Denning ecology and habitat use by fisher (Martes pennanti) in pine dominated ecosystems of the Chilcotin Plateau

I used radio-telemetry to monitor 24 fisher (Martes pennanti) in the Chilcotin area of British Columbia. Fisher used heart rot cavities in old lodgepole pine (Pinus contorta), Douglas-fir (Pseudotsuga menziesii var. glauca), and trembling aspen (Populus tremuloides) trees located primarily on south aspects for reproductive dens. Den trees in the Chilcotin were smaller in diameter than those documented elsewhere in western North America, but were locally large. Fisher used both arboreal and terrestrial rest sites in the Chilcotin, but terrestrial sites were preferred during periods of deep snow. Arboreal rest sites were usually on rust brooms in white spruce (Picea glauca) and terrestrial rest sites were typically associated with large diameter coarse woody debris. Mean home range size for 10 females in my study was 30 km2 and the male fisher I monitored had a home range of 166 km2. Within home ranges, fisher preferred areas close to streams.