27 hasil untuk "David J. Yurkowski"
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Artikel Jurnal Teks lengkap
A temporal shift in trophic diversity among a predator assemblage in a warming Arctic
Climate change is leading to northward shifts in species distributions that is altering interspecific interactions at low- and mid-trophic levels. However, little attention has been focused on the effects of redistributions of species on the trophic ecology of a high trophic-level predator…
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Spring distribution of ringed seals (Pusa hispida) in Eclipse Sound and Milne Inlet, Nunavut: implications for potential ice-breaking activities
Resource development in Arctic waters is proceeding rapidly leading to increased interactions with Arctic wildlife. As sea ice extent decreases, the demand for shipping and ice-breaking operations will expand into winter and spring with greater impact on ice-dependent pinnipeds. However, knowledge…
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Artikel Jurnal
Comparing infrared imagery to traditional methods for estimating ringed seal density
ABSTRACT When conducting aerial surveys of wildlife populations, a number of animals go undetected by observers. The use of infrared imagery may offer a solution to improve detection rates and reduce visibility bias. Our objective was to compare the use of an infrared camera system with traditional…
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Multi-dietary tracer approach reveals little overlap in foraging ecology between seasonally sympatric ringed and harp seals in the high Arctic
The rapid rate of climate change in the Arctic is causing broad-scale changes to the physical environment and biological communities. Characterizing the foraging ecology and habitat use of Arctic marine top predators of high ecological and cultural significance is essential to our understanding of…
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Artikel Jurnal
Patterns of uncertainty in life-history and extinction risk for Arctic vertebrates
Conserving Arctic wildlife will be challenging given the ongoing environmental changes in the region. In addition, there is a lack of fundamental biological information for many Arctic species, including a dearth of knowledge surrounding conservation threats and the risk of extinction. In this…
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Artikel Jurnal Teks lengkap
Demographic, ecological, and physiological responses of ringed seals to an abrupt decline in sea ice availability
To assess whether demographic declines of Arctic species at the southern limit of their range will be gradual or punctuated, we compared large-scale environmental patterns including sea ice dynamics to ringed seal (Pusa hispida) reproduction, body condition, recruitment, and stress in Hudson Bay…
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Artikel Jurnal
Larger body size leads to greater female beluga whale ovarian reproductive activity at the southern periphery of their range
Abstract Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the…
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Artikel Jurnal
Biologging reveals rapid movements of harbour seals between freshwater and marine habitats in the subarctic
Biologging tools can provide invaluable information on the movement and behaviour of animals, facilitating the elucidation of ecological dynamics, especially for wide-ranging species, and supporting conservation and management efforts. Harbour seals (Phoca vitulina) exhibit extensive habitat…
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Artikel Jurnal
Variation in Ringed Seal (Pusa hispida) Density Along a Latitudinal Gradient of Sea‐Ice Conditions
ABSTRACT Anthropogenic climate warming is triggering poleward species redistributions, highlighting the importance of understanding how species distributions and abundance vary along latitudinal gradients. Ringed seals (Pusa hispida) rely on sea ice as habitat during key periods of their life…
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Narwhal (Monodon monoceros) detection by infrared flukeprints from aerial survey imagery
Abstract Visual and observer aerial surveys are important for monitoring wildlife populations but are subject to visibility biases where animals may go undetected. The use of infrared technology in aerial surveys has the potential to reduce visibility biases, both when recording data and in the…
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Artikel Jurnal Teks lengkap
High contributions of sea ice derived carbon in polar bear (Ursus maritimus) tissue.
Polar bears (Ursus maritimus) rely upon Arctic sea ice as a physical habitat. Consequently, conservation assessments of polar bears identify the ongoing reduction in sea ice to represent a significant threat to their survival. However, the additional role of sea ice as a potential, indirect, source…
Juga tersedia di: PLOS
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Artikel Jurnal
Marine mammal biodiversity and rare narwhal (Monodon monoceros) observations near northern Ellesmere Island, Canada
Abstract A climate‐driven decline of sea ice has increased international interest in understanding the ecology of seldom studied high‐Arctic regions projected to retain the last remnants of summer sea ice. Arctic marine mammals are vulnerable to future environmental change due to their high…
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Artikel Jurnal
Long-distance movements and associated diving behaviour of ringed seals (Pusa hispida) in the eastern Canadian Arctic
Animal distribution and movement facilitate energy and nutrient transfer within and between regions, thus influencing ecosystem structure and function. Ringed seals (Pusa hispida (Schreber, 1775)) have been observed making sustained, extensive migrations (>1000 km) in the western Canadian Arctic…
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An introduction to statistical models used to characterize species-habitat associations with animal movement data
Abstract Understanding species-habitat associations is fundamental to ecological sciences and for species conservation. Consequently, various statistical approaches have been designed to infer species-habitat associations. Due to their conceptual and mathematical differences, these methods can…
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Artikel Jurnal
Biomarkers in Ringed Seals Reveal Recent Onset of Borealization in the High- Compared to the Mid-Latitude Canadian Arctic
Warming of the Arctic has resulted in environmental and ecological changes, termed borealization, leading to the northward shift of temperate species. Borealization has occurred across all trophic levels, altering the structure of the food web. The onset and rate of borealization likely varies with…
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Artikel Jurnal
Black-legged kittiwakes (Rissa tridactyla) readily consume Arctic cod (Boreogadus saida) in the Canadian Arctic: insights from stomach content and stable isotope analyses
The Arctic is undergoing rapid declines in sea ice and changes in Arctic ecosystems. The diet of one of the Arctic’s most abundant seabirds, the black-legged kittiwake (Rissa tridactyla), has been used as an indicator of ecosystem changes in the European Arctic, yet little is known about their diet…
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Artikel Jurnal
Spatial variation in carbon source use and trophic position of ringed seals across a latitudinal gradient of sea ice
Anthropogenic climate change is causing changes to the Arctic sea-ice system with implications for the magnitude and timing of Arctic pelagic and ice-associated (sympagic) primary production that influences food web interactions. Ringed seals (Pusa hispida) are generalist predators that, as a…
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Artikel Jurnal
Microbiome baseline for an Arctic sentinel: spatial patterning of nasal and anal microbiomes in ringed seals
IntroductionRinged seals (Pusa hispida) are sentinel species of Arctic change, yet baseline microbiome data across their circumpolar range remain limited.MethodsWe profiled nasal and anal microbiomes from 90 free-ranging ringed seals across eight Arctic and sub-Arctic locations in Canada using 16S…
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Artikel Jurnal
Linking movement and dive data to prey distribution models: new insights in foraging behaviour and potential pitfalls of movement analyses
Abstract Background Animal movement data are regularly used to infer foraging behaviour and relationships to environmental characteristics, often to help identify critical habitat. To characterize foraging, movement models make a set of assumptions rooted in theory, for example, time spent foraging…