Sex-selective harvesting of polar bears Ursus maritimus
| Autor: | François Messier, Mitchell K. Taylor, Philip D. McLoughlin |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
education.field_of_study
Ecology Ursus maritimus Maximum sustainable yield media_common.quotation_subject Population Mean age Population based Management Monitoring Policy and Law Biology Animal science biology.animal Reproduction education Ecology Evolution Behavior and Systematics Sex ratio Nature and Landscape Conservation media_common |
| Zdroj: | Wildlife Biology. 14:52-60 |
| ISSN: | 0909-6396 |
| DOI: | 10.2981/0909-6396(2008)14[52:shopbu]2.0.co;2 |
| Popis: | We explored limits and consequences of male-biased harvesting of polar bears Ursus maritimus using a simulated population based on empirically-derived estimates of age-specific rates of survival and reproduction. The maximum sustainable yield (MSY) was identified as the total kill in which the number of females that could be taken resulted in ≤5% change in females older than 50 years. MSY depended on the proportion of males in the harvest, although the effect of male selection on the post-harvest population was to reduce the mean age and number of males. A practical limit to the increase in MSY possible from male-selective harvesting was identified at the 3 : 1 (M/F) sex ratio. At 3 : 1 (M/F), all males were eventually harvested as 2-year olds, and males were reduced to 25% of pre-harvest levels. A more conservative harvest strategy of 2 : 1 (M/F) resulted in a 30% reduction of males and a reduction of the mean age of males from 10.0 to 7.7 years post-harvest. We thus recommend that sex-selective... |
| Databáze: | OpenAIRE |
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