American black bears and hair snares: a behavioral analysis

Abstract

Despite the widespread use of noninvasive hair-sampling for American black bear (Ursus americanus) population monitoring, there is no explicit analysis of black bear behavior at hair snare sites. During 2016, we deployed hair snares and camera traps at 40 sites across the northern Lower Peninsula of Michigan, USA, and collected 560 video recordings of black bear activity. Our objectives were to develop an ethogram of bear behaviors at snare sites and quantify their occurrence. We found that bears allocated their time consistently when they were physically inside or outside of the snare, but they divided their time among multiple behaviors when crossing the wire. The inconsistencies in wire crossing revealed unexpected behaviors with important implications for study design. Our findings explicitly describe how black bears interact with hair snares, provide recommendations for addressing the influence of behavior on sampling efficiency, and establish a foundation for further study of animal behavior at hair snares.