Knowledge Tree
polar bear
Also known as: polar bear, polar bears
Facts (31)
Sources
A review of climate change impacts on migration patterns of marine ... frontiersin.org Oct 25, 2024 28 facts
measurementIn the southern Beaufort Sea, polar bears remaining on land exhibit annual utilization distributions that are 88% smaller than those of polar bears remaining on sea ice, which have increased their home range sizes and migrate longer distances, according to Pagano et al. (2021).
referenceOlson et al. (2017) used collar temperature sensor data to reveal long-term patterns in southern Beaufort Sea polar bear den distribution on pack ice and land.
referencePagano, A. M., Durner, G. M., Atwood, T. C., and Douglas, D. C. published the paper 'Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea' in Ecosphere in 2021.
claimSome polar bear populations exhibit exceptions to standard migration patterns, such as denning on sea ice in the Beaufort Sea and a portion of the Barents Sea population remaining ashore year-round.
referenceRode et al. (2015) published a study titled 'Increased land use by Chukchi Sea polar bears in relation to changing sea ice conditions' in PLoS ONE.
referenceBiddlecombe et al. (2021) investigated the effects of sea ice fragmentation on the migratory movements of polar bears in Hudson Bay.
referenceA 2017 study by Hamilton et al. analyzed climate change impacts on coastal space use by polar bears and ringed seals in an Arctic predator-prey system.
claimThe disappearance of summer offshore sea ice in Baffin Bay during the 2000s led to reduced movement rates for polar bears compared to the 1990s, according to Laidre et al. (2018).
claimPolar bears in Svalbard no longer migrate south to islands like Hopen Island for denning because sea ice no longer forms that far south in the late fall and early winter, as noted by Andersen et al. (2012).
referenceAtwood et al. (2021) published a study titled 'Long-term variation in polar bear body condition and maternal investment relative to a changing environment' in Global Ecology and Conservation, volume 32, article e01925.
referenceMcKinney et al. (2013) studied the effects of global climate change on the long-term feeding ecology and contaminant exposure levels of East Greenland polar bears.
claimHooded seals off the east coast of Greenland are experiencing increased rates of polar bear predation because the drift ice now occurs much closer to the shore than it did in previous decades.
claimPolar bears in Hudson Bay move onto land when wind conditions and temperatures cause early seasonal ice breakup, demonstrating how ice concentration, wind speed, and wind direction interact to affect migratory movements.
claimPolar bears in Hudson Bay are spending more time on sea ice that is distributed farther north than in the past, with migrations to and from coastal areas tightly coupled to sea-ice concentrations and fragmentation, according to Miller et al. (2022) and Biddlecombe et al. (2021).
referenceLaidre et al. (2018) studied changes in winter and spring resource selection by polar bears (Ursus maritimus) in Baffin Bay over two decades of sea-ice loss.
claimMiller et al. (2022) studied the autumn migration phenology of polar bears (Ursus maritimus) in Hudson Bay, Canada.
claimThe polar bear population in the southern Beaufort Sea has shown a trend toward less denning on sea ice and more denning on land, as documented by Olson et al. (2017).
claimFemale polar bears generally migrate between foraging areas on offshore sea ice during the summer and denning areas on land for the winter, with landfast sea ice serving as an important spring foraging area for mothers with young-of-the-year cubs.
referenceBengtsson et al. (2021) documented the distribution and habitat characteristics of pinnipeds and polar bears in the Svalbard Archipelago between 2005 and 2018.
referenceAndersen et al. (2012) published a study titled 'Polar bear (Ursus maritimus) maternity den distribution in Svalbard, Norway' in Polar Biology, volume 35, pages 499–508.
claimPolar bear migrations involve significantly more swimming time in areas where sea ice has declined, which has energetic implications for individuals, according to Pilfold et al. (2017).
referenceAars et al. (2017) published a study titled 'The number and distribution of polar bears in the western Barents Sea' in Polar Research, volume 36, article 1374125.
referenceBohart et al. (2021) analyzed the migration dynamics of polar bears (Ursus maritimus) in western Hudson Bay.
referencePilfold, N. W., McCall, A., Derocher, A. E., Lunn, N. J., and Richardson, E. published the paper 'Migratory response of polar bears to sea ice loss: to swim or not to swim' in Ecography in 2017.
claimIvory gulls forage on sea ice by scavenging on the remains of kills made by polar bears (Ursus maritimus) or polar foxes (Vulpes lagopus).
referenceEscajeda et al. (2018) published 'Identifying shifts in maternity den phenology and habitat characteristics of polar bears (Ursus maritimus) in Baffin Bay and Kane Basin' in Polar Biology, analyzing changes in polar bear denning behavior.
claimChukchi Sea polar bears are moving onto land for longer time periods due to reduced sea-ice cover, as reported by Rode et al. (2015; 2022).
claimReductions in sea ice are causing phenological changes in polar bear movement patterns, with some bears moving onto land earlier in the fall and departing later in the spring.
How Climate Change is Changing Animal Habits neefusa.org Oct 4, 2023 2 facts
claimMelting Arctic ice reduces polar bear access to habitat and seal hunting ranges.
claimIn 2008, polar bears were the first species listed as 'threatened' under the Endangered Species Act due to the impacts of climate change, specifically the melting of Arctic ice which reduces their access to habitat and seal hunting ranges.
Dualism (Stanford Encyclopedia of Philosophy/Winter 2016 Edition) plato.stanford.edu Aug 19, 2003 1 fact
claimFrank Jackson (1982) argues that mental states are evolutionary by-products of brain states, using the analogy that the heaviness of a polar bear's coat is a side effect of the coat's warmth-providing function.