Demography and population viability of polar bears in the Gulf of Boothia, Nunavut
Abstract We estimated demographic parameters and harvest risks for polar bears ( Ursus maritimus ) inhabiting the Gulf of Boothia, Nunavut, from 1976 to 2000. We computed survival and abundance from capture–recapture and recovery data (630 marks) using a Burnham joint live–dead model implemented in...
| Published in: | Marine Mammal Science |
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| Main Authors: | , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
2009
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1111/j.1748-7692.2009.00302.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2009.00302.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2009.00302.x |
| Summary: | Abstract We estimated demographic parameters and harvest risks for polar bears ( Ursus maritimus ) inhabiting the Gulf of Boothia, Nunavut, from 1976 to 2000. We computed survival and abundance from capture–recapture and recovery data (630 marks) using a Burnham joint live–dead model implemented in program MARK. Annual mean total survival (including harvest) was 0.889 ± 0.179 (x̄± 1 SE) for cubs, 0.883 ± 0.087 for subadults (ages 1–4), 0.919 ± 0.044 for adult females, and 0.917 ± 0.041 for adult males. Abundance in the last 3 yr of study was 1,592 ± 361 bears. Mean size of newborn litters was 1.648 ± 0.098 cubs. By age 7, 0.97 ± 0.30 of available females were producing litters. Harvest averaged 38.4 ± 4.2 bears/year in the last 5 yr of study; however, the 2002–2007 kill averaged 56.4 bears/yr. We used a harvested Population Viability Analysis (PVA) to examine impacts of increasing rates of harvest. We estimated the current population growth rate, λ H , to be 1.025 ± 0.032. Although this suggests the population is growing, progressive environmental changes may require more frequent population inventory studies to maintain the same levels of harvest risk. |
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