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Fisher (West Coast DPS)

Fisher

Scientific name: Pekania pennanti

Status: Species of concern

Listing: The west coast population of the fisher was accorded federal candidate status in April 2004.  The west coast distinct population segment of the fisher was proposed for listing as threatened under the Endangered Species Act in October of 2014.

In Washington, this species potentially occurs in Clallam, Mason, Grays Harbor, Thurston, and Jefferson counties.

  • Historic Status and Current Trends

    Historically, fishers occurred in northern coniferous and mixed forests of Canada and the northern United States. Their range extended from the mountainous areas in the southern Yukon and Labrador Provinces southward to central California and Wyoming, the Great Lakes and Appalachian regions, and New England. Currently, the distribution of the fisher has retracted significantly south of the Canadian border and in the western United States and has remained similar to the historic range in the Yukon in Canada and the extreme northeastern United States. The west coast Distinct Population Segment of the fisher includes the populations in Washington, Oregon, and California. The fisher’s range and distribution within this DPS have been greatly reduced and fragmented. In Washington, fishers historically occurred in most forested habitats, including those both east and west of the Cascade Crest and on the Olympic Peninsula.

    In Washington, due to lack of recent sightings or trapping reports, the fisher is considered to be extirpated except for where they have been reintroduced. Between December 2007 and February 2010, 90 fishers (50 females and 40 males) were captured in British Columbia and released into Olympic National Park. Although fishers on the Olympic Peninsula are now broadly distributed and reproduction has been documented, it is still too early to determine if the reintroduced population is successful.

    Description and Life History

    The fisher, a member of the weasel family (Mustelidae), has a long body, short legs and a long, bushy tail. The head is broad and flat with a sharp, pronounced muzzle. The ears are broad, rounded, and low. Fur color varies from light brown to dark blackish brown, although the face, neck, and shoulders may have a lighter grizzled gray appearance. Adults range in length from roughly 2.5 to 4 feet. Males weigh 7 to 13 pounds; females weight about 3 to 5.5 pounds. It is estimated that fishers live up to 10 years. Retractable claws and the ability to rotate their large feet allow fishers to run down trees head first like a squirrel. Central pads on the hind paws have circular patches of coarse hair which are associated with plantar glands. These glands produce a distinctive odor believed to be used for communication to enhance reproduction. Fishers are generally solitary animals except during the breeding season which typically occurs from late February through April. Implantation is delayed up to ten months, resulting in births nearly 1 year after copulation. Fishers have a low annual reproductive capacity, and reproductive rates may fluctuate widely from year to year. Fishers are opportunistic predators. Their diet includes birds, porcupines, snowshoe hare, squirrels, mice, shrews, voles, reptiles, insects, carrion, vegetation, and fruit.

    Habitat

    Late-successional coniferous or mixed forests that contain key habitat and structural components are the most suitable fisher habitat because they provide abundant potential den sites, rest sites, and preferred prey species. Key habitat components include relatively large diameter trees, high canopy closure, large trees (hardwood and conifer) with cavities, and large down wood. Younger forests, in which complex forest structural components such as large logs and snags, and tree cavities are maintained in significant numbers, may also be suitable for fishers. However, intensive forest management does not typically retain key habitat and structural components. Therefore, early and mid-successional forests, especially those that have resulted from prior timber harvest, are unlikely to provide the same prey resources, protection from predators, and rest and den sites as more mature forests.

    Reasons for Decline

    The extent of past timber harvest is one of the primary causes of fisher decline across the United States and may be one of the main reasons fishers have not recovered in Washington, Oregon, and portions of California. In addition, the fisher has been commercially trapped since the early-1800s. Although exact numbers are unknown, trapping caused a severe decline in fisher populations.

    Conservation Efforts

    Continued implementation of the Northwest Forest Plan is expected to provide a network of connected reserves of late successional forest habitat. Implementation of the plan will lead to a substantial improvement in current habitat conditions for the fisher on Federal lands. The Washington Department of Fish and Wildlife, National Park Service, USFWS-Washington Fish and Wildlife Office and The U.S. Geological Survey began reintroducing fishers in Olympic National Park in 2007. Between December 2007 and February 2010, 90 fishers were released at several locations in the park. All the released fishers were fitted with radio collars and were tracked to document movement patterns and survival.  Current efforts to track the new population include working with our partners to operate an array of camera stations and hair-snares across the entire Olympic Peninsula.  WDFW and the National Park Service are hoping to begin a new fisher reintroduction effort in the Cascades as soon as December 2015.

    References and Links

    WFWO 2014 News Release

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