Pacific Fisher Background and Recovery

Fishers are small carnivores and members of the weasel family. Like other carnivores, fishers play an important role in the maintenance of healthy ecosystems. They declined or became extinct in much of their range due to habitat loss and heavy trapping in the 18th century. Although fishers have rebounded in some areas, reintroduction efforts are critical in re-establishing the fisher to former portions of its range.

Behavior and Habitat

Next to the wolverine, the Pacific Fisher is the second largest North American terrestrial mustelid and the only forest carnivore that can regularly kill porcupines, which it dispatches with repeated bites to the face. This is no small task.  

The Pacific Fisher (Martes pennanti) depends on mature old growth forests for habitat and these carnivores use large areas of primarily coniferous forests with fairly dense canopies, large trees, snags, and down logs. Much of this habitat has been impacted by decades of logging and road building, thus the above-mentioned biological characteristics put the fisher in direct conflict with human modification of the landscape. 

Yet even in areas with relative fisher abundance, fishers are extremely secretive and are rarely seen by humans. This compounds problems with population monitoring and predictive models intended to derive how to best save this imperiled species. 

Pacific fisher range and population

The Pacific fisher (Martes pennanti pacifica) population has declined throughout the majority of its range in the Pacific Northwest due primarily to habitat loss and fragmentation. The Pacific fisher has been extirpated from Washington state and the northern Sierra Nevada and remains in an isolated, reintroduced population in Oregon, northwest California and the southern Sierra Nevada. The FWS has determined that the Pacific fisher should be listed under the Endangered Species Act.

Protection Status

In 2000, conservation groups petitioned the U.S. Fish and Wildlife Service to protect the fisher under the Endangered Species Act. In April 2004 the USFWS determined that the Pacific fisher is critically imperiled and warrants protection under the Endangered Species Act, but that this protection was precluded by other actions to protect species.

Instead, the agency placed the Pacific fisher on the growing list of species that are considered "candidates" for eventual protection under the act.  In turn, a timber industry has filed lawsuit filed seeking to remove the Pacific fisher from the list of species that are candidates for protection. Given the high stakes of fisher habitat, this conflict is likely to persist and intensify in the future.

Recovery Efforts

Although fishers have rebounded in some areas, reintroduction efforts are critical in re-establishing the fisher to former portions of its range.  In California, only three small, isolated populations remain. This includes native populations in northwestern California and the southern Sierra Nevada and a reintroduced population in the southern Oregon Cascades.

An analysis by Forest Service researchers indicates that, in the absence of stronger protection measures, the fisher is likely to become extinct in the southern Sierra within 50 years. Moreover, without connectivity between the two populations, they are vulnerable to stochastic events such as fires that could wipe out an isolated population. While fire regimes and their affect on the fisher remain uncertain, Defenders is working with scientists studying both the southern and northern Californian fisher populations to develop better predictive models which show probable affects of logging and fire on the fisher.

Fishers Reintroduced to Tennessee October 2002

Defenders of Wildlife, with the Tennessee-based Extirpated Species Foundation and the Tennessee Wildlife Resources Agency, reintroduced the fisher to Tennessee in October of 2002. Read our press release about this event.

Mesocarnivore conservation challenges

Fishers, like many other mid-sized or mesocarnivores, are losing ground. This is due to their large habitat requirements and diverse environmental needs. They face many of the same conservation challenges as large carnivores, yet they lack the charisma to garner support as some of their larger counterparts. In fact, while conservationists have focused much attention on restoring wolves and grizzlies to the northern Rockies, an entire group of smaller, less glamorous and in some cases more hard-pressed predators is quietly being ushered out. These are the midsized forest carnivores, the fisher, marten, wolverine and lynx -- animals that could be poster children for the last wild places in the American West. Like the grizzly and wolf, these smaller predators tend to avoid roads, clearcuts and people.