| Growing and expanding American black bear (Ursus americanus) populations and increased societal demand for honey bee pollination services have resulted in conflict between bears and beekeepers. Developing devices to protect mobile beehives from black bears is important for reducing economic losses to beekeepers and for conflict mitigation. I tested the effectiveness of 4 portable electric fence designs for excluding black bears from bait sites in northern Michigan, 2010. I determined the effectiveness of each fence design by observing bear behavior obtained from 24-hr video surveillance. From > 433 minutes of bear-fence interactions (BFI), I recorded 168 BFIs in 73 visits by an estimated 15 bears. The only fence design deemed 100% effective consisted of 3 polytape strands charged with approx. 5,000 V and spaced 0.58, 0.39, and 0.23 m from the ground. To help ensure that different bears interacted with the fence designs, I identified individual bears using several physical characteristics and unique behavior, when observed. I evaluated the repeatability of this methodology by determining the inter-rater reliability of students trained in my bear identification methods. Each student was given a 20-question test consisting of paired photographs or video recordings of unique or different bears collected during the study. Fleiss' kappa for the photographic tests was 0.49 (n = 35, z = 53.1, p < 0.001) for all students and 0.78 (z = 11, p < 0.001) for the top 5, indicating moderate and substantial agreement, respectively. Fleiss' kappa for the video test was 0.52 (n = 5, z = 7.3, p < 0.001) indicating moderate agreement. Results indicate that my techniques for identifying individual bears from photos and videos were generally repeatable. |
