WCS North America


The fisher (Pekania pennanti) is a mammal of many talents. A member of the mustelid, or weasel, family, this small carnivore is native to North American coniferous and mixed forests and lives a semi-arboreal, or tree-climbing, lifestyle. Tree-top dens in cavities provide protection against the elements and potential predators and are crucial for long-term fisher survival. Although denning in tree cavities tens or even hundreds of feet off the ground may seem dangerous, fishers have developed several remarkable adaptations that allow them to take advantage of their habitat. For example, fishers can turn their hind feet nearly 180 degrees backwards, allowing them to descend from trees head-first. So when a female fisher is moving her kits from den to den, she is able to quickly and safely carry her offspring although it might weigh nearly one-quarter of her own body weight. Fishers are also adept forest predators themselves - one of the few carnivores that regularly prey on prickly porcupines!

Despite their many unique abilities, fisher populations have declined across their range due to commercial fur trapping and habitat loss, primarily from logging. WCS is working with agencies such as the U. S. Fish & Wildlife Service and the California Department of Fish & Wildlife, industrial forest companies like Sierra Pacific Industries, and other conservation organizations to develop sustainable forest management practices that reduce the threats to fishers. A new threat has also recently emerged: the indiscriminate use of rodenticides on marijuana cultivation sites.

The cumulative threat to fishers and the recent decline in their population in the Pacific Northwest have led the U. S. Fish & Wildlife Service to propose to list the fisher as threatened on the federal Endangered Species List. WCS's efforts have contributed to this proposal, and our research and conservation efforts in the northern Sierra Nevada Mountains and the Klamath River Watershed will continue to inform the Service's decision. To learn more about the proposal and to submit a public comment, visit the USFWS Pacific Southwest Regional Office's webpage about the fisher.


Fisher on Hoopa Tribal Lands

WCS began working in the Klamath-Siskiyou in 2004, building a collaboration between the Hoopa Valley Tribe, the U. S. Fish & Wildlife Service, and other federal, state, and private partners to develop region-wide forest management recommendations to benefit the imperiled and culturally-significant fisher. Our conservation approach involved developing collaborative, field-science based solutions to reduce the impacts of the diverse group of extractive and agricultural industries that supports livelihoods in the region. WCS's work with the Hoopa Tribe exemplifies how our organization assists Native American communities to inform their natural resource management and wildlife conservation decision-making.


Fisher Translocation to the Northern Sierra Nevada

Concern for the status of the fisher in California stimulated a cooperative venture among the U. S. Fish & Wildlife Service, California Department of Fish & Wildlife, Sierra Pacific Industries, and North Carolina State University to translocate fishers to the northern Sierra Nevada to increase the species' range and long-term survival. WCS and our partners are assessing the impact of removing fishers from a source population in the Klamath River Watershed and translocating the animals to the northern Sierra Nevada Mountains. We are also evaluating the success of the translocation by monitoring fisher survival, reproduction, habitat selection, and long-term population persistence in their new habitat. We are also building a base of data on the responses of fishers to industrial forest management practices.



WCS North America Program
212 South Wallace Avenue, Suite 101 Bozeman, MT, 59715 USA
(406) 522-9333

Key Staff