Evaluating effects of natural and anthropogenic factors on American black bear occupancy in northern Georgia, USA

Abstract

Although previously close to extirpation in the southeastern United States, American black bear (Ursus americanus) abundance and distribution have increased with habitat management and harvest regulation. The north Georgia black bear population, the most abundant and widely distributed in the state, is currently being exposed to pressures from increasing anthropogenic disturbances, such as recreation and vehicle traffic. We evaluated the effects of environmental factors and anthropogenic activity on habitat use of black bears within a wildlife management area open to public recreation. We used detection/non-detection data from camera surveys conducted at 448 locations from April to December 2023 to fit hierarchical single-species occupancy models. Black bear detection was best explained by Julian date, its quadratic effect, and weekly human activity index. Detection increased through the spring, peaked in June, and declined throughout late summer and fall. In contrast to detection, occupancy was not affected by seasonal differences in black bear activity. Occupancy increased with increasing elevation, distance to water, and distance to high-use recreation areas. The spatial distribution of food resources likely contributed to the observed black bear occupancy pattern related to elevation and distance to water, while human disturbance in the study area also influenced black bear occupancy. Thus, our results suggest that in a landscape open to public recreation, black bear occupancy was driven by a combination of environmental and anthropogenic factors. Identifying patterns of occupancy at a scale typical of management provides important information for managing black bear populations throughout the large, connected network of national forests in the Appalachian region.