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

Wilderness DAUs were considered valuable because they served as reservoir areas
where, due to difficult access and topography, lenient hunting seasons could be allowed
without significantly reducing dispersal into adjacent areas like the Salmon DAU and
parts of Warren DAU (Power 1985, Harris 1991). To evaluate changes in cougar harvest
rate through time, we selected Unit 26 which is contained within the Frank Church River
of No Return Wilderness area. In addition to state harvest records, four cougar research
projects (Hornocker 1970, Seidensticker et al. 1973, Quigley et al. 1989, Akenson et al.
2005) were conducted in Unit 26 resulting in cougar population estimates between 1969
and 2003.
DAU Comparisons
We compared Idaho Department of Fish and Game cougar harvest data from the 1972-
2006 Big Game Management Records database (B. Ackerman, Idaho Department of Fish
and Game, unpublished data) from 2 areas (Warren DAU and Selway DAU) designated
by Idaho Department of Fish and Game as source populations, an adjacent sink area
(Salmon DAU), and 2 distant areas (Pocatello DAU and Oakley DAU) that historically
had low harvest levels, but had increased harvest since the 1990s. We compared longterm
harvest trends among DAUs from 1983-2006 and compared the mean proportion of
females in the harvest per decade (1980s, 1990s, 2000s) among DAUs. We pooled
harvest data for each DAU from 1998-2006 because of low sample sizes and high annual
variation in age and sex composition. We evaluated differences among DAUs in harvest
age–sex composition using 2 age classes: subadults (kitten to 2 years old) and adults (at
least 3 years old) and compared adult versus subadult proportions, proportion of females
and adult females in the harvest. We evaluated differences among DAUs in age structure
of harvested males using 4 age classes: kitten to 2 years old, 3 years old, 4-7 years old,
and at least 8 years old. We used a subset of Warren DAU that only included wilderness
units (Units 20A, 26, 27) for the comparisons of age–sex data, male ages, and the
proportion of female cougars in the harvest.
Harvest Rate Change
Since 1973, Idaho Department of Fish and Game has sustained a mandatory check of
harvested cougars and maintains a database that includes annual harvest numbers and sex
composition by game management unit. The cougar harvest database has included age
data from tooth cementum annuli since 1988. We calculated mean annual cougar harvest
in Unit 26 by decade from the 1973-2006 Big Game Management Records database (B.
Ackerman, Idaho Department of Fish and Game, unpublished data).
In Unit 26, we compared the change in harvest levels with changes in resident cougar
populations by decade over a 40-year period to assess changes in cougar harvest rate. We
calculated a harvest ratio for each decade based on mean annual harvest relative to
resident cougar population estimates from research. Harvest ratios were used as an index
to harvest rates, because numbers of subadult and transient cougars were not known for
research population estimates.
Proceedings of the Ninth Mountain Lion Workshop
174