Efficacy of ground‐based trapping of coastal American black bears in Prince William Sound, Alaska

Abstract

Ground-based trapping can be the most practical approach for capturing American black bears (Ursus americanus) in remote portions of Alaska. During the summers of 2016-2018 we captured 106 black bears in a coastal portion of southcentral Alaska, USA, using bucket cable traps and Aldrich snare sets, 2 common foot snaring techniques. Despite widespread use, little research has focused on factors contributing to success and differences in safety for both foot snaring techniques. We compared trap engagement and success and found that bears engaged with bucket cable traps at a 31% (CL = 3-50%) lower rate than with Aldrich snare sets but once engaged were equally likely to be successfully snared. Prebaiting sites increased capture success 362% (CL = 21-1663%) but it was unclear if success improved when sites were prebaited multiple times. Regardless of trap type, bear engagement with sets were 194% higher (CL = 94-345%) during mid-day hours (0800-1559) compared to crepuscular or nocturnal hours. We observed average injury scores of less than 11 points (out of 400 possible points) for both set types, consistent with the score given for minor lacerations.Both methods performed well within the recommended safety standards of the American Society of Mammalogists.