Abstract
Population estimates for bears (Ursidae), by a combination of noninvasive genetic sampling using hair-snares and capture-mark-recapture methods using DNA individual identification, are widely used in the world. In several areas of Japan, attempts have been undertaken to apply these noninvasive techniques. Compared with conventional methods, noninvasive methods have several advantages: 1) live-trapping of bears is unnecessary, 2) sampling is less biased than that of live-trapping, 3) sampling can cover larger geographical areas than traditional capture-mark-recapture sampling, and 4) genetic tags are permanent. However, we have to understand the structure of the methods and solve many issues before we apply this method, in order to estimate an accurate population size. In this paper, we describe procedures for these methods, including trap structures, study site selection, trap placement, hair sampling, individual identification by DNA analysis, and capture-mark-recapture models to estimate population size, and described points to notice.
