Unknown and charismatic

Fishers

by Jeff Lewis, wildlife biologist, Washington Department of Fish and Wildlife

Let’s be very clear. It’s not a wader-clad, worm-toting angler, nor a stout-billed perching bird that dives for minnows; it’s a fisher, an elusive forest carnivore. It’s the larger, darker member of the weasel family that once roamed the deep coniferous forests of Washington.

However, it’s difficult to be clear about a predator that seems entirely charismatic but is virtually unknown. There is no work boot or mountain resort or smallish bulldozer named after this species; unfortunately, the fisher is not really part of our collective wildlife consciousness.

The fisher’s anonymity was achieved by being almost undetectable where it does occur and by disappearing from a large portion of its North American range before most of us were born.  

The fisher was apparently lost from Washington by the mid-1900s as a result of commercial trapping and the loss and fragmentation of older coniferous forests. In the early 1900s, fur buyers paid trappers as much as $200 for a fisher pelt, and the lack of trapping regulations at the time made it easy for fisher populations to be overexploited.

The establishment of the Washington Fish and Wildlife Commission in 1934 resulted in the first trapping regulations in the state, which included the prohibition of fisher trapping. Despite more than 60 years of protection from trapping, the fisher population did not recover in Washington and was listed as a state endangered species in 1998. 

Fisher, the animal, not a fisherman

The fisher has several remarkable qualities which, again, few people know about. Fishers are uniquely skilled at preying on and eating porcupines, and they can do this without suffering significant injuries. Foresters in the Great Lakes states and New England quickly recognized the value of restoring the fisher in areas where overabundant porcupines were devouring merchantable timber. Fisher reintroductions not only served to address porcupine over-population concerns, they also reestablished a valuable furbearer to a region. Fishers are among the most successfully reintroduced carnivores, and with the loss of fishers throughout much of their range, reintroductions are an important tool for fisher conservation.

Washington Department of Fish and Wildlife, Olympic National Park, and Conservation Northwest recognized the need for reintroductions to recover fishers in Washington. These organizations along with the US Geological Survey, US Fish and Wildlife Service, US Forest Service, and British Columbia Ministry of Environment became partners, and we embarked on fisher reintroduction, monitoring, and research efforts.

The release of 18 British Columbia fishers to Olympic National Park in January and March of 2008 was the first step toward reestablishing a self-sustaining fisher population in Washington. By 2010, we hope to complete the reintroduction of 100 fishers to the Olympic Peninsula and find that a self-sustaining population is becoming established.

Prior to releasing the first 18 fishers (12 females and 6 males, each equipped with a radio-transmitter so we can monitor them), we expected that most would make exploratory movements before settling into an area to give birth or establish a home range.

Most of the fishers did make exploratory movements, but the movements were more frequent, much greater in distance (commonly >30 km and one of 99 km) and continued much longer into the summer than we expected. We’ve had fishers travel to the four corners of the Olympic Peninsula: from the Elwha Valley and Hurricane Ridge release sites northwest to Neah Bay, southwest to Ocean Shores, southeast to Lake Cushman, and east toward Quilcene. There is little of the Olympic Peninsula that has not already been surveyed, scrutinized, and sniffed by a fisher.

We hoped for high first-year survival of released fishers (e.g., >65%), but we knew that survival of fishers reintroduced into an unfamiliar landscape could be very low (e.g., <35%). Although we’ve monitored these released fishers for only 6 to 8 months, it seems very encouraging that only two fishers have died. 

We have not yet been able to document reproduction, but we continue to track females that may have kits in tow. Because Olympic National Park is challenging when it comes to tracking a wide-ranging carnivore on foot, we are also using alternative techniques to detect the presence of young fishers.

We have placed digital cameras at remote bait stations within the commonly used areas of one female in an effort to photograph her and any kits she may have. We are also planning to use hair snare stations to get DNA from released fishers and their young. 

Overall, we are really impressed with how well released fishers can traverse the Olympic Peninsula. They don’t seem to be impeded by the rugged terrain of the interior of Olympic National Park, which may be a good sign for suitability of habitat in other parts of the state.
Our present goal is to establish a substantial, self-sustaining population of fishers on the Olympic Peninsula. If we succeed at that, we may be able to reintroduce Olympic fishers to the Washington Cascades, which will be a huge step toward fisher recovery in the Pacific Northwest.