نتایج جستجو برای: new wintering population

تعداد نتایج: 2458768  

Journal: :Science 2005
Stuart Bearhop Wolfgang Fiedler Robert W Furness Stephen C Votier Susan Waldron Jason Newton Gabriel J Bowen Peter Berthold Keith Farnsworth

There have been numerous recent observations of changes in the behavior and dynamics of migratory bird populations, but the plasticity of the migratory trait and our inability to track small animals over large distances have hindered investigation of the mechanisms behind migratory change. We used habitat-specific stable isotope signatures to show that recently evolved allopatric wintering popu...

Journal: :Proceedings. Biological sciences 2004
D Ryan Norris Peter P Marra T Kurt Kyser Thomas W Sherry Laurene M Ratcliffe

Identifying the factors that control population dynamics in migratory animals has been constrained by our inability to track individuals throughout the annual cycle. Using stable carbon isotopes, we show that the reproductive success of a long-distance migratory bird is influenced by the quality of habitat located thousands of kilometres away on tropical wintering grounds. For male American red...

Journal: :Ecological indicators 2014
Eli S Bridge Jeffrey F Kelly Xiangming Xiao John Y Takekawa Nichola J Hill Mat Yamage Enam Ul Haque Mohammad Anwarul Islam Taej Mundkur Kiraz Erciyas Yavuz Paul Leader Connie Y H Leung Bena Smith Kyle A Spragens Kurt Vandegrift Parviez R Hosseini Samia Saif Samiul Mohsanin Andrea Mikolon Ausrafal Islam Acty George Balachandran Sivananinthaperumal Peter Daszak Scott H Newman

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 migrato...

Journal: :The American naturalist 2011
James S Sedinger Jason L Schamber David H Ward Christopher A Nicolai Bruce Conant

We used observations of individually marked female black brant geese (Branta bernicla nigricans; brant) at three wintering lagoons on the Pacific coast of Baja California-Laguna San Ignacio (LSI), Laguna Ojo de Liebre (LOL), and Bahía San Quintín (BSQ)-and the Tutakoke River breeding colony in Alaska to assess hypotheses about carryover effects on breeding and distribution of individuals among ...

Journal: :Proceedings. Biological sciences 2004
Silke Nebel Alison Cloutier Graham J Thompson

Population sex ratios in monogamous birds are often male biased. One factor that can affect population sex ratios is sex-biased predation. However, most estimates of sex-biased predation in birds have focused on species with obvious sexual colour dimorphism or body size dimorphism. Data on sexually monomorphic birds are generally lacking. In the present study, we adopt a PCR-based sexing proced...

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