Proceedings of the Ninth Mountain Lion Workshop - Carnivore ...

and access, and annual variations in hunting weather conditions and harvest rates. If
cougar harvest rates in Idaho have increased while the population has declined, source
populations may no longer be able to maintain adequate reproductive output to supply
adjacent sink areas with dispersers. Cougar harvest rates are difficult to calculate in most
Game Management Units (Units), because cougar population size is unknown. Unit 26 –
Big Creek, a wilderness unit, is an exception. Cougar population size was determined
during 4 research projects in Unit 26 from 1965-2003 (Hornocker 1970, Seidensticker et
al. 1973, Quigley et al. 1989, Akenson et al. 2005).
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Figure 1. Idaho cougar harvest 1984-2006 (from Idaho Department of Fish and Game
Big Game Management Records database).
A cougar source population is characterized by-older aged residents with infrequent
vacancies of home range areas, a high reproductive rate and high dispersal rate. A sink
population is characterized by frequent replacement of resident cougars, resulting in
lower male and female ages and a lower reproductive rate: mortality exceeds production:
and immigration exceeds dispersal. Differences in cougar population age and sex ratios
and harvest age and sex composition over time should be detectable between source and
sink populations.
Our objectives were: 1) compare harvest-age and sex-composition data among 5 areas to
determine whether the wilderness cougar population still functioned as a source
population and 2) to evaluate changes in wilderness cougar population size and harvest
level over a 40-year period. We predicted that the wilderness cougar harvest rate had
increased to a degree that brings into question whether this population remains as a
source.
Proceedings of the Ninth Mountain Lion Workshop
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