Vista Publishing

Determining kill rates of ungulate calves by brown bears using neck mounted cameras: camera collars on Brown Bears

By Christopher J. Brockman

Measured Kill Rates

Of the 7 brown bears with sufficient data for analysis, 4 were documented consuming adult ungulates. The mean adult ungulate kills/bear for all 7 brown bears while the cameras were working (15 May–17 Jun) was 1.4 (0–5.3), consisting of 0.6 adult moose, 0.6 adult caribou, and 0.2 unknown adult ungulates (either moose or caribou). Among these bears, the mean number of observed calf kills/bear observed was 28.4, including 13.3 moose calves (0–30.6), 11.9 caribou calves (0–30), and 3.3 unknown calves (either moose or caribou; 0–8.0 [Table 1]). The number of sample days (1 day post– collar-deployment until camera failure or removal) ranged from 11 to 31 (x¼23.4)/brown bear, resulting in a mean rate of 1.2 calf kills/day (range ¼0.3–1.8).