64 hasil untuk "Steven H Ferguson"
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Artikel Jurnal
The relationship between weather and caribou productivity for the La-Poile Caribou Herd, Newfoundland
To describe the relationship between weather and caribou (Rangifer tarandus) productivity, we compared weather variables (snow on ground, winter temperature and measures of growing season) with measures of productivity (calves seen by hunters, calves and yearlings in the harvest and percent calves…
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Artikel Jurnal
Validation of dentine deposition rates in beluga whales by interspecies cross dating of temporal δ13C trends in teeth
Isotopic time series from sequentially sampled growth layer groups (GLGs) in marine mammal teeth can be combined to build chronologies allowing assessment of isotopic variation in marine ecosystems. Synchronous recording of baseline isotopic variation across dentinal GLGs of species with temporal…
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Artikel Jurnal
Fractal measures of female caribou movements
Understanding caribou movement during short-term searches for specific habitats, potential mates, and refugia against predators can help resolve ecological questions on how individual caribou perceive their environment. We used measures of fractal dimension and standardized pathlength to compare…
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Artikel Jurnal
Killer whale (Orcinus orca) photo-identification in the eastern Canadian Arctic
We identified individual killer whales (Orcinus orca) using recent (2004–09) photographs to obtain a minimum count of whales that use eastern Canadian Arctic waters. Fifty-three individuals were identified from nine different sightings; 11 individuals from western Hudson Bay sightings and 42 from…
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Artikel Jurnal
Observation of marine mammal and bird interactions focused around a commercial fishing vessel in central Baffin Bay, Nunavut
A detailed account of a variety of species foraging on Greenland halibut (Reinhardtius hippoglossoides (Walbaum, 1792)) fisheries discards associated with a commercial fishing vessel in central Baffin Bay, Nunavut, Canada is presented. Species observed included three marine mammals: northern…
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Artikel Jurnal Teks lengkap
Amino acid δ15N differences consistent with killer whale ecotypes in the Arctic and Northwest Atlantic.
Ecotypes are groups within a species with different ecological adaptations than their conspecifics. Eastern North Pacific (ENP) killer whale (Orcinus orca) ecotypes differ in their diet, behavior, and morphology, but the same is not known for this species in the eastern Canadian Arctic (ECA) and…
Juga tersedia di: PLOS
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Artikel Jurnal
Spatio-temporal summer distribution of Cumberland Sound beluga whales (Delphinapterus leucas) in Clearwater Fiord, Nunavut, Canada
The Cumberland Sound (Nunavut, Canada) beluga whale (Delphinapterus leucas (Pallas, 1776)) population has been designated as threatened and updated biological information about summer distribution is required for a sound recovery plan. Variation in aerial survey counts are speculated to occur due…
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Artikel Jurnal Teks lengkap
Assessing seasonal spatial segregation by age class of beluga whales ( Delphinapterus leucas ) in Western Hudson Bay estuaries
Segregation of adult males from adult females and immature animals is known to occur in some beluga whale populations, but it is unclear if such segregation occurs in Hudson Bay, where the largest summering population in the world is found. Using imagery from a photographic aerial survey conducted…
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Artikel Jurnal
Intraspecific and temporal variability in the diet composition of female polar bears in a seasonal sea ice regime
Predator foraging behaviour is influenced by a suite of intrinsic and extrinsic factors, including energetic requirements, resource availability, and habitat conditions. Polar bears (Ursus maritimus) are specialized predators of marine mammals and are adapted to a seasonal sea ice regime in much of…
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Artikel Jurnal
Comparison of δ13C and δ15N of ecologically relevant amino acids among beluga whale tissues
Abstract Ecological applications of compound-specific stable isotope analysis (CSIA) of amino acids (AAs) include 1) tracking carbon pathways in food webs using essential AA (AAESS) δ13C values, and 2) estimating consumer trophic position (TP) by comparing relative differences of ‘trophic’ and…
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Artikel Jurnal
Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada
Climate warming and associated physical and biological changes will likely force widespread species redistribution, particularly in polar environments. However, tracking such distributional shifts is difficult. The dietary habits of apex predators, like polar bears (Ursus maritimus), may provide…
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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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Artikel Jurnal
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
How toothed whales divide up the world: phylogeny and ecology shape life-history strategies of odontocetes
Abstract Background Understanding the evolution of life-history strategies within a taxonomic guild offers critical insights into how species allocate energy toward growth, reproduction, and survival in response to environmental pressures. We examined 42 odontocete whale species using six key…
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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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Artikel Jurnal Teks lengkap
A Review of Circumpolar Arctic Marine Mammal Health—A Call to Action in a Time of Rapid Environmental Change
The impacts of climate change on the health of marine mammals are increasingly being recognised. Given the rapid rate of environmental change in the Arctic, the potential ramifications on the health of marine mammals in this region are a particular concern. There are eleven endemic Arctic marine…
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Artikel Jurnal
Distributions of Arctic and Northwest Atlantic killer whales inferred from oxygen isotopes
Abstract Killer whales (Orcinus orca) are distributed widely in all oceans, although they are most common in coastal waters of temperate and high-latitude regions. The species’ distribution has not been fully described in the northwest Atlantic (NWA), where killer whales move into seasonally…
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Artikel Jurnal
Amino acid δ15N underestimation of cetacean trophic positions highlights limited understanding of isotopic fractionation in higher marine consumers
Abstract Compound‐specific stable isotope analysis (CSIA) of amino acids (AAs) has been rapidly incorporated in ecological studies to resolve consumer trophic position (TP). Differential 15N fractionation of “trophic” AAs, which undergo trophic 15N enrichment, and “source” AAs, which undergo…
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Artikel Jurnal
Pilot study: decoding the skin microbiome of bowhead (Balaena mysticetus) and killer whales (Orcinus orca) in Nunavut, Canada
Given the increasing challenges that Arctic cetaceans face, it is critical to investigate novel methods for assessing their health. Skin microbiomes have emerged as a promising method of detecting health issues that can help guide conservation efforts for free-ranging cetaceans. This study…