Pacific Fisher Is One Cool Critter

KS Wild has been working for many years to learn about the elusive Pacific fisher, and protect its forest habitat. Most recently, we sought federal Endangered Species Act protections for the rare forest carnivore. After biologists determined that the species needed these conservation measures, a political decision was made that failed to take action to protect the species. In addition to habitat loss from logging, rat poisons and illegal cannabis operations threaten the fisher.

The Pacific fisher is an ecologically important forest carnivore that lives in low elevation old-growth forests. Genetic work established that West Coast populations, living in the Sierra Nevada and the Klamath-Siskiyou region of northern California and southern Oregon, are distinct, verifying the notion of a "Pacific" subspecies. The extinction of the Pacific fisher would be a huge loss to the temperate forests of the Klamath-Siskiyou.

The fisher is about the size of a housecat. It has a long slender body with short legs. The face, neck and shoulders are silver or light brown, contrasting with the tail, legs and rump, which are black. Fisher prey mostly on small and medium-sized mammals, such as rabbits, porcupines, and squirrels, and will also consume birds, carrion, and even fruit on occasion. Instead of chasing prey, the fisher uses the "sneak attack," often from a tree perch.

The fisher plays a key role in regulating the populations of its prey species, many of which can become destructive if left unchecked. Most notably, it is a specialized predator of porcupines, which it kills by flipping over to expose the non-quilled belly.

Fisher are tied to closed canopy forests and require large trees for denning. They frequently travel along waterways and rest in or on live trees, snags, or logs with cavities. These characteristics are usually only found in large, undisturbed tracts of old forest. Douglas fir is the common tree used for resting in northern California. The diameter of trees used by fisher for resting and denning is consistently large. Rest sites are widely distributed throughout fisher habitat. Each individual travels over a home range of 50-150 square miles, even more in winter when food is scarce.

Logging and development have caused severe loss and fragmentation of old-growth forests, and now as little as 15% remains in California, Oregon and Washington. Historically, fisher occurred in closed canopy forest types down the West Coast to the southern Sierra Nevada.

In recent years the Pacific fisher has disappeared from Washington and most of Oregon. Around the turn of the twentieth century, fisher numbers dropped drastically and their range experienced an extreme contraction. Concurrent with trapping of fisher for fur was logging of fisher habitat, both for timber and to clear land for agriculture. The latter of these activities has led to the current isolation of fisher populations.

Severe loss and fragmentation of habitat caused by logging, trapping, and road building has led to the near extirpation of the fisher from its West Coast range. The recent large scale fragmentation of older forests on the West Coast and the combination of threats to this species have led to its precarious status. Fisher are still accidentally trapped and their low elevation habitat is the target of many current logging operations. Fisher experts recommend significantly increasing protections for this species, due to these threats.

The Pacific fisher desperately needs the protections of the Endangered Species Act. Immediate protection of this species is warranted by the small size and isolation of the remaining populations. Continued habitat loss from logging, development, and the use of anticoagulant rodenticides places the Pacific fisher in serious danger of extinction.