Coexisting with Black Bears: Modeling Habitat Connectivity and Conflict in California’s North Bay

American black bears play a crucial ecological role in California, and in recent years, the species has been expanding its range into the North San Francisco Bay Area. This expansion has the potential to increase conflict with humans, causing property damage, vehicle collisions, trash storage break-ins, and pet or livestock predation. Therefore, proactive action is needed to promote healthy coexistence between humans and black bears in the North Bay. For our project, we created three models to analyze habitat suitability, conflict, and connectivity in the region. We also performed seasonal data analysis, and distributed a survey to land managers to gauge the current perceptions on bear conflict and mitigation. From our analyses, we found that suitable habitat is driven by food availability, the presence of protected areas, shrubland, and forest cover. Our conflict model suggests that areas with developed roads and mixed wilderness-urban landscapes, such as the wildlife urban interface, have elevated levels of conflict. Bear activity is likely highest during the warmest months of the year. When assessing connectivity, we found that a wildlife corridor across Highway 101 could potentially lower the risk of bear-vehicle collisions along the highway. From our survey, we found that vineyard managers and owners reported the highest rates of conflict, and that the general sentiment towards bears is positive in the North Bay. Our findings provide a baseline for how coexistence can be promoted with a path forward for humans and bears.

Acknowledgements

Bren School of Environmental Science & Management: Dr. Sarah Anderson, Interim Dean; Allie Caughman, PhD Candidate; Dr. Christopher Jerde, Associate Researcher; Kat Le, Technical Applications Manager; Dr. Andrew MacDonald, Assistant Professor; Dr. David Tillman, Distinguished Professor

Pepperwood Foundation: Steven Hammerich, Wildlife Research Coordinator; Kai Henifin, Regional Climate Resilience Manager; Dr. Laura Ward, Conservation Science Director

North Bay Bear Collaborative: Meghan Walla-Murphy, Educator and Collaborative Liaison

Additional Acknowledgements: Kim Daly, Graphic Design Consultant; Dr. Kevin Hunt & Basant Pant, Mississippi State University; California Department of Fish and Wildlife (CDFW); Survey and Interview Participants; Dr. Nate Svoboda, Alaska Department of Fish and Game Wildlife Biologist