Southern Sierra Fisher ESA Listing
On May 14, 2020, the U.S. Fish and Wildlife Service (USFWS) officially listed the Southern Sierra fisher population as an endangered species under the Endangered Species Act (ESA). The ESA designation is significant in that it recognizes the imminent threats facing the population and sets the stage to plan for recovery of the species.
To survive, these rare forest carnivores require suitable habitat, which includes large, old trees with cavities, areas of dense canopy, and enough diversity to support a variety of prey species. They are also sensitive to forest fragmentation, and require enough connectivity between their home-ranges and those of other individuals to breed and disperse. Four consecutive years of severe drought in the Southern Sierra Nevada mountains, combined with rising temperatures and bark beetle infestations resulted in a massive tree die-off and, consequently, a tremendous loss and fragmentation of suitable fisher habitat. This, on top of the increased poisoning and mortality due to illegal marijuana cultivation on public lands, resulted in the USFWS decision to list the Southern Sierra Nevada population as endangered as opposed to threatened.
CBI has been at the forefront of multi-agency efforts to conserve and recover the isolated and imperiled population of fisher (Pekania pennanti) in the southern Sierra Nevada, California. In 2008, the CBI team - led by Dr. Wayne Spencer and in collaboration with the U.S. Forest Service (USFS) developed the Southern Sierra Nevada Fisher Assessment as a baseline evaluation of the isolated fisher population. In the years following, CBI and the USFS developed the Southern Sierra Nevada Fisher Conservation Assessment and Strategy, as well as the Southern Sierra Nevada Fisher Conservation Strategy – Interim Recommendations, which currently guides the conservation of fisher in the region. CBI’s senior analyst, Heather Rustigian-Romsos, has led efforts to develop fisher habitat models which are currently being used to guide forest management activities throughout the region. CBI also worked with the USFS and the USFWS to identify important landscape connectivity areas in the lower and mid-Klamath Basin for the American marten and the fisher.
Sierra Nevada forests currently face a variety of threats from climate change, insect outbreaks, and wildfire. Restoring resiliency to these landscapes is challenging, and balancing this with the conservation of fisher habitat is even more so. CBI will continue to work toward finding collaborative solutions to these issues, sustaining and recovering this unique native species.
To learn more about CBI’s extensive efforts to conserve and recover the Southern Sierra fisher population, explore more content here:
- CBI lead reviewer for monitoring plan
- Help or hindrance for species conservation
- Modeling the Potential for Large High-Severity Fires in the Klamath Basin Region of California and Oregon and Their Potential Impacts on Marten and Fisher
- Decision-support Maps and Recommendations for Conserving Rare Carnivores in the Interior Mountains of California
- Habitat Connectivity for Fishers & Martens in the Klamath Basin Region of CA & OR
- Explore Data Basin's Klamath Basin Ecological Connectivity for Pacific Fisher Gallery
- The Killing Fields
**The banner photo was taken by Morgan Heim; the photo above is courtesy of USFS Pacific Southwest Research Station.
To view the official listing, please click here.