migrations. It is possible that re-distribution of birds at smaller scales could...-0040; 91200-1231-9BPP-L2] RIN 1018-AX06 Migratory Bird Hunting; Final Frameworks for Early-Season...

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

    Science.gov (United States)

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

    2014-08-01

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

  17. Using Autumn Hawk Watch to track raptor migration and to monitor populations of North American birds of prey

    Science.gov (United States)

    Kyle McCarty; Keith L. Bildstein

    2005-01-01

    Raptors are secretive, area-sensitive predators whose populations can be logistically difficult and financially prohibitive to monitor. Many North American populations of raptors are migratory however, and on migration raptors are frequently counted at traditional migration watchsites. Experiences at Hawk Mountain Sanctuary (HMS) and elsewhere suggest that long-term...

  18. Disease dynamics and bird migration--linking mallards Anas platyrhynchos and subtype diversity of the influenza A virus in time and space.

    Directory of Open Access Journals (Sweden)

    Gunnar Gunnarsson

    Full Text Available The mallard Anas platyrhynchos is a reservoir species for influenza A virus in the northern hemisphere, with particularly high prevalence rates prior to as well as during its prolonged autumn migration. It has been proposed that the virus is brought from the breeding grounds and transmitted to conspecifics during subsequent staging during migration, and so a better understanding of the natal origin of staging ducks is vital to deciphering the dynamics of viral movement pathways. Ottenby is an important stopover site in southeast Sweden almost halfway downstream in the major Northwest European flyway, and is used by millions of waterfowl each year. Here, mallards were captured and sampled for influenza A virus infection, and positive samples were subtyped in order to study possible links to the natal area, which were determined by a novel approach combining banding recovery data and isotopic measurements (δ(2H of feathers grown on breeding grounds. Geographic assignments showed that the core natal areas of studied mallards were in Estonia, southern and central Finland, and northwestern Russia. This study demonstrates a clear temporal succession of latitudes of natal origin during the course of autumn migration. We also demonstrate a corresponding and concomitant shift in virus subtypes. Acknowledging that these two different patterns were based in part upon different data, a likely interpretation worth further testing is that the early arriving birds with more proximate origins have different influenza A subtypes than the more distantly originating late autumn birds. If true, this knowledge would allow novel insight into the origins and transmission of the influenza A virus among migratory hosts previously unavailable through conventional approaches.

  19. Tracking bird migration at the Baie-des-Sables wind farm site : Innergex II Inc.; Suivi des migrations des oiseaux sur le site d'implantation d'un parc eolien a Baie-des-Sables : Innergex II Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Castonguay, M.; Beauchesne, J.A.; Ouellet, J.F.; Pelletier, N.; Gallant, F.; Lavoie, J. [Pesca Environnement, Maria, PQ (Canada)

    2004-12-21

    The global production of electricity from wind power has increased significantly in recent years. As part of Hydro-Quebec's plans to increase wind power production, Cartier Wind Power plans to install 61 wind turbines at Baie-des-Sables on Quebec's Gaspe Peninsula where wind energy is abundant. This study evaluated the impact of the proposed wind turbine array on birds and their habitat and migration patterns. In particular, it characterized the migratory passage of birds in the area through 900 hours of visual and auditory observation beginning with spring migration, spring nesting to autumnal migration. The behavior of different migratory birds as well as local species was studied and the results of the ornithological inventory were revealed in terms of species abundance and diversity; distribution and use of the territory by birds; migratory activities; period and importance of migration; characterization of displacement; height of flight; direction of migration; and, use of the territory by the avifauna. The inventory identified 121 species of birds including 14 species of raptors which moved mainly along the river and flew very high. The study revealed that although the bird habitats at Baie-des-Sables were already strongly disturbed by agricultural activities, it is unlikely that the turbines will not have any impact on the avifauna. However, most of the wind turbines will be installed in farmers fields, and as such, will not exert additional pressure on the forest medium. The factors that influence the rate of bird collisions with wind turbines were discussed. In order to lessen the impact on birds, it was suggested that installation work should occur outside of the nesting season and that the electrical supply networks should be hidden to limit the harmful effects posed by power lines. 16 refs., 9 tabs., 4 figs., 11 maps, 9 appendices.

  20. Identification of Rickettsia africae and Wolbachia sp. in Ceratophyllus garei fleas from Passerine birds migrated from Africa.

    Science.gov (United States)

    Sekeyová, Zuzana; Mediannikov, Oleg; Roux, Véronique; Subramanian, Geetha; Spitalská, Eva; Kristofík, Jano; Darolová, Alžbeta; Raoult, Didier

    2012-07-01

    The aim of the study was to reveal new aspects of the role of flea vector taken from migratory birds by screening of specimens with molecular biological methods. A field study was done in fishponds in Slovakia. Actually, 47 fleas were collected from reed warblers (Acrocephalus scirpaceus) and their nests. DNA was extracted and analyzed for representatives of the orders Rickettsiales. A rickettsia that shares 99.7% of identity by gltA gene with Rickettsia africae was identified in Ceratophyllus garei collected from A. scirpaceus. Moreover, two Wolbachia sp. were also detected in fleas. This is the first record of R. africae and Wolbachia sp. identified so far in Central Europe in fleas collected from migratory bird returning from Africa. This molecular study extends the geographic range and vector spectrum of arthropod-borne agents.

  1. The puzzle of partial migration: Adaptive dynamics and evolutionary game theory perspectives.

    Science.gov (United States)

    De Leenheer, Patrick; Mohapatra, Anushaya; Ohms, Haley A; Lytle, David A; Cushing, J M

    2017-01-07

    We consider the phenomenon of partial migration which is exhibited by populations in which some individuals migrate between habitats during their lifetime, but others do not. First, using an adaptive dynamics approach, we show that partial migration can be explained on the basis of negative density dependence in the per capita fertilities alone, provided that this density dependence is attenuated for increasing abundances of the subtypes that make up the population. We present an exact formula for the optimal proportion of migrants which is expressed in terms of the vital rates of migrant and non-migrant subtypes only. We show that this allocation strategy is both an evolutionary stable strategy (ESS) as well as a convergence stable strategy (CSS). To establish the former, we generalize the classical notion of an ESS because it is based on invasion exponents obtained from linearization arguments, which fail to capture the stabilizing effects of the nonlinear density dependence. These results clarify precisely when the notion of a "weak ESS", as proposed in Lundberg (2013) for a related model, is a genuine ESS. Secondly, we use an evolutionary game theory approach, and confirm, once again, that partial migration can be attributed to negative density dependence alone. In this context, the result holds even when density dependence is not attenuated. In this case, the optimal allocation strategy towards migrants is the same as the ESS stemming from the analysis based on the adaptive dynamics. The key feature of the population models considered here is that they are monotone dynamical systems, which enables a rather comprehensive mathematical analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Monitoring breeding and migration of neotropical migratory birds at Point Loma, San Diego County, California, 5-year summary, 2011–15

    Science.gov (United States)

    Lynn, Suellen; Madden, Melanie C.; Kus, Barbara E.

    2017-04-27

    Executive SummaryWe operated a bird banding station on the Point Loma peninsula in western San Diego County, California, during spring and summer from 2011 to 2015. The station was established in 2010 as part of a long-term monitoring program for neotropical migratory birds during spring migration and for breeding birds as part of the Monitoring Avian Productivity and Survivorship (MAPS) program.During spring migration (April and May), 2011–15, we captured 1,760 individual birds of 54 species, 91 percent (1,595) of which were newly banded, fewer than 1 percent (3) of which were recaptures that were banded in previous years, and 9 percent (143 hummingbirds, 2 hawks, and 17 other birds) of which we released unbanded. We observed an additional 22 species that were not captured. Thirty-four individuals were captured more than once. Bird capture rate averaged 0.49 ± 0.07 captures per net-hour (range 0.41–0.56). Species richness per day averaged 6.87 ± 0.33. Cardellina pusilla (Wilson’s warbler) was the most abundant spring migrant captured, followed by Empidonax difficilis (Pacific-slope flycatcher), Vireo gilvus (warbling vireo), Zonotrichia leucophrys (white-crowned sparrow), and Selasphorus rufus (rufous hummingbird). Captures of white-crowned sparrow decreased, and captures of Pacific-slope flycatcher increased, over the 5 years of our study. Fifty-six percent of known-sex individuals were male and 44 percent were female. The peak number of new species arriving per day ranged from April 1 (2013-six species) to April 16 (2012-five species). A significant correlation was determined between the number of migrants captured each day per net-hour and the density of echoes on the Next-Generation Radar (NEXRAD) images across all 5 years, and in each year except 2014. NEXRAD radar imagery appears to be a useful tool for detecting pulses in migration.Our results indicate that Point Loma provides stopover habitat during migration for 76 migratory species, including 20

  3. Understanding the migratory orientation program of birds

    DEFF Research Database (Denmark)

    Thorup, Kasper; Holland, Richard A.; Tøttrup, Anders P.

    2010-01-01

    orient during migration. Despite the difficulties associated with following free-flying birds over long distances, a number of possibilities currently exist for tracking the long distance, sometimes even globe-spanning, journeys undertaken by migrating birds. Birds fitted with radio transmitters can......For many years, orientation in migratory birds has primarily been studied in the laboratory. Although a laboratory-based setting enables greater control over environmental cues, the laboratory-based findings must be confirmed in the wild in free-flying birds to be able to fully understand how birds...... system that enables experienced birds to navigate and guide inexperienced, young birds to their species-specific winter grounds...

  4. International Migration with Heterogeneous Agents: Theory and Evidence for Germany, 1967-2009

    DEFF Research Database (Denmark)

    Brücker, Herbert; Schröder, Philipp

    2012-01-01

    Temporary migration, though empirically relevant, is often ignored in formal models. This paper proposes a migration model with heterogeneous agents and persistent cross country income differentials that features temporary migration. In equilibrium there exists a positive relation between the stock...... of migrants and the income differential, while the net migration flow becomes zero. Consequently, existing empirical migration models, estimating net migration flows, instead of stocks, may be misspecified. This suspicion appears to be confirmed by our investigation of the cointegration relationships...... of German migration stocks and flows since 1967. We find that (i) panel-unit root tests reject the hypothesis that migration flows and the explanatory variables are integrated of the same order, while migration stocks and the explanatory variables are all I(1) variables, and (ii) the hypothesis...

  5. Energy beyond food: foraging theory informs time spent in thermals by a large soaring bird.

    Science.gov (United States)

    Shepard, Emily L C; Lambertucci, Sergio A; Vallmitjana, Diego; Wilson, Rory P

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered.

  6. Energy beyond food: foraging theory informs time spent in thermals by a large soaring bird.

    Directory of Open Access Journals (Sweden)

    Emily L C Shepard

    Full Text Available Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus. Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered.

  7. Birds of Prey of Wisconsin.

    Science.gov (United States)

    Hamerstrom, Frances

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

  8. Synchronization of Stochastically Coupled Oscillators: Dynamical Phase Transitions and Large Deviations Theory (or Birds and Frogs)

    Science.gov (United States)

    Teodorescu, Razvan

    2009-10-01

    Systems of oscillators coupled non-linearly (stochastically or not) are ubiquitous in nature and can explain many complex phenomena: coupled Josephson junction arrays, cardiac pacemaker cells, swarms or flocks of insects and birds, etc. They are know to have a non-trivial phase diagram, which includes chaotic, partially synchronized, and fully synchronized phases. A traditional model for this class of problems is the Kuramoto system of oscillators, which has been studied extensively for the last three decades. The model is a canonical example for non-equilibrium, dynamical phase transitions, so little understood in physics. From a stochastic analysis point of view, the transition is described by the large deviations principle, which offers little information on the scaling behavior near the critical point. I will discuss a special case of the model, which allows a rigorous analysis of the critical properties of the model, and reveals a new, anomalous scaling behavior in the vicinity of the critical point.

  9. Priority areas for surveillance and prevention of avian influenza during the water-bird migration season in Pakistan

    Directory of Open Access Journals (Sweden)

    Tariq Abbas

    2011-11-01

    Full Text Available Avian influenza viruses may be introduced into domestic poultry through migratory wild birds, particularly from Pakistan, which is situated across the migratory Indus flyway and holds more than 225 wetlands. To answer the question which areas should be given priority in surveillance and prevention with respect to notifiable avian influenza during the migratory season, a subset of Asian waterbird census data was reviewed. The dataset contains 535 local sites and available counts of waterbirds reported from 1987 to 2007. However, as the majority of the sites are not counted regularly gaps in data matrix appeared. The coordinates of 270 known sites completely fitted the administrative boundaries of the country. These coordinates were geo-processed with polygons of water-bodies and a raster map of predicted poultry density. Pixels representing the estimated number of poultry per km2 were found within a 3 to 9 km range of the census sites (or water-bodies in their proximity. The coordinates were also used to map the maximum reported counts of waterbirds and local clusters of under-sampled sites. A retrospective case-series analysis of previous outbreaks (2006-2008 of influenza A virus, subtype H5N1 was performed, which revealed that 64% of outbreaks, reported to Office International des Epizooties, the World Organization for Animal Health, occurred during the migratory period. This paper highlights the potential use and limitations of the Asian waterbirds census data in the context of avian influenza. The proposed methodology may be used to prioritize districts for surveillance and economize prevention measures provided better data are generated in future.

  10. Follow-up on the migration of birds of prey at L'Anse-a-Valleau wind park site : preliminary report; Suivi de la migration des oiseaux de proie sur le site d'implantation du parc eolien de l'Anse-a-Valleau : rapport preliminaire

    Energy Technology Data Exchange (ETDEWEB)

    Castonguay, M.; Beauchesne, J.A.; Boulianne, F.; Bujold, J.; Ouellet, J.F. [Pesca Environnement, Maria, PQ (Canada)

    2005-06-15

    Cartier Wind Power plans to install a wind turbine array at L'Anse-a-Valleau in the Gaspe Peninsula. This study evaluated the impact of the proposed wind turbine array on the thousands of birds of prey that fly along Quebec's St. Lawrence River each year. Their migration patterns were evaluated through visual and auditory observations during the springtime reproductive and nesting season. The proposed 100.5 MW wind turbine park in L'Anse-a-Valleau was presented to the Quebec Ministry of Sustainable Development, Environment and Parks. In order to complete a feasibility study for this project, it was necessary to document and characterize the spring migration pattern of birds of prey in the area. An inventory of raptors was carried out between April 1 and May 14, 2005. This current study supplemented an existing inventory from a previous study carried out in the spring of 2003. This current study included data on dates of observations of the migratory birds over a 12 day period in L'Anse-a-Valleau as well as Lac du Grand Etang. During the 12 day observation period, bird watching took place for about four hours a day, from 10:00 to 15:00, given favourable weather conditions such as absence of rain and good visibility. Overall, 14 birds of prey were observed over a period of 44 hours. With 5 sightings, the red-tailed hawk was the most frequently observed species during this study. Very few signs of migration were noticed in L'Anse-a-Valleau. The results indicate that this region is not on the migratory path of birds of prey during their flight on the south side of the Saint-Lawrence River. 6 refs., 1 tab., 4 figs., 3 appendices.

  11. Human Capital Theory and Internal Migration: Do Average Outcomes Distort Our View of Migrant Motives?

    Science.gov (United States)

    Korpi, Martin; Clark, William A W

    2017-05-01

    By modelling the distribution of percentage income gains for movers in Sweden, using multinomial logistic regression, this paper shows that those receiving large pecuniary returns from migration are primarily those moving to the larger metropolitan areas and those with higher education, and that there is much more variability in income gains than what is often assumed in models of average gains to migration. This suggests that human capital models of internal migration often overemphasize the job and income motive for moving, and fail to explore where and when human capital motivated migration occurs.

  12. The Bird.

    Science.gov (United States)

    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)

  13. Follow-up on the migration of birds of prey at the Baie-des-Sables wind park site : preliminary report; Suivi de la migration des oiseaux de proie sur le site d'implantation du parc eolien de Baie-des-Sables : rapport preliminaire

    Energy Technology Data Exchange (ETDEWEB)

    Castonguay, M.; Beauchesne, J.A.; Boulianne, F.; Bujold, J.; Ouellet, J.F. [Pesca Environnement, Maria, PQ (Canada)

    2005-06-15

    Cartier Wind Power plans to install a wind turbine array at Baie-des-Sables in the Gaspe Peninsula. This study evaluated the impact of the proposed wind turbine array on the thousands of birds of prey that fly along Quebec's St. Lawrence River each year. Their migration patterns were evaluated through visual and auditory observations during the springtime reproductive and nesting season. The proposed 109.5 MW wind turbine park in Baie-des-Sables was presented to the Quebec Ministry of Sustainable Development, Environment and Parks. In order to complete a feasibility study for this project, it was necessary to document and characterize the spring migration pattern of birds of prey in the area. An inventory of raptors was carried out between March 31 and May 23, 2005. This current study supplemented an existing inventory from a previous study carried out in the spring of 2004. This current study included data on dates of observations of the migratory birds during the monitoring period. Nine species of birds of prey were identified. Overall, 448 individual birds were observed over a total period of 92 hours. With 137 sightings of the red-tailed hawk and 95 sightings of the rough-legged hawk, these 2 species were the most frequently indexed species, accounting for 51.8 per cent of the sightings. No evidence of nesting particular to birds of prey was observed at the site. The flight patterns of the birds were also observed with reference to height and direction of flight. 7 refs., 4 tabs., 1 fig., 3 appendices.

  14. Automatic identification of bird targets with radar via patterns produced by wing flapping

    NARCIS (Netherlands)

    Zaugg, S.; Saporta, G.; van Loon, E.; Schmaljohann, H.; Liechti, F.

    2008-01-01

    Bird identification with radar is important for bird migration research, environmental impact assessments (e.g. wind farms), aircraft security and radar meteorology. In a study on bird migration, radar signals from birds, insects and ground clutter were recorded. Signals from birds show a typical

  15. Twin migration in Fe-based bcc crystals: theory and experiments

    Science.gov (United States)

    Ojha, A.; Sehitoglu, H.; Patriarca, L.; Maier, H. J.

    2014-06-01

    We establish an overall energy expression to determine the twin migration stress in bcc metals. Twin migration succeeds twin nucleation often after a load drop, and a model to establish twin migration stress is of paramount importance. We compute the planar fault energy barriers and determine the elastic energies of twinning dislocations including the role of residual dislocations (br) and twin intersection types such as ?1 1 0?, ?1 1 3? and ?2 1 0?. The energy expression derived provides the twin migration stress in relation to the twin nucleation stress with a ratio of 0.5-0.8 depending on the resultant residual burgers vector and the intersection types. Utilizing digital image correlation, it was possible to differentiate the twin nucleation and twin advancement events experimentally, and transmission electron microscopy observations provided further support to the modelling efforts. Overall, the methodology developed provides an enhanced understanding of twin progression in bcc metals, and most importantly the proposed model does not rely on empirical constants. We utilize Fe-50at.%Cr in our experiments, and subsequently predict the twin migration stress for pure Fe, and Fe-3at.%V from the literature showing excellent agreement with experiments.

  16. Maryland ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  17. Alabama ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, gulls, and terns...

  18. Methanesulfonic acid (MSA) migration in polar ice: data synthesis and theory

    Science.gov (United States)

    Osman, Matthew; Das, Sarah B.; Marchal, Olivier; Evans, Matthew J.

    2017-11-01

    Methanesulfonic acid (MSA; CH3SO3H) in polar ice is a unique proxy of marine primary productivity, synoptic atmospheric transport, and regional sea-ice behavior. However, MSA can be mobile within the firn and ice matrix, a post-depositional process that is well known but poorly understood and documented, leading to uncertainties in the integrity of the MSA paleoclimatic signal. Here, we use a compilation of 22 ice core MSA records from Greenland and Antarctica and a model of soluble impurity transport in order to comprehensively investigate the vertical migration of MSA from summer layers, where MSA is originally deposited, to adjacent winter layers in polar ice. We find that the shallowest depth of MSA migration in our compilation varies over a wide range (˜ 2 to 400 m) and is positively correlated with snow accumulation rate and negatively correlated with ice concentration of Na+ (typically the most abundant marine cation). Although the considered soluble impurity transport model provides a useful mechanistic framework for studying MSA migration, it remains limited by inadequate constraints on key physico-chemical parameters - most notably, the diffusion coefficient of MSA in cold ice (DMS). We derive a simplified version of the model, which includes DMS as the sole parameter, in order to illuminate aspects of the migration process. Using this model, we show that the progressive phase alignment of MSA and Na+ concentration peaks observed along a high-resolution West Antarctic core is most consistent with 10-12 m2 s-1 DMS DMS values previously estimated from laboratory studies. More generally, our data synthesis and model results suggest that (i) MSA migration may be fairly ubiquitous, particularly at coastal and (or) high-accumulation regions across Greenland and Antarctica; and (ii) can significantly change annual and multiyear MSA concentration averages. Thus, in most cases, caution should be exercised when interpreting polar ice core MSA records, although

  19. Landscape associations of birds during migratory stopover

    Science.gov (United States)

    Diehl, Robert Howard

    The challenge for migratory bird conservation is habitat preservation that sustains breeding, migration, and non-breeding biological processes. In choosing an appropriately scaled conservation arena for habitat preservation, a conservative and thorough examination of stopover habitat use patterns by migrants works back from the larger scales at which such relationships may occur. Because the use of stopover habitats by migrating birds occurs at spatial scales larger than traditional field techniques can easily accommodate, I quantify these relationship using the United States system of weather surveillance radars (popularly known as NEXRAD). To provide perspective on use of this system for biologists, I first describe the technical challenges as well as some of the biological potential of these radars for ornithological research. Using data from these radars, I then examined the influence of Lake Michigan and the distribution of woodland habitat on migrant concentrations in northeastern Illinois habitats during stopover. Lake Michigan exerted less influence on migrant abundance and density than the distribution and availability of habitat for stopover. There was evidence of post-migratory movement resulting in habitats within suburban landscapes experiencing higher migrant abundance but lower migrant density than habitats within nearby urban and agricultural landscapes. Finally, in the context of hierarchy theory, I examined the influence of landscape ecological and behavioral processes on bird density during migratory stopover. Migrant abundance did not vary across landscapes that differed considerably in the amount of habitat available for stopover. As a result, smaller, more isolated patches held higher densities of birds. Spatial models of migrant habitat selection based on migrant proximity to a patch explained nearly as much variance in the number of migrants occupying patches (R2 = 0.88) as selection models based on migrant interception of patches during

  20. Migration on Wings Aerodynamics and Energetics

    CERN Document Server

    Kantha, Lakshmi

    2012-01-01

    This book is an effort to explore the technical aspects associated with bird flight and migration on wings. After a short introduction on the birds migration, the book reviews the aerodynamics and Energetics of Flight and presents the calculation of the Migration Range. In addition, the authors explains aerodynamics of the formation flight and finally introduces great flight diagrams.

  1. The North Sea Bird Club

    International Nuclear Information System (INIS)

    Doyle, P.A.T.; Gorman, M.L.; Patterson, I.J.; Howe, S.

    1991-01-01

    This paper reports that the creation of a club for the purpose of encouraging oil and gas workers to watch birds may not at first seem a viable proposition. To the layperson, birds offshore conjures up an image of hundreds of seagulls following fishing boats, and very little else. Also, the act of birdwatching is not seen as a typical offshore worker's activity. Anyone who has worked on an installation offshore and who has any interest in wildlife will be aware of the occasional presence of land-birds. Two decades ago, prompted by some keen offshore workers, a single oil company set up a monitoring program, which quickly became popular with a number of its employees. Birds seem offshore were recorded on data forms and collected together. At this stage the club was purely another recreation facility; however, when the data were collated it was soon realized that installations offshore were being used as staging posts by birds on migration, and that the information being collected would be of great interest in the study of bird movements. All over Britain, at strategic points on the coastline, there are bird observatories which record the arrival and departure of migrating birds. The presence of several hundred solid structures up and down the North Sea, which are used by birds en route, represents a huge, unique bird observatory, capable of uncovering facts about bird migration which have long eluded land-based scientists. Eleven years ago, the North Sea Bird Club began, composed of eight member companies, a recorder from Aberdeen University and a representative from the Nature Conservancy Council. The club received data from 41 installations, and the recorder collated these on Aberdeen University's computer and produced an annual report of sightings

  2. Gender, international migration and social reproduction: implications for theory, policy, research and networking.

    Science.gov (United States)

    Truong T-d

    1996-01-01

    "This paper aims to contribute to the development of an analytical framework that provides the space for the understanding of female migrants as reproductive workers in a cross-national transfer of labor. It will first provide some hypothetical guidelines for the explanation of female migration in the context of reproductive labor. Based on accessible data, a discussion on the case of Japan will be presented to highlight the main issues and problems concerning female migrants as reproductive workers. Finally, implications on policy-making and networking at the international and national level will be analyzed and discussed, taking into account the specific ideological, political and socioeconomic constraints." excerpt

  3. Mapping global diversity patterns for migratory birds.

    Directory of Open Access Journals (Sweden)

    Marius Somveille

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

  4. The kelp highway hypothesis: marine ecology, the coastal migration theory, and the peopling of the Americas

    Science.gov (United States)

    Erlandson, Jon M.; Graham, Michael H.; Bourque, Bruce J.; Corbett, Debra; Estes, James A.; Steneck, Robert S.

    2007-01-01

    In this article, a collaborative effort between archaeologists and marine ecologists, we discuss the role kelp forest ecosystems may have played in facilitating the movement of maritime peoples from Asia to the Americas near the end of the Pleistocene. Growing in cool nearshore waters along rocky coastlines, kelp forests offer some of the most productive habitats on earth, with high primary productivity, magnified secondary productivity, and three-dimensional habitat supporting a diverse array of marine organisms. Today, extensive kelp forests are found around the North Pacific from Japan to Baja California. After a break in the tropicswhere nearshore mangrove forests and coral reefs are highly productivekelp forests are also found along the Andean Coast of South America. These Pacific Rim kelp forests support or shelter a wealth of shellfish, fish, marine mammals, seabirds, and seaweeds, resources heavily used historically by coastal peoples. By about 16,000 years ago, the North Pacific Coast offered a linear migration route, essentially unobstructed and entirely at sea level, from northeast Asia into the Americas. Recent reconstructions suggest that rising sea levels early in the postglacial created a highly convoluted and island-rich coast along Beringia's southern shore, conditions highly favorable to maritime hunter-gatherers. Along with the terrestrial resources available in adjacent landscapes, kelp forests and other nearshore habitats sheltered similar suites of food resources that required minimal adaptive adjustments for migrating coastal peoples. With reduced wave energy, holdfasts for boats, and productive fishing, these linear kelp forest ecosystems may have provided a kind of kelp highway for early maritime peoples colonizing the New World.

  5. Screamy Bird

    DEFF Research Database (Denmark)

    Tarby, Sara; Cermak, Daniel

    2016-01-01

    Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016.......Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016....

  6. The microbiome of neotropical ticks parasitizing on passerine migratory birds

    OpenAIRE

    Budachetri, Khemraj; Williams, Jaclyn; Mukherjee, Nabanita; Sellers, Michael; Moore, Frank; Karim, Shahid

    2016-01-01

    Seasonal migration of passerine birds between temperate North America and tropical Central and South America is an ecological phenomenon. Migration of birds has been associated with the introduction of ectoparasites like ticks or tick-borne pathogens across the avian migration routes. In this study, the microbial diversity was determined in the ticks and bird DNA samples using 454 pyrosequencing of bacterial 16S rRNA gene. Tick DNA samples showed the dominance of genera Lactococcus, Francisel...

  7. Disease dynamics and bird migration-linking mallards Anas platyrhynchos and subtype diversity of the influenza a virus in time and space

    NARCIS (Netherlands)

    G. Gunnarsson (Gunnar); N. Latorre-Margalef (Neus); K.A. Hobson (Keith); S.L. van Wilgenburg (Steven); J. Elmberg (Johan); B. Olsen (Björn); R.A.M. Fouchier (Ron); J. Waldenström (Jonas)

    2012-01-01

    textabstractThe mallard Anas platyrhynchos is a reservoir species for influenza A virus in the northern hemisphere, with particularly high prevalence rates prior to as well as during its prolonged autumn migration. It has been proposed that the virus is brought from the breeding grounds and

  8. Theory to predict particle migration and margination in the pressure-driven channel flow of blood

    Science.gov (United States)

    Qi, Qin M.; Shaqfeh, Eric S. G.

    2017-09-01

    The inhomogeneous concentration distribution of erythrocytes and platelets in microchannel flows particularly in directions normal to the mean flow plays a significant role in hemostasis, drug delivery, and microfluidic applications. In this paper, we develop a coarse-grained theory to predict these distributions in pressure-driven channel flow at zero Reynolds number and compare them to experiments and simulations. We demonstrate that the balance between the deformability-induced lift force and the shear-induced diffusion created by hydrodynamic interactions in the suspension results in both a peak concentration of red blood cells at the channel center and a cell-free or Fahraeus-Lindqvist layer near the walls. On the other hand, the absence of a lift force and the strong red blood cell-platelet interactions result in an excess concentration of platelets in the cell-free layer. We demonstrate a strong role of hematocrit (i.e., erythrocyte volume fraction) in determining the cell-free layer thickness and the degree of platelet margination. We also demonstrate that the capillary number of the erythrocytes, based on the membrane shear modulus, plays a relatively insignificant role in the regimes that we have studied. Our theory serves as a good and simple alternative to large-scale computer simulations of the cross-stream transport processes in these mixtures.

  9. Operating without a Safety Net: Gay Male Adolescents and Emerging Adults' Experiences of Marginalization and Migration, and Implications for Theory of Syndemic Production of Health Disparities

    Science.gov (United States)

    Bruce, Douglas; Harper, Gary W.

    2011-01-01

    Health disparities among gay men (HIV, substance use, depression) have been described as a mutually occurring "syndemic" that is socially produced through two overarching dynamics: marginalization and migration. Although the syndemic theory proposes a developmental trajectory, it has been largely based on epidemiological studies of adult gay men…

  10. Estimation of migration-time and mobility distributions in organelle capillary electrophoresis with statistical-overlap theory.

    Science.gov (United States)

    Davis, Joe M; Arriaga, Edgar A

    2010-01-01

    The separation of organelles by capillary electrophoresis (CE) produces large numbers of narrow peaks, which commonly are assumed to originate from single particles. In this paper, we show this is not always true. Here, we use established methods to partition simulated and real organelle CEs into regions of constant peak density and then use statistical-overlap theory to calculate the number of peaks (single particles) in each region. The only required measurements are the number of observed peaks (maxima) and peak standard deviation in the regions and the durations of the regions. Theory is developed for the precision of the estimated peak number and the threshold saturation above which the calculation is not advisable due to fluctuation of peak numbers. Theory shows that the relative precision is good when the saturation lies between 0.2 and 1.0 and is optimal when the saturation is slightly greater than 0.5. It also shows the threshold saturation depends on the peak standard deviation divided by the region's duration. The accuracy and precision of peak numbers estimated in different regions of organelle CEs are verified by computer simulations having both constant and nonuniform peak densities. The estimates are accurate to 6%. The estimated peak numbers in different regions are used to calculate migration-time and electrophoretic-mobility distributions. These distributions are less biased by peak overlap than ones determined by counting maxima and provide more correct measures of the organelle properties. The procedure is applied to a mitochondrial CE, in which over 20% of peaks are hidden by peak overlap.

  11. Carry-Over Effects of Nonbreeding Habitat on Start-to-Finish Spring Migration Performance of a Songbird.

    Science.gov (United States)

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

    2015-01-01

    For migratory animals, conditions during the nonbreeding period may carry-over to influence spring migration performance. Animals in low-quality habitats are predicted to be in poorer condition, show later migration timing, and travel at slower speeds. This can result in subsequent negative effects on fitness. We tested the hypothesis that nonbreeding season body condition and habitat quality carry-over to affect spring migration performance of a long-distance migratory songbird, the Wood Thrush (Hylocichla mustelina). We tracked individual birds between multiple breeding sites in North America and nonbreeding sites in Central America. First, we compared body condition of nonbreeding birds migrating to the same general region of the breeding range with spring migration performance (timing, speed, and duration) obtained from light-level geolocators. Second, we assessed the Normalized Difference Vegetation Index (NDVI) as a proxy for nonbreeding habitat quality, and predicted that birds from wetter habitat or in wetter years (higher NDVI) would show improved migration performance relative to birds from drier sites. We found no evidence of individual-level carry-over effects of nonbreeding season body condition on spring migration performance. Lower NDVI of nonbreeding habitat resulted in delayed spring migration departure, but this effect disappeared by arrival at breeding sites. Birds occupying drier nonbreeding sites migrated faster and for fewer days, compensating for their relatively late departure. We also documented a broader pattern in NDVI and migration timing and distance, in that birds that occupied the wettest areas in the southern part of the nonbreeding range departed significantly later and migrated farther. Our results suggest that individual carry-over effects of nonbreeding habitat quality may be compensated for by a faster and shorter migration strategy. At a broad scale, consistently later spring timing and longer migration distances were

  12. Carry-Over Effects of Nonbreeding Habitat on Start-to-Finish Spring Migration Performance of a Songbird.

    Directory of Open Access Journals (Sweden)

    Emily A McKinnon

    Full Text Available For migratory animals, conditions during the nonbreeding period may carry-over to influence spring migration performance. Animals in low-quality habitats are predicted to be in poorer condition, show later migration timing, and travel at slower speeds. This can result in subsequent negative effects on fitness. We tested the hypothesis that nonbreeding season body condition and habitat quality carry-over to affect spring migration performance of a long-distance migratory songbird, the Wood Thrush (Hylocichla mustelina. We tracked individual birds between multiple breeding sites in North America and nonbreeding sites in Central America. First, we compared body condition of nonbreeding birds migrating to the same general region of the breeding range with spring migration performance (timing, speed, and duration obtained from light-level geolocators. Second, we assessed the Normalized Difference Vegetation Index (NDVI as a proxy for nonbreeding habitat quality, and predicted that birds from wetter habitat or in wetter years (higher NDVI would show improved migration performance relative to birds from drier sites. We found no evidence of individual-level carry-over effects of nonbreeding season body condition on spring migration performance. Lower NDVI of nonbreeding habitat resulted in delayed spring migration departure, but this effect disappeared by arrival at breeding sites. Birds occupying drier nonbreeding sites migrated faster and for fewer days, compensating for their relatively late departure. We also documented a broader pattern in NDVI and migration timing and distance, in that birds that occupied the wettest areas in the southern part of the nonbreeding range departed significantly later and migrated farther. Our results suggest that individual carry-over effects of nonbreeding habitat quality may be compensated for by a faster and shorter migration strategy. At a broad scale, consistently later spring timing and longer migration

  13. Wind assistance: A requirement for migration of shorebirds?

    Science.gov (United States)

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

    1997-01-01

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

  14. Migration strategy of a flight generalist, the Lesser Black-backed Gull Larus fuscus

    NARCIS (Netherlands)

    Klassen, R.H.G.; Ens, B.J.; Shamoun-Baranes, J.; Exo, K.M.; Bairlein, F.

    2012-01-01

    Migrating birds are believed to minimize the time spent on migration rather than energy. Birds seem to maximize migration speed in different ways as a noteworthy variation in migration strategies exists. We studied migration strategies of a flight mode and feeding generalist, the Lesser Black-backed

  15. Bird guard

    Science.gov (United States)

    Fairchild, Dana M [Armour, SD

    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. Turnover Dynamics of Breeding Land Birds on Islands: is Island Biogeographic Theory ‘True but Trivial’ over Decadal Time-Scales?

    Directory of Open Access Journals (Sweden)

    Duncan McCollin

    2017-01-01

    Full Text Available The theory of island biogeography has revolutionised the study of island biology stimulating considerable debate and leading to the development of new advances in related areas. One criticism of the theory is that it is ‘true but trivial’, i.e., on the basis of analyses of annual turnovers of organisms on islands, it has been posited that stochastic turnover mainly comprises rare species, or repeated immigrations and extinctions thereof, and thereby contribute little to the overall ecological dynamics. Here, both the absolute and relative turnover of breeding land birds are analysed for populations on Skokholm, Wales, over census intervals of 1, 3, 6, 12, and 24 years. As expected, over short census intervals (≤6 years, much of the turnover comprised repeated colonisations and extinctions of rare species. However, at longer intervals (12 and 24 years, a sizeable minority of species (11% of the total recorded showed evidence of colonisation and/or extinction events despite sizeable populations (some upwards of 50 pairs. These results suggest that a longer-term view is required to take into account turnover involving more common species.

  17. Combined Fish and Birds survey in the Dutch coastal zone

    NARCIS (Netherlands)

    Ybema, M.S.; Couperus, A.S.; Grift, R.E.

    2004-01-01

    Knowledge on the relationship between birds and fish is important when assessing the impact of infrastructural development on birds and fish in the coastal zone. It can have a direct effect on bird migration routes and resting areas. It can also have an indirect effect by changing the fish community

  18. Teaching Civic Education in a Migrating Global Community: How Can Students with a Migration Background Contribute to Didactics and Civic Education Theory?

    Science.gov (United States)

    Gessner, Susann

    2017-01-01

    Purpose: The article enquires about how young migrants perceive and evaluate civic education in school and what expectations they have of the subject. Method: The article is based on a qualitative-oriented research work based on the Grounded Theory; surveys were made by interviews with students. Findings: The article emphasises that educational…

  19. Vacancy migration energy dependence on local chemical environment in Fe–Cr alloys: A Density Functional Theory study

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D., E-mail: davide.costa.ge@gmail.com [Unité Matériaux et Transformations, CNRS UMR8207, Université de Lille 1, F-59655 Villeneuve d’Ascq Cédex (France); EDF-R and D Département MMC, Les Renardières, F-77818 Moret sur Loing Cédex (France); Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); Adjanor, G. [EDF-R and D Département MMC, Les Renardières, F-77818 Moret sur Loing Cédex (France); Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); Becquart, C.S. [Unité Matériaux et Transformations, CNRS UMR8207, Université de Lille 1, F-59655 Villeneuve d’Ascq Cédex (France); Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); Olsson, P. [Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); KTH Royal Institute of Technology, Reactor Physics, Roslagstullsbacken 21, 106 91 Stockholm (Sweden); and others

    2014-09-15

    The first step towards the understanding and the modelling of the Fe–Cr alloy kinetic properties consists in estimating the migration energies related to the processes that drive the microstructure evolution. The vacancy’s migration barrier is expected to depend on the vacancy–migrating atom pair atomic environment as pointed out by Nguyen-Manh et al. or Bonny et al. In this paper, we address the issue of the dependence on the vacancy’s local atomic environment of both the vacancy migration energy and the configurational energy change ΔE that occurs when the vacancy jumps towards one of its nearest neighbour sites. A DFT approach is used to determine the ground state energy associated to a given configuration of the system. The results are interpreted in the light of the chromium–chromium and chromium–vacancy binding energies as well as the substitutional chromium atoms magnetic properties.

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

    Science.gov (United States)

    King, James G.; King, Mary Lou

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

  1. Risk Considerations of Bird Strikes to Space Launch Vehicles

    Science.gov (United States)

    Hales, Christy; Ring, Robert

    2016-01-01

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

  2. Hawaii ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for endangered waterbirds and passerine birds, migratory shorebirds and waterfowl, gulls and terns,...

  3. Tracking radar techniques for studying migratory birds

    Science.gov (United States)

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

    1972-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  5. Migration and breeding biology of Arctic terns in Greenland

    DEFF Research Database (Denmark)

    Egevang, Carsten

    ) in the central part of the North Atlantic Ocean before continuing south. Close to Equator (~10º N) a divide in the migration path way occurred: seven birds migrated along the coast of Africa, while four birds crossed the Atlantic Ocean to follow the coast of South America. The northbound migration from...... scale and on a national scale. The study on Arctic tern migration (Manus I) – the longest annual migration ever recorded in any animal – is a study with an international appeal. The study documented how Greenland and Iceland breeding terns conduct the roundtrip migration to the Weddell Sea in Antarctica...... and back. Although the sheer distance (71,000 km on average) travelled by the birds is interesting, the study furthermore showed how the terns depend on high-productive at-sea areas during their massive migration. On the southbound migration, the birds would stop for almost a month (25 days on average...

  6. Concealed by darkness: interactions between predatory bats and nocturnally migrating songbirds illuminated by DNA sequencing

    OpenAIRE

    Ibáñez, Carlos; Popa-Lisseanu, Ana G.; Pastor-Beviá, David; García-Mudarra, Juan L.; Juste, Javier

    2016-01-01

    Recently, several species of aerial-hawking bats have been found to prey on migrating songbirds, but details on this behaviour and its relevance for bird migration are still unclear. We sequenced avian DNA in feather-containing scats of the bird-feeding bat Nyctalus lasiopterus from Spain collected during bird migration seasons. We found very high prey diversity, with 31 bird species from eight families of Passeriformes, almost all of which were nocturnally flying sub-Saharan migrants. Moreov...

  7. Columbia River ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, diving birds, seabirds, passerine birds, gulls, and terns in...

  8. Birds Kept as Pets

    Science.gov (United States)

    ... of pet birds. Because of the risk of avian influenza (bird flu), USDA restricts the importation of pet birds from ... or look dirty may be ill. Learn the signs of illness in a bird, which include appearing ...

  9. Return migration as failure or success? : The determinants of return migration intentions among Moroccan migrants in Europe

    NARCIS (Netherlands)

    de Haas, H.; Fokkema, T.; Fihri, M.F.

    2015-01-01

    Different migration theories generate competing hypotheses with regard to determinants of return migration. While neoclassical migration theory associates migration to the failure to integrate at the destination, the new economics of labour migration sees return migration as the logical stage after

  10. The Migration of Highly Skilled Asian Workers

    OpenAIRE

    Horáková, Jana

    2012-01-01

    This thesis is focused on migration of highly skilled workforce. The aim of this work to show current migration flows of highly skilled workers and particularly flows of highly skilled Asian migrants. First chapter explains migration terms and examines highly skilled migration causes through migration theories. Second chapter studies international migration flows and their long-term development. Last chapter is focused on migration flows of highly skilled Asians to OECD countries and within A...

  11. Bird feeders and their effects on bird-window collisions at residential houses

    Directory of Open Access Journals (Sweden)

    Justine A. Kummer

    2015-12-01

    Full Text Available Feeding wild birds creates an important link between homeowners and conservation. The effects of bird feeders and year-round feeding on birds have not been well studied, however, particularly in relationship to bird-window collisions. We determined effects of bird feeder presence and placement on bird-window collisions at residential homes. Paired month-long trials in which a feeder was either present or absent for one month and then removed or added for the second month were completed at 55 windows at 43 houses. In each trial, homeowners were asked to search their study window daily for evidence of a bird-window collision. During the study there were 51 collisions when there was no bird feeder and 94 when the feeder was present. The season when each trial was set up was the best individual predictor of bird-window collisions. The largest number of collisions was observed during fall migration and the lowest during the winter months. There were no collisions at 26 of the study windows. High variance was observed in the number of collisions at different houses, indicating that effects of bird feeders are context dependent. Changing the occurrence, timing, and placement of feeders can alter collision rates but is only one of many factors that influence whether a residential house is likely to have a bird window-collision or not.

  12. Migration et hivernage de quelques passereaux au Maroc: Mise au ...

    African Journals Online (AJOL)

    The analysis of the autumn migration across Morocco confirms that many birds pass near the Atlantic coast. Winter recoveries in Morocco are mainly concentrated in the northern and central regions. The analysis of the spring migration shows that most birds use approximately the same routes in both autumn and spring, but ...

  13. The physiological basis of bird flight.

    Science.gov (United States)

    Butler, Patrick J

    2016-09-26

    Flapping flight is energetically more costly than running, although it is less costly to fly a given body mass a given distance per unit time than it is for a similar mass to run the same distance per unit time. This is mainly because birds can fly faster than they can run. Oxygen transfer and transport are enhanced in migrating birds compared with those in non-migrators: at the gas-exchange regions of the lungs the effective area is greater and the diffusion distance smaller. Also, migrating birds have larger hearts and haemoglobin concentrations in the blood, and capillary density in the flight muscles tends to be higher. Species like bar-headed geese migrate at high altitudes, where the availability of oxygen is reduced and the energy cost of flapping flight increased compared with those at sea level. Physiological adaptations to these conditions include haemoglobin with a higher affinity for oxygen than that in lowland birds, a greater effective ventilation of the gas-exchange surface of the lungs and a greater capillary-to-muscle fibre ratio. Migrating birds use fatty acids as their source of energy, so they have to be transported at a sufficient rate to meet the high demand. Since fatty acids are insoluble in water, birds maintain high concentrations of fatty acid-binding proteins to transport fatty acids across the cell membrane and within the cytoplasm. The concentrations of these proteins, together with that of a key enzyme in the β-oxidation of fatty acids, increase before migration.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. © 2016 The Author(s).

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

    Science.gov (United States)

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

    2014-01-01

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

  15. Migrações internacionais: teorias, políticas e movimentos sociais International migrations: theories, policies and social movements

    Directory of Open Access Journals (Sweden)

    Neide Lopes Patarra

    2006-08-01

    Full Text Available APRESENTAM-SE subsídios para o debate sobre políticas de migração internacional que já se estende para movimentos sociais de expressivos contingentes documentados e não-documentados nos principais países de destino. Recomendações de organismos internacionais defendem políticas migratórias em termos de direitos humanos e na supervisão de remessas, consideradas um dos aspectos positivos das migrações e auxílio no combate à pobreza dos países de origem. O contraponto com formulações teóricas sobre o fenômeno evidencia incoerências e inviabilidades dessas propostas se não forem articuladas com esforços para o desenvolvimento econômico e social dos países envolvidos.THE TEXT presents arguments for the debate concerning international migration policies; this debate, nowadays, involve social movements of increasing number of documented and undocumented migrants in the main destination countries. International organisms recommend migration policies based on human rights and remittances, considered as a way of reducing poverty in origin countries. Nevertheless, considering theoretical approaches and recent mass movements we can argue about the viability of the propositions as well as the necessity of also considering the structural conditions for the development efforts in these countries as a fundamental manner of combating poverty and improving their level of life.

  16. Overseas seed dispersal by migratory birds.

    Science.gov (United States)

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

    2016-01-13

    Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution. © 2016 The Author(s).

  17. 9 CFR 93.104 - Certificate for pet birds, commercial birds, zoological birds, and research birds.

    Science.gov (United States)

    2010-01-01

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

  18. The definition of illegal migration

    OpenAIRE

    DZHANSARAYEVA RIMA YERENATOVNA; MALIKOVA SHOLPAN BALTABEKOVNA

    2015-01-01

    The article analyzes the definitions of illegal migration. In theory, there is no consensus on the concept of illegal immigration. In the scientific revolution applied the concept of “illegal migration”, “illegal immigration”, “migration of the crime” and “criminal migration”. Crime and illegal migration, although they have common features, are different concepts. For the concept of illegal immigration is characterized by violation of migration laws. For the concept of mandatory criminal migr...

  19. Co-Creating theories and research design for an interdisciplinary project dealing with capacity building for people with migration background in Austria

    Science.gov (United States)

    Weber, Karin; Tscharner, Susanna; Stickler, Therese; Fuchs, Britta; Damyanovic, Doris; Hübl, Johannes

    2017-04-01

    Understanding spatial and social aspects of vulnerability is of growing importance in the context of climate change and natural hazards. The interplay of structural factors, socio-demographic aspects, current risk communication strategies, spatial planning instruments and related processes and the current spatial and environmental situation, including hazards and hazard zones, geographical locations, building and settlement types, contributing to people`s vulnerabilities needs to be analysed and understood to reduce vulnerability and to foster resilience. The project "CCCapMig" (Climate change and capacity building for people with migration background in Austria) aims at linking spatial and technical, as well as organisational and social aspects of climate change and natural hazards. This paper focuses on the co-creation of the theoretical framework and concepts and outlines the research design for this interdisciplinary cross-analysis of several case studies in rural Austria. The project is designed as an inter- and transdisciplinary survey and brings together engineering sciences, spatial sciences and social sciences. Reflecting the interdisciplinary approach, a theoretical framework was developed that refers to a combination of both theories and frameworks from vulnerability research, theories of risk perception and spatial theories and methods like the Sustainable Livelihoods Framework, the Protection-Motivation Theory and Landscape-Planning Theories: The "Sustainable Livelihoods Framework" adapted (by FA0) for disaster risk management offers an analytical framework to understand the emergence of vulnerabilities from the perspective of people`s livelihoods on individual and community level. It includes human, social, natural, physical and financial aspects and the role of institutions, policies and legal rights in reducing or increasing exposure to disaster risk and coping capacities. Additionally, theories on risk perception, especially Protection

  20. Aspects of population dynamics and feeding by piscivorous birds in ...

    African Journals Online (AJOL)

    Breaching events were associated with a change in feeding groups from waders to pursuit feeders, and a decrease in total bird numbers, most likely due to loss of potential littoral zone foraging habitat for waders resulting from reduced water levels. The highest bird numbers were recorded in winter reflecting the migration of ...

  1. Seasonal variation in diversity and abundance of understorey birds ...

    African Journals Online (AJOL)

    Our findings suggest that in a situation where there is no natural forest, an exotic plantation with suitable indigenous understorey cover can help in protection of birds, including endemic and near-endemic species. Keywords: birds, conservation, Eastern Arc Mountains, plantation, seasonal altitudinal migration, seasons, ...

  2. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    Full Text Available Ringing of birds unveiled many aspects of avian migration and dispersal movements. However, there is even much more to be explored by the use of ringing and other marks. Dispersal is crucial in understanding the initial phase of migration in migrating birds as it is to understand patterns and processes of distribution and gene flow. So far, the analysis of migration was largely based on analysing spatial and temporal patters of recoveries of ringed birds. However, there are considerable biases and pitfalls in using recoveries due to spatial and temporal variation in reporting probabilities. Novel methods are required for future studies separating the confounding effects of spatial and temporal heterogeneity of recovery data and heterogeneity of the landscape as well. These novel approaches should aim a more intensive and novel use of the existing recovery data by taking advantage of, for instance, dynamic and multistate modeling, should elaborate schemes for future studies, and should also include other marks that allow a more rapid data collection, like telemetry, geolocation and global positioning systems, and chemical and molecular markers. The latter appear to be very useful in the delineating origin of birds and connectivity between breeding and non–breeding grounds. Many studies of migration are purely descriptive. However, King and Brooks (King & Brooks, 2004 examine if movement patterns of dolphins change after the introduction of a gillnet ban. Bayesian methods are an interesting approach to this problem as they provide a meaningful measure of the probability that such a change occurred rather than simple yes/no response that is often the result of classical statistical methods. However, the key difficulty of a general implementation of Bayesian methods is the complexity of the modelling —there is no general userfriendly package that is easily accessible to most scientists. Drake and Alisauskas (Drake & Alisauskas, 2004 examine the

  3. Burning for birds: concepts and applications

    Science.gov (United States)

    R. Todd Engstrom; David J. Brownlie

    2002-01-01

    Prescribed fire is being used extensively for habitat management of non-game birds, although the area burned today is small relative to the amount of land that burned historically. Results of a non-scientific questionnaire of public and private land managers in the eastern U.S. revealed prescribed fire is being used to provide winter, breeding season, and migration...

  4. Bird-marking in the Netherlands

    NARCIS (Netherlands)

    Oort, van E.D.

    1911-01-01

    Since May of this year the Museum of Natural History at Leyden is carrying into execution the inquiry into migration and other movements of birds in the Netherlands by means of aluminium rings. The results will be published in this periodical and at the same time in Dutch in the periodical of the

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

    Science.gov (United States)

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

  6. Detection of tick-borne encephalitis virus in I. ricinus ticks collected from autumn migratory birds in Latvia.

    Science.gov (United States)

    Kazarina, Alisa; Japiņa, Kristīne; Keišs, Oskars; Salmane, Ineta; Bandere, Dace; Capligina, Valentina; Ranka, Renāte

    2015-03-01

    Birds have a potential of spreading ticks via bird migration routes. In this study, we screened 170 ticks removed during autumn 2010 from 55 birds belonging to 10 species for the presence of tick-borne encephalitis virus (TBEV). In total, TBEV RNA was detected in 14% of I. ricinus tick samples obtained from different birds species. The results of this study indicate the possible role of migrating birds in the dispersal of TBEV-infected ticks along the southward migration route. Copyright © 2014 Elsevier GmbH. All rights reserved.

  7. Investigations of migratory birds during operation of Horns Rev offshore wind farm. Annual status report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Kjaer Christensen, T.; Hounisen, J.P. [NERI, Dept. of Wildlife Ecology and Biodiversity, Roskilde (Denmark)

    2005-07-01

    The aim of the project is to assess the collision risk between birds and wind turbines at the Horns Rev wind farm. The study focused on describing bird movements in relation to the wind farm and to identify the species-specific behavioural responses towards the wind turbines shown by migrating and staging bird species. The study was based on data from spring 2004. The Horns Rev area lies in a region known to be of importance for substantial water bird migration as well as holding internationally important numbers of several wintering and staging water bird species. (au)

  8. Investigations of migratory birds during operation of Horns Rev offshore wind farm. Annual status report 2004

    International Nuclear Information System (INIS)

    Kjaer Christensen, T.; Hounisen, J.P.

    2005-01-01

    The aim of the project is to assess the collision risk between birds and wind turbines at the Horns Rev wind farm. The study focused on describing bird movements in relation to the wind farm and to identify the species-specific behavioural responses towards the wind turbines shown by migrating and staging bird species. The study was based on data from spring 2004. The Horns Rev area lies in a region known to be of importance for substantial water bird migration as well as holding internationally important numbers of several wintering and staging water bird species. (au)

  9. Towards a new understanding of migration timing

    NARCIS (Netherlands)

    Kölzsch, Andrea; Muskens, Gerard; Kruckenberg, Helmut; Glazov, Peter; Weinzierl, Rolf; Nolet, Bart A.; Wikelski, Martin

    2016-01-01

    According to migration theory and several empirical studies, long-distance migrants are more time-limited during spring migration and should therefore migrate faster in spring than in autumn. Competition for the best breeding sites is supposed to be the main driver, but timing of migration is

  10. Bird impact study on the 10 MW wind farm of La Pena (Tarifa)

    International Nuclear Information System (INIS)

    Cererols, N.; Martinez, A.; Ferrer, M.

    1996-01-01

    This paper shows the conclusions of a 16 month study of the possible impacts on the local and migrating population of birds of a wind farm located in the passageway of migrating birds between Africa and Europe. On the whole, the wind farm did not prove to represent an important impact on the birds present in its surroundings and, on the contrary, created a new habitat for some species not present in adjacent areas. (author)

  11. Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

    Science.gov (United States)

    Muijres, Florian T; Johansson, L Christoffer; Bowlin, Melissa S; Winter, York; Hedenström, Anders

    2012-01-01

    Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate longer distances

  12. Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

    Directory of Open Access Journals (Sweden)

    Florian T Muijres

    Full Text Available Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate

  13. Comparing Aerodynamic Efficiency in Birds and Bats Suggests Better Flight Performance in Birds

    Science.gov (United States)

    Muijres, Florian T.; Johansson, L. Christoffer; Bowlin, Melissa S.; Winter, York; Hedenström, Anders

    2012-01-01

    Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate longer distances

  14. Torn Paper Birds.

    Science.gov (United States)

    Harrington, Carolyn Lang

    1998-01-01

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

  15. The effect of the Sep wind park near Oosterbierum, Friesland, The Netherlands, on birds

    International Nuclear Information System (INIS)

    Winkelman, J.E.

    1992-01-01

    The title study concerns the period 1984-1991. The wind park consists of 18 three-bladed 300 kW horizontal axis wind turbines of 35 meters height, and a rotor diameter of 30 meters, seven meteorological towers, and three cluster and control buildings. Aspects studied included disturbance of breeding, resting or feeding, and migrating birds, behavior of birds approaching the wind turbines during the day and night, and bird victims due to collision with the wind turbines and the meteorological towers. In this report attention is paid to the disturbance of the bird's biotope. The results show that four species of grassland birds, breeding in the park, were hardly disturbed by the wind turbines. For feeding and resting birds, however, disturbance effects were noted, even at a distance of 500 meters from the outside wind turbine array. The present number of bird species reduced 60-95%, dependent on the species, after the wind park was put into operation. Also the behavior of migrating birds was influenced by the wind park, showed in clustering of groups or avoiding the wind park, sometimes up to 67% of the birds did so. It is therefore recommended not to implement new wind parks in important bird migration and bird feeding or bird resting areas. Bird popular areas, however, are mostly windy areas. 15 figs., 25 tabs., 56 app., 128 refs

  16. The Role of Remittances in Migration Decision: Evidence from Turkish Migration

    OpenAIRE

    Sule Akkoyunlu; Boriss Siliverstovs

    2007-01-01

    In this study we analyse the impact of workers' remittances on the decision to migrate by means of cointegration analysis. In traditional migration theories, especially in human capital models, the decision to migrate is based upon comparison of expected future incomes in the sending and the receiving countries adjusted for the cost of migration. By contrast, the new economics of labour migration suggests that the migration decision is made jointly by the migrant and his family. One important...

  17. The function of migratory bird calls

    DEFF Research Database (Denmark)

    Reichl, Thomas; Andersen, Bent Bach; Larsen, Ole Næsbye

    migration and to stimulate migratory restlessness in conspecifics. We wished to test if conspecific flight calls influence the flight direction of a nocturnal migrant, the European Robin (Erithacus rubecula), i.e. if flight calls help migrants keeping course. Wild caught birds showing migratory restlessness...... the experimental bird could be activated successively to simulate a migrating Robin cruising E-W, W-E, S-N or N-S at a chosen height (mostly about 40 m), at 10 m/s and emitting Robin flight calls of 80 dB(A) at 1 m. The simulated flight of a "ding" sound served as a control. During an experiment the bird was first...... allowed to settle and express migratory restlessness for at least 30 minutes. Secondly, the flight simulation axis (e.g. E-W or N-S) with the largest angle relative to the bird's migration course was chosen and "flights" of simulated calling conspecifics or the "ding" sound along this axis continued...

  18. Optimal moult strategies in migratory birds.

    Science.gov (United States)

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

    2008-01-27

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

  19. Light-Activated Magnetic Compass in Birds

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2013-01-01

    Migrating birds fly thousand miles without having a map, or a GPS unit. But they may carry their own sensitive navigational tool, which allows them "see" the Earth’s magnetic field. Here we review the important physical and chemical constraints on a possible compass sensor and discuss...... the suggestion that radical pairs in a photoreceptor cryptochrome might provide a biological realization for a magnetic compass. Finally, we review the current evidence supporting a role for radical pair reactions in the magnetic compass of birds....

  20. Turnover Dynamics of Breeding Land Birds on Islands: is Island Biogeographic Theory ‘True but Trivial’ over Decadal Time-Scales?

    OpenAIRE

    Duncan McCollin

    2017-01-01

    The theory of island biogeography has revolutionised the study of island biology stimulating considerable debate and leading to the development of new advances in related areas. One criticism of the theory is that it is ‘true but trivial’, i.e., on the basis of analyses of annual turnovers of organisms on islands, it has been posited that stochastic turnover mainly comprises rare species, or repeated immigrations and extinctions thereof, and thereby contribute little to the overall ecological...

  1. Number of Migration Scenarios Passing through each HUC (future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forest dwelling neotropical migratory birds require intact forested stopovers during migration. The number of paths that pass through a HUC highlight that huc's...

  2. Number of Migration Scenarios Passing through each HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forest dwelling neotropical migratory birds require intact forested stopovers during migration. The number of paths that pass through a HUC highlight that huc's...

  3. Evaluation of peak overlap in migration-time distributions determined by organelle capillary electrophoresis: Type-II error analogy based on statistical-overlap theory.

    Science.gov (United States)

    Davis, Joe M; Arriaga, Edgar A

    2009-08-28

    Organelles commonly are separated by capillary electrophoresis (CE) with laser-induced-fluorescence detection. Usually, it is assumed that peaks observed in the CE originate from single organelles, with negligible occurrence of peak overlap. Under this assumption, migration-time and mobility distributions are obtained by partitioning the CE into different regions and counting the number of observed peaks in each region. In this paper, criteria based on statistical-overlap theory (SOT) are developed to test the assumption of negligible peak overlap and to predict conditions for its validity. For regions of the CE having constant peak density, the numbers of peaks (i.e., intensity profiles of single organelles) and observed peaks (i.e., maxima) are modeled by probability distributions. For minor peak overlap, the distributions partially merge, and their mergence is described by an analogy to the Type-II error of hypothesis testing. Criteria are developed for the amount of peak overlap, at which the number of observed peaks has an 85% or 90% probability of lying within the 95% confidence interval of the number of peaks of single organelles. For this or smaller amounts of peak overlap, the number of observed peaks is a good approximation to the number of peaks. A simple procedure is developed for evaluating peak overlap, requiring determination of only the peak standard deviation, the duration of the region occupied by peaks, and the number of observed peaks in the region. The procedure can be applied independently to each region of the partitioned CE. The procedure is applied to a mitochondrial CE.

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

    Science.gov (United States)

    The Azov and Black Sea basins are part of the transcontinental wild bird migration routes from Northern Asia and Europe to the Mediterranean, Africa and Southwest Asia. These regions constitute an area of transit, stops during migration, and nesting for many different bird species. From September ...

  5. Contrasting extreme long-distance migration patterns in bar-tailed godwits

    NARCIS (Netherlands)

    Battley, P.F.; Warnock, N.; Tibbitts, T.L; Gill, R.E.; Piersma, T.; Hassel, C.J.; Douglas, D.C.; Mulcahy, D.M.; Gartell, B.D.; Schuckard, R.; Melville, D.S.; Riegen, A.D.

    2012-01-01

    Migrating birds make the longest non-stop endurance flights in the animal kingdom. Satellite technology is now providingdirect evidence on the lengths and durations of these flights and associated staging episodes for individual birds. Using thistechnology, we compared the migration performance of

  6. Contrasting extreme long-distance migration patterns in bar-tailed godwits Limosa lapponica

    NARCIS (Netherlands)

    Battley, Phil F.; Warnock, Nils; Tibbitts, T. Lee; Gill, Robert E.; Piersma, Theunis; Hassell, Chris J.; Douglas, David C.; Mulcahy, Daniel M.; Gartrell, Brett D.; Schuckard, Rob; Melville, David S.; Riegen, Adrian C.

    Migrating birds make the longest non-stop endurance flights in the animal kingdom. Satellite technology is now providing direct evidence on the lengths and durations of these flights and associated staging episodes for individual birds. Using this technology, we compared the migration performance of

  7. CONSEQUENCES OF WEIGHT DECREASE ON FLIGHT PERFORMANCE DURING MIGRATION

    NARCIS (Netherlands)

    VIDELER, JJ

    1995-01-01

    Migrating birds, flying nonstop over long distances, are substantially heavier at the start than at the end of their journey. Aerodynamic models predict that these birds would optimally have to fly faster in the beginning of their flight, and end at a slower speed. Energy expenditure would be

  8. Energy Expenditure and Metabolic Changes of Free-Flying Migrating Northern Bald Ibis

    NARCIS (Netherlands)

    Bairlein, Franz; Fritz, Johannes; Scope, Alexandra; Schwendenwein, Ilse; Stanclova, Gabriela; van Dijk, Gertjan; Meijer, Harro A J; Verhulst, Simon; Dittami, John

    2015-01-01

    Many migrating birds undertake extraordinary long flights. How birds are able to perform such endurance flights of over 100-hour durations is still poorly understood. We examined energy expenditure and physiological changes in Northern Bald Ibis Geronticus eremite during natural flights using birds

  9. Abundância sazonal de aves migratórias na Área de Proteção Ambiental de Piaçabuçu, Alagoas, Brasil Seasonal abundance of migratory birds in the Piaçabuçu Protection Area, Alagoas, Brazil

    Directory of Open Access Journals (Sweden)

    Susanna A. S. Cabral

    2006-09-01

    Full Text Available Todos os anos milhares de aves limícolas e migratórias invernam ao longo da costa da América do Sul, entre setembro e abril, onde adquirem massa corpórea e realizam mudas para retornar aos sítios de reprodução. Estudos quali-quantitativos foram realizados na Área de Proteção Ambiental de Piaçabuçu, Alagoas, Brasil, através da contagem direta, objetivando o acompanhamento das flutuações sazonais da avifauna migrante. Foram registradas cinco espécies da família Charadriidae: Vanellus chilensis (Wagler, 1827; Pluvialis squatarola (Linnaeus, 1758; Charadrius semipalmatus Bonaparte, 1825; Charadrius collaris Vieillot, 1818 e Charadrius wilsonia (Ord, 1814 e cinco espécies da família Scolopacidae: Arenaria interpres (Linnaeus, 1758; Actitis macularius (Linnaeus, 1766; Catoptrophorus semipalmatus (Gmelin, 1789; Calidris pusilla (Linnaeus, 1766 e Calidris alba (Pallas, 1764. Pluvialis squatarola, Charadrius semipalmatus, Charadrius collaris, Arenaria interpres, Calidris pusilla e Calidris alba foram consideradas constantes (presentes em mais de 50% das observações. Charadrius semipalmatus e Calidris alba apresentaram os maiores índices de freqüência de ocorrência nos meses de novembro e dezembro e, março e setembro, respectivamente. A correlação de Spearman demonstra uma forte dependência na migração destas espécies. A fidelidade dessas aves a APA de Piaçabuçu observada nessa pesquisa indica ser a área um sítio de invernada, reforçando sua importância para a conservação das espécies migratórias que utilizam o local.Every year, thousands of limicola and migratory birds winter on the South American coast, between September and April, where they acquire body mass and undergo moulting before returning to their reproduction sites. Qualitative and quantitative studies were performed in the Piaçabuçu Protection Area located in the state of Alagoas, Brazil, by direct counting, aiming to follow upon the birds' seasonal

  10. Demographic outcomes of diverse migration strategies assessed in a metapopulation of tundra swans.

    Science.gov (United States)

    Ely, Craig R; Meixell, Brandt W

    2016-01-01

    Migration is a prominent aspect of the life history of many avian species, but the demographic consequences of variable migration strategies have only infrequently been investigated, and rarely when using modern technological and analytical methods for assessing survival, movement patterns, and long-term productivity in the context of life history theory. We monitored the fates of 50 satellite-implanted tundra swans (Cygnus columbianus) over 4 years from five disparate breeding areas in Alaska, and used known-fate analyses to estimate monthly survival probability relative to migration distance, breeding area, migratory flyway, breeding status, and age. We specifically tested whether migratory birds face a trade-off, whereby long-distance migrants realize higher survival rates at the cost of lower productivity because of reduced time on breeding areas relative to birds that migrate shorter distances and spend more time on breeding areas. Annual migration distances varied significantly among breeding areas (1020 to 12720 km), and were strongly negatively correlated with time spent on breeding areas (r = -0.986). Estimates of annual survival probability varied by wintering area (Pacific coast, Alaska Peninsula, and Eastern seaboard) and ranged from 0.79 (95%CI: 0.70-0.88) to 1.0, depending on criteria used to discern mortalities from radio failures. We did not find evidence for a linear relationship between migration distance and survival as swans from the breeding areas with the shortest and longest migration distances had the highest survival probabilities. Survival was lower in the first year post-marking than in subsequent years, but there was not support for seasonal differences in survival. Productivity varied among breeding populations and was generally inversely correlated to survival, but not migration distance or time spent on breeding areas. Tundra swans conformed to a major tenet of life history theory, as populations with the highest survival

  11. Chewing lice from wild birds in northern Greece.

    Science.gov (United States)

    Diakou, Anastasia; Pedroso Couto Soares, José Bernardo; Alivizatos, Haralambos; Panagiotopoulou, Maria; Kazantzidis, Savas; Literák, Ivan; Sychra, Oldřich

    2017-10-01

    Greece represents an important area for wild birds due to its geographical position and habitat diversity. Although the bird species in Greece are well recorded, the information about the chewing lice that infest them is practically non-existent. Thus, the aim of the present study was to record the species of lice infesting wild birds in northern Greece and furthermore, to associate the infestation prevalence with factors such as the age, sex, migration and social behaviour of the host as well as the time of the year. In total 729 birds, (belonging to 9 orders, 32 families and 68 species) were examined in 7 localities of northern Greece, during 9 ringing sessions from June 2013 until October 2015. Eighty (11%) of the birds were found to be infested with lice. In 31 different bird species, 560 specimens of lice, belonging to 33 species were recorded. Mixed infestations were recorded in 11 cases where birds were infested with 2-3 different lice species. Four new host-parasite associations were recorded i.e. Menacanthus curuccae from Acrocephalus melanopogon, Menacanthus agilis from Cettia cetti, Myrsidea sp. from Acrocephalus schoenobaenus, and Philopretus citrinellae from Spinus spinus. Moreover, Menacanthus sinuatus was detected on Poecile lugubris, rendering this report the first record of louse infestation in this bird species. The statistical analysis of the data collected showed no association between parasitological parameters (prevalence, mean and median intensity and mean abundance) in two different periods of the year (breeding vs post-breeding season). However, there was a statistically significant difference in the prevalence of infestation between a) migrating and sedentary passerine birds (7.4% vs 13.2%), b) colonial and territorial birds (54.5% vs 9.6%), and c) female and male birds in breeding period (2.6% vs 15.6%). Copyright © 2017. Published by Elsevier B.V.

  12. Migratory birds and West Nile virus

    Czech Academy of Sciences Publication Activity Database

    Rappole, J. H.; Hubálek, Zdeněk

    2003-01-01

    Roč. 94, s1 (2003), s. 47-58 ISSN 1364-5072. [Conference of Society for Applied Microbiology (U.K.) "Pathogens in the Environment and Changing Ecosystems". Nottingham, 08.07.2002-11.07.2002] Institutional research plan: CEZ:AV0Z6093917 Keywords : West Nile virus * bird migration Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.743, year: 2003

  13. Gendering Migration

    Directory of Open Access Journals (Sweden)

    Mirjana Morokvašić

    2014-12-01

    Full Text Available Migration patterns, migration discourse and underlying representations, migrants’ experiences, obligations and duties as well as the expectations relative to their migration are gendered. Since the pioneering feminist migration scholars’ questioning of men as a universal reference and the invisibility of women or their stereotypical representations as dependents in the mainstream production of knowledge on migration, the scholarship has evolved considerably. It is argued in the paper that the ongoing process of cross-fertilization of developments in two separate epistemologies, each initially questioning monolithic and essentialist visions of a “migrant” on one hand and a “woman” on the other, produced a fecund subfield of research “migration and gender”. The paper provides an insight into this, reviewing work on the issues related to gendering different phases of migration. Bridging migration and gender brought to the top of research agendas issues that used to be on the margins, creating new visibilities but leaving out other gendered dimensions of complex realities of migrant experience.

  14. A study on density functional theory of the effect of pressure on the formation and migration enthalpies of intrinsic point defects in growing single crystal Si

    Science.gov (United States)

    Sueoka, Koji; Kamiyama, Eiji; Kariyazaki, Hiroaki

    2012-05-01

    In 1982, Voronkov presented a model describing point defect behavior during the growth of single crystal Si from a melt and derived an expression to predict if the crystal was vacancy- or self-interstitial-rich. Recently, Vanhellemont claimed that one should take into account the impact of compressive stress introduced by the thermal gradient at the melt/solid interface by considering the hydrostatic pressure dependence of the formation enthalpy of the intrinsic point defects. To evaluate the impact of thermal stress more correctly, the pressure dependence of both the formation enthalpy (Hf) and the migration enthalpy (Hm) of the intrinsic point defects should be taken into account. Furthermore, growing single crystal Si is not under hydrostatic pressure but almost free of external pressure (generally in Ar gas under reduced pressure). In the present paper, the dependence of Hf and Hm on the pressure P, or in other words, the pressure dependence of the formation energy (Ef) and the relaxation volume (vf), is quantified by density functional theory calculations. Although a large number of ab initio calculations of the properties of intrinsic point defects have been published during the last years, calculations for Si crystals under pressure are rather scarce. For vacancies V, the reported pressure dependences of HfV are inconsistent. In the present study, by using 216-atom supercells with a sufficient cut-off energy and mesh of k-points, the neutral I and V are found to have nearly constant formation energies EfI and EfV for pressures up to 1 GPa. For the relaxation volume, vfI is almost constant while vfV decreases linearly with increasing pressure P. In case of the hydrostatic pressure Ph, the calculated formation enthalpy HfI and migration enthalpy HmI at the [110] dumbbell site are given by HfI = 3.425 - 0.057 × Ph (eV) and HmI = 0.981 - 0.039 × Ph (eV), respectively, with Ph given in GPa. The calculated HfV and HmV dependencies on Ph given by HfV = 3.543 - 0

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Amy Pocewicz

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

  17. North Slope, Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls and terns, seabirds, shorebirds, and waterfowl for the North Slope of Alaska....

  18. Baseline and Stress-Induced Plasma Corticosterone during Long-Distance Migration in the Bar-Tailed Godwit, Limosa lapponica

    NARCIS (Netherlands)

    Landys-Ciannelli, MM; Ramenofsky, M; Piersma, T; Jukema, J; Wingfield, JC

    2002-01-01

    The specific roles of corticosterone in promotion of avian migration remain unclear even though this glucocorticosteroid is elevated in many migrating bird species. In general, glucocorticosteroids promote metabolic homeostasis and may elicit effects on feeding and locomotion. Because the migratory

  19. Birds of Sabaki Birds of Sabaki

    African Journals Online (AJOL)

    CJ

    2005-02-25

    Feb 25, 2005 ... covers approximately 250ha.The area encompassed by this study extends from Mambrui to the north, the sea to the east, the opposite bank of the estuary to the south and the Sabaki bridge and Malindi-Garsen road to the west. The area is defined as an Important Bird Area(IBA) by BirdLife International in ...

  20. [Speed of migratory movements in birds as adaptive behaviour].

    Science.gov (United States)

    Paevskiĭ, V A

    2012-01-01

    Migration speed of 115 bird species from 35 families of 14 orders was analyzed. The data were collected from published sources based on ringing recoveries. It was found that average speed varies between 10 and 880 km/day, and the maximum speed varies between 30 and 1392 km/day, but in the majority of species the average speed values are in the range of 20-100, and the maximum speed values are in the range of 40-360 km/day There is significant positive correlation between the average and maximum speed. The ratio between maximum and average speed in different species varies significantly, and overall for all birds is 4:1. On average, shorebirds migrate twice as rapidly as passerines, and average speed of the raptors is rather higher than in shorebirds. The species from Turdidae family migrate significantly faster than the species from Fringillidae family, and the latter migrate faster than tits. No significant differences in migration speed were found between the species from Sylviidae and Turdidae families, as well as between Sylviidae and Motacillidae. Significant negative correlation was found between the body mass and average migration speed in the shorebirds, but no relationship between these parameters was found in the passerines. In many bird species, adult birds migrate significantly faster than juveniles, and in some species no difference in speed was found between males and females. In the passerines, the average migration speed is significantly higher among long-distance early-departing nocturnal migrants as compared with the short-distance late-departing diurnal ones. The spring migration speed was much higher than autumn speed, but in some species only. The beha-vior of migrants at flight and at stopovers is governed by a complex interaction between their species-specific foraging features, weather conditions, and habitat.

  1. Angry Birds in Space

    Science.gov (United States)

    Halford, A. J.

    2017-12-01

    When space computers first started listening into space radio, they noticed that there were radio noises that happened on the morning side of the Earth. Because these waves sounded like noises birds make in the morning, we named these waves after them. These bird sounding waves can move around the Earth, flying up and down, and sometimes move into an area where there is more stuff. This area is also much colder than where these bird noises are first made. When the waves move into this cold area where there is more stuff, they start to sound like angry birds instead of happy birds. Both of these waves, the happy and angry bird sounding waves, are very important to our understanding of how the tiny things in space move and change. Sometimes the waves which sound like birds can push these tiniest of things into the sky. The happy bird sounding waves can push the tiniest things quickly while the angry bird sounding waves push the tinest of things more slowly. When the tiny things fall into the sky, they create beautiful space lights and light that burns which can hurt people in up goers and not so up goers as well as our things like phones, and space computers. We study these waves that sound like birds to better understand when and where the tiny things will fall. That way we can be prepared and enjoy watching the pretty space lights at night with no worries.

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

    Science.gov (United States)

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

    2016-06-01

    This study was carried out to determine chewing louse species of wild birds in the Ria Formosa Natural Park, located in southern Portugal. In addition, the hypothesis that bird age, avian migration and social behaviour have an impact on the louse prevalence was tested. Between September and December of 2013, 122 birds (belonging to 10 orders, 19 families, 31 genera and 35 species) captured in scientific ringing sessions and admitted to the Wildlife Rehabilitation and Investigation Centre of Ria Formosa were examined for lice. Twenty-six (21.3%) birds were found to be infested with at least one chewing louse species. The chewing lice identified include 18 species. Colonial birds (34.9%) and migratory birds (29.5%) had statistically significant higher prevalence than territorial birds (6.8%) and resident birds (13.1%), respectively. This paper records 17 louse species for the first time in southern Portugal: Laemobothrion maximum, Laemobothrion vulturis, Actornithophilus piceus lari, Actornithophilus umbrinus, Austromenopon lutescens, Colpocephalum heterosoma, Colpocephalum turbinatum, Eidmanniella pustulosa, Nosopon casteli, Pectinopygus bassani, Pseudomenopon pilosum, Trinoton femoratum, Trinoton querquedulae, Craspedorrhynchus platystomus, Degeeriella fulva, Falcolipeurus quadripustulatus, Lunaceps schismatus. Also a nymph of the genus Strigiphilus was collected from a Eurasian eagle-owl. These findings contribute to the knowledge of avian chewing lice from important birds areas in Portugal. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Diseases Transmitted by Birds.

    Science.gov (United States)

    Levison, Matthew E

    2015-08-01

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

  4. Extreme migration and the individual quality spectrum

    NARCIS (Netherlands)

    Conklin, J.R.; Senner, N.R.; Battley, P.F.; Piersma, T.

    2017-01-01

    Costsof migration, in terms of time, energy, and mortality risk, have a strong theoretical and empirical foundation in thestudy of birds. We expect these costs to be most severe for extreme long-distance migratory landbirds, whose demandingannual routines (e.g. non-stop flights  8000 km and return

  5. Extreme migration and the individual quality spectrum

    NARCIS (Netherlands)

    Conklin, Jesse R.; Senner, Nathan R.; Battley, Philip F.; Piersma, Theunis

    Costs of migration, in terms of time, energy, and mortality risk, have a strong theoretical and empirical foundation in the study of birds. We expect these costs to be most severe for extreme long-distance migratory landbirds, whose demanding annual routines (e.g. non-stop flights > 8000 km and

  6. Migration stopover ecology of western avian populations: A southwestern migration workshop

    Science.gov (United States)

    Skagen, Susan K.; Melcher, Cynthia P.; Hazelwood, Rob

    2004-01-01

    The importance of migration stopover sites in ensuring that migratory birds successfully accomplish their journeys between breeding and non-breeding ranges has come to the forefront of avian research. Migratory birds that breed in western United States (US) and Canada and overwinter primarily in western Mexico migrate across the arid region of northern Mexico and southwestern US. Many of these migrants use lowland riparian stopover habitats, which comprise less than 0.1% of the western U.S. landscape. These habitats represent a significant conservation priority.

  7. Mitigation of artifacts in rtm with migration kernel decomposition

    KAUST Repository

    Zhan, Ge

    2012-01-01

    The migration kernel for reverse-time migration (RTM) can be decomposed into four component kernels using Born scattering and migration theory. Each component kernel has a unique physical interpretation and can be interpreted differently. In this paper, we present a generalized diffraction-stack migration approach for reducing RTM artifacts via decomposition of migration kernel. The decomposition leads to an improved understanding of migration artifacts and, therefore, presents us with opportunities for improving the quality of RTM images.

  8. Flexible navigation response in common cuckoos Cuculus canorus displaced experimentally during migration

    DEFF Research Database (Denmark)

    Willemoes, Mikkel; Blas, Julio; Wikelski, Martin

    2015-01-01

    Migrating birds follow innate species-specific migration programs capable of guiding them along complex spatio-temporal routes, which may include several separate staging areas. Indeed, migration routes of common cuckoos Cuculus canorus show little variation between individuals; yet, satellite...... tracks of 11 experimentally displaced adults revealed an unexpected flexibility in individual navigation responses. The birds compensated for the translocation to unfamiliar areas by travelling toward population-specific staging areas, demonstrating true navigation capabilities. Individual responses...

  9. Migration chemistry

    International Nuclear Information System (INIS)

    Carlsen, L.

    1992-05-01

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional K D concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  10. Guam and the Northern Mariana Islands ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for pelagic birds, shorebirds, wading birds, waterfowl, gulls, terns, and passerine birds in Guam and the...

  11. Coastal Resources Atlas: Long Island: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  12. Bird of Passage at Four Universities

    Indian Academy of Sciences (India)

    IAS Admin

    RESONANCE │ May 2010. GENERAL │ ARTICLE. Bird of Passage at Four Universities. Student Days of Rudolph Peierls. G Baskaran. Keywords. Peierls, Sommerfeld, Heisen- berg, Pauli, theoretical physics, electron theory of solids. G Baskaran is a theoretical physicist. This article is his first contribution to. Resonance.

  13. A Broader Look on Migration: A Two Way Interaction Between Development and Migration in the Country Of Origin

    OpenAIRE

    Cristian ÎNCALTARAU; Sorin-Stefan MAHA; Liviu-George MAHA

    2011-01-01

    Most studies on migration are limited to economic impact of migration. But this is only one side of the coin. In order to understand it better, international migration should be placed within the broader context of development. The first part of the article shows the channels through which international migration affects the home country. But the new migration theories have moved to a wider view, considering that development leads by itself to migration, first internally and then externally. ...

  14. Determinants of spring migration departure decision in a bat.

    Science.gov (United States)

    Dechmann, Dina K N; Wikelski, M; Ellis-Soto, D; Safi, K; O'Mara, M Teague

    2017-09-01

    Migratory decisions in birds are closely tied to environmental cues and fat stores, but it remains unknown if the same variables trigger bat migration. To learn more about the rare phenomenon of bat migration, we studied departure decisions of female common noctules ( Nyctalus noctula ) in southern Germany. We did not find the fattening period that modulates departure decisions in birds. Female noctules departed after a regular evening foraging session, uniformly heading northeast. As the day of year increased, migratory decisions were based on the interactions among wind speed, wind direction and air pressure. As the migration season progressed, bats were likely to migrate on nights with higher air pressure and faster tail winds in the direction of travel, and also show high probability of migration on low-pressure nights with slow head winds. Common noctules thus monitor complex environmental conditions to find the optimal migration night. © 2017 The Authors.

  15. Morphological constraints on changing avian migration phenology.

    Science.gov (United States)

    Møller, A P; Rubolini, D; Saino, N

    2017-06-01

    Many organisms at northern latitudes have responded to climate warming by advancing their spring phenology. Birds are known to show earlier timing of spring migration and reproduction in response to warmer springs. However, species show heterogeneous phenological responses to climate warming, with those that have not advanced or have delayed migration phenology experiencing population declines. Although some traits (such as migration distance) partly explain heterogeneity in phenological responses, the factors affecting interspecies differences in the responsiveness to climate warming have yet to be fully explored. In this comparative study, we investigate whether variation in wing aspect ratio (reflecting relative wing narrowness), an ecomorphological trait that is strongly associated with flight efficiency and migratory behaviour, affects the ability to advance timing of spring migration during 1960-2006 in a set of 80 European migratory bird species. Species with larger aspect ratio (longer and narrower wings) showed smaller advancement of timing of spring migration compared to species with smaller aspect ratio (shorter and wider wings) while controlling for phylogeny, migration distance and other life-history traits. In turn, migration distance positively predicted aspect ratio across species. Hence, species that are better adapted to migration appear to be more constrained in responding phenologically to rapid climate warming by advancing timing of spring migration. Our findings corroborate the idea that aspect ratio is a major evolutionary correlate of migration, and suggest that selection for energetically efficient flights, as reflected by high aspect ratio, may hinder phenotypically plastic/microevolutionary adjustments of migration phenology to ongoing climatic changes. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  16. Is a bird in the hand worth two in the future? Intertemporal choice, attachment and theory of mind in school-aged children

    Science.gov (United States)

    Marchetti, Antonella; Castelli, Ilaria; Sanvito, Laura; Massaro, Davide

    2014-01-01

    Intertemporal choice is a decision-making dilemma related to outcomes of different entity located at different time points. Economic and psychological literature on this topic showed the phenomen of temporal discounting, i.e., the proclivity to devalue the outcome distant in time on the basis of the time delay necessary to obtain it. The goals of this research are to investigate two different components of intertemporal choice separately, namely time and outcome, in school-age children, and the possible link among such components and the security of attachment style and theory of mind. Ninety one children aged between 6 and 10 years performed two intertemporal choice tasks, first and second order false belief tasks and the Separation Anxiety Task in the Family and School versions. Results showed that the two components of intertemporal choice (waiting tolerance and sensitivity to delayed outcome) are stately interrelated; the quality of the attachment to the family caregiver affects the tolerance to waiting time and first order false belief understanding affects both the components of intertemporal choice. PMID:24904496

  17. Is a bird in the hand worth two in the future? Intertemporal choice, attachment and theory of mind in school-aged children.

    Science.gov (United States)

    Marchetti, Antonella; Castelli, Ilaria; Sanvito, Laura; Massaro, Davide

    2014-01-01

    Intertemporal choice is a decision-making dilemma related to outcomes of different entity located at different time points. Economic and psychological literature on this topic showed the phenomen of temporal discounting, i.e., the proclivity to devalue the outcome distant in time on the basis of the time delay necessary to obtain it. The goals of this research are to investigate two different components of intertemporal choice separately, namely time and outcome, in school-age children, and the possible link among such components and the security of attachment style and theory of mind. Ninety one children aged between 6 and 10 years performed two intertemporal choice tasks, first and second order false belief tasks and the Separation Anxiety Task in the Family and School versions. Results showed that the two components of intertemporal choice (waiting tolerance and sensitivity to delayed outcome) are stately interrelated; the quality of the attachment to the family caregiver affects the tolerance to waiting time and first order false belief understanding affects both the components of intertemporal choice.

  18. Genetic Analysis of Avian Influenza Virus from Wild Birds and Mallards Reared for Shooting in Denmark

    DEFF Research Database (Denmark)

    Handberg, Kurt; Therkildsen, O. R.; Jørgensen, Poul Henrik

    2010-01-01

    Denmark forms a geographical bottleneck along the migration route of many water birds breeding from northeastern Canada to north Siberia that gather to winter in Europe and Africa. Potentially, the concentration of such large numbers of water birds enhances the risk of avian influenza virus (AIV...

  19. Observations of new bird species for San Salvador Island, the Bahamas

    Science.gov (United States)

    Michael E. Akresh; David I. King

    2015-01-01

    We present our recent observations and compile other accounts of sightings or captures of 30 additional bird species reported for San Salvador Island, The Bahamas, since Sordahl compiled his checklist in 1996. Most are Nearctic-Neotropical migratory birds that either spend the non-breeding season on the island or stop over during migration. Additionally, based on our...

  20. A new conservation partnership: conserving the migratory birds of the Americas

    Science.gov (United States)

    Jack C. Capp; David Mehlman

    Over five billion birds move each year across the Americas, flying great distances over almost every location and habitat on the continents (Weidensaul 1999). Over 350 of the over 800 bird species in the United States migrate each year to Latin America and the Caribbean (Degraaf and Rappole 1995). Some fly each way over 4000 miles, chasing the seasons across oceans and...

  1. MIGRATORY GAME BIRDS AS A SOURCE OF PUBLIC EXPOSURE FROM THE FUKUSHIMA NUCLEAR POWER PLANT ACCIDENT

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2011-01-01

    Full Text Available This article examines assessments of the impact of the Fukushima nuclear power plant accident on exposure of the Russian Federation population related to the seasonal migration of game birds. Intake of artificial radionuclides with meat of migratory game birds is shown to be one of the major pathways for the population exposure in the Far Eastern region of the country.

  2. Technology on the Move: Recent and Forthcoming Innovations for Tracking Migratory Birds

    DEFF Research Database (Denmark)

    Bridge, Eli S.; Thorup, Kasper; Bowlin, Melissa S.

    2011-01-01

    Basic questions about the life histories of migratory birds have confounded scientists for generations, yet we are nearing an era of historic discovery as new tracking technologies make it possible to determine the timing and routes of an increasing number of bird migrations. Tracking small flying...

  3. Migration of brine inclusions in salt

    International Nuclear Information System (INIS)

    Pigford, T.H.

    1982-01-01

    Theories of the migration of brine inclusions in salt are interpreted as simple physical processes, and theories by Russian and U.S. workers are shown to yield the same results. The migration theory is used to predict threshold temperature gradients below which migration of brine inclusions should not occur. The predicted threshold gradients are compared with the temperature gradients expected at the Waste Isolation Pilot Plant in New Mexico. The theory of a threshold gradient helps explain the existence of brine inclusions in natural salt deposits

  4. Nanoscale magnetoreceptors in birds

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2012-01-01

    The Earth's magnetic field provides an important source of directional information for many living organisms, especially birds, but the sensory receptor responsible for magnetic field detection still has to be identified. Recently, magnetic iron oxide particles were detected in dendritic endings...... field, by a bird....

  5. Avian Influenza in Birds

    Science.gov (United States)

    ... However, some ducks can be infected without any signs of illness. Top of Page Avian Influenza in Wild Birds Avian influenza A viruses have ... hours. Some ducks can be infected without any signs of illness. Avian influenza outbreaks are of concern in domesticated birds for ...

  6. Urban bird conservation

    NARCIS (Netherlands)

    Snep, Robbert P.H.; Kooijmans, Jip Louwe; Kwak, Robert G.M.; Foppen, Ruud P.B.; Parsons, Holly; Awasthy, Monica; Sierdsema, Henk L.K.; Marzluff, John M.; Fernandez-Juricic, Esteban; Laet, de Jenny

    2016-01-01

    Following the call from the United Nations Convention on Biological Diversity “Cities & Biodiversity Outlook” project to better preserve urban biodiversity, this paper presents stakeholder-specific statements for bird conservation in city environments. Based upon the current urban bird

  7. The healing bird

    African Journals Online (AJOL)

    Greek mythology it was a nondescript bird but in the medieval bestiaries it became pure white. The caladrius is used in the coats of arms of the South African Medical and Dental Council and also the Medical University of Soufhern Africa. These appear to be the first use of this medically significant bird in modern heraldry.

  8. Seasonal diets of insectivorous birds using canopy gaps in a bottomland forest.

    Energy Technology Data Exchange (ETDEWEB)

    Moorman, Christopher, E.; Bowen, Liessa, T.; Kilgo, John, C.; Sorenson, Clyde E.; Hanula, James L.; Horn, Scott; Ulyshen, Mike D.

    2007-07-01

    ABSTRACT. Little is known about how insectivorous bird diets are influenced by arthropod availability and about how these relationships vary seasonally. We captured birds in forest-canopy gaps and adjacent mature forest during 2001 and 2002 at the Savannah River Site in Barnwell County, South Carolina, and flushed their crops to gather information about arthropods eaten during four periods: spring migration, breeding, postbreeding, and fall migration. Arthropod availability for foliage- and ground-gleaning birds was examined by leaf clipping and pitfall trapping. Coleopterans and Hemipterans were used by foliage- and ground-gleaners more than expected during all periods, whereas arthropods in the orders Araneae and Hymenoptera were used as, or less than, expected based on availability during all periods. Ground-gleaning birds used Homopterans and Lepidopterans in proportions higher than availability during all periods. Arthropod use by birds was consistent from spring through all migration, with no apparent seasonal shift in diet. Based on concurrent studies, heavily used orders of arthropods were equally abundant or slightly less abundant in canopy gaps than in the surrounding mature forest, but bird species were most frequently detected in gaps. Such results suggest that preferential feeding on arthropods by foliage-gleaning birds in p p habitats reduced arthropod densities or, alternatively, that bird use of gap and forest habitat was not determined y food resources. The abundance of arthropods across the stand may have allowed birds to remain in the densely vegetated gaps where thick cover provides protection from predators.

  9. Geography of spring landbird migration through riparian habitats in southwestern North America

    Science.gov (United States)

    Susan K. Skagen; Jeffrey F. Kelly; Charles van Riper III; Richard L. Hutto; Deborah M. Finch; David J. Krueper; Cynthia P. Melcher

    2005-01-01

    Migration stopover resources, particularly riparian habitats, are critically important to landbirds migrating across the arid southwestern region of North America. To explore the effects of species biogeography and habitat affinity on spring migration patterns, we synthesized existing bird abundance and capture data collected in riparian habitats of the borderlands...

  10. The microbiome of neotropical ticks parasitizing on passerine migratory birds.

    Science.gov (United States)

    Budachetri, Khemraj; Williams, Jaclyn; Mukherjee, Nabanita; Sellers, Michael; Moore, Frank; Karim, Shahid

    2017-01-01

    Seasonal migration of passerine birds between temperate North America and tropical Central and South America is an ecological phenomenon. Migration of birds has been associated with the introduction of ectoparasites like ticks or tick-borne pathogens across the avian migration routes. In this study, the microbial diversity was determined in the ticks and bird DNA samples using 454 pyrosequencing of bacterial 16S rRNA gene. Tick DNA samples showed the dominance of genera Lactococcus, Francisella, Raoultella, Wolbachia and Rickettsia across all the ticks, but birds DNA did not share common microbial diversity with ticks. Furthermore, "Candidatus Rickettsia amblyommii" infection in the 91 ticks collected off the songbirds was also quantified by qPCR assay. Interestingly, "Candidatus R. amblyommii" was tested positive in 24 ticks (26% infection), and infection varied from as low as three copies to thousands of copies, but bird blood samples showed no amplification. Our results provide evidence that songbirds serve as transport carrier for immature ticks, and less likely to be a reservoir for "Candidatus R. amblyommii". Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. Condition varies with habitat choice in postbreeding forest birds

    Science.gov (United States)

    Scott H. Stoleson

    2013-01-01

    Many birds that are experiencing population declines require extensive tracts of mature forest habitat for breeding. Recent work suggests that at least some may shift their habitat use to early-successional areas after nesting but before migration. I used constant-effort mist netting in regenerating clearcuts (4-8 years postcut) and dense mature-forest understories to...

  12. Economic impotance of flying visitors: migratory birds | Egwumah ...

    African Journals Online (AJOL)

    ... are also capable of producing oil. Nature based tourism and recreation, such as the viewing of wildlife coupled with; management of migratory birds promotes market for other industrial goods such as lead shot, guns and binocular. Keywords: Migration; Recreation and Tourism; Trophies; Ornament; Food; Production of Oil ...

  13. An annotated checklist of pathogenic microorganisms associated with migratory birds

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk

    2004-01-01

    Roč. 40, č. 4 (2004), s. 639-659 ISSN 0090-3558 R&D Projects: GA ČR GA206/03/0726 Institutional research plan: CEZ:AV0Z6093917 Keywords : Arboviruses * birds * migration Subject RIV: EE - Microbiology, Virology Impact factor: 0.741, year: 2004 http://www.jwildlifedis.org/cgi/reprint/40/4/639

  14. Is there a "migratory syndrome" common to all migrant birds?

    NARCIS (Netherlands)

    Piersma, T; Perez-Tris, J; Mouritsen, H; Bauchinger, U; Bairlein, F; Bauchinger, U; Goymann, W; JenniEiermann, S

    2005-01-01

    Bird migration has been assumed, mostly implicitly, to represent a distinct class of animal behavior, with deep and strong homologies in the various phenotypic expressions of migratory behavior between different taxa. Here the evidence for the existence of what could be called a "migratory

  15. Highly pathogenic avian influenza virus among wild birds in Mongolia

    Science.gov (United States)

    The central Asian country of Mongolia supports large populations of migratory water birds that migrate across much of Asia where highly pathogenic avian influenza (HPAI) virus subtype H5N1 is endemic. This, together with the near absence of domestic poultry, makes Mongolia an ideal location to unde...

  16. Breeding of marine birds on Farwa Island, western Libya | Etayeb ...

    African Journals Online (AJOL)

    The Libyan coast is characterised by many wetlands that are used as stopover routes for many migratory marine birds. They provide food, shelter and nesting grounds for many avifauna during their migration from their home to wintering grounds. Farwa Island, which is located at the furthermost western part of Libya, ...

  17. True navigation in migrating gulls requires intact olfactory nerves

    DEFF Research Database (Denmark)

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna

    2015-01-01

    debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to birds westward (1080 km) or eastward (885 km......During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still......) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch...

  18. Wild bird surveillance in the Netherlands around outbreaks of highly pathogenic avian influenza H5N8 virus in 2014 within the context of global flyways

    NARCIS (Netherlands)

    Verhagen, J.H.; Van der Jeugd, Henk; Nolet, Bart A.; Slaterus, R.; Kharitonov, S.P.; De Vries, Peter; Vuong, O.; Majoor, F.; Kuiken, T.; Fouchier, R.A.M

    2015-01-01

    Highly pathogenic avian influenza (HPAI) A(H5N8) viruses that emerged in poultry in east Asia since 2010 spread to Europe and North America by late 2014. Despite detections in migrating birds, the role of free-living wild birds in the global dispersal of H5N8 virus is unclear. Here, wild bird

  19. Dateline Migration.

    Science.gov (United States)

    Tomasi, Lydio E., Ed.

    1995-01-01

    Presents data on international migration and its effects in and between various countries in North America, Europe, and Africa. Discussions include refugee, immigrant, and migrant worker flows; the legal, political, and social problems surrounding immigrants; alien terrorism and law enforcement problems; and migrant effects on education, social…

  20. Migrating Worker

    DEFF Research Database (Denmark)

    Hansen, Hans

    This is the preliminary report on the results obtained in the Migrating Worker-project. This project was initiated by the Danish Ministry of Finance with the aim of illustrating the effects of the 1408/71 agreement and the bilateral double taxation agreements Denmark has with the countries included...

  1. Quantifying the roles of random motility and directed motility using advection-diffusion theory for a 3T3 fibroblast cell migration assay stimulated with an electric field.

    Science.gov (United States)

    Simpson, Matthew J; Lo, Kai-Yin; Sun, Yung-Shin

    2017-03-17

    Directed cell migration can be driven by a range of external stimuli, such as spatial gradients of: chemical signals (chemotaxis); adhesion sites (haptotaxis); or temperature (thermotaxis). Continuum models of cell migration typically include a diffusion term to capture the undirected component of cell motility and an advection term to capture the directed component of cell motility. However, there is no consensus in the literature about the form that the advection term takes. Some theoretical studies suggest that the advection term ought to include receptor saturation effects. However, others adopt a much simpler constant coefficient. One of the limitations of including receptor saturation effects is that it introduces several additional unknown parameters into the model. Therefore, a relevant research question is to investigate whether directed cell migration is best described by a simple constant tactic coefficient or a more complicated model incorporating saturation effects. We study directed cell migration using an experimental device in which the directed component of the cell motility is driven by a spatial gradient of electric potential, which is known as electrotaxis. The electric field (EF) is proportional to the spatial gradient of the electric potential. The spatial variation of electric potential across the experimental device varies in such a way that there are several subregions on the device in which the EF takes on different values that are approximately constant within those subregions. We use cell trajectory data to quantify the motion of 3T3 fibroblast cells at different locations on the device to examine how different values of the EF influences cell motility. The undirected (random) motility of the cells is quantified in terms of the cell diffusivity, D, and the directed motility is quantified in terms of a cell drift velocity, v. Estimates D and v are obtained under a range of four different EF conditions, which correspond to normal

  2. Bird brood parasitism.

    Science.gov (United States)

    Stevens, Martin

    2013-10-21

    For many animals, the effort to rear their young is considerable. In birds, this often includes building nests, incubating eggs, feeding the chicks, and protecting them from predators. Perhaps for this reason, about 1% of birds (around 100 species) save themselves the effort and cheat instead. They are obligate brood parasites, laying their eggs in the nests of other species and leaving the hosts or foster parents to rear the foreign chicks for them. Some birds also cheat on individuals of the same species (intraspecific brood parasitism). Intraspecific brood parasitism has been reported in around 200 species, but is likely to be higher, as it can often only be detected by genetic analyses.

  3. Hatching synchrony in birds

    OpenAIRE

    Tippeltová, Zuzana

    2011-01-01

    This bachelor thesis is about hatching synchrony in birds. Generally, among birds there are two types of hatching - asynchronous and synchronous- and the type of hatching is primarily determined by the time of the onset of incubation. In many bird species, including most precocial ones, incubation does not begin until the last egg has been laid, which results in hatching of all the eggs within a few hours. In synchronously-hatched broods, all the chicks are about the same age. Thus no single ...

  4. Breeding Dispersal by Birds in a Dynamic Urban Ecosystem.

    Science.gov (United States)

    Marzluff, John M; DeLap, Jack H; Oleyar, M David; Whittaker, Kara A; Gardner, Beth

    2016-01-01

    Changes in land cover during urbanization profoundly affect the diversity of bird communities, but the demographic mechanisms affecting diversity are poorly known. We advance such understanding by documenting how urbanization influences breeding dispersal-the annual movement of territorial adults-of six songbird species in the Seattle, WA, USA metropolitan area. We color-banded adults and mapped the centers of their annual breeding activities from 2000-2010 to obtain 504 consecutive movements by 337 adults. By comparing movements, annual reproduction, and mate fidelity among 10 developed, 5 reserved, and 11 changing (areas cleared and developed during our study) landscapes, we determined that adaptive breeding dispersal of sensitive forest species (Swainson's Thrush and Pacific wren), which involves shifting territory and mate after reproductive failure, was constrained by development. In changing lands, sensitive forest specialists dispersed from active development to nearby forested areas, but in so doing suffered low annual reproduction. Species tolerant of suburban lands (song sparrow, spotted towhee, dark-eyed junco, and Bewick's wren) dispersed adaptively in changing landscapes. Site fidelity ranged from 0% (Pacific wren in changing landscape) to 83% (Bewick's wren in forest reserve). Mate fidelity ranged from 25% (dark-eyed junco) to 100% (Bewick's wren). Variation in fidelity to mate and territory was consistent with theories positing an influence of territory quality, asynchronous return from migration, prior productivity, and reproductive benefits of retaining a familiar territory. Costly breeding dispersal, as well as reduced reproductive success and lowered survival cause some birds to decline in the face of urbanization. In contrast, the ability of species that utilize edges and early successional habitats to breed successfully, disperse to improve reproductive success after failure, and survive throughout the urban ecosystem enables them to maintain

  5. Breeding Dispersal by Birds in a Dynamic Urban Ecosystem.

    Directory of Open Access Journals (Sweden)

    John M Marzluff

    Full Text Available Changes in land cover during urbanization profoundly affect the diversity of bird communities, but the demographic mechanisms affecting diversity are poorly known. We advance such understanding by documenting how urbanization influences breeding dispersal-the annual movement of territorial adults-of six songbird species in the Seattle, WA, USA metropolitan area. We color-banded adults and mapped the centers of their annual breeding activities from 2000-2010 to obtain 504 consecutive movements by 337 adults. By comparing movements, annual reproduction, and mate fidelity among 10 developed, 5 reserved, and 11 changing (areas cleared and developed during our study landscapes, we determined that adaptive breeding dispersal of sensitive forest species (Swainson's Thrush and Pacific wren, which involves shifting territory and mate after reproductive failure, was constrained by development. In changing lands, sensitive forest specialists dispersed from active development to nearby forested areas, but in so doing suffered low annual reproduction. Species tolerant of suburban lands (song sparrow, spotted towhee, dark-eyed junco, and Bewick's wren dispersed adaptively in changing landscapes. Site fidelity ranged from 0% (Pacific wren in changing landscape to 83% (Bewick's wren in forest reserve. Mate fidelity ranged from 25% (dark-eyed junco to 100% (Bewick's wren. Variation in fidelity to mate and territory was consistent with theories positing an influence of territory quality, asynchronous return from migration, prior productivity, and reproductive benefits of retaining a familiar territory. Costly breeding dispersal, as well as reduced reproductive success and lowered survival cause some birds to decline in the face of urbanization. In contrast, the ability of species that utilize edges and early successional habitats to breed successfully, disperse to improve reproductive success after failure, and survive throughout the urban ecosystem enables them

  6. LINKING THE COMMUNITY IN THE MIGRATORY RAPTOR BIRDS COUNTS (BIRDS: FALCONIFORM IN EASTERN CUBA

    Directory of Open Access Journals (Sweden)

    Naylien Barreda-Leyva

    2010-09-01

    Full Text Available Through interviews, workshops, conferences and sociocultural meeting, is carried out the linking of three communities from the high area of Gran Piedra to the studies and counts of migratory raptors birds developed in the east of Cuba. These small communities are near to one of the two points of count of migratory raptors of the region. During the interviews we could verify that some residents possessed basic knowledge on the raptors birds, but didn't know about the migration of these birds. 100 % of the interviewees coincided in that the main local problematic is the loss of birds of pen due to the attack of raptors, specifically the endemic Cuban threatened Accipitter gundlachi. The workshops were able to create spaces of exchange and reflection about the importance of the raptor’s conservation in the region. This linkage of cooperation and increasing awareness, allow an approaching between the communitarians and the researchers and volunteers that work in the counts of raptor birds in Cuba and the feedback of the scientific knowledge with the popular knowledge.

  7. Forest fragmentation and its effects on birds

    Science.gov (United States)

    Robbins, C.S.; Johnson, James E.

    1988-01-01

    Fragmentation of forest land, whether by suburban development, highways, transmission lines, or poorly planned cutting regimes, seriously affects reproduction by the large numbers of obligate forest interior birds. Many of our warblers, vireos, thrushes, tanagers, and flycatchers are highly migratory insectivorous birds that spend more than half the year in the neotropics, but migrate north to the United States and Canada to rear their young. These tropical visitors are especially vulnerable to predation and cowbird parasitism and are unable to maintain their populations within 100-200 m of forest edge. Habitats for these declining species can be provided by managing forest lands in large blocks so as to maintain at all times extensive contiguous areas of successional stages as well as of mature forest. Avoiding scattered small cuts will also help by reducing edge, road construction, and other disturbance.

  8. A characterization of autumn nocturnal migration detected by weather surveillance radars in the northeastern USA.

    Science.gov (United States)

    Farnsworth, Andrew; Van DOREN, Benjamin M; Hochachka, Wesley M; Sheldon, Daniel; Winner, Kevin; Irvine, Jed; Geevarghese, Jeffrey; Kelling, Steve

    2016-04-01

    Billions of birds migrate at night over North America each year. However, few studies have described the phenology of these movements, such as magnitudes, directions, and speeds, for more than one migration season and at regional scales. In this study, we characterize density, direction, and speed of nocturnally migrating birds using data from 13 weather surveillance radars in the autumns of 2010 and 2011 in the northeastern USA. After screening radar data to remove precipitation, we applied a recently developed algorithm for characterizing velocity profiles with previously developed methods to document bird migration. Many hourly radar scans contained windborne "contamination," and these scans also exhibited generally low overall reflectivities. Hourly scans dominated by birds showed nightly and seasonal patterns that differed markedly from those of low reflectivity scans. Bird migration occurred during many nights, but a smaller number of nights with large movements of birds defined regional nocturnal migration. Densities varied by date, time, and location but peaked in the second and third deciles of night during the autumn period when the most birds were migrating. Migration track (the direction to which birds moved) shifted within nights from south-southwesterly to southwesterly during the seasonal migration peaks; this shift was not consistent with a similar shift in wind direction. Migration speeds varied within nights, although not closely with wind speed. Airspeeds increased during the night; groundspeeds were highest between the second and third deciles of night, when the greatest density of birds was migrating. Airspeeds and groundspeeds increased during the fall season, although groundspeeds fluctuated considerably with prevailing winds. Significant positive correlations characterized relationships among bird densities at southern coastal radar stations and northern inland radar stations. The quantitative descriptions of broadscale nocturnal migration

  9. Population specific migration patterns of an European-Afrotropical songbird

    DEFF Research Database (Denmark)

    Pedersen, Lykke; Tøttrup, Anders P.; Thorup, Kasper

    Every year, billions of songbirds migrate thousands of kilometres between the European and African continent. The fascinating behaviour of migration that we are witnessing today is assumed to have evolved through a series of dispersal events from Africa into Europe since the last glaciation perio...... Africa we will expect to find at least some overlap in staging areas between populations.......Every year, billions of songbirds migrate thousands of kilometres between the European and African continent. The fascinating behaviour of migration that we are witnessing today is assumed to have evolved through a series of dispersal events from Africa into Europe since the last glaciation period....... Recent technological advances are currently enabling us to track yet smaller songbirds throughout their migration cycle providing valuable insight into the life cycle of individual birds. However, direct tracking of migratory birds has so far mainly been conducted on single populations and our...

  10. Flight response of slope-soaring birds to seasonal variation in thermal generation

    Science.gov (United States)

    Adam E. Duerr; Tricia A. Miller; Michael Lanzone; David Brandes; Jeff Cooper; Kieran O' Malley; Charles Maisonneuve; Junior A. Tremblay; Todd. Katzner

    2014-01-01

    Animals respond to a variety of environmental cues, including weather conditions, when migrating. Understanding the relationship between weather and migration behaviour is vital to assessing time- and energy limitations of soaring birds. Different soaring modes have different efficiencies, are dependent upon different types of subsidized lift and are weather dependent...

  11. Frequency of migrants and migratory activity are genetically correlated in a bird population: Evolutionary implications

    NARCIS (Netherlands)

    Pulido, F.; Berthold, P.; Van Noordwijk, A.J.

    1996-01-01

    Most migratory bird populations are composed of individuals that migrate and individuals that remain resident, While the role of ecological factors in maintaining this behavioral dimorphism has received much attention, the importance of genetic constraints on the evolution of avian migration has not

  12. Carrying large fuel loads during sustained bird flight is cheaper than expected

    NARCIS (Netherlands)

    Kvist, A; Lindström, A; Green, M; Piersma, T.; Visser, G.H.

    2001-01-01

    Birds on migration alternate between consuming fuel stores during flights and accumulating fuel stores during stopovers. The optimal timing and length of flights and stopovers for successful migration depend heavily on the extra metabolic power input (fuel use) required to carry the fuel stores

  13. Nuisance Birds Webinar Report

    Science.gov (United States)

    All over the nation, birds of all shapes and sizes attempt to make schools a their favorite hangout. Their arrival can lead to sanitation issues, added facility degradation, distracted students and health problems.

  14. Birds - Breeding [ds60

    Data.gov (United States)

    California Natural Resource Agency — This data set provides access to information gathered on annual breeding bird surveys in California using a map layer developed by the Department. This data layer...

  15. Barrier Infrared Detector (BIRD)

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in MWIR detector design, has resulted in a high operating temperature (HOT) barrier infrared detector (BIRD) that is capable of spectral...

  16. Avian Influenza (Bird Flu)

    Science.gov (United States)

    ... in People Spread of Bird Flu Viruses Between Animals and People Examples of Human Infections with Avian Influenza A ... Subtypes Transmission of Avian Influenza A Viruses Between Animals and People Related Links Research Glossary of Influenza (Flu) Terms ...

  17. Breeding bird survey data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data are maintained by the USGS (https://www.pwrc.usgs.gov/bbs/RawData/) and provides information on the trends and status of North American bird populations...

  18. Awesome Audubon Birds

    Science.gov (United States)

    Kahler, Laura

    2010-01-01

    In this article, the author describes a watercolor art lesson on Audubon birds. She also discusses how science, technology, writing skills, and the elements and principles of art can be incorporated into the lesson.

  19. Birds in portuguese literature

    OpenAIRE

    Queiroz, Ana Isabel; Soares, Filipa

    2016-01-01

    UID/ELT/00657/2013 WOS:000374914600004 IF/00222/2013 Birds are emblematic natural elements of landscapes. Readily noticeable and appreciated due to their songs and flight, they have been thoroughly used as components of literary scenarios. This paper analyses their representations in a broad corpus (144 writings by 67 writers) since the nineteenth century, divided in three time-periods. It aims to understand which wild birds are represented in Portuguese literature, how those represe...

  20. Concealed by darkness: interactions between predatory bats and nocturnally migrating songbirds illuminated by DNA sequencing.

    Science.gov (United States)

    Ibáñez, Carlos; Popa-Lisseanu, Ana G; Pastor-Beviá, David; García-Mudarra, Juan L; Juste, Javier

    2016-10-01

    Recently, several species of aerial-hawking bats have been found to prey on migrating songbirds, but details on this behaviour and its relevance for bird migration are still unclear. We sequenced avian DNA in feather-containing scats of the bird-feeding bat Nyctalus lasiopterus from Spain collected during bird migration seasons. We found very high prey diversity, with 31 bird species from eight families of Passeriformes, almost all of which were nocturnally flying sub-Saharan migrants. Moreover, species using tree hollows or nest boxes in the study area during migration periods were not present in the bats' diet, indicating that birds are solely captured on the wing during night-time passage. Additional to a generalist feeding strategy, we found that bats selected medium-sized bird species, thereby assumingly optimizing their energetic cost-benefit balance and injury risk. Surprisingly, bats preyed upon birds half their own body mass. This shows that the 5% prey to predator body mass ratio traditionally assumed for aerial hunting bats does not apply to this hunting strategy or even underestimates these animals' behavioural and mechanical abilities. Considering the bats' generalist feeding strategy and their large prey size range, we suggest that nocturnal bat predation may have influenced the evolution of bird migration strategies and behaviour. © 2016 John Wiley & Sons Ltd.

  1. Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

    Science.gov (United States)

    Stilianakis, Nikolaos I.

    2007-01-01

    The claim that migratory birds are responsible for the long-distance spread of highly pathogenic avian influenza viruses of subtype H5N1 rests on the assumption that infected wild birds can remain asymptomatic and migrate long distances unhampered. We critically assess this claim from the perspective of ecologic immunology, a research field that analyzes immune function in an ecologic, physiologic, and evolutionary context. Long-distance migration is one of the most demanding activities in the animal world. We show that several studies demonstrate that such prolonged, intense exercise leads to immunosuppression and that migratory performance is negatively affected by infections. These findings make it unlikely that wild birds can spread the virus along established long-distance migration pathways. However, infected, symptomatic wild birds may act as vectors over shorter distances, as appears to have occurred in Europe in early 2006. PMID:17953082

  2. Modeling birds on wires.

    Science.gov (United States)

    Aydoğdu, A; Frasca, P; D'Apice, C; Manzo, R; Thornton, J M; Gachomo, B; Wilson, T; Cheung, B; Tariq, U; Saidel, W; Piccoli, B

    2017-02-21

    In this paper we introduce a mathematical model to study the group dynamics of birds resting on wires. The model is agent-based and postulates attraction-repulsion forces between the interacting birds: the interactions are "topological", in the sense that they involve a given number of neighbors irrespective of their distance. The model is first mathematically analyzed and then simulated to study its main properties: we observe that the model predicts birds to be more widely spaced near the borders of each group. We compare the results from the model with experimental data, derived from the analysis of pictures of pigeons and starlings taken in New Jersey: two different image elaboration protocols allow us to establish a good agreement with the model and to quantify its main parameters. We also discuss the potential handedness of the birds, by analyzing the group organization features and the group dynamics at the arrival of new birds. Finally, we propose a more refined mathematical model that describes landing and departing birds by suitable stochastic processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Data Mining Approaches for Habitats and Stopovers Discovery of Migratory Birds

    Directory of Open Access Journals (Sweden)

    Qiang Xu

    2013-03-01

    Full Text Available This paper focuses on using data mining technology to efficiently and accurately discover habitats and stopovers of migratory birds. The three methods we used are as follows: 1. a density-based clustering method, detecting stopovers of birds during their migration through density-based clustering of location points; 2. A location histories parser method, detecting areas that have been overstayed by migratory birds during a set time period by setting time and distance thresholds; and 3. A time-parameterized line segment clustering method, clustering directed line segments to analyze shared segments of migratory pathways of different migratory birds and discover the habitats and stopovers of these birds. Finally, we analyzed the migration data of the bar-headed goose in the Qinghai Lake Area through the three above methods and verified the effectiveness of the three methods and, by comparison, identified the scope and context of the use of these three methods respectively.

  4. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  5. Bosnia: Migrations

    Directory of Open Access Journals (Sweden)

    Stjepan Pavičić

    2000-12-01

    Full Text Available The paper is a reprint of a very informative review of migrations in Bosnia published almost 60 years ago. The author first notes that the [Slavic] population that first settled Bosnia spoke variants of the ikavian-ţakavian dialect spoken also in neighbouring parts of Croatia (although the interrogative ča itself was not common. From the 13th century the jekavian-štokavian dialect expanded from the Southeast, from areas in modern Montenegro. This change was greatly due to immigration of Vlachs, who had adopted jekavian-štokavian. Although earlier Vlach immigrants had adopted the indigenous ikavian idiom, as well as associating themselves with Catholicism or with the Patarene Bosnian Church, later arrivals spoke jekavian-štokavian and adhered to Eastern Orthodoxy. In the 14th century the former group, living on both sides of the Neretva valley and in the Dinaric range, expanded to areas of Croatia, whereas the Eastern Vlachs had already established themselves on the left bank of the Drina river. By 1450 all Vlachs in Bosnia spoke jekavian-štokavian. In the 15–16th centuries the Ottomans favoured the settlement of Vlachs in Bosnia. The Vlachs served in Ottoman military structures, provided transportation services and were useful in the integration of conquered western and northwestern lands. In general, the establishment of Ottoman rule in Bosnia induced major changes in the population and in migration flows. The author divides this history into three periods. The first lasted from the initial Ottoman conquests to the wars of 1683–1699. At its start in the 15th century almost all Patarenes adopted Islam, especially in areas where the Bosnian Church was strong, but also in areas where Catholicism dominated, where some Catholics embraced Islam. Conversions of Catholics to Islam intensified in the 16th century and throughout the 17th, to a different degree in various regions: a in Central Bosnia conversion was almost total, b along the Sava

  6. Aerodynamics of bird flight

    Directory of Open Access Journals (Sweden)

    Dvořák Rudolf

    2016-01-01

    Full Text Available Unlike airplanes birds must have either flapping or oscillating wings (the hummingbird. Only such wings can produce both lift and thrust – two sine qua non attributes of flying.The bird wings have several possibilities how to obtain the same functions as airplane wings. All are realized by the system of flight feathers. Birds have also the capabilities of adjusting the shape of the wing according to what the immediate flight situation demands, as well as of responding almost immediately to conditions the flow environment dictates, such as wind gusts, object avoidance, target tracking, etc. In bird aerodynamics also the tail plays an important role. To fly, wings impart downward momentum to the surrounding air and obtain lift by reaction. How this is achieved under various flight situations (cruise flight, hovering, landing, etc., and what the role is of the wing-generated vortices in producing lift and thrust is discussed.The issue of studying bird flight experimentally from in vivo or in vitro experiments is also briefly discussed.

  7. Sex Reversal in Birds.

    Science.gov (United States)

    Major, Andrew T; Smith, Craig A

    2016-01-01

    Sexual differentiation in birds is controlled genetically as in mammals, although the sex chromosomes are different. Males have a ZZ sex chromosome constitution, while females are ZW. Gene(s) on the sex chromosomes must initiate gonadal sex differentiation during embryonic life, inducing paired testes in ZZ individuals and unilateral ovaries in ZW individuals. The traditional view of avian sexual differentiation aligns with that expounded for other vertebrates; upon sexual differentiation, the gonads secrete sex steroid hormones that masculinise or feminise the rest of the body. However, recent studies on naturally occurring or experimentally induced avian sex reversal suggest a significant role for direct genetic factors, in addition to sex hormones, in regulating sexual differentiation of the soma in birds. This review will provide an overview of sex determination in birds and both naturally and experimentally induced sex reversal, with emphasis on the key role of oestrogen. We then consider how recent studies on sex reversal and gynandromorphic birds (half male:half female) are shaping our understanding of sexual differentiation in avians and in vertebrates more broadly. Current evidence shows that sexual differentiation in birds is a mix of direct genetic and hormonal mechanisms. Perturbation of either of these components may lead to sex reversal. © 2016 S. Karger AG, Basel.

  8. International Migration of Labor: Boon or Bane?

    Science.gov (United States)

    Martin, Philip L.; Richards, Alan

    1980-01-01

    According to international trade theory, free labor flows across national borders should benefit workers, employers, and societies. But recent evidence indicates that such migration may not provide these desired benefits. (Author/SK)

  9. Migration and breeding biology of Arctic terns in Greenland

    DEFF Research Database (Denmark)

    Egevang, Carsten

    and back. Although the sheer distance (71,000 km on average) travelled by the birds is interesting, the study furthermore showed how the terns depend on high-productive at-sea areas during their massive migration. On the southbound migration, the birds would stop for almost a month (25 days on average...... by the distribution of breeding Arctic terns as suggested by Egevang et al. (2004). Included in the thesis are furthermore results with an appeal to the Greenland management agencies. Along with estimates of the Arctic tern population size at the two most important Arctic tern colonies in West Greenland and East...

  10. Birds as biodiversity surrogates

    DEFF Research Database (Denmark)

    Larsen, Frank Wugt; Bladt, Jesper Stentoft; Balmford, Andrew

    2012-01-01

    1. Most biodiversity is still unknown, and therefore, priority areas for conservation typically are identified based on the presence of surrogates, or indicator groups. Birds are commonly used as surrogates of biodiversity owing to the wide availability of relevant data and their broad popular...... appeal. However, some studies have found birds to perform relatively poorly as indicators. We therefore ask how the effectiveness of this approach can be improved by supplementing data on birds with information on other taxa. 2. Here, we explore two strategies using (i) species data for other taxa...... and (ii) genus- and family-level data for invertebrates (when available). We used three distinct species data sets for sub-Saharan Africa, Denmark and Uganda, which cover different spatial scales, biogeographic regions and taxa (vertebrates, invertebrates and plants). 3. We found that networks of priority...

  11. Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  12. BIRD ATTACK OCULAR INJURIES.

    Science.gov (United States)

    Tabatabaei, Seyed Ali; Soleimani, Mohammad; Behrouz, Mahmoud Jabbarvand

    2017-03-29

    To report 30 patients with bird attack-related eye injuries. This study was performed among patients coming to Farabi Eye Hospital, Tehran, Iran, from 2010 to 2015 with a history of bird attack causing eye injury. The inclusion criteria were a history of bird attack by pecking causing eye injury and having treatment and follow-up record for at least 6 months after treatment. The primary eye examinations included a full ophthalmic examination including evaluation of uncorrected visual acuity and best-corrected visual acuity (BCVA), anterior segment slit lamp biomicroscopy, and photography. For all patients with penetrating injury, primary repair was undertaken. Thirty patients (10 females and 20 males) with a mean age of 23.3 ± 18.5 years entered the study. The most common zone of injury was zone 1 (P < 0.001), and lensectomy was not needed in majority of patients (P < 0.001). The most common bird causing the injury was mynah (P < 0.001). Those patients with baseline BCVA of less than 20/200 or those with endophthalmitis had statistically worse final BCVA after treatment. Patients attacked by mynah bird had significantly better pretreatment uncorrected visual acuity and BCVA. The most common bird causing the eye injury among the sample of patients from Iran was mynah, which differs with previous studies indicating the rooster attack as the most common cause of eye injury. The authors also found that the most common zone of injury was zone 1, and the presence of endophthalmitis and lower baseline BCVA were significant risk factors for worse visual outcomes.

  13. Biomechanics of bird flight.

    Science.gov (United States)

    Tobalske, Bret W

    2007-09-01

    Power output is a unifying theme for bird flight and considerable progress has been accomplished recently in measuring muscular, metabolic and aerodynamic power in birds. The primary flight muscles of birds, the pectoralis and supracoracoideus, are designed for work and power output, with large stress (force per unit cross-sectional area) and strain (relative length change) per contraction. U-shaped curves describe how mechanical power output varies with flight speed, but the specific shapes and characteristic speeds of these curves differ according to morphology and flight style. New measures of induced, profile and parasite power should help to update existing mathematical models of flight. In turn, these improved models may serve to test behavioral and ecological processes. Unlike terrestrial locomotion that is generally characterized by discrete gaits, changes in wing kinematics and aerodynamics across flight speeds are gradual. Take-off flight performance scales with body size, but fully revealing the mechanisms responsible for this pattern awaits new study. Intermittent flight appears to reduce the power cost for flight, as some species flap-glide at slow speeds and flap-bound at fast speeds. It is vital to test the metabolic costs of intermittent flight to understand why some birds use intermittent bounds during slow flight. Maneuvering and stability are critical for flying birds, and design for maneuvering may impinge upon other aspects of flight performance. The tail contributes to lift and drag; it is also integral to maneuvering and stability. Recent studies have revealed that maneuvers are typically initiated during downstroke and involve bilateral asymmetry of force production in the pectoralis. Future study of maneuvering and stability should measure inertial and aerodynamic forces. It is critical for continued progress into the biomechanics of bird flight that experimental designs are developed in an ecological and evolutionary context.

  14. Birds and wind power. Technical report 1977-1982; Faglar och vindkraft. Teknisk rapport 1977-1982

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Johnny

    1983-02-15

    The impact of wind power plants on birds has been studied. The risk of migrating birds colliding with high buildings has been investigated. Different hazards and accidents are described and reported in 12 appendices. Preliminary data from the sites of wind power plants are presented.

  15. Wind power and bird kills

    International Nuclear Information System (INIS)

    Raynolds, M.

    1998-01-01

    The accidental killing of birds by wind generators, and design improvements in the towers that support the turbines that might cut down on the bird killings were discussed. The first problem for the industry began in the late 1980s when the California Energy Commission reported as many as 160 birds (the majority being raptors, including the protected golden eagle) killed in one year in the vicinity of wind power plants. The key factor identified was the design of the towers as birds of prey are attracted to lattice towers as a place to hunt from. Tubular towers do not provide a place for the birds to perch, therefore they reduce the potential for bird strikes. Bird strikes also have been reported in Spain and the siting of the towers have been considered as the principal cause of the bird strikes. In view of these incidents, the wind power industry is developing standards for studying the potential of bird strikes and is continuing to study bird behaviour leading to collisions, the impact of topography, cumulative impacts and new techniques to reduce bird strikes. Despite the reported incidents, the risk of bird strikes by wind turbines, compared to other threats to birds such as pollution, oil spills, and other threats from fossil and nuclear fuels, is considered to be negligible. With continuing efforts to minimize incidents by proper design and siting, wind power can continue to grow as an environmentally sound and efficient source of energy

  16. Reviving a Legacy Citizen Science Project to Illuminate Shifts in Bird Phenology

    Directory of Open Access Journals (Sweden)

    Jessica Zelt

    2012-01-01

    Full Text Available Climate change has been of high interest to both the scientific community and the public at large since the phenomenon was first suggested. Subsequently, and with growing evidence of its impending ramifications, numerous studies have attempted to illuminate climate change impacts on bird migration. Migration is a key event in the annual cycle in the reproductive success of birds, and changes in migration in response to climate may indicate that species populations are at risk. Previous studies report earlier arrival dates in response to climate change in many bird species, although specific mechanisms are often difficult to explain at broad spatial and temporal scales. Using a newly revived dataset of historical migration cards for over 870 species and spanning 90 years throughout North America, we are developing an historical baseline of bird arrival dates to compare with contemporary records. Here we chronicle the history and reemergence of the North American Bird Phenology Program. We present two case studies illustrating how data from this program has been used to model historical arrival dates of Ruby-Throated Hummingbird (Archilochus colubris and Purple Martin (Progne subis throughout eastern North America. Our results show the importance of considering spatial and temporal variability in understanding patterns of bird spring arrivals.

  17. Spring migration of Ruffs Philomachus pugnax in Fryslan : estimates of staging duration using resighting data

    NARCIS (Netherlands)

    Verkuil, Yvonne I.; Wijmenga, Jan J.; Piersma, Theunis; Hooijmeijer, Jos C.E.W.

    2010-01-01

    Seasonal bird migration involves long flights, but most time is actually spent at intermediate staging areas. The duration of stay at these sites can be evaluated with mark recapture methods that employ day-to-day local encounters of individually marked birds. Estimates of staging duration are based

  18. Hitchhikers’ guide to analysing bird ringing data

    Directory of Open Access Journals (Sweden)

    Harnos Andrea

    2015-12-01

    Full Text Available Bird ringing datasets constitute possibly the largest source of temporal and spatial information on vertebrate taxa available on the globe. Initially, the method was invented to understand avian migration patterns. However, data deriving from bird ringing has been used in an array of other disciplines including population monitoring, changes in demography, conservation management and to study the effects of climate change to name a few. Despite the widespread usage and importance, there are no guidelines available specifically describing the practice of data management, preparation and analyses of ringing datasets. Here, we present the first of a series of comprehensive tutorials that may help fill this gap. We describe in detail and through a real-life example the intricacies of data cleaning and how to create a data table ready for analyses from raw ringing data in the R software environment. Moreover, we created and present here the R package; ringR, designed to carry out various specific tasks and plots related to bird ringing data. Most methods described here can also be applied to a wide range of capture-recapture type data based on individual marking, regardless to taxa or research question.

  19. The spring migration of adult North American Ospreys

    Science.gov (United States)

    Martell, Mark S.; Bierregaard, Richard O.; Washburn, Brian E.; Elliott, John E.; Henny, Charles J.; Kennedy, Robert S.; MacLeod, Iain

    2014-01-01

    Most North American Ospreys (Pandion haliaetus) are migratory, breeding in northern latitudes and migrating long distances to and from their wintering grounds in the tropics. Although fall migration patterns of North American Ospreys have been described and studied, very little has been published about the spring migration of these birds. We used satellite telemetry to: (1) determine the characteristics (timing, duration, migratory routes) of spring migrations of Ospreys; (2) determine if differences in spring migration patterns existed between sexes and among three breeding populations (east coast, midwestern, and western); and (3) compare consecutive fall and spring migrations of individual Ospreys. The median dates for departure from the wintering grounds and arrival on the breeding grounds did not differ significantly between adult male and female Ospreys. Compared to their fall migrations, all male and all east coast Ospreys spent fewer days on migration, fewer days in stopover periods along the migration route, traveled shorter distances overall, and traveled farther (on average) each day during spring. In contrast, fall and spring migration characteristics of all female and western Ospreys were similar. Our findings suggest that, although sex and breeding location might influence the spring migration strategy used by individual Ospreys, both males and females minimize the time spent on migration to ensure a timely arrival on the breeding grounds to establish or defend a nesting territory.

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

    Science.gov (United States)

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

    2017-12-01

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

  1. Population trends and migration strategy of the Wood Sandpiper Tringa glareola at Ottenby, SE Sweden

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola; Stervander, Martin; Helseth, Anders

    2013-01-01

    Long-term ringing data are useful for understanding population trends and migration strategies adopted by migratory bird species during migration. To investigate the patterns in demography, phenology of migration and stopover behaviour in Wood Sandpipers Tringa glareola trapped on autumn migration...... recovery data. Over the years, trapping of both adults and juveniles has declined significantly. Median trapping dates were 10 July for adults and 6 August for juveniles. Average migration speed of juvenile birds was 58.1 km d-1. Adults stayed on average 3.5 days and juveniles 5.2 days, with average fuel...... deposition rates of 2.5 and 0.7 g day-1 respectively. Juvenile birds probably vary their strategy according to time of season and prevailing conditions. Both adults and juveniles followed the Mediterranean Flyway, but juveniles displayed significantly more southerly and significantly more scattered migratory...

  2. Bird or bat: comparing airframe design and flight performance.

    Science.gov (United States)

    Hedenström, Anders; Johansson, L Christoffer; Spedding, Geoffrey R

    2009-03-01

    Birds and bats have evolved powered flight independently, which makes a comparison of evolutionary 'design' solutions potentially interesting. In this paper we highlight similarities and differences with respect to flight characteristics, including morphology, flight kinematics, aerodynamics, energetics and flight performance. Birds' size range is 0.002-15 kg and bats' size range is 0.002-1.5 kg. The wingbeat kinematics differ between birds and bats, which is mainly due to the different flexing of the wing during the upstroke and constraints by having a wing of feathers and a skin membrane, respectively. Aerodynamically, bats appear to generate a more complex wake than birds. Bats may be more closely adapted for slow maneuvering flight than birds, as required by their aerial hawking foraging habits. The metabolic rate and power required to fly are similar among birds and bats. Both groups share many characteristics associated with flight, such as for example low amounts of DNA in cells, the ability to accumulate fat as fuel for hibernation and migration, and parallel habitat-related wing shape adaptations.

  3. Bird or bat: comparing airframe design and flight performance

    International Nuclear Information System (INIS)

    Hedenstroem, Anders; Johansson, L Christoffer; Spedding, Geoffrey R

    2009-01-01

    Birds and bats have evolved powered flight independently, which makes a comparison of evolutionary 'design' solutions potentially interesting. In this paper we highlight similarities and differences with respect to flight characteristics, including morphology, flight kinematics, aerodynamics, energetics and flight performance. Birds' size range is 0.002-15 kg and bats' size range is 0.002-1.5 kg. The wingbeat kinematics differ between birds and bats, which is mainly due to the different flexing of the wing during the upstroke and constraints by having a wing of feathers and a skin membrane, respectively. Aerodynamically, bats appear to generate a more complex wake than birds. Bats may be more closely adapted for slow maneuvering flight than birds, as required by their aerial hawking foraging habits. The metabolic rate and power required to fly are similar among birds and bats. Both groups share many characteristics associated with flight, such as for example low amounts of DNA in cells, the ability to accumulate fat as fuel for hibernation and migration, and parallel habitat-related wing shape adaptations

  4. Bird or bat: comparing airframe design and flight performance

    Energy Technology Data Exchange (ETDEWEB)

    Hedenstroem, Anders; Johansson, L Christoffer [Department of Theoretical Ecology, Ecology Building, SE-223 62 Lund (Sweden); Spedding, Geoffrey R [Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90098-1191 (United States)], E-mail: anders.hedenstrom@teorekol.lu.se

    2009-03-01

    Birds and bats have evolved powered flight independently, which makes a comparison of evolutionary 'design' solutions potentially interesting. In this paper we highlight similarities and differences with respect to flight characteristics, including morphology, flight kinematics, aerodynamics, energetics and flight performance. Birds' size range is 0.002-15 kg and bats' size range is 0.002-1.5 kg. The wingbeat kinematics differ between birds and bats, which is mainly due to the different flexing of the wing during the upstroke and constraints by having a wing of feathers and a skin membrane, respectively. Aerodynamically, bats appear to generate a more complex wake than birds. Bats may be more closely adapted for slow maneuvering flight than birds, as required by their aerial hawking foraging habits. The metabolic rate and power required to fly are similar among birds and bats. Both groups share many characteristics associated with flight, such as for example low amounts of DNA in cells, the ability to accumulate fat as fuel for hibernation and migration, and parallel habitat-related wing shape adaptations.

  5. Climate change impacts: birds

    NARCIS (Netherlands)

    Tomotani, B.M.; Ramakers, J.J.C.; Gienapp, P.

    2016-01-01

    Climate change can affect populations and species in various ways. Rising temperatures can shift geographical distributions and lead to (phenotypic or genetic) changes in traits, mostly phenology, which may affect demography. Most of these effects are well documented in birds. For example, the

  6. Timber and forest birds

    Science.gov (United States)

    Brian Roy Lockhart

    2009-01-01

    Many years ago, I had an epiphany that I would like to share. Several students and I were installing research plots in the forests on Pittman Island, Issaquena County, Mississippi, an island adjacent to the Mississippi River, near the borders of Arkansas, Mississippi, and Louisiana. While eating lunch, we watched a bird, more specifically a prothonotary warbler (

  7. Bird Flu (Avian Influenza)

    Science.gov (United States)

    ... domesticated birds. If possible, avoid rural areas, small farms and open-air markets. Wash your hands. This is one of the simplest and best ways to prevent infections of all kinds. Use an alcohol-based hand sanitizer containing at least 60 percent alcohol ...

  8. Breeding Ecology of Birds

    Indian Academy of Sciences (India)

    http://www.ias.ac.in/article/fulltext/reso/008/07/0022-0032. Keywords. Birds. nesting. territory; coloniality; heronries. ecology; nesting strategies. Author Affiliations. Abdul Jamil Urfi1. Department of Environmental Biology, School of Environmental Studies, University of Delhi, Delhi 110007. Resonance – Journal of Science ...

  9. Europe's last Mesozoic bird

    NARCIS (Netherlands)

    Dyke, Gareth J.; Dortangs, Rudi W.; Jagt, John W.; Mulder, Eric W. A.; Schulp, Anne S.; Chiappe, Luis M.

    2002-01-01

    Birds known from more than isolated skeletal elements are rare in the fossil record, especially from the European Mesozoic. This paucity has hindered interpretations of avian evolution immediately prior to, and in the aftermath of, the Cretaceous-Tertiary (K-T) extinction event. We report on a

  10. The Umbrella Bird

    NARCIS (Netherlands)

    Crandall, Lee S.

    1949-01-01

    When CHARLES CORDIER arrived from Costa Rica on October 9, 1942, bringing with him, among other great rarities, three Bare-necked Umbrella Birds (Cephalopterus ornatus glabricollis), it seemed to us that the mere possession of such fabulous creatures was satisfaction enough. True, they were not

  11. Birds of Prey.

    Science.gov (United States)

    Irwin, Harriet

    Introducing students to different hawks and owls found in Wisconsin and building a basis for appreciation of these birds in their own environment is the purpose of this teacher's guide. Primarily geared for upper elementary and junior high grades, the concepts presented could be used in conjunction with the study of ecology. A filmstrip is…

  12. Rethinking international migration: a review and critique.

    Science.gov (United States)

    Papademetriou, D G

    1983-01-01

    A new style of international migration, temporary and often illegal immigration in order to work, began to emerge after World War II. Many countries initiated immigration policies that gave the appearance of control, while their back doors remained open and, possibly, unclosable. In the US, it is slowly becoming obvious that foreign workers cannot be used as a temporary labor force at will. 2 usual theories of migration are the classical and the conflicts schools. The classical school presents migration as a rational, economic act that leads to economic adjustment between sending and receiving countries. The conflict school, often Marxist, views migration as an unequal process that leads to the inclusion of developing countries into the world capitalist system and to a widenin gap between rich and poor countries. The convergence of these 2 theories leads to the idea that although migration may be a survival strategy of individuals and households, it is also determined by a country's integration in the world economic system. The author reviews several books on immigration theory, which appreciate the complexity and worldwide character of migration; indicate that migration patterns are persistent; and support the view that migration is an economic, social, and political problem; and recommend that policies must be integrated and address the entire issue.

  13. Innovative Visualizations Shed Light on Avian Nocturnal Migration.

    Directory of Open Access Journals (Sweden)

    Judy Shamoun-Baranes

    Full Text Available Globally, billions of flying animals undergo seasonal migrations, many of which occur at night. The temporal and spatial scales at which migrations occur and our inability to directly observe these nocturnal movements makes monitoring and characterizing this critical period in migratory animals' life cycles difficult. Remote sensing, therefore, has played an important role in our understanding of large-scale nocturnal bird migrations. Weather surveillance radar networks in Europe and North America have great potential for long-term low-cost monitoring of bird migration at scales that have previously been impossible to achieve. Such long-term monitoring, however, poses a number of challenges for the ornithological and ecological communities: how does one take advantage of this vast data resource, integrate information across multiple sensors and large spatial and temporal scales, and visually represent the data for interpretation and dissemination, considering the dynamic nature of migration? We assembled an interdisciplinary team of ecologists, meteorologists, computer scientists, and graphic designers to develop two different flow visualizations, which are interactive and open source, in order to create novel representations of broad-front nocturnal bird migration to address a primary impediment to long-term, large-scale nocturnal migration monitoring. We have applied these visualization techniques to mass bird migration events recorded by two different weather surveillance radar networks covering regions in Europe and North America. These applications show the flexibility and portability of such an approach. The visualizations provide an intuitive representation of the scale and dynamics of these complex systems, are easily accessible for a broad interest group, and are biologically insightful. Additionally, they facilitate fundamental ecological research, conservation, mitigation of human-wildlife conflicts, improvement of meteorological

  14. Innovative Visualizations Shed Light on Avian Nocturnal Migration

    Science.gov (United States)

    Farnsworth, Andrew; Aelterman, Bart; Alves, Jose A.; Azijn, Kevin; Bernstein, Garrett; Branco, Sérgio; Desmet, Peter; Dokter, Adriaan M.; Horton, Kyle; Kelling, Steve; Kelly, Jeffrey F.; Leijnse, Hidde; Rong, Jingjing; Sheldon, Daniel; Van den Broeck, Wouter; Van Den Meersche, Jan Klaas; Van Doren, Benjamin Mark; van Gasteren, Hans

    2016-01-01

    Globally, billions of flying animals undergo seasonal migrations, many of which occur at night. The temporal and spatial scales at which migrations occur and our inability to directly observe these nocturnal movements makes monitoring and characterizing this critical period in migratory animals’ life cycles difficult. Remote sensing, therefore, has played an important role in our understanding of large-scale nocturnal bird migrations. Weather surveillance radar networks in Europe and North America have great potential for long-term low-cost monitoring of bird migration at scales that have previously been impossible to achieve. Such long-term monitoring, however, poses a number of challenges for the ornithological and ecological communities: how does one take advantage of this vast data resource, integrate information across multiple sensors and large spatial and temporal scales, and visually represent the data for interpretation and dissemination, considering the dynamic nature of migration? We assembled an interdisciplinary team of ecologists, meteorologists, computer scientists, and graphic designers to develop two different flow visualizations, which are interactive and open source, in order to create novel representations of broad-front nocturnal bird migration to address a primary impediment to long-term, large-scale nocturnal migration monitoring. We have applied these visualization techniques to mass bird migration events recorded by two different weather surveillance radar networks covering regions in Europe and North America. These applications show the flexibility and portability of such an approach. The visualizations provide an intuitive representation of the scale and dynamics of these complex systems, are easily accessible for a broad interest group, and are biologically insightful. Additionally, they facilitate fundamental ecological research, conservation, mitigation of human–wildlife conflicts, improvement of meteorological products, and public

  15. Birding--Fun and Science

    Science.gov (United States)

    McIntosh, Phyllis

    2014-01-01

    This feature article presents the basics of birding, or bird watching, and discusses its appeal, especially to serious birders. A section on "citizen scientists" explains organizations that collect data on birds and describes projects they organize. Other sections discuss the legacy of John James Audubon and the bald eagle.

  16. Language Policy, In-Migration and Discursive Debates in Wales

    Science.gov (United States)

    Edwards, Catrin Wyn

    2017-01-01

    Drawing on theory from critical language policy literature, this article explores the impact of discourses on in-migration on Welsh language policy. By focussing on discursive debates surrounding the subject of in-migration, the article analyses how a range of actors produce and reproduce discourses on in-migration in Wales and how these…

  17. The Monetary Rewards of Migration Within the U.S.

    Science.gov (United States)

    Wertheimer, Richard F., II

    This study focuses on the economic benefits derived by the migrant from migration. The report presents a methodology for computing monetary benefits, an estimate of these benefits, and implications of the findings for public policy. Included are a discussion of domestic migration and public policy, an economic theory of migration, an explanation…

  18. Foraging behaviour of pink-footed geese (Anser brachyrhynchus) during spring migration

    DEFF Research Database (Denmark)

    Chudzińska, Magda Ewa

    For many Arctic-breeding birds migrating in steps, migration is not only a transit between wintering and breeding areas, but also a preparation for breeding, because for these birds breeding must commence soon after arrival to the breeding area. Foraging decisions at each stopover site and their ......For many Arctic-breeding birds migrating in steps, migration is not only a transit between wintering and breeding areas, but also a preparation for breeding, because for these birds breeding must commence soon after arrival to the breeding area. Foraging decisions at each stopover site...... and their energetic consequences are therefore of great importance to these birds. In this thesis, I have aimed to address some aspects of the foraging decisions and behaviour of pink-footed geese during their spring migration to the Arctic breeding area. I combined field techniques with telemetry technology as well...... as modelling tools to address questions about how geese forage and fuel during their spring migration. The first three presented manuscripts focus on changes in goose foraging behaviour and energetics over the course of the day, a stopover season and the entire migration. They also focus on variety of factors...

  19. 14 CFR 33.76 - Bird ingestion.

    Science.gov (United States)

    2010-01-01

    ... single bird, the single largest medium bird which can enter the inlet, and the large flocking bird must...) (d) Large flocking bird. An engine test will be performed as follows: (1) Large flocking bird engine.... (4) Ingestion of a large flocking bird under the conditions prescribed in this paragraph must not...

  20. Visual and radar observations of birds in relation to collision risk at the Horns Rev offshore wind farm. Annual status report 2003

    Energy Technology Data Exchange (ETDEWEB)

    Kjaer Christensen, T.; Hounisen, J.P.; Clausager, I.; Krag Petersen, I.

    2004-07-01

    The aim of the project is to assess the collision risk between birds and wind turbines at the Horns Rev wind farm. In 2003 the studies focused on describing bird movements in relation to the wind farm and to identify the species-specific behavioural responses towards the wind turbines shown by migrating and staging species. The Horns Rev area lies in a region known to be important for substantial water bird migration as well as holding internationally important numbers of several wintering and staging water bird species. (au)

  1. Birds and Dutch elm disease control

    Science.gov (United States)

    DeWitt, J.B.

    1958-01-01

    Brief, factual review of information on effect of DDT and other insecticides on birds. One program for control of elm disease caused 22% decrease in number of adult birds and 56% mortality of nestlings. Quail fed 3 oz. of DDT per ton of food had 16% reduction in young hatched and 500% increase in defective chicks. Quail fed same dosage during winter and breeding seasons had 30% decrease in fertile eggs and 800% increase in defective chicks. More than 90% of their chicks died in first 6 weeks although fed no insecticide. Almost equally bad results came from feeding Pheasants diets with about 1 oz. DDT per ton. Other common insecticides (chlorinated hydrocarbons) also caused lowered chick survival and higher percentages of crippled chicks. From field data we know that 2 lbs. DDT/acre can affect birds and has even worse effects on cold-blooded animals. Efforts to control elm disease have left as much as 196 lbs. DDT/acre in top 3 inches of soil. Earthworms concentrate DDT in their tissues. Thus the treated areas can be traps for birds and other animals. What can be done? 1) In control of elm disease, use minimum effective amount of insecticide; mist blowers use less than sprayers. 2) Avoid applications during migration and nesting seasons. It has been reported that adequate control can be obtained with dormant sprays and that foliar applications may not be required. Tables of this paper show effects of DDT on reproduction of Quail, relative toxicity to quail of 8 insecticides, and amounts of 7 insecticides required to cause 40% or more decrease in Quail reproduction. These comparisons demonstrate that Aldrin, Endrin, and Dieldrin are 20 to 200 times as toxic as DDT and that Heptachlor and Chlordane are only slightly less toxic than Dieldrin. Methoxychlor and Strobane are less toxic to Quail than is DDT.

  2. The influence of migration speed on cooperation in spatial games

    Science.gov (United States)

    Li, Wen-Jing; Jiang, Luo-Luo; Gu, Changgui; Yang, Huijie

    2017-12-01

    Migration is a common phenomenon in human society which provides a person an opportunity to search for a new life from one area to another. In the framework of game theory, people may migrate to escape from a current adverse environment (evading defection). Since people may migrate at different speeds, it is interesting to figure out the influence of migration speed on the evolution of cooperative behavior. In an attempt to discover the influence, we propose here a model based on an adaptive migration mechanism. In this model, an individual migrates or updates his/her strategy asynchronously, which is tuned by migration frequency. Firstly, it is found that an appropriate migration speed may evoke an effective mechanism, which enables cooperators dominate even in highly adverse conditions. Secondly, we check how migration speed alters the paradigm of cooperation quantitatively in the conditions of different migration frequency. When migration frequency is high, cooperation is promoted only at a small migration speed. However, when migration frequency is low, cooperation is always promoted at any migration speed. In addition, we also investigated the influence of temptation to defect on cooperation for the case of different migration speeds and migration frequencies. Our results may provide a fresh perspective on the understanding of how human behavior affects cooperation.

  3. The Globalisation of migration

    OpenAIRE

    Milan Mesić

    2002-01-01

    The paper demonstrates that contemporary international migration is a constitutive part of the globalisation process. After defining the concepts of globalisation and the globalisation of migration, the author discusses six key themes, linking globalisation and international migration (“global cities”, the scale of migration; diversification of migration flows; globalisation of science and education; international migration and citizenship; emigrant communities and new identities). First, in ...

  4. Autumn phenology and morphometrics in the Garden Warbler Sylvia borin at the Ottenby Bird Observatory, Sweden

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye B.; Hedenström, Anders; Ottosson, Ulf

    2012-01-01

    Trapping and ringing near ecological barriers can provide useful information about the migration strategies of bird species. In this paper we analyzed ringing data of the Garden Warbler, collected within the period of 1950-2008 at the Ottenby Bird Observatory, south-eastern Sweden, and describe...... patterns in migration phenology, morphometrics and fuel load. A total of 4,351 individuals aged as either adults or juveniles were ringed during the period (yearly averages 7.3 adults and 83.1 juveniles) in addition to 1,514 birds of unknown age. Both age-specific and combined yearly totals did...... not significantly vary over the years. Median passage dates were 24 August, 30 August and 2 September for adults, juveniles and birds of unknown age, respectively. Median passage did not change significantly over the years. Among adults, larger individuals passed the observatory earlier than smaller individuals...

  5. Partial altitudinal migration of a Himalayan Forest pheasant.

    Science.gov (United States)

    Norbu, Nawang; Wikelski, Martin C; Wilcove, David S; Partecke, Jesko; Ugyen; Tenzin, Ugyen; Sherub; Tempa, Tshering

    2013-01-01

    Altitudinal migration systems are poorly understood. Recent advances in animal telemetry which enables tracking of migrants across their annual cycles will help illustrate unknown migration patterns and test existing hypotheses. Using telemetry, we show the existence of a complex partial altitudinal migration system in the Himalayas and discuss our findings to help better understand partial and altitudinal migration. We used GPS/accelerometer tags to monitor the migration of Satyr tragopan (Tragopan satyra) in the Bhutan Himalayas. We tagged 38 birds from 2009 - 2011 and found that tragopans are partially migratory. Fall migration lasted from the 3(rd) week of September till the 3(rd) week of November with migrants traveling distances ranging from 1.25 km to 13.5 km over 1 to 32 days. Snowfall did not influence the onset of migration. Return migration started by the 1(st) week of March and lasted until the 1(st) week of April. Individuals returned within 4 to 10 days and displayed site fidelity. One bird switched from being a migrant to a non-migrant. Tragopans displayed three main migration patterns: 1) crossing multiple mountains; 2) descending/ascending longitudinally; 3) moving higher up in winter and lower down in summer. More females migrated than males; but, within males, body size was not a factor for predicting migrants. Our observations of migrants traversing over multiple mountain ridges and even of others climbing to higher elevations is novel. We support the need for existing hypotheses to consider how best to explain inter- as well as intra-sexual differences. Most importantly, having shown that the patterns of an altitudinal migration system are complex and not a simple up and down slope movement, we hope our findings will influence the way altitudinal migrations are perceived and thereby contribute to a better understanding of how species may respond to climate change.

  6. Partial altitudinal migration of a Himalayan Forest pheasant.

    Directory of Open Access Journals (Sweden)

    Nawang Norbu

    Full Text Available BACKGROUND: Altitudinal migration systems are poorly understood. Recent advances in animal telemetry which enables tracking of migrants across their annual cycles will help illustrate unknown migration patterns and test existing hypotheses. Using telemetry, we show the existence of a complex partial altitudinal migration system in the Himalayas and discuss our findings to help better understand partial and altitudinal migration. METHODOLOGY/PRINCIPAL FINDINGS: We used GPS/accelerometer tags to monitor the migration of Satyr tragopan (Tragopan satyra in the Bhutan Himalayas. We tagged 38 birds from 2009 - 2011 and found that tragopans are partially migratory. Fall migration lasted from the 3(rd week of September till the 3(rd week of November with migrants traveling distances ranging from 1.25 km to 13.5 km over 1 to 32 days. Snowfall did not influence the onset of migration. Return migration started by the 1(st week of March and lasted until the 1(st week of April. Individuals returned within 4 to 10 days and displayed site fidelity. One bird switched from being a migrant to a non-migrant. Tragopans displayed three main migration patterns: 1 crossing multiple mountains; 2 descending/ascending longitudinally; 3 moving higher up in winter and lower down in summer. More females migrated than males; but, within males, body size was not a factor for predicting migrants. CONCLUSIONS/SIGNIFICANCE: Our observations of migrants traversing over multiple mountain ridges and even of others climbing to higher elevations is novel. We support the need for existing hypotheses to consider how best to explain inter- as well as intra-sexual differences. Most importantly, having shown that the patterns of an altitudinal migration system are complex and not a simple up and down slope movement, we hope our findings will influence the way altitudinal migrations are perceived and thereby contribute to a better understanding of how species may respond to climate change.

  7. Data from: Towards a new understanding of migration timing: slower spring than autumn migration in geese reflects different decision rules for stopover use and departure

    NARCIS (Netherlands)

    Koelzsch, Andrea; Kruckenberg, Helmut; Glazov, Peter; Muskens, G.J.D.M.; Wikelski, Martin

    2016-01-01

    According to migration theory and several empirical studies, long-distance migrants are more time-limited during spring migration and should therefore migrate faster in spring than in autumn. Competition for the best breeding sites is supposed to be the main driver, but timing of migration is often

  8. Towards a new understanding of migration timing: slower spring than autumn migration in geese reflects different decision rules for stopover use and departure

    NARCIS (Netherlands)

    Kölzsch, Andrea; Müskens, G.J.D.M.; Kruckenberg, H.; Glazov, P.; Weinzierl, R.; Nolet, B.A.; Wikelski, M.

    2016-01-01

    According to migration theory and several empirical studies, long-distance migrants are more time-limited during spring migration and should therefore migrate faster in spring than in autumn. Competition for the best breeding sites is supposed to be the main driver, but timing of migration is often

  9. Temporal and spatial variation in bird and human use of beaches in southern California.

    Science.gov (United States)

    Lafferty, Kevin D; Rodriguez, Donald A; Chapman, Angela

    2013-12-01

    Southern California's beaches can support a remarkable diversity of birds along the Pacific Flyway. We asked whether seasonal, annual, and spatial factors affect bird richness and abundance on public beaches. To do so, we conducted three years of monthly bird surveys on 12 sandy beaches in Ventura California. Across all surveys, we counted 22 shorebird species, 8 gull species, 24 other water bird species, and 24 landbird species. Sanderling, western gull, Heerman's gull, willet, marbled godwit, and whimbrel were the most abundant members of the bird community. Beach wrack was uncommon, particularly where beaches were groomed, and did not have a large effect on bird abundance, though it was positively associated with overall bird richness. Beaches near estuaries tended to be wide, and such beaches had a higher richness and abundance of birds. Beaches with shallow slopes tended to have more gulls and shorebirds. People and (illegal) unleashed dogs were common, particularly at beaches fronted by houses. The abundance and richness of shorebirds and the richness of other waterbirds was lower where human activity was high. Bird richness and abundance was strongly affected by season, with the highest density of birds being seen during the fall shorebird migration. Gull abundance peaked earlier (August-September) than shorebird abundance (October through December). A brief pulse of shorebirds also occurred in May due to spring migration. Comparing these data with surveys in the 1990's found no evidence for a decline in shorebirds over time, though black-bellied plover appear to still be recovering from the strong 1997-1998 ENSO. Opportunities to conserve birds on these beaches are limited, but could include enforcing leash laws and setting up human exclosures near estuary mouths.

  10. Spatiotemporal Distributions of Migratory Birds: Patchy Models with Delay

    Science.gov (United States)

    Gourley, Stephen A.; Liu, Rongsong; Wu, Jianhong

    2010-01-01

    We derive and analyze a mathematical model for the spatiotemporal distribution of a migratory bird species. The birds have specific sites for breeding and winter feeding, and usually several stopover sites along the migration route, and therefore a patch model is the natural choice. However, we also model the journeys of the birds along the flyways, and this is achieved using a continuous space model of reaction-advection type. In this way proper account is taken of flight times and in-flight mortalities which may vary from sector to sector, and this information is featured in the ordinary differential equations for the populations on the patches through the values of the time delays and the model coefficients. The seasonality of the phenomenon is accommodated by having periodic migration and birth rates. The central result of the paper is a very general theorem on the threshold dynamics, obtained using recent results on discrete monotone dynamical systems, for birth functions which are subhomogeneous. For such functions, depending on the spectral radius of a certain operator, either there is a globally attracting periodic solution, or the bird population becomes extinct. Evaluation of the spectral radius is difficult, so we also present, for the particular case of just one stopover site on the migration route, a verifiable sufficient condition for extinction or survival in the form of an attractive periodic solution. This threshold is illustrated numerically using data from the U.S. Geological Survey on the bar-headed goose and its migration to India from its main breeding sites around Lake Qinghai and Mongolia.

  11. Webcams for Bird Detection and Monitoring: A Demonstration Study

    Directory of Open Access Journals (Sweden)

    Willem W. Verstraeten

    2010-04-01

    Full Text Available Better insights into bird migration can be a tool for assessing the spread of avian borne infections or ecological/climatologic issues reflected in deviating migration patterns. This paper evaluates whether low budget permanent cameras such as webcams can offer a valuable contribution to the reporting of migratory birds. An experimental design was set up to study the detection capability using objects of different size, color and velocity. The results of the experiment revealed the minimum size, maximum velocity and contrast of the objects required for detection by a standard webcam. Furthermore, a modular processing scheme was proposed to track and follow migratory birds in webcam recordings. Techniques such as motion detection by background subtraction, stereo vision and lens distortion were combined to form the foundation of the bird tracking algorithm. Additional research to integrate webcam networks, however, is needed and future research should enforce the potential of the processing scheme by exploring and testing alternatives of each individual module or processing step.

  12. Birds of Prey at the International Airport "Strigino", Russia

    Directory of Open Access Journals (Sweden)

    Nadezhda E. Kolesova

    2016-04-01

    Full Text Available In this article we discuss the seasonal dynamics and population density of Birds of Prey at the Nizhniy Novgorod International airport “Strigino”, based on data collected from November, 2013 to November, 2014. During this period a total of 71 raptors of 9 species were observed, including one breeding species – the Eurasian Marsh Harrier (Circus aeruginosus. The seasonal population dynamics and species composition of Birds of Prey on the territory of the airport was studied. The highest population density and species number occurred during end of June – July, in September and in April. The summer population peak was caused by regular observations of hunting birds, whose nests were located on the territory of the airport and in the close vicinity. Young birds also made a contribution to this peak. Autumn and spring population peaks were caused by more frequent observations of migrating raptors during the seasonal migrations. The lowest number of raptors in the airport was observed in winter.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2010-03-01

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

  15. Circannual basis of geographically distinct bird schedules.

    Science.gov (United States)

    Helm, Barbara; Schwabl, Ingrid; Gwinner, Eberhard

    2009-05-01

    To anticipate seasonal change, organisms schedule their annual activities by using calendrical cues like photoperiod. The use of cues must be fitted to local conditions because schedules differ between species and habitats. In complete absence of temporal information, many species show persistent circannual cycles that are synchronised, but not driven, by photoperiod. The contribution of circannual rhythms to timing under natural photoperiodic conditions is still unclear. In a suite of experiments, we examined timing in two closely related songbirds (Siberian and European stonechats) that inhabit similar latitudes but differ in seasonal behaviour. Under a more continental climate, Siberian stonechats breed later, moult faster and migrate further than European stonechats. We tested hypotheses for seasonal timing mechanisms by comparing the birds under constant and naturally changing daylengths. The taxa retained characteristic reproductive and moult schedules and hybrids behaved roughly intermediately. Based on their distinct circannual cycles, we expected European and Siberian stonechats to differ in photoperiodic responses at a given time of year. We found that the taxa responded, as predicted, in opposite ways to photoperiodic simulations as experienced on different migration routes. The findings indicate that circannual rhythms reflect geographically distinct periodic changes in seasonal disposition and cue-response mechanisms. Under natural daylengths, the phase relationship of the underlying circannual rhythm to the external year determines the action of photoperiod. Circannual rhythms are widespread among long-lived species. Accordingly, responses to environmental change, range expansion and novel migration patterns may depend on the particulars of a species' underlying circannual programming.

  16. Luanda-Holanda; irregular migration from Angola to the Netherlands

    NARCIS (Netherlands)

    van Wijk, J.

    2008-01-01

    Against the backdrop of push-pull and social network theories on migration and criminological theory on human smuggling, this article tries to answer the questions of why and how Angolan asylum-seekers migrated to the Netherlands since the end of the 1990s. The study shows that the migrants can be

  17. Prevalence of avian haemosporidia among injured wild birds in Tokyo and environs, Japan

    Directory of Open Access Journals (Sweden)

    Mizue Inumaru

    2017-12-01

    Full Text Available Avian haemosporidia have been reported in various birds of Japan, which is part of the East Asian-Australian flyway and is an important stopover site for migratory birds potentially carrying new pathogens from other areas. We investigated the prevalence of avian malaria in injured wild birds, rescued in Tokyo and surrounding areas. We also evaluated the effects of migration by examining the prevalence of avian malaria for each migratory status. 475 birds of 80 species were sampled from four facilities. All samples were examined for haemosporidian infection via nested polymerase chain reaction (PCR of the cytochrome b (cytb gene. 100 birds (21.1% of 43 species were PCR positive for avian haemosporidia. Prevalence in wintering birds, migratory breeders, and resident birds was 46.0%, 19.3%, 17.3% respectively. There was a bias in wintering birds due to Eurasian coot (Fulica atra and Anseriformes. In wintering birds, lineages which are likely to be transmitted by Culiseta sp. in Northern Japan and lineages from resident species of Northern Japan or continental Asia were found, suggesting that wintering birds are mainly infected at their breeding sites. Meanwhile, there were numerous lineages found from resident and migratory breeders, suggesting that they are transmitted in Japan, some possibly unique to Japan. Although there are limits in studying rescued birds, rehabilitation facilities make sampling of difficult-to-catch migratory species possible and also allow for long-term monitoring within areas. Keywords: Avian haemosporidia, Japan, Rescued wild birds, Migratory birds, Parasite diversity, Cytochrome b

  18. Timing of pre-nuptial migration and leap-frog patterns in Yellow ...

    African Journals Online (AJOL)

    nuptial migration period, in parts of the wintering grounds most distant from the breeding area. Birds breeding at the highest latitudes are the latest to depart on prenuptial migration, and so can take advantage of this surge by extending their ...

  19. Ontogenetic development of migration: Lagrangian drift trajectories suggest a new paradigm for sea turtles

    DEFF Research Database (Denmark)

    Hays, Graeme C.; Fossette, Sabrina; Katselidis, Kostas A.

    2010-01-01

    Long distance migration occurs in a wide variety of taxa including birds, insects, fishes, mammals and reptiles. Here, we provide evidence for a new paradigm for the determinants of migration destination. As adults, sea turtles show fidelity to their natal nesting areas and then at the end...

  20. Insights into Wilson's Warbler migration from analyses of hydrogen stable-isotope ratios

    Science.gov (United States)

    Jeffrey F. Kelly; Viorel Atudorei; Zachary D. Sharp; Deborah M. Finch

    2002-01-01

    Our ability to link the breeding locations of individual passerines to migration stopover sites and wintering locations is limited. Stable isotopes of hydrogen contained in bird feathers have recently shown potential in this regard. We measured hydrogen stable-isotope ratios (deltaD) of feathers from breeding, migrating, and wintering Wilson's Warblers. Analyses...

  1. Autumn and spring migration of the Reed Warbler Acrocephalus ...

    African Journals Online (AJOL)

    At three stations more birds per day were caught in spring than in autumn. Deviating geographical conditions induced high capturing numbers at the Red Sea coast, particularly in autumn. Differences between spring and autumn may indicate loop migration and/or seasonally differing flight or resting strategies. Wing-length ...

  2. Migration pattern of Icelandic Lesser Black-backed Gulls

    NARCIS (Netherlands)

    Hallgrimsson, G.T.; Gunnarsson, H.V.; Torfason, O.; Buijs, R.-J.; Camphuysen, K.C.J.

    2012-01-01

    On the species level, the non-breeding distribution and the migration patterns of most European birds are well known. In contrast, the knowledge of the contribution of different breeding populations to particular non-breeding sites (migratory connectivity) is far more limited. We studied the

  3. Migration routes and staging areas of Abdim's Storks Ciconia ...

    African Journals Online (AJOL)

    This paper presents the results of a satellite tracking study of seven adult Abdim's Storks Ciconia abdimii that were followed from the nesting areas in southern Niger across the equator to the non-breeding range and back. Post-breeding migration started between early November and early December when all birds ...

  4. Migration patterns of the Osprey Pandion haliaetus on the Eastern ...

    African Journals Online (AJOL)

    We analysed migration strategies of the Osprey Pandion haliaetus on the poorly studied Eastern European– East African flyway. Four adult birds were equipped with GPS-based satellite-transmitters or data-loggers in their breeding sites in Estonia (north-eastern Europe) and tracked to their wintering grounds in Africa and ...

  5. Migration of red-backed shrikes from the Iberian Peninsula

    DEFF Research Database (Denmark)

    Tøttrup, Anders P.; Pedersen, Lykke; Onrubia, Alejandro

    2017-01-01

    e current Northern Hemisphere migration systems are believed to have arisen since the last glaciation. In many cases, birds do not migrate strait from breeding to non-breeding areas but fly via a detour. All western European populations of red-backed shrikes Lanius collurio are assumed to reach...... their southern African wintering grounds detouring via southeast Europe. Based on theoretical considerations under an optimality framework this detour is apparently optimal. Here, we use individual geolocator data on red-backed shrikes breeding in Spain to show that these birds do indeed detour via southeast...... Europe en route to southern Africa where they join other European populations of red-backed shrikes and return via a similar route in spring. Disregarding potential wind assistance, the routes taken for the tracked birds in autumn were not optimal compared to crossing the barrier directly. For spring...

  6. Long-term phenological shifts in raptor migration and climate.

    Directory of Open Access Journals (Sweden)

    Mikaël Jaffré

    Full Text Available Climate change is having a discernible effect on many biological and ecological processes. Among observed changes, modifications in bird phenology have been widely documented. However, most studies have interpreted phenological shifts as gradual biological adjustments in response to the alteration of the thermal regime. Here we analysed a long-term dataset (1980-2010 of short-distance migratory raptors in five European regions. We revealed that the responses of these birds to climate-induced changes in autumn temperatures are abrupt and synchronous at a continental scale. We found that when the temperatures increased, birds delayed their mean passage date of autumn migration. Such delay, in addition to an earlier spring migration, suggests that a significant warming may induce an extension of the breeding-area residence time of migratory raptors, which may eventually lead to residency.

  7. Long-term phenological shifts in raptor migration and climate.

    Science.gov (United States)

    Jaffré, Mikaël; Beaugrand, Grégory; Goberville, Eric; Jiguet, Frédéric; Kjellén, Nils; Troost, Gerard; Dubois, Philippe J; Leprêtre, Alain; Luczak, Christophe

    2013-01-01

    Climate change is having a discernible effect on many biological and ecological processes. Among observed changes, modifications in bird phenology have been widely documented. However, most studies have interpreted phenological shifts as gradual biological adjustments in response to the alteration of the thermal regime. Here we analysed a long-term dataset (1980-2010) of short-distance migratory raptors in five European regions. We revealed that the responses of these birds to climate-induced changes in autumn temperatures are abrupt and synchronous at a continental scale. We found that when the temperatures increased, birds delayed their mean passage date of autumn migration. Such delay, in addition to an earlier spring migration, suggests that a significant warming may induce an extension of the breeding-area residence time of migratory raptors, which may eventually lead to residency.

  8. Using avian radar to examine relationships among avian activity, bird strikes, and meteorological factors

    Science.gov (United States)

    Coates, Peter S.; Casazza, Michael L.; Halstead, Brian J.; Fleskes, Joseph P.; Laughlin, James A.

    2011-01-01

    Radar systems designed to detect avian activity at airfields are useful in understanding factors that influence the risk of bird and aircraft collisions (bird strikes). We used an avian radar system to measure avian activity at Beale Air Force Base, California, USA, during 2008 and 2009. We conducted a 2-part analysis to examine relationships among avian activity, bird strikes, and meteorological and time-dependent factors. We found that avian activity around the airfield was greater at times when bird strikes occurred than on average using a permutation resampling technique. Second, we developed generalized linear mixed models of an avian activity index (AAI). Variation in AAI was first explained by seasons that were based on average migration dates of birds at the study area. We then modeled AAI by those seasons to further explain variation by meteorological factors and daily light levels within a 24-hour period. In general, avian activity increased with decreased temperature, wind, visibility, precipitation, and increased humidity and cloud cover. These effects differed by season. For example, during the spring bird migration period, most avian activity occurred before sunrise at twilight hours on clear days with low winds, whereas during fall migration, substantial activity occurred after sunrise, and birds generally were more active at lower temperatures. We report parameter estimates (i.e., constants and coefficients) averaged across models and a relatively simple calculation for safety officers and wildlife managers to predict AAI and the relative risk of bird strike based on time, date, and meteorological values. We validated model predictability and assessed model fit. These analyses will be useful for general inference of avian activity and risk assessment efforts. Further investigation and ongoing data collection will refine these inference models and improve our understanding of factors that influence avian activity, which is necessary to inform

  9. ILO - International Migration Programme.

    Science.gov (United States)

    Boudraa, Miriam

    2011-01-01

    In a wide International Context characterised not only by the economical development but also by the social, cultural, political and individual development, we witness more and more to a exchange between the developed and the developing countries, which can be translated especially in the migration of the work force. In theory, all countries are either countries of origin either countries of transit or destination, and they are all responsible for the rights of migrant workers by promoting the rights, by monitoring and by preventing the abusive conditions. The process of migration of the workforce can be divided into three stages: the first coincides with the period prior to departure, the second is represented by the aftermath of the departure and the period of stay in the country of destination, the third stage corresponds to the return in the country of origin. The workers must be protected throughout this process by the international organizations that perform the catalytic role of communication and exchange between countries, for the only purpose of protecting the rights of immigrant and/or immigrants workers. The responsibility for the protection of workers is divided among the various players in the International Labour Organisation. Every country has to apply measures according to the international standards regarding workers' rights, standards that guide the various countries in the formulation and implementation of their policies and legislation. These standards are suggested by International Conventions, the ILO Conventions and other international instruments such as the human rights instrument. There has been a big step forward once the ILO Fundamental Conventions and Conventions on Migrant Workers where implemented and this implementation represented the use of the Guidelines "ILO Multilateral Framework on Labour Migration".

  10. Low intensity blood parasite infections do not reduce the aerobic performance of migratory birds

    Science.gov (United States)

    Dimitrov, Dimitar; Ivanova, Karina; Zehtindjiev, Pavel

    2018-01-01

    Blood parasites (Haemosporidia) are thought to impair the flight performance of infected animals, and therefore, infected birds are expected to differ from their non-infected counterparts in migratory capacity. Since haemosporidians invade host erythrocytes, it is commonly assumed that infected individuals will have compromised aerobic capacity, but this has not been examined in free-living birds. We tested if haemosporidian infections affect aerobic performance by examining metabolic rates and exercise endurance in migratory great reed warblers (Acrocephalus arundinaceus) experimentally treated with Plasmodium relictum pGRW04 and in naturally infected wild birds over consecutive life-history stages. We found no effect of acute or chronic infections on resting metabolic rate, maximum metabolic rate or exercise endurance in either experimentally treated or free-living birds. Oxygen consumption rates during rest and while undergoing maximum exercise as well as exercise endurance increased from breeding to migration stages in both infected and non-infected birds. Importantly, phenotypic changes associated with preparation for migration were similarly unaffected by parasitaemia. Consequently, migratory birds experiencing parasitaemia levels typical of chronic infection do not differ in migratory capacity from their uninfected counterparts. Thus, if infected hosts differ from uninfected conspecifics in migration phenology, other mechanisms besides aerobic capacity should be considered. PMID:29386365

  11. Improving The Accuracy Of Selection Of Bird Radar Echoes Against A Background Of Atomized Clouds And Atmospheric Inhomogeneities

    Directory of Open Access Journals (Sweden)

    Dinevich Leonid

    2015-12-01

    Full Text Available The algorithm for bird radar echo selection was developed in Israel and has been successfully used for many years to monitor birds in periods of massive intercontinental migration in order to ensure flight safety in civil and military aviation. However, it has been found that under certain meteorological conditions the bird echo selection algorithm does not filter out false signals formed by atomized clouds and atmospheric inhomogeneities. Although the algorithm is designed to identify and sift false signals, some useful echoes from smaller birds are erroneously sifted as well.

  12. Threatened bird valuation in Australia.

    Directory of Open Access Journals (Sweden)

    Kerstin K Zander

    Full Text Available 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.

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

    NARCIS (Netherlands)

    Kölzsch, A.; Bauer, S.; De Boer, R.; Griffin, L.; Cabot, D.; Exo, K-M.; Van der Jeugd, H.P.; Nolet, B.A.

    2015-01-01

    1.Herbivorous birds are hypothesized to migrate in spring along a seasonal gradient of plant profitability towards their breeding grounds (green wave hypothesis). For Arctic-breeding species in particular, following highly profitable food is important, so that they can replenish resources along the

  14. Application of ground-truth for classification and quantification of bird movements on migratory bird habitat initiative sites in southwest Louisiana: final report

    Science.gov (United States)

    Barrow, Wylie C.; Baldwin, Michael J.; Randall, Lori A.; Pitre, John; Dudley, Kyle J.

    2013-01-01

    This project was initiated to assess migrating and wintering bird use of lands enrolled in the Natural Resources Conservation Service’s (NRCS) Migratory Bird Habitat Initiative (MBHI). The MBHI program was developed in response to the Deepwater Horizon oil spill in 2010, with the goal of improving/creating habitat for waterbirds affected by the spill. In collaboration with the University of Delaware (UDEL), we used weather surveillance radar data (Sieges 2014), portable marine radar data, thermal infrared images, and visual observations to assess bird use of MBHI easements. Migrating and wintering birds routinely make synchronous flights near dusk (e.g., departure during migration, feeding flights during winter). Weather radars readily detect birds at the onset of these flights and have proven to be useful remote sensing tools for assessing bird-habitat relations during migration and determining the response of wintering waterfowl to wetland restoration (e.g., Wetlands Reserve Program lands). However, ground-truthing is required to identify radar echoes to species or species group. We designed a field study to ground-truth a larger-scale, weather radar assessment of bird use of MBHI sites in southwest Louisiana. We examined seasonal bird use of MBHI fields in fall, winter, and spring of 2011-2012. To assess diurnal use, we conducted total area surveys of MBHI sites in the afternoon, collecting data on bird species composition, abundance, behavior, and habitat use. In the evenings, we quantified bird activity at the MBHI easements and described flight behavior (i.e., birds landing in, departing from, circling, or flying over the MBHI tract). Our field sampling captured the onset of evening flights and spanned the period of collection of the weather radar data analyzed. Pre- and post-dusk surveys were conducted using a portable radar system and a thermal infrared camera. Landbirds, shorebirds, and wading birds were commonly found on MBHI fields during diurnal

  15. Effects of alien woody plant invasion on the birds of Mountain ...

    African Journals Online (AJOL)

    1989-04-18

    Apr 18, 1989 ... alien A. cyclops is apparently enhanced by dispersal of the seeds by frugivorous birds (Glyphis, Milton & .... Friedman two-way analysis of variance by ranks (Con- over 1971) was used to assess the significance of ...... Towards a theory of continental species diversities: bird distributions over mediterranean ...

  16. Tritrophic effects of birds and ants on a canopy food web, tree growth, and phytochemistry

    Science.gov (United States)

    Kailen A. Mooney

    2007-01-01

    Insectivorous birds and ants co-occur in most terrestrial communities, and theory predicts that emergent properties (i.e., nonadditive effects) can determine their combined influence on arthropods and plants. In a three-year factorial experiment, I investigated whether the effects of birds on pine and its arthropods differed based on the presence of ants that were...

  17. Migration - utopia or myopia?

    Directory of Open Access Journals (Sweden)

    Peter Osborne

    1998-03-01

    Full Text Available Peter Osborne spent a sabbatical in northern America and was surprised that so many scientists and students stated that caribou migration was largely the result of mosquito pressure. He failed however to find any documented evidence of this claim although he was constantly confronted by the well known «facts» that mosquitoes had been observed to drive caribou crazy and even kill juveniles. The issue Osborne wishes to focus is that an experimentally unsubstantiated anthropomorphism appears to have become critical evidence in support of a theory. A recent article in Nature (393, 511-513, 1998 devoted to the uses of 'science in fiction' to stimulate thought and discussion about aspects of academia encouraged him to write the following comment in the form of a parody of ancient Greek dialogues.

  18. Campylobacter jejuni and Campylobacter coli in wild birds on Danish livestock farms

    DEFF Research Database (Denmark)

    Hald, Birthe; Skov, Marianne Nielsine; Nielsen, Eva Møller

    2016-01-01

    , fat score, gender, and migration range were not found to be associated with Campylobacter spp. carriage. A correlation was found between the prevalence (%) of C. jejuni in wild birds and the proportions (%) of C. jejuni in both manure on cattle farms (R-2 = 0.92) and poultry farms (R-2 = 0....... The farm environment provides attractive foraging and breeding habitats for some bird species reported to carry thermophilic Campylobacter spp. We investigated the Campylobacter spp. carriage rates in 52 wild bird species present on 12 Danish farms, sampled during a winter and a summer season, in order...... to study the factors influencing the prevalence in wild birds according to their ecological guild. In total, 1607 individual wild bird cloacal swab samples and 386 livestock manure samples were cultured for Campylobacter spp. according to the Nordic Committee on Food Analysis method NMKL 119.Results...

  19. BIRDS SEASONAL FLUCTIATIONS IN SMALL RIVERS’ VALLEYS OF THE SOUTHERN PART OF ZAPOROZHSKAYA REGION

    Directory of Open Access Journals (Sweden)

    Matruhan T.I.

    2011-10-01

    Full Text Available Role of river valleys in the existence of a large number of bird species is greater than in the breeding period andduring seasonal migrations and movements. Total during the year they recorded 102 bird species, including 62 speciesof breeding period. Feature of the habitat of the valleys of small rivers is the combination in small areas of differenthabitats. This increases the patchiness of zonal steppe landscape, which allows the expansion of areas along the riverbeds of individual species. Flood regime of rivers is the determining factor for the birds: The most diverse speciescomposition and abundance of avifauna of individual species in the high-water seasons.

  20. Advancing migratory bird conservation and management by using radar: An interagency collaboration

    Science.gov (United States)

    Ruth, Janet M.; Barrow, Wylie C.; Sojda, Richard S.; Dawson, Deanna K.; Diehl, Robert H.; Manville, Albert; Green, Michael T.; Krueper, David J.; Johnston, Scott

    2005-01-01

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

  1. Bird Movements and Behaviors in the Gulf Coast Region: Relation to Potential Wind-Energy Developments

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, M. L.

    2006-06-01

    The purpose of this paper is to discuss the possible impacts of wind development to birds along the lower Gulf Coast, including both proposed near-shore and offshore developments. The report summarizes wind resources in Texas, discusses timing and magnitude of bird migration as it relates to wind development, reviews research that has been conducted throughout the world on near- and offshore developments, and provides recommendations for research that will help guide wind development that minimizes negative impacts to birds and other wildlife resources.

  2. On the specification and estimation of macro rural-urban migration functions: with an application to Indian data.

    Science.gov (United States)

    Banerjee, B; Kanbur, S M

    1981-01-01

    The authors suggest several extensions and modifications to the existing specifications of macro migration functions as suggested by Todar through a more careful investigation of the micro theory underlying migration decisions. They use a probabilistic migration model to examine internal migration in India and present evidence that migration tends first to rise and then to fall as rural income rises

  3. Using WSR-88D Polarimetric Data to Identify Bird-Contaminated Doppler Velocities

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    2013-01-01

    Full Text Available As an important part of Doppler velocity data quality control for radar data assimilation and other quantitative applications, an automated technique is developed to identify and remove contaminated velocities by birds, especially migrating birds. This technique builds upon the existing hydrometeor classification algorithm (HCA for dual-polarimetric WSR-88D radars developed at the National Severe Storms Laboratory, and it performs two steps. In the first step, the fuzzy-logic method in the HCA is simplified and used to identify biological echoes (mainly from birds and insects. In the second step, another simple fuzzy logic method is developed to detect bird echoes among the biological echoes identified in the first step and thus remove bird-contaminated velocities. The membership functions used by the fuzzy logic method in the second step are extracted from normalized histograms of differential reflectivity and differential phase for birds and insects, respectively, while the normalized histograms are constructed by polarimetric data collected during the 2012 fall migrating season and sorted for bird and insects, respectively. The performance and effectiveness of the technique are demonstrated by real-data examples.

  4. Where the Birds Live

    Science.gov (United States)

    MaKinster, James; Trautmann, Nancy; Burch, Carol; Watkins, Michelle

    2015-01-01

    Species richness, migration, habitats, ecological niches, adaptations: Concepts such as these come alive when students explore and analyze landscapes, environmental characteristics, and related biological features represented on digital maps. Most students are familiar with navigation tools integrated into smartphone apps but may be surprised to…

  5. Influence of weather conditions on the flight of migrating black storks

    OpenAIRE

    Chevallier, D.; Handrich, Y.; Georges, J.-Y.; Baillon, F.; Brossault, P.; Aurouet, A.; Le Maho, Y.; Massemin, S.

    2010-01-01

    This study tested the potential influence of meteorological parameters (temperature, humidity, wind direction, thermal convection) on different migration characteristics (namely flight speed, altitude and direction and daily distance) in 16 black storks (Ciconia nigra). The birds were tracked by satellite during their entire autumnal and spring migration, from 1998 to 2006. Our data reveal that during their 27-day-long migration between Europe and Africa (mean distance of 4100 km), the period...

  6. Tropical birds take small risks

    OpenAIRE

    Anders Pape Møller; Wei Liang

    2013-01-01

    The life history of tropical birds differs from that of their temperate counterparts by late start of reproduction, small clutch sizes, and high rates of adult survival. Thus, tropical species should have greater residual reproductive value than temperate species. Therefore, tropical birds can be predicted to take smaller risks than closely related temperate birds in order not to jeopardize their prospects of survival, which is the single most important component of fitness, and which is grea...

  7. Ticks, Lyme disease spirochetes, trypanosomes, and antibody to encephalitis viruses in wild birds from coastal Georgia and South Carolina.

    Science.gov (United States)

    Durden, L A; McLean, R G; Oliver, J H; Ubico, S R; James, A M

    1997-12-01

    Ticks and blood samples were collected from wild birds mist-netted on St. Catherine's Island, Georgia, and at the Wedge Plantation in coastal South Carolina in 1994 and 1995. Immature stages of 5 species of ixodid ticks were recovered from 10 of 148 (7%) birds belonging to 6 species in Georgia, whereas 6 ixodid species were recovered from 45 of 259 (17%) birds representing 10 avian species in South Carolina. Borrelia burgdorferi sensu lato was isolated from 27 of 120 (23%) screened ticks (Ixodes scapularis and Ixodes minor) recovered from South Carolina birds, but from none of 16 screened ticks removed from Georgia birds. This spirochete was also isolated from 1 of 97 (1%) birds in South Carolina. In 1995, neither eastern equine encephalitis (EEE) virus nor St. Louis encephalitis (SLE) virus was isolated from any of 218 bird sera screened, but serum neutralizing antibodies were found to EEE virus in 4 of 121 (3%) sera and to SLE virus in 2 of 121 (2%) sera from South Carolina. No antibody to either virus was detected in 51 avian sera screened from Georgia. Trypanosomes (probably Trypanosoma avium) were isolated from 1 of 51 (2%) birds from Georgia and from 13 of 97 (13%) birds from South Carolina. Our data suggest that some wild birds may be reservoir hosts for the Lyme disease spirochete and for encephalitis viruses in coastal Georgia and South Carolina and that migrating birds can disperse immature ticks infected with B. burgdorferi.

  8. Impact of Environmental Changes on Migratory Bird Survival

    Directory of Open Access Journals (Sweden)

    Sabine Stöcker-Segre

    2014-01-01

    Full Text Available We present a mathematical model that studies and simulates the interconnection between energetic and ecological aspects of bird migration. By comparing model predictions with experimental data, we show that it can be used to assess the impact of changing environmental conditions in breeding, wintering, and stop-over sites on migratory success. We relate in particular to the European white stork (Ciconia ciconia and its Eastern migration route and discuss questions concerning the timing, stopover, and feeding behavior en route. Opinions concerning the importance of resource availability and resource quality en route are divided. Whereas some studies have shown that storks gain weight in the wintering site, but almost do not feed en route, others stress the importance of the quality of stop-over locations. We address these questions and simulate the development of stork populations for changing environmental conditions. We demonstrate that resource availability and competition for breeding sites are crucial factors determining the timing of spring migration and the length of stop-over periods. Analyzing the robustness of migration strategies with respect to changing environmental conditions, we show that birds will shorten their stay in stop-over places of poor resource availability rather than prolonging it in the attempt to gain time for accumulating fat reserves.

  9. Rhode Island, Connecticut, New York, and New Jersey ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, passerine birds, gulls and...

  10. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for alcids, diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

  11. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

  12. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds, and...

  13. Proceedings of the Wind Energy and Birds/Bats Workshop: Understanding and Resolving Bird and Bat Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Susan Savitt (ed.)

    2004-09-01

    Most conservation groups support the development of wind energy in the US as an alternative to fossil and nuclear-fueled power plants to meet growing demand for electrical energy. However, concerns have surfaced over the potential threat to birds, bats, and other wildlife from the construction and operation of wind turbine facilities. Co-sponsored by the American Bird Conservancy (ABC) and the American Wind Energy Association (AWEA), the Wind Energy and Birds/Bats Workshop was convened to examine current research on the impacts of wind energy development on avian and bat species and to discuss the most effective ways to mitigate such impacts. On 18-19 May 2004, 82 representatives from government, non-government organizations, private business, and academia met to (1) review the status of the wind industry and current project development practices, including pre-development risk assessment and post-construction monitoring; (2) learn what is known about direct, indirect (habitat), and cumulative impacts on birds and bats from existing wind projects; about relevant aspects of bat and bird migration ecology; about offshore wind development experience in Europe; and about preventing, minimizing, and mitigating avian and bat impacts; (3) review wind development guidelines developed by the USFWS and the Washington State Department of Fish and Wildlife; and (4) identify topics needing further research and to discuss what can be done to ensure that research is both credible and accessible. These Workshop Proceedings include detailed summaries of the presentations made and the discussions that followed.

  14. Ecology of tern flight in relation to wind, topography and aerodynamic theory.

    Science.gov (United States)

    Hedenström, Anders; Åkesson, Susanne

    2016-09-26

    Flight is an economical mode of locomotion, because it is both fast and relatively cheap per unit of distance, enabling birds to migrate long distances and obtain food over large areas. The power required to fly follows a U-shaped function in relation to airspeed, from which context dependent 'optimal' flight speeds can be derived. Crosswinds will displace birds away from their intended track unless they make compensatory adjustments of heading and airspeed. We report on flight track measurements in five geometrically similar tern species ranging one magnitude in body mass, from both migration and the breeding season at the island of Öland in the Baltic Sea. When leaving the southern point of Öland, migrating Arctic and common terns made a 60° shift in track direction, probably guided by a distant landmark. Terns adjusted both airspeed and heading in relation to tail and side wind, where coastlines facilitated compensation. Airspeed also depended on ecological context (searching versus not searching for food), and it increased with flock size. Species-specific maximum range speed agreed with predicted speeds from a new aerodynamic theory. Our study shows that the selection of airspeed is a behavioural trait that depended on a complex blend of internal and external factors.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. © 2016 The Author(s).

  15. Flexibility of continental navigation and migration in European mallards

    DEFF Research Database (Denmark)

    van Toor, Mariëlle L.; Hedenström, Anders; Waldenström, Jonas

    2013-01-01

    The ontogeny of continent-wide navigation mechanisms of the individual organism, despite being crucial for the understanding of animal movement and migration, is still poorly understood. Several previous studies, mainly conducted on passerines, indicate that inexperienced, juvenile birds may...... not generally correct for displacement during fall migration. Waterbirds such as the mallard (Anas platyrhynchos, Linnaeus 1758) are more flexible in their migration behavior than most migratory songbirds, but previous experiments with waterbirds have not yet allowed clear conclusions about their navigation...... abilities. Here we tested whether immature mallard ducks correct for latitudinal displacement during fall migration within Europe. During two consecutive fall migration periods, we caught immature females on a stopover site in southeast Sweden, and translocated a group of them ca. 1,000 km to southern...

  16. Aspects of general linear modelling of migration.

    Science.gov (United States)

    Congdon, P

    1992-01-01

    "This paper investigates the application of general linear modelling principles to analysing migration flows between areas. Particular attention is paid to specifying the form of the regression and error components, and the nature of departures from Poisson randomness. Extensions to take account of spatial and temporal correlation are discussed as well as constrained estimation. The issue of specification bears on the testing of migration theories, and assessing the role migration plays in job and housing markets: the direction and significance of the effects of economic variates on migration depends on the specification of the statistical model. The application is in the context of migration in London and South East England in the 1970s and 1980s." excerpt

  17. A note on migration with borrowing constraints.

    Science.gov (United States)

    Ghatak, S; Levine, P

    1994-12-01

    "This note examines an important conflict between the theory and evidence on migration in LDCs. While the Harris-Todaro class of models explain the phenomenon of migration mainly by expected income differential between the economically advanced and the backward regions, the actual evidence in some cases suggests that migration could actually rise following a rise in income in backward areas. We resolve this puzzle by analysing migration in the context of the existence of imperfect credit markets in LDCs. We show that under certain plausible conditions, the rate of migration from the rural to the urban areas may actually rise when rural wages rise, as they ease the constraints on borrowing by potential migrants." excerpt

  18. OECD migration, welfare and skill selectivity

    DEFF Research Database (Denmark)

    Pedersen, Peder; Pytlikova, Mariola; Smith, Nina

    of the immigrants have been from poor countries, where the educational level of the population is low. The comprehensive income support schemes, social safety net and a high tax pressure, may play a role in changing the composition of migration flows. This paper presents empirical evidence on immigration flows...... into 27 OECD countries over the period of 12 years, 1989-2000. Using a fixed effects panel data model, we analyze the determinants of the migration flows during the latest decade. We study whether there are significant selectivity effects in international migration flows, i.e. whether the countries......Recent migration patterns show growing migration pressure and changing composition of immigrants in many Western countries. According to theory, the impact of immigration depends on the skill distribution of immigrants compared to the natives. During the latest decade, an increasing proportion...

  19. Optimal Foraging by Birds: Experiments for Secondary & Postsecondary Students

    Science.gov (United States)

    Pecor, Keith W.; Lake, Ellen C.; Wund, Matthew A.

    2015-01-01

    Optimal foraging theory attempts to explain the foraging patterns observed in animals, including their choice of particular food items and foraging locations. We describe three experiments designed to test hypotheses about food choice and foraging habitat preference using bird feeders. These experiments can be used alone or in combination and can…

  20. East Africa's diminishing bird habitats and bird species

    African Journals Online (AJOL)

    ... resultant intensive agricultural projects that follow. Such impacts have resulted in a decline in both bird habitats and biodiversity. Of particular concern are the areas important to all our endemic bird species, and already we are witnessing a series of very worrying developments. Taking each. Scopus 32: 27–34, June 2013 ...

  1. The BIRD payload platform

    Science.gov (United States)

    Walter, Ingo; Briess, Klaus; Baerwald, Wolfgang; Skrbek, Wolfgang; Schrandt, Fredrich

    2003-04-01

    For hot spot events as forest fires, volcanic activity or burning oil spills and coal seams a dedicate dspace instrumentation does not exist. With its successful launch end of October 2001 with the Indian Polar Satellite Launch Vehicle the German Aerospace Center starts closing this gap with the micro-satellite mission BIRD. As space segment serves a three-axis stabilized satellite of 92 kg including a contingent of over 30% for the scientific instruments. The main payload of the BIRD micro-satellite is the newly developed Hot Spot Recognition System. It's a dual-channel instrument for middle and thermal IR imagery based on cooled MCT line detectors. The miniaturization by integrated detector/cooler assemblies provides a highly efficient design. A complement for the hot spot detection is the wide-angle stereo-scanner WAOSS-B. It is a hardware re-use dedicated to vegetation and cloud assessment in the visible spectral range. Besides the main objective of hot spot detection the mission has to answer several technological questions of the operation of cooled detectors in space, special aspects of their adaptation to the satellite platform as well as their calibration.

  2. Movement ecology of migration in turkey vultures.

    Science.gov (United States)

    Mandel, J T; Bildstein, K L; Bohrer, G; Winkler, D W

    2008-12-09

    We develop individual-based movement ecology models (MEM) to explore turkey vulture (Cathartes aura) migration decisions at both hourly and daily scales. Vulture movements in 10 migration events were recorded with satellite-reporting GPS sensors, and flight behavior was observed visually, aided by on-the-ground VHF radio-tracking. We used the North American Regional Reanalysis dataset to obtain values for wind speed, turbulent kinetic energy (TKE), and cloud height and used a digital elevation model for a measure of terrain ruggedness. A turkey vulture fitted with a heart-rate logger during 124 h of flight during 38 contiguous days showed only a small increase in mean heart rate as distance traveled per day increased, which suggests that, unlike flapping, soaring flight does not lead to greatly increased metabolic costs. Data from 10 migrations for 724 hourly segments and 152 daily segments showed that vultures depended heavily upon high levels of TKE in the atmospheric boundary layer to increase flight distances and maintain preferred bearings at both hourly and daily scales. We suggest how the MEM can be extended to other spatial and temporal scales of avian migration. Our success in relating model-derived atmospheric variables to migration indicates the potential of using regional reanalysis data, as here, and potentially other regional, higher-resolution, atmospheric models in predicting changing movement patterns of soaring birds under various scenarios of climate and land use change.

  3. Toward conservation of midcontinental shorebird migrations

    Science.gov (United States)

    Skagen, Susan K.; Knopf, Fritz L.

    1993-01-01

    Shorebirds represent a highly diverse group of species, many of which experience tremendous energy demands associated with long-distance migratory flights. Transcontinental migrants are dependant upon dynamic freshwater wetlands for stopover resources essential for replenishment of lipid reserves and completion of migration. Patterns of shorebird migration across midcontinental wetlands were detected from migration reports to American Birds and information provided by U.S. Fish and Wildlife Service national wildlife refuges. Patterns in species composition and abundance varied geographically, emphasizing the uniqueness of different regions to migrating shorebirds. Smaller species and neotropical migrants moved primarily across the Great Plains, whereas larger species and North American migrants predominated in assemblages in the intermountain west. Shorebirds were broadly dispersed in wetland habitats with dynamic water regimes. Whereas populations of shorebirds in coastal system appear to concentrate at sites of seasonally predictable and abundant food resources, we propose that transcontinental shorebirds disperse and use wetlands opportunistically. This migration system exemplifies the need for large-scale, coordinated regional management efforts that recognize the dynamic nature of ecosystem processes.

  4. Possible linkage between neuronal recruitment and flight distance in migratory birds.

    Science.gov (United States)

    Barkan, Shay; Roll, Uri; Yom-Tov, Yoram; Wassenaar, Leonard I; Barnea, Anat

    2016-02-24

    New neuronal recruitment in an adult animal's brain is presumed to contribute to brain plasticity and increase the animal's ability to contend with new and changing environments. During long-distance migration, birds migrating greater distances are exposed to more diverse spatial information. Thus, we hypothesized that greater migration distance in birds would correlate with the recruitment of new neurons into the brain regions involved with migratory navigation. We tested this hypothesis on two Palearctic migrants - reed warblers (Acrocephalus scirpaceus) and turtle doves (Streptopelia turtur), caught in Israel while returning from Africa in spring and summer. Birds were injected with a neuronal birth marker and later inspected for new neurons in brain regions known to play a role in navigation - the hippocampus and nidopallium caudolateral. We calculated the migration distance of each individual by matching feather isotopic values (δ(2)H and δ(13)C) to winter base-maps of these isotopes in Africa. Our findings suggest a positive correlation between migration distance and new neuronal recruitment in two brain regions - the hippocampus in reed warblers and nidopallium caudolateral in turtle doves. This multidisciplinary approach provides new insights into the ability of the avian brain to adapt to different migration challenges.

  5. Isolation and genetic characterization of avian influenza viruses isolated from wild birds in the Azov-Black Sea Region of Ukraine (2001–2012)

    Science.gov (United States)

    Wild bird surveillance for avian influenza virus (AIV) was conducted from 2001 to 2012 in the Azov - Black Sea region of the Ukraine, considered part of the transcontinental wild bird migration routes from northern Asia and Europe to the Mediterranean, Africa, and southwest Asia. A total of 6281 sam...

  6. Divergence of Borrelia burgdorferi sensu lato spirochetes could be driven by the host: diversity of Borrelia strains isolated from ticks feeding on a single bird

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Belfiore, N. M.; Grubhoffer, Libor; Oliver, J. H., Jr.

    2014-01-01

    Roč. 7, JAN 2014 (2014), s. 4 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Borrelia burgdorferi sensu lato * Ixodes minor * bird migration * bird reservoir host * multilocus sequence analysis * multilocus sequence typing * recombinant genotypes * Southeastern United States Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.430, year: 2014

  7. Divergence of Borrelia burgdorferi sensu lato spirochetes could be driven by the host: diversity of Borrelia strains isolated from ticks feeding on a single bird

    Science.gov (United States)

    2014-01-01

    Background The controversy surrounding the potential impact of birds in spirochete transmission dynamics and their capacity to serve as a reservoir has existed for a long time. The majority of analyzed bird species are able to infect larval ticks with Borrelia. Dispersal of infected ticks due to bird migration is a key to the establishment of new foci of Lyme borreliosis. The dynamics of infection in birds supports the mixing of different species, the horizontal exchange of genetic information, and appearance of recombinant genotypes. Methods Four Borrelia burgdorferi sensu lato strains were cultured from Ixodes minor larvae and four strains were isolated from Ixodes minor nymphs collected from a single Carolina Wren (Thryothorus ludovicianus). A multilocus sequence analysis that included 16S rRNA, a 5S-23S intergenic spacer region, a 16S-23S internal transcribed spacer, flagellin, p66, and ospC separated 8 strains into 3 distinct groups. Additional multilocus sequence typing of 8 housekeeping genes, clpA, clpX, nifS, pepX, pyrG, recG, rplB, and uvrA was used to resolve the taxonomic status of bird-associated strains. Results Results of analysis of 14 genes confirmed that the level of divergence among strains is significantly higher than what would be expected for strains within a single species. The presence of cross-species recombination was revealed: Borrelia burgdorferi sensu stricto housekeeping gene nifS was incorporated into homologous locus of strain, previously assigned to B. americana. Conclusions Genetically diverse Borrelia strains are often found within the same tick or same vertebrate host, presenting a wide opportunity for genetic exchange. We report the cross-species recombination that led to incorporation of a housekeeping gene from the B. burgdorferi sensu stricto strain into a homologous locus of another bird-associated strain. Our results support the hypothesis that recombination maintains a majority of sequence polymorphism within Borrelia

  8. Characterizing the International Migration Barriers with a Probabilistic Multilateral Migration Model

    Science.gov (United States)

    Li, Xiaomeng; Xu, Hongzhong; Chen, Jiawei; Chen, Qinghua; Zhang, Jiang; di, Zengru

    2016-09-01

    Human migration is responsible for forming modern civilization and has had an important influence on the development of various countries. There are many issues worth researching, and “the reason to move” is the most basic one. The concept of migration cost in the classical self-selection theory, which was introduced by Roy and Borjas, is useful. However, migration cost cannot address global migration because of the limitations of deterministic and bilateral choice. Following the idea of migration cost, this paper developed a new probabilistic multilateral migration model by introducing the Boltzmann factor from statistical physics. After characterizing the underlying mechanism or driving force of human mobility, we reveal some interesting facts that have provided a deeper understanding of international migration, such as the negative correlation between migration costs for emigrants and immigrants and a global classification with clear regional and economic characteristics, based on clustering of migration cost vectors. In addition, we deconstruct the migration barriers using regression analysis and find that the influencing factors are complicated but can be partly (12.5%) described by several macro indexes, such as the GDP growth of the destination country, the GNI per capita and the HDI of both the source and destination countries.

  9. Projected changes in prevailing winds for transatlantic migratory birds under global warming.

    Science.gov (United States)

    La Sorte, Frank A; Fink, Daniel

    2017-03-01

    A number of terrestrial bird species that breed in North America cross the Atlantic Ocean during autumn migration when travelling to their non-breeding grounds in the Caribbean or South America. When conducting oceanic crossings, migratory birds tend to associate with mild or supportive winds, whose speed and direction may change under global warming. The implications of these changes for transoceanic migratory bird populations have not been addressed. We used occurrence information from eBird (1950-2015) to estimate the geographical location of population centres at a daily temporal resolution across the annual cycle for 10 transatlantic migratory bird species. We used this information to estimate the location and timing of autumn migration within the transatlantic flyway. We estimated how prevailing winds are projected to change within the transatlantic flyway during this time using daily wind speed anomalies (1996-2005 and 2091-2100) from 29 Atmosphere-Ocean General Circulation Models implemented under CMIP5. Autumn transatlantic migrants have the potential to encounter strong westerly crosswinds early in their transatlantic journey at intermediate and especially high migration altitudes, strong headwinds at low and intermediate migration altitudes within the Caribbean that increase in strength as the season progresses, and weak tailwinds at intermediate and high migration altitudes east of the Caribbean. The CMIP5 simulations suggest that, during this century, the likelihood of autumn transatlantic migrants encountering strong westerly crosswinds will diminish. As global warming progresses, the need for species to compensate or drift under the influence of strong westerly crosswinds during the initial phase of their autumn transatlantic journey may be diminished. Existing strategies that promote headwind avoidance and tailwind assistance will likely remain valid. Thus, climate change may reduce time and energy requirements and the chance of mortality or

  10. Migration within China and from China to the USA: the effects of migration networks, selectivity, and the rural political economy in Fujian Province.

    Science.gov (United States)

    Liang, Zai; Chunyu, Miao David

    2013-07-01

    This paper tests a new strategy for simultaneously studying internal migration within, and international migration from, China. Our theoretical discussion draws on ideas from migration-networks theory and studies of the transition to a market-oriented economy. Data collection is modelled on the Mexican Migration Project. We find that education is more important in initiating internal migration than international migration. Second, although the role of migration networks at a community level seems similar to that for Mexico-USA migration, the networks at a family level show a different pattern. Third, there is evidence that internal and international migration are competing options. Finally, we find that individuals with cadres (public officials) in the family are less likely to undertake internal migration, but more likely to participate in international migration, a finding that highlights the continuing significance of the cadres in coastal rural China.

  11. Transport of Ixodid ticks and tick-borne pathogens by migratory birds.

    Directory of Open Access Journals (Sweden)

    Gunnar eHasle

    2013-09-01

    Full Text Available Birds, particularly passerines, can be parasitized by Ixodid ticks, which may be infected with tick-borne pathogens, like Borrelia spp., Babesia spp., Anaplasma, Rickettsia/Coxiella, and tick-borne encephalitis virus. The prevalence of ticks on birds varies over years, season, locality and different bird species. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground. In Europe, the Turdus spp., especially the blackbird, Turdus merula, appears to be most important for harboring ticks. Birds can easily cross barriers, like fences, mountains, glaciers, desserts and oceans, which would stop mammals, and they can move much faster than the wingless hosts. Birds can potentially transport tick-borne pathogens by transporting infected ticks, by being infected with tick-borne pathogens and transmit the pathogens to the ticks, and possibly act as hosts for transfer of pathogens between ticks through co-feeding. Knowledge of the bird migration routes and of the spatial distribution of tick species and tick-borne pathogens is crucial for understanding the possible impact of birds as spreaders of ticks and tick-borne pathogens. Successful colonization of new tick species or introduction of new tick-borne pathogens will depend on suitable climate, vegetation and hosts. Although it has never been demonstrated that a new tick species, or a new tick pathogen, actually has been established in a new locality after being seeded there by birds, evidence strongly suggests that this could occur.

  12. Wild geese do not increase flight behaviour prior to migration.

    Science.gov (United States)

    Portugal, Steven J; Green, Jonathan A; White, Craig R; Guillemette, Magella; Butler, Patrick J

    2012-06-23

    Hypertrophy of the flight muscles is regularly observed in birds prior to long-distance migrations. We tested the hypothesis that a large migratory bird would increase flight behaviour prior to migration, in order to cause hypertrophy of the flight muscles, and upregulate key components of the aerobic metabolic pathways. Implantable data loggers were used to record year-round heart rate in six wild barnacle geese (Branta leucopsis), and the amount of time spent in flight each day was identified. Time in flight per day did not significantly increase prior to either the spring or the autumn migration, both between time periods prior to migration (5, 10 and 15 days), or when compared with a control period of low activity during winter. The lack of significant increase in flight prior to migration suggests that approximately 22 min per day is sufficient to maintain the flight muscles in condition for prolonged long-distance flight. This apparent lack of a requirement for increased flight activity prior to migration may be attributable to pre-migratory mass gains in the geese increasing workload during short flights, potentially prompting hypertrophy of the flight muscles.

  13. Arthropod abundance and seasonal bird use of bottomland forest harvest gaps.

    Energy Technology Data Exchange (ETDEWEB)

    Moorman, Christopher, E.; Bowen, Liessa T.; Kilgo, John, C.; Hanula, James, L.; Horn, Scott; Ulyshen, Michael, D.

    2012-03-01

    We investigated the influence of arthropod abundance and vegetation structure on shifts in avian use of canopy gap, gap edge, and surrounding forest understory in a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. We compared captures of foliage-gleaning birds among locations during four periods (spring migration, breeding, post-breeding, and fall migration). Foliage arthropod densities were greatest in the forest understory in all four seasons, but understory vegetation density was greatest in gaps. Foliage-gleaning bird abundance was positively associated with foliage-dwelling arthropods during the breeding (F = 18.5, P < 0.001) and post-breeding periods (F = 9.4, P = 0.004), and negatively associated with foliage-dwelling arthropods during fall migration (F = 5.4, P = 0.03). Relationships between birds and arthropods were inconsistent, but the arthropod prey base seemed to be least important during migratory periods. Conversely, bird captures were positively correlated with understory vegetation density during all four periods (P < 0.001). Our study suggests high bird abundance associated with canopy gaps during the non-breeding period resulted less from high arthropod food resource availability than from complex understory and midstory vegetation structure.

  14. Water requirements and drinking rates of homing pigeons: A consideration for exposure risk of migratory birds.

    Science.gov (United States)

    Perez, Cristina R; Moye, John K; Pritsos, Chris A

    2017-09-01

    Access to water along a bird's migratory flyway is essential during the vital process of migration. Because of the scarcity of water in some environments, there is potential for migratory birds to encounter and drink from contaminated bodies of water. Ingestion of contaminated water may cause injury and compromise flying ability, leading to a disruption of migration. To determine injury to birds from potential exposure, it is essential to know not only the concentration of a given contaminant in the water but also the quantity and rate of water consumption by the birds. Homing pigeons (Columba livia) were used in a series of experiments to determine differences in drinking behavior after various flights and after periods of resting. Results from the present study demonstrate that homing pigeons' water consumption is dramatically different when assessed according to activity, flight distance, and time elapsed after flight. This suggests that the drinking rates of birds during migration are extremely important and much greater than estimated using traditional exposure assessment procedures. Thus, exposure to contaminants via drinking water may be greatly underestimated, and the rate of water consumption should be considered when estimating potential exposure risk to avian species. Integr Environ Assess Manag 2017;13:870-876. © 2017 SETAC. © 2017 SETAC.

  15. Hippocampal Astrocytes in Migrating and Wintering Semipalmated Sandpiper Calidris pusilla

    Directory of Open Access Journals (Sweden)

    Dario Carvalho-Paulo

    2018-01-01

    Full Text Available Seasonal migratory birds return to the same breeding and wintering grounds year after year, and migratory long-distance shorebirds are good examples of this. These tasks require learning and long-term spatial memory abilities that are integrated into a navigational system for repeatedly locating breeding, wintering, and stopover sites. Previous investigations focused on the neurobiological basis of hippocampal plasticity and numerical estimates of hippocampal neurogenesis in birds but only a few studies investigated potential contributions of glial cells to hippocampal-dependent tasks related to migration. Here we hypothesized that the astrocytes of migrating and wintering birds may exhibit significant morphological and numerical differences connected to the long-distance flight. We used as a model the semipalmated sandpiper Calidris pusilla, that migrates from northern Canada and Alaska to South America. Before the transatlantic non-stop long-distance component of their flight, the birds make a stopover at the Bay of Fundy in Canada. To test our hypothesis, we estimated total numbers and compared the three-dimensional (3-D morphological features of adult C. pusilla astrocytes captured in the Bay of Fundy (n = 249 cells with those from birds captured in the coastal region of Bragança, Brazil, during the wintering period (n = 250 cells. Optical fractionator was used to estimate the number of astrocytes and for 3-D reconstructions we used hierarchical cluster analysis. Both morphological phenotypes showed reduced morphological complexity after the long-distance non-stop flight, but the reduction in complexity was much greater in Type I than in Type II astrocytes. Coherently, we also found a significant reduction in the total number of astrocytes after the transatlantic flight. Taken together these findings suggest that the long-distance non-stop flight altered significantly the astrocytes population and that morphologically distinct astrocytes

  16. Unzipping bird feathers.

    Science.gov (United States)

    Kovalev, Alexander; Filippov, Alexander E; Gorb, Stanislav N

    2014-03-06

    The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understanding mechanics of the entire feather structure. This study was undertaken to estimate the separation force of single hooklets and their arrays using force measurement of an unzipping feather vane. The hooklets usually separate in some number synchronously (20 on average) with the highest observed separation force of 1.74 mN (average force 0.27 mN), whereas the single hooklet separation force was 14 μN. A simple numerical model was suggested for a better understanding of zipping and unzipping behaviour in feathers. The model demonstrates features similar to those observed in experiments.

  17. Conservation of wading birds

    Science.gov (United States)

    Kushlan, J.A.

    1996-01-01

    The conservation and management of wading birds has received considerable attention over the past twenty years, through research, population monitoring, habitat protection, and through activities of specialist groups devoted to all three groups, the herons, ibises and allies, and flamingos. While populations are best known in North America, greatest advances in knowledge may have come in Australasia. The status of most species and many populations is now sufficiently known to allow assessment of risk. Conservation and management techniques allow creation of global and regional action plans for conservation of many species. Global action plans are being developed, but few regional plans have been undertaken. Management of nesting sites is now particularly well appreciated. Although known in broad stroke, much remains to be learned about managing feeding habitat. Problems related to disturbance, conflict with humans, habitat loss, contaminants and other environmental stresses remain for some species and many populations. New challenges lie in creating conservation action that account for genetic stocks.

  18. Understanding the biological concept "bird": A kindergarten case study

    Science.gov (United States)

    Buchholz, Dilek

    The purpose of this qualitative, multiple case study of 14 students in a metropolitan public school in the Deep South was to find out, during a period of three months, what these kindergarten-aged children knew about birds, whether this knowledge represented current scientific thought, if such science instruction meaningfully affected their prior knowledge, and if so, what the factors during instruction that seemed to influence their understanding of the concept of bird were. The research was conducted in three phases; preinstruction interviews, instruction, and postinstruction interviews. The theoretical framework for this research was based on the Human Constructivism theory of learning (Mintzes, Wandersee and Novak, 1997). Instructional materials consisted of carefully chosen books (both fiction and non-fiction), guest speakers, field trips, a live bird in the classroom, students' observation journals, teacher-made classification and sorting activities, and picture-based concept maps. The findings suggest that young children's knowledge of birds was limited chiefly to birds' anatomical and morphological characteristics, with repeated references being made by the children to human characteristics. There was a positive, significant difference in young children's pre- and postinstruction scientific knowledge of birds. Although performance varied from child to child after instruction, most children were able to identify some common birds by name. Just one child resisted conceptual change. Kindergarten children's basic knowledge of bird behavior was limited to flight and eating. Although the children had more conceptual knowledge at the end, understanding still appeared to be shallow. The children did develop their skill in observing markedly. It also became evident that these kindergarten children needed more (a) experience in asking questions, (b) practice in techniques of visual representation, and (c) language development in order to be able to explain what they

  19. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

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

    Science.gov (United States)

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

    2012-01-01

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