Five orphaned black bear cubs that were rehabilitated and released into northern California in November 2025 successfully hibernated through the winter and returned to the landscape this spring healthy and active, according to recent data reviewed by California Department of Fish and Wildlife (CDFW) scientists.
These bears were part of an experimental effort led by the department’s Wildlife Rehabilitation Program, in coordination with CDFW’s Game Conservation Program and North Central Region, to test the viability of releasing rehabilitated juvenile black bears back in the wild in the fall versus the typical spring release. This practice – which can be helpful in mitigating human-wildlife conflict – has been successful in other states but had yet to be tested in California.
All five bears were ear-tagged, microchipped and fitted with GPS collars for scientific study and individual identification. Based on collar data, all five bears successfully established dens, hibernated during the winter, and reemerged this spring back on the landscape.
“This is a massive win. These bears spent their first winter hibernating naturally in the wild as opposed to staying overwinter in a facility, which can be costly and difficult to do. It means less time in rehabilitation and less opportunity to get comfortable around humans,” said Dr. Heather Perry, CDFW’s Wildlife Rehabilitation Program Coordinator. “We were able to work together to release these healthy young animals back to the wild where they belong. It highlights the important and unique role of wildlife rehabilitators – and wildlife rehabilitation by its very definition – in the conservation of California’s native wildlife.”
The releases were made possible by CDFW’s wildlife rehabilitation partners with support from the CDFW Wildlife Health Lab and veterinary staff who provided health assessments prior to release. CDFW decided to test the fall bear releases after noting the success of fall releases in other western states, specifically Nevada and Washington.
“Bears are incredibly resilient. They have an innate behavior to find shelter when snow starts to accumulate on the ground,” said Alexia Ronning, CDFW Environmental Scientist and Tahoe bear specialist. “They teach us all the time that we need to trust their ability to survive on the landscape.”
The five bears include:
- Two female siblings reported to CDFW as orphaned near Nevada City, Nevada County in May 2025. Both cubs were captured and taken to the Sonoma County Wildlife Rescue for rehabilitation then returned together to suitable habitat in Nevada County.
- One male cub reported to CDFW as abandoned in South Lake Tahoe, El Dorado County in July 2025. The cub was captured and taken to Sonoma County Wildlife Rescue for rehabilitation then returned to suitable habitat in El Dorado County.
- Three male siblings reported to CDFW as abandoned in Arnold, Calaveras County in July 2025. The cubs were captured and taken to the San Diego Humane Society’s Ramona Wildlife Center for rehabilitation. One sibling arrived sick and was humanely euthanized. The remaining two cubs were transferred to Sonoma County Wildlife Rescue then returned together to suitable habitat in Calaveras County.
CDFW provides year-round education, outreach and community support on living responsibly with black bears and recreating in bear country through its affiliations with the Tahoe Interagency Bear Team (TIBT) and BearWise. Preventing black bears from accessing trash, human food sources and other attractants is key to preventing human-bear conflicts.
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Media Contact:
Peter Tira, CDFW Communications, (916) 215-3858
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CDFW Image: A cluster of GPS points overlayed on satellite imagery over a three-month period in winter shows very little movement and indicates to CDFW biologists that the GPS-collared Calaveras County bear wearing the collar found a den and hibernated.