نتایج جستجو برای: new wintering population

تعداد نتایج: 2458768  

2012
Susanne Åkesson Raymond Klaassen Jan Holmgren James W. Fox Anders Hedenström

The tracking of small avian migrants has only recently become possible by the use of small light-level geolocators, allowing the reconstruction of whole migration routes, as well as timing and speed of migration and identification of wintering areas. Such information is crucial for evaluating theories about migration strategies and pinpointing critical areas for migrants of potential conservati...

Journal: :Molecular ecology 2007
Austin L Hughes Mary Ann K Hughes

Nucleotide sequence diversity at mitochondrial protein-coding loci from 72 species of birds from different geographical regions was analysed in order to test the hypothesis that temperate zone species show population genetic effects of past glaciation. Temperate zone species showed reduced nucleotide diversity in comparison to tropical mainland species, suggesting that the latter have long-term...

2004
Inga F. Sidor Mark A. Pokras Andrew R. Major Kate M. Taylor Rose M. Miconi

Diagnostic findings are presented on 522 common loons (Gavia immer) found dead or moribund in New England (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont, USA) between 1987 and 2000. Common loon numbers and range in New England have decreased from historic levels over the last century due to a number of proposed factors. Goals of this study were to identify and cate...

Journal: :Proceedings. Biological sciences 2004
Allan J Baker Patricia M González Theunis Piersma Lawrence J Niles Inês de Lima Serrano do Nascimento Philip W Atkinson Nigel A Clark Clive D T Minton Mark K Peck Geert Aarts

Most populations of migrant shorebirds around the world are in serious decline, suggesting that vital condition-dependent rates such as fecundity and annual survival are being affected globally. A striking example is the red knot (Calidris canutus rufa) population wintering in Tierra del Fuego, which undertakes marathon 30,000 km hemispheric migrations annually. In spring, migrant birds forage ...

2017
Thomas K Lameris Femke Jochems Alexandra J van der Graaf Mattias Andersson Juul Limpens Bart A Nolet

During spring migration, herbivorous waterfowl breeding in the Arctic depend on peaks in the supply of nitrogen-rich forage plants, following a "green wave" of grass growth along their flyway to fuel migration and reproduction. The effects of climate warming on forage plant growth are expected to be larger at the Arctic breeding grounds than in temperate wintering grounds, potentially disruptin...

2017
Nara Gyzely de Morais Magalhães Cristovam Guerreiro Diniz Daniel Guerreiro Diniz Ediely Pereira Henrique Patrick Douglas Corrêa Pereira Isis Ananda Matos Moraes Mauro André Damasceno de Melo David Francis Sherry Cristovam Wanderley Picanço Diniz

Long distance migratory birds find their way by sensing and integrating information from a large number of cues in their environment. These cues are essential to navigate over thousands of kilometers and reach the same breeding, stopover, and wintering sites every year. The semipalmated sandpiper (Calidris pusilla) is a long-distance migrant that breeds in the arctic tundra of Canada and Alaska...

Journal: :The Iowa Review 1977

2016
Yuzhan Yang Aibin Zhan Lei Cao Fanjuan Meng Wenbin Xu

Food availability and diet selection are important factors influencing the abundance and distribution of wild waterbirds. In order to better understand changes in waterbird population, it is essential to figure out what they feed on. However, analyzing their diet could be difficult and inefficient using traditional methods such as microhistologic observation. Here, we addressed this gap of know...

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