Yosemite Raccoon Project

Managing human-wildlife incidents dominates the attention and resources of many wildlife management programs. National Parks in the United States have a long history with human-wildlife interactions and conflicts. Improvements in communication with visitors, food-storage infrastructure, regulation enforcement, and the management of habituated and food-conditioned animals have led to decreases in human-wildlife conflicts. Yosemite National Park is well known for its history of human-bear conflicts but in the Yosemite Valley portion of Yosemite National Park, conflicts with raccoons now outnumber those with black bears. Like bears, raccoons pose a risk of property damage and injury to humans, but they also pose a risk of zoonotic disease transmission and a risk of predation to species of conservation concern.

To better understand the behavior and ecology of Yosemite Valley raccoons and to inform future management efforts aimed at reducing these potential negative outcomes, we collaborated with Yosemite National Park to evaluate the influence of anthropogenic food availability on raccoon space use using global positioning system tracking collars. We collected a mean (SD) of 555 (349) locations on 11 raccoons (7M, 4F) between December 2016 and May 2018 and developed a resource selection model to evaluate selection by raccoons within their home ranges in Yosemite Valley.

Raccoons were located more frequently in developed areas (i.e., areas with structures or other capital projects) of Yosemite Valley compared to undeveloped areas and showed a stronger selection pattern for developed areas where people gathered for consuming food (e.g., picnic areas, campgrounds). Leveraging the successful strategies for managing human-bear interactions and adapting management to accommodate the ecology and behaviors of raccoons and other species involved in human-wildlife conflict will offer a foundation for a holistic human-wildlife interaction program in our National Parks (Anderson et al. In Press).