نتایج جستجو برای: new wintering population

تعداد نتایج: 2458768  

2003
Kristin L. Laidre Mads Peter Heide-Jørgensen Rune Dietz Roderick C. Hobbs Ole A. Jørgensen

Variation in resource selection among sub-populations may elucidate differences in fitness and life history strategies. Specifically for top marine predators, differences in movements and behavior may result from responses to variation in a patchy, dynamic environment. Satellite-linked time-depth recorders (SLTDRs) were used to examine differences in narwhal Monodon monoceros diving behavior an...

Journal: :Ecotoxicology 2010
Michael A Yates Mark R Fuller Charles J Henny William S Seegar Jaqueline Garcia

Locations of contaminant exposure for nesting migratory species are difficult to fully understand because of possible additional sources encountered during migration or on the wintering grounds. A portion of the migratory white-faced ibis (Plegadis chihi) nesting at Carson Lake, Nevada continues to be exposed to dichloro-diphenyldichloro-ethylene (DDE) with no change, which is unusual, observed...

2018
Diann J. Prosser Changqing Ding R. Michael Erwin Taej Mundkur Jeffery D. Sullivan Erle C. Ellis

Background: A number of conservation and societal issues require understanding how species are distributed on the landscape, yet ecologists are often faced with a lack of data to develop models at the resolution and extent desired, resulting in inefficient use of conservation resources. Such a situation presented itself in our attempt to develop waterfowl distribution models as part of a multi-...

2000
D. A. CLARK W. CARTER B. WALSH C. D. WAUGH

Concern at the effect of winter pasture residuals on pasture productivity led to the comparison of different wintering systems at the DRC No. 3 Dairy from May-December 1993. Three farmlets were designed to have 2000 kg DM/ha average farm cover at calving, but with pastures grazed to either 900, 1400 or 1800 kg DM/ha at least once during the winter. A fourth farmlet was spelled from grazing from...

2017
Viviane Hénaux Mark P. Vrtiska Keith A. Hobson

Increases in Snow Goose (Chen caerulescens) populations and large-scale habitat changes in North America have contributed to the concentration of migratory waterfowl on fewer wetlands, reducing resource availability, and enhancing risks of disease transmission. Predicting wintering locations of migratory individuals is critical to guide wildlife population management and habitat restoration. We...

Journal: :Proceedings. Biological sciences 2014
Christiane Trierweiler Raymond H G Klaassen Rudi H Drent Klaus-Michael Exo Jan Komdeur Franz Bairlein Ben J Koks

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 pop...

2016
RUBEN LIMIÑANA BEATRIZ ARROYO JULIEN TERRAUBE MICHAEL MCGRADY FRANÇOIS MOUGEOT

Understanding the ecology of migratory birds during the non-breeding season is necessary for ensuring their conservation. Using satellite telemetry data we describe winter ranging behaviour and movements of pallid harriers Circus macrourus that bred in Kazakhstan. We developed an ecological niche model for the species in Africa, to identify the most suitable wintering areas for pallid harriers ...

2016
Ivan Maggini Benjamin Metzger Maren Voss Christian C Voigt Franz Bairlein

BACKGROUND Describing migratory connectivity in mobile animals is crucial for understanding the selective pressures acting on different populations throughout their life cycle. Tracking single individuals has provided valuable data, but for most species the data available are still spurious and usually limited to a few individuals. Since different populations of migratory birds can be distingui...

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