Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes

  title={Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes},
  author={Anthony S. Fischbach and Steven C. Amstrup and David C. Douglas},
  journal={Polar Biology},
Polar bears (Ursus maritimus) in the northern Alaska region den in coastal areas and on offshore drifting ice. We evaluated changes in the distribution of polar bear maternal dens between 1985 and 2005, using satellite telemetry. We determined the distribution of maternal dens occupied by 89 satellite collared female polar bears between 137°W and 167°W longitude. The proportion of dens on pack ice declined from 62% in 1985–1994 to 37% in 1998–2004 (P = 0.044) and among pack ice dens fewer… 
Changes in winter and spring resource selection by polar bears Ursus maritimus in Baffin Bay over two decades of sea-ice loss
It is indicated that significant changes in available sea-ice habitat and habitat use in Baffin Bay have occurred since the mid-1990s and this subpopulation will likely experience negative population-level impacts related to a changing climate in the coming decades.
Polar Bear Distribution and Habitat Association Reflect Long-term Changes in Fall Sea Ice Conditions in the Alaskan Beaufort Sea
The polar bear ( Ursus maritimus ) is considered an indicator species of ecosystem health because of its longevity, life-history requirements, reliance on sea ice (i.e., sea ice obligate), and
Shifting polar bear Ursus maritimus denning habitat availability in the European Arctic
Climate warming has resulted in extensive sea ice loss across the Arctic. Polar bears (Ursus maritimus) rely on sea ice for hunting, resting, travelling and in some parts of the Arctic also maternity
Increased Land Use by Chukchi Sea Polar Bears in Relation to Changing Sea Ice Conditions
Comparing land use patterns in the Chukchi Sea between two periods when substantial summer sea-ice loss occurred suggests that the ecology of this region may provide a degree of resilience to sea ice loss, and is consistent with other studies supporting increased land use as a common response of polar bears to sea- ice loss.
Polar bear denning distribution in the Canadian Arctic
Most coastal regions in northern Canada supported denning, but large areas exist where denning is unreported, and gaps remain in the knowledge of polar bear denning in Canada and filling these will aid the conservation and management of polar bears in a changing Arctic.
Polar bears and sea ice habitat change
The polar bear (Ursus maritimus) is an obligate apex predator of Arctic sea ice and as such can be affected by climate warming-induced changes in the extent and composition of pack ice and its
Summer refugia of polar bears (Ursus maritimus) in the southern Beaufort Sea
Overall, bears made high use of ice over shallow waters, and bears that remained near terrestrial areas used sea ice (presumably to hunt from) when it was available, and Energetic expenditure is anticipated to increase as bears are required to travel further on a seasonal basis.
Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline.
Investigation of the population dynamics of polar bears in the southern Beaufort Sea from 2001 to 2010 suggests that factors other than sea ice can influence survival, and refined understanding of the ecological mechanisms underlying polar bear population dynamics is necessary.
Effects of sea ice extent and food availability on spatial and temporal distribution of polar bears during the fall open-water period in the Southern Beaufort Sea
The results suggest that long-term reductions in sea-ice could result in an increasing proportion of the Southern Beaufort Sea polar bear population coming on land during the fall open-water period and an increase in the amount of time individual bears spend on land.
Changes in Land Distribution of Polar Bears in Western Hudson Bay
We examined the capture locations of polar bears ( Ursus maritimus ) on land in western Hudson Bay over 19 years (1986–2004) to assess temporal trends in the distribution of the population. We found


Polar Bears in a Warming Climate1
It is unlikely that polar bears will survive as a species if the sea ice disappears completely as has been predicted by some, but the effects of climate change are likely to show large geographic, temporal and even individual differences and be highly variable, making it difficult to develop adequate monitoring and research programs.
Human Disturbances of Denning Polar Bears in Alaska
Polar bears ( Ursus maritimus ) give birth in dens of snow and ice. The altricial neonates cannot leave the den for >2 months post-partum and are potentially vulnerable to disturbances near dens. The
Polar bear maternity denning in the Beaufort Sea
It is determined that denning in the Beaufort Sea region was sufficient to account for the estimated population there and captured and radiocollared polar bears between 1981 and 1991.
Observations of mortality associated with extended open-water swimming by polar bears in the Alaskan Beaufort Sea
It is speculated that mortalities due to offshore swimming during late-ice (or mild ice) years may be an important and unaccounted source of natural mortality given energetic demands placed on individual bears engaged in long-distance swimming.
Movements and distribution of polar bears in the Beaufort Sea
Net geographic movements from the beginning to the end of each month were smaller for females with cubs of the year than for solitary females, and larger in November than in April, May, or July.
Terrestrial Maternity Denning of Polar Bears in the Eastern Beaufort Sea Area
Observations on the location of polar bear (Ursus maritimus) maternity dens, the locations of females with young cubs on the sea ice just after leaving their dens, and observations of Inuvialuit
Spatial and temporal variations in the age structure of Arctic sea ice
Spatial and temporal variations in the age structure of Arctic sea ice are investigated using a new reverse‐chronology algorithm that tracks ice‐covered pixels to their location and date of origin
Abrupt decline in the Arctic winter sea ice cover
Although the Arctic perennial ice cover has been on a rapid decline, the winter ice cover had been unexpectedly stable. We report and provide insights into a remarkable turn of events, with the
The Polar Bear Management Agreement for the Southern Beaufort Sea : An Evaluation of the First Ten Years of a Unique Conservation Agreement
Polar bears ( Ursus maritimus ) of the southern Beaufort Sea population, distributed from approximately Icy Cape, west of Point Barrow, Alaska, to Pearce Point, east of Paulatuk in Canada, are