Effects of Earlier Sea Ice Breakup on Survival and Population Size of Polar Bears in Western Hudson Bay

@inproceedings{Regehr2007EffectsOE,
  title={Effects of Earlier Sea Ice Breakup on Survival and Population Size of Polar Bears in Western Hudson Bay},
  author={Eric V. Regehr and Nicholas J. Lunn and Steven C. Amstrup and Ian Stirling},
  year={2007}
}
Abstract Some of the most pronounced ecological responses to climatic warming are expected to occur in polar marine regions, where temperature increases have been the greatest and sea ice provides a sensitive mechanism by which climatic conditions affect sympagic (i.e., with ice) species. Population-level effects of climatic change, however, remain difficult to quantify. We used a flexible extension of Cormack–Jolly–Seber capture–recapture models to estimate population size and survival for… 
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TLDR
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.
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TLDR
The effects of sea ice loss on polar bears in the southern Beaufort Sea may apply to polar bear populations in other portions of the polar basin that have similar sea ice dynamics and have experienced similar, or more severe, sea ice declines.
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TLDR
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Home range size was predicted by season, ice break-up date, and individual in a multiple regression, though R2 was low, and solitary females had smaller home ranges and were closer to land compared to females with offspring.
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TLDR
Evidence that documents how loss of sea ice negatively affects polar bears' long-term survival is summarized, with quantifiable negative effects being documented first in the more southerly subpopulations, such as those in Hudson Bay or the southern Beaufort Sea.
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TLDR
Results indicate that multi-decadal loss of sea ice has resulted in shifts in polar bear habitat use in EG, and there was a statistically significant and stronger winter preference in the 2000s for adult females to select for higher sea ice concentrations.
Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range
The Southern Hudson Bay polar bear (Ursus maritimus Phipps, 1774) subpopulation is considered stable, but conflicting evidence lends uncertainty to that designation. Capture–recapture studies
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Until recently, the sea ice habitat of polar bears was understood to be variable, but environ- mental variability was considered to be cyclic or random, rather than progressive. Harvested populations
Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations
TLDR
Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears.
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