ARCTIC Mortality Rates of North American Bears
ABSTRACT. The age structures of 39 populations of three species of North American bears were analyzed. Estimated mortality rates of cubs in their first year were 30-40 % for brown bears and 25-30 % for black bears. Apparent subadult mortality rates derived from living animals (15-35 % an-nually) wer...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.535.4481 2023-05-15T14:19:48+02:00 ARCTIC Mortality Rates of North American Bears F. L. Bunnell D. E. N. Tait The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.535.4481 http://pubs.aina.ucalgary.ca/arctic/Arctic38-4-316.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.535.4481 http://pubs.aina.ucalgary.ca/arctic/Arctic38-4-316.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://pubs.aina.ucalgary.ca/arctic/Arctic38-4-316.pdf Key words age distribution bears mortality rates North America sex ratios Vrsus species text ftciteseerx 2016-01-08T10:47:50Z ABSTRACT. The age structures of 39 populations of three species of North American bears were analyzed. Estimated mortality rates of cubs in their first year were 30-40 % for brown bears and 25-30 % for black bears. Apparent subadult mortality rates derived from living animals (15-35 % an-nually) were higher than those of adults. Apparent mean annual mortality rates of subadult and adult females combined were 17.2, 16.8, and 18.8% for black, brown, and polar bears respectively. Comparable values for males were 25.5, 23.0, and 22.6 % annually. Because hunting appears to be the major mortality factor in most North American bear populations, interpretation of age structures is facilitated by explicitly incorporating the effects of hunting and its associated biases in the analyses. The simple model proposed to accommodate the hunter-bear interaction clarifies differences in age distributions between species and between sexes within species. Most of the differences in sex-specific mortali-ty rates are a product of differential vulnerability related to home range size and method of hunting. Text Arctic Arctic Unknown Arctic |
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Key words age distribution bears mortality rates North America sex ratios Vrsus species |
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Key words age distribution bears mortality rates North America sex ratios Vrsus species F. L. Bunnell D. E. N. Tait ARCTIC Mortality Rates of North American Bears |
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Key words age distribution bears mortality rates North America sex ratios Vrsus species |
description |
ABSTRACT. The age structures of 39 populations of three species of North American bears were analyzed. Estimated mortality rates of cubs in their first year were 30-40 % for brown bears and 25-30 % for black bears. Apparent subadult mortality rates derived from living animals (15-35 % an-nually) were higher than those of adults. Apparent mean annual mortality rates of subadult and adult females combined were 17.2, 16.8, and 18.8% for black, brown, and polar bears respectively. Comparable values for males were 25.5, 23.0, and 22.6 % annually. Because hunting appears to be the major mortality factor in most North American bear populations, interpretation of age structures is facilitated by explicitly incorporating the effects of hunting and its associated biases in the analyses. The simple model proposed to accommodate the hunter-bear interaction clarifies differences in age distributions between species and between sexes within species. Most of the differences in sex-specific mortali-ty rates are a product of differential vulnerability related to home range size and method of hunting. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
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Text |
author |
F. L. Bunnell D. E. N. Tait |
author_facet |
F. L. Bunnell D. E. N. Tait |
author_sort |
F. L. Bunnell |
title |
ARCTIC Mortality Rates of North American Bears |
title_short |
ARCTIC Mortality Rates of North American Bears |
title_full |
ARCTIC Mortality Rates of North American Bears |
title_fullStr |
ARCTIC Mortality Rates of North American Bears |
title_full_unstemmed |
ARCTIC Mortality Rates of North American Bears |
title_sort |
arctic mortality rates of north american bears |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.535.4481 http://pubs.aina.ucalgary.ca/arctic/Arctic38-4-316.pdf |
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Arctic |
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Arctic Arctic |
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Arctic Arctic |
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http://pubs.aina.ucalgary.ca/arctic/Arctic38-4-316.pdf |
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http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.535.4481 http://pubs.aina.ucalgary.ca/arctic/Arctic38-4-316.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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