The Southern Sierra Nevada Fisher Conservation Assessment and Strategy is an ongoing, now 15-year, multi-agency effort to conserve and recover an imperiled population of Pacific fisher (Pekania pennanti), a large member of the weasel family that lives in the southern Sierra Nevada mountains of California. Begun in 2007, this effort has progressed through several phases of research, assessment, habitat modeling, strategy recommendations, and updates to the habitat models and recommendations in response to changing conditions in the Sierra Nevada.

Since 2007 CBI has collaborated with The Fisher Inter agency Leadership Team (Sierra Nevada Conservancy, USDA Forest Service, National Park Service, US Fish and Wildlife Service, and California Department of Fish and Wildlife) to develop the 2015 Southern Sierra Fisher Conservation Assessment and 2017 Southern Sierra Fisher Conservation Strategy with associated decision-support tools under funding provided by Sierra Nevada Conservancy (SNC), the USDA Forest Service (Pacific Southwest Region), Resources Legacy Fund, and the US Fish and Wildlife Service (USFWS).

The 2015 Conservation Assessment summarizes information about fishers in the southern Sierra Nevada, including population size, distribution, and trends; ecology; habitat requirements across multiple spatial scales (from the population or landscape scale to the scale of individual denning or resting structures); and threats to fishers and their habitat. It is a focused review of information most relevant to crafting a strategy to conserve the population in the southern Sierra Nevada. This assessment provides the biological and ecological foundations for the 2017 Southern Sierra Nevada Fisher Conservation Strategy.

The 2017 Southern Sierra Nevada Fisher Conservation Strategy provides science-based guidance for reducing threats and increasing the quality and resiliency of fisher habitat. The strategy is based on the best available scientific information on fishers and their habitats in the area of that time, as summarized in the 2015 Southern Sierra Nevada Fisher Conservation Assessment. The 2015 Strategy met the needs of multiple agencies with an interest in fisher conservation and land management in the Sierra Nevada, and was intended to be compatible with diverse agency missions, objectives, and legal requirements.

Since those studies were completed, conditions have changed dramatically for Sierra Nevada fishers. In 2014 climate-change induced tree mortality began sweeping through the Sierra Nevada. Catastrophic fires have burned much of the remaining denning and population connectivity habitat. To date tens of millions of trees have died, including many of the large pines that fishers rely on for denning and rest sites. Accustomed to moving through dense forest, Sierra fishers instead have found themselves facing large, open areas where their risk of being spotted and killed by larger predators is much greater.

In 2017 the partnership published the addendum to the 2015 Fisher Conservation Strategy, Changed Circumstances and Implementation of the Southern Sierra Nevada Fisher Conservation Strategy Note from the Authors, March 2017. In June of 2020 the US Fish and Wildlife Service officially listed the southern Sierra Nevada fisher population as Endangered. Numerous efforts were launched by the US Forest Service and National Park Service, along with private organizations such as timber and utility companies, to adopt fisher-friendly management practices. In February 2020, CBI and US Forest Service partners produced the report Southern Sierra Nevada Fisher Conservation Strategy Interim Recommendations, and in 2021 released an updated Pacific Fisher Reproductive Habitat Model and Report. Funding is currently being sought from the California Department of Fish and Wildlife to update the Fisher Conservation Assessment and Strategy.

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