Fisher
Pekania pennanti
Background: In the nineteenth century, fishers became scarce due to forest logging, clearing for agriculture, and overexploitation. By the 1900s, fishers were considered extirpated from the state. Reforestation and changes in land-use practices have restored the suitability of the fisher’s habitat in part of its historic range, allowing a population to recolonize the northeastern section of the state. Fishers did not recolonize suitable habitat in northwestern Connecticut, since the region was isolated from a source population. Fishers were rare in western Massachusetts, and the developed and agricultural habitats of the Connecticut River Valley were a barrier to westward expansion by fishers in northeastern Connecticut.
A project to reintroduce this native mammal into northwestern Connecticut was initiated by the Wildlife Division in 1988. Funds from reimbursement of trapping wild turkeys in Connecticut for release in Maine were used to purchase fishers caught by cooperating trappers in New Hampshire and Vermont. In what is termed a "soft release," fishers were penned and fed at the release site for a couple of weeks prior to being released. Through radio and snow tracking, biologists later found that the fishers that were released in northwestern Connecticut had high survival rates and successfully reproduced. As a result of this project, a viable, self-sustaining population of this native mammal is now established in western Connecticut. Fishers found throughout eastern Connecticut are a result of natural range expansion.
In 2005, Connecticut instituted its first modern day regulated trapping season for fishers. Most northern states have regulated fisher trapping seasons. Fisher fur is valuable, especially the smoother, more silky pelts of the females.
Range: The fisher ranges from southeastern Alaska to Hudson Bay, through Canada, south into
the northern United States. It can also be found in the Rocky Mountains in Wyoming and the Sierra Nevada in California.
Description: The fisher’s long, slender body, short legs, and elongated bushy tail are usually dark brown to nearly black. The tail, rump, and feet are darkest in contrast to the head and shoulders, which are lighter in color and often grizzled in appearance, especially in males. Some individuals have a white chest patch. Fishers have 5 toes on each foot and semi-retractable claws, which contribute to their ability to climb trees.
Males typically weigh 8 to 14 pounds and measure 36 to 40 inches in length. Females weigh 4 to 6 pounds and measure 30 to 36 inches long.
Habitat and Diet: Fishers prefer large tracts of coniferous or mixed hardwood-softwood forests containing large trees for denning.
Their diet consists of squirrels, rabbits, mice, voles, carrion, fruits, mast (primarily beechnuts), porcupines, birds, and frogs.
Life History: In Connecticut, fishers have their young in March and April. The 2 to 4 kits are born with closed eyes and are helpless. The few accounts of natal dens indicate that tree cavities are used for birth and the early rearing of young. Only the female cares for the young. The kits develop rapidly and are weaned in 4 months. Both males and females are sexually mature at 1 year of age, but females will not bear offspring until age 2.
Interesting Facts: The fisher is a large member of the Mustelidae (weasel) family. Its name is misleading because unlike the closely related river otter, fishers seldom eat fish. The name may have been derived from “fitch,” the European polecat, a species familiar to early settlers who may have seen a resemblance or mistaken the fisher for the polecat. In French, the pelt of a polecat is called “fiche,” “ficheux,” or “fichet,” names which are similar to “fisher.” Common names include fisher cat, black cat, and pekan.
The fisher has a high metabolism typical of most members of the weasel family. Although primarily nocturnal, it is active day and night throughout the year. Fishers are also generally solitary, except for a brief period during the breeding season. All mustelids, including fishers, undergo delayed implantation; the fertilized ovum develops only slightly and then remains dormant for nine to 10 months before attaching to the uterine wall and completing growth. About one week after a female gives birth, she breeds again.
Because fishers seldom travel in open areas and tend to be nocturnal, they are rarely seen by humans. They have not been studied as extensively as many other wildlife species, since they are often difficult to observe. Home range estimates vary, ranging from three to 15 square miles and averaging four to eight square miles in suitable habitat. Males range over larger areas than females. Population density also varies with habitat suitability; there may be an average of one fisher per three to five square miles in quality habitats.
Fishers also use tree cavities as non-natal dens and will den or rest in the thick growth of conifer trees and in tree nests of squirrels or large birds. They are known to use ground cavities such as rock crevices in winter.
Fishers hunt by zig-zagging through areas of thick, regenerating forest vegetation, but they traverse areas with little ground cover in a relatively straight line, hardly changing direction. Capable climbers, fishers often investigate large trees that might harbor prey such as squirrels, which den or nest in trees. They do not stalk or chase prey but rely on surprising their quarry.
Alert and secretive, the fisher is a rewarding sight to the wildlife observer. Finding and identifying fisher tracks can add interest to a winter hike or cross-country ski trip.
Tracks: A fisher’s foot has 5 digits. The palm pad of the front foot is C-shaped, curving away from the toes. The heel pad sometimes shows in the track impression of the front foot. Claw marks are visible. Fishers hunt by zig-zagging through areas of thick, regenerating forest vegetation. Fisher tracks can look different depending on substrate conditions. The track pattern above illustrates the fisher’s 2-2 running pattern; it exaggerates the size of the tracks because there are actually 4 prints – 2 hind tracks overlapped over 2 front tracks.
The Technical Assistance Informational Series is 75 percent funded by Federal Aid to Wildlife Restoration - Pittman-Robertson (P-R) Program. The P-R Program provides funding through an excise tax on the sale of sporting firearms, ammunition, and archery equipment. The remaining 25 percent of the funding is matched by the Connecticut Wildlife Division. (rev. 2/18)