Estimating population size of grizzly bears using hair capture, DNA profiling, and mark-recapture analysis

We used. DNA analysis to estimate grizzly bear (Ursus arctos) population si ze in a 9,866-km(2) area in southeast British Columbia and a 5,030-km(2) ar ea in southwest Alberta. We sampled bears by removing hair at bait sites su rrounded by a single strand of barbed, wire. DNA profiling with microsatell ites of the root portion of the hair was used to identify individuals. We c ollected hair from 109 different bears and had 25 recaptures in 5 10-day tr apping sessions in British Columbia. In Alberta we collected hair from 37 b ears and had 9 recaptures in 4 14-day sessions. A model in program CAPTURE (M-h) that accommodates heterogeneity in individual capture probabilities e stimated the population size in British Columbia as 262 (95% CI = 224-313) and in Alberta as 74 (60-100). We believe that hair capture combined, with DNA profiling is a promising technique for estimating distribution and abun dance of bears and potentially many other species. This approach is of spec ial interest to management biologists because it can be applied at the scal e conservation and management decisions are made.