When our wildlife researchers captured a picture of a black bear at Bouverie Preserve back in August, we thought it might be an anomaly. But a second, larger, bear showed up just two weeks ago at the same spot! According to the California Department of Fish and Wildlife, these are the southernmost documented sightings of black bears from the Mayacamas Range. The bears were photographed by one of six motion-sensor cameras installed on the Bouverie Preserve as part of ACR’s wildlife corridor monitoring program.
The Bouverie Preserve is centrally located within a 5 mile wide wildlife corridor that links Sonoma Mountain with the Mayacamas Range. Staff at the Bouverie Preserve has been monitoring cameras for four years to understand and enhance wildlife movement between patches of protected lands. In this research, the Bouverie cameras have photo-captured over 20 wildlife species, but the bear sighting is undoubtedly the most exciting.
It is not surprising that a black bear was seen at the 535 acre Bouverie Preserve since the property is home to five different habitat types, including mixed evergreen, chaparral and riparian forest which are all highly attractive to bears. As omnivores, black bears prefer a plant-based diet but also consume ants and insects in summer and acorns and manzanita berries in the fall. Black bear home ranges vary depending upon the availability of food, water and den habitat, but they typically extend between 15-80 square miles for a single bear. Black bears in Sonoma County belong to the North Coast subpopulation of black bears which are geographically and genetically distinct from the Sierra Nevada and Central Coast populations.
California's black bear population has been increasing over the past 25 years from 10,000 in 1982 to 25,000 in 2012. Due to the relatively low population size and scarcity of regional bear research, it is unclear whether the Bouverie Preserve bear sighting is due to a population increase or drought-related food shortage.
Black bears generally do not present a threat to humans or pets, but they can adapt to human presence. Bears can be attracted to human garbage, pet food and agricultural crops when natural foods are scarce, particularly in late summer and fall and especially during years of poor berry and acorn yields. For homeowners living in the wildland-urban interface, it is important to store garbage in bear-proof containers and remove tree fruit as soon as it falls to the ground. Learn more about how to live responsibly in bear country at https://www.wildlife.ca.gov/Keep-Me-Wild/Bear