Fisher (Martes pennanti)
Fishers (locally called fisher-cat, although they're not related to cats nor do they eat a lot of cats) have long, slender bodies with muscular, short legs similar to their cousins -- weasel, mink, marten, and otter. Their thick, grayish-brown to brownish-black glossy fur tends to be darker on females. White-tipped hairs on older fisher give a grizzled appearance. Fisher have strong claws for climbing and a long, bushy, black, tapered tail. Males average 4-12 pounds, about twice the size of females.
Range and Distribution
Fisher are found from southeastern Alaska and British Columbia east to northern Minnesota, upstate New York, northern New England, and eastern Canada and south to the California Sierra Nevada Mountains and the Rocky Mountains in Wyoming.
Once common throughout New England, fisher declined due to over-trapping, logging, and land conversion. Trapping regulations and agricultural abandonment leading to natural reforestation enabled fisher populations to rebound throughout the Granite State.
Habits and Habitats
Fisher, although carnivorous, generally eat whatever comes along. Their main prey include snowshoe hare, porcupine, small mammals (mice, voles, shrews, moles) , and squirrels (gray, red, and flying squirrels). They also feed on birds, amphibians, insects, fruits, nuts, and carrion. They help keep mice and vole numbers under control. Fisher kill porcupines by repeated swift attacks to the face and head. After killing the porcupine, the fisher flips it over on its back and starts eating the belly. Mating occurs in March and April with a litter of 1-6 (average is 3) kits born nearly a year later. Females usually give birth in a tree cavity 20-30 feet off the ground.
Fishers are solitary except during the mating season. Fisher travel along ridges, crossing stream valleys to reach the next ridge.
They range widely in search of food, traveling up to 60 miles on some hunting forays. They regularly travel over 10-20 square miles, although this home range is not defended. Fisher are active throughout the year, mostly at night, sunrise, and sunset.
Fisher occupy mature softwood, mixed hardwood-softwood, and forested wetlands. The amount of structural diversity is likely more important as habitat criteria than the tree species and forest types. Fisher use hollow trees and logs, rocky outcrops, old porcupine dens, root masses, and brush piles as den sites and hunting areas. They'll tear apart decaying snags in search of their prey. To keep warm during cold spells they seek shelter in these temporary dens or under the snow. The meandering tracks of fisher are easily seen on snow cover in winter, whereas the animal itself is elusive. Deep snows, however, limit the mobility of fisher.
The following management strategies will help maintain fisher habitat:
- Retain a diversity of dead, dying and down woody material, including cavity trees.
- Retain or create dense forest patches of softwood understory cover.
- Release and maintain wild apple trees.
- Create small forest openings to enhance vegetation diversity and prey abundance.
- Minimize fragmentation of forested habitat from development.