Polar bears are inefficient predators of seabird eggs [PDF]
Royal Society Open Science, 2021 Climate-mediated sea-ice loss is disrupting the foraging ecology of polar bears (Ursus maritimus) across much of their range. As a result, there have been increased reports of polar bears foraging on seabird eggs across parts of their range.
H Grant Gilchrist +2 more
exaly +4 more sources
A colonial-nesting seabird shows limited heart rate responses to natural variation in threats of polar bears [PDF]
Royal Society Open Science, 2023 Several predator–prey systems are in flux as an indirect result of climate change. In the Arctic, earlier sea-ice loss is driving polar bears (Ursus maritimus) onto land when many colonial nesting seabirds are breeding.
Erica A. Geldart +5 more
doaj +2 more sources
Wildlife Letters, 2023 This review explores whether recent hybridization events between polar bears (Ursus maritimus) and grizzly bears (Ursus arctos horribilis) will eventually contribute to the extinction of the modern polar bear.
Craig L. Shafer
doaj +2 more sources
Distinct fecal microbiome between wild and habitat-housed captive polar bears (Ursus maritimus): Impacts of captivity and dietary shifts. [PDF]
PLoS ONEUnderstanding the gut microbiome of polar bears can shed light on the effects of climate change-induced prolonged ice-free seasons on their health and nutritional status as a sentinel species.
Jing Lu +4 more
doaj +2 more sources
Analyses of key genes involved in Arctic adaptation in polar bears suggest selection on both standing variation and de novo mutations played an important role [PDF]
BMC Genomics, 2020 Background Polar bears are uniquely adapted to an Arctic existence. Since their relatively recent divergence from their closest living relative, brown bears, less than 500,000 years ago, the species has evolved an array of novel traits suited to its ...
Jose Alfredo Samaniego Castruita +2 more
doaj +2 more sources
The Adrenal Cortisol Response to Increasing Ambient Temperature in Polar Bears (Ursus maritimus) [PDF]
Animals, 2022 Our objective was to identify the upper ambient temperature threshold that triggers an increase in cortisol in response to increased thermoregulatory demands in polar bears.
Emily M. Leishman +10 more
doaj +2 more sources
Land-based foraging by polar bears reveals sexual conflict outside mating season [PDF]
Scientific ReportsAccording to sexual selection theory, the sexes are faced with opposing evolutionary goals. Male fitness benefits from access to females, whereas female fitness is constrained by food resources and safety for themselves and their offspring.
Jouke Prop +5 more
doaj +2 more sources
Telemetry without collars: performance of fur- and ear-mounted satellite tags for evaluating the movement and behaviour of polar bears [PDF]
Animal BiotelemetryThe study of animal movement provides insights into underlying ecological processes and informs analyses of behaviour and resource use, which have implications for species management and conservation.
Tyler R. Ross +10 more
doaj +2 more sources
Laparoscopic Evaluation of the Reproductive Tract in Two Female Polar Bears (Three Procedures) (Ursus maritimus) [PDF]
LifePolar bears (Ursus maritimus) face a number of challenges that threaten the survival of the species. Captive breeding represents one essential facet of species conservation, but aspects of the polar bear’s reproductive physiology, such as follicle ...
Ellison D. Aldrich +7 more
doaj +2 more sources
Genomic evidence for island population conversion resolves conflicting theories of polar bear evolution. [PDF]
PLoS Genetics, 2013 Despite extensive genetic analysis, the evolutionary relationship between polar bears (Ursus maritimus) and brown bears (U. arctos) remains unclear. The two most recent comprehensive reports indicate a recent divergence with little subsequent admixture ...
James A Cahill +10 more
doaj +1 more source