Survival rates of radio-collared female polar bears and their dependent young

Canadian Journal of Zoology

and ORCID iD


  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS | Dublin Core


Polar bears are hunted throughout most of their range. In addition to hunting, polar bears of the Beaufort Sea region are exposed to mineral and hydrocarbon extraction and related human activities such as shipping, road building, and seismic testing. As human populations increase and demands for polar bears and other arctic resources escalate, reliable estimates of survivorship of polar bears are needed to predict and manage the impacts of those activities. We used the Kaplan-Meier model to estimate annual survival (with 95% confidence intervals) for radio-collared female polar bears and their dependent young that were followed during a 12-year study in the Alaskan Beaufort Sea. Survival of adult female polar bears was higher than had been previously thought: S = 0.969 (range 0.952-0.983). If human-caused mortalities were deleted, the computed survival rate was 0.996 (0.990-1.002). Survival of young from den exit to weaning was 0.676 (0.634-0.701). Survival during the second year of life, 0.860 (0.751-0.903), was substantially higher than during the first year, 0.651 (0.610-0.675). Shooting by local hunters accounted for 85% of the documented deaths of adult female polar bears. Conversely, 90% of documented losses of young were independent of litter size (P = 0.36), indicating that parental investment in single cubs was not different from investment in litters of two or more. Precise estimates of the survival of independent juveniles and adult males still need to be developed.

Additional publication details

Publication type:
Publication Subtype:
Journal Article
Survival rates of radio-collared female polar bears and their dependent young
Series title:
Canadian Journal of Zoology
Year Published:
Contributing office(s):
Alaska Biological Science Center
pp. 1312-1322
Larger Work Type:
Larger Work Subtype:
Journal Article
Larger Work Title:
Canadian Journal of Zoology
First page:
Last page: