Dissertation
Effects of hunting on cougar population demography
Washington State University
Doctor of Philosophy (PhD), Washington State University
12/2008
DOI:
https://doi.org/10.7273/000005825
Abstract
Hunting is commonly used by wildlife agencies to provide recreational opportunities and to reduce human/wildlife conflicts. Game managers rely on accurate population estimates to assess population trends and effectiveness of management decisions. Because such direct counts are difficult to achieve for cougar populations, managers often use survival and fecundity models to assess effects of hunting. Many of these rate-based models assume a closed population structure, whereby emigration and immigration are balanced or considered unimportant. However, for large carnivores, which have large home ranges and disperse long distances, an open population structure may be more appropriate. From 2001 - 2008, I investigated the effects of hunting on two Washington cougar populations (one heavily hunted and one lightly hunted) using both survival/fecundity models and density estimates derived from direct counts. In the lightly hunted population, survival/fecundity rates predicted a 10% annual population increase, whereas direct counts indicated a stable population. In the heavily hunted population, the survival/fecundity model predicted a 27% decrease, but counts revealed only a 9% annual decrease. We believe the difference between the predicted and observed growth rates was likely caused by immigration and emigration. High hunter harvest triggered immigration, decreased female numbers, and produced a younger overall age structure. Low hunter harvest triggered emigration, stable female numbers, and resulted in an older overall age structure. These results suggest that cougar populations may be self-regulating, and that traditional survival/fecundity harvest models are unable to accurately predict the population responses to hunting.
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Details
- Title
- Effects of hunting on cougar population demography
- Creators
- Hilary Stuart Cooley
- Contributors
- Robert B. Wielgus (Chair)Gary M Koehler (Committee Member)Lisa Shipley (Committee Member) - Washington State University, School of the Environment (CAHNRS)Rich Alldredge (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- College of Agricultural, Human, and Natural Resource Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 88
- Identifiers
- 99901055037601842
- Language
- English
- Resource Type
- Dissertation