Fisher have long slender bodies and range in color from gray brown to dark brown to nearly black with a long, tapering, bushy tail. Males weigh 7.5 to 12 pounds, and females 4.5 to 5.5 pounds. Adult males measure 35.5 to 47 inches in length, with females shorter at 29.5 to 37.5 inches. Fisher have two anal scent glands that produce a foul-smelling liquid. Fisher are primarily nocturnal and travel mostly on the ground, but they are agile tree climbers and sometimes swim.
Fisher are found in the northwest U.S., upper Great Lakes, and New England in dense forests of conifers mixed with hardwoods near water. Nest dens are high in hollow trees, with temporary dens under logs, brush, or tree roots. Fisher travel widely with a home range of 50 to 150 square miles, more if food is scarce. They prey on snowshoe hares, porcupines, rodents, birds, eggs, and carrion. Fisher are eaten by hawks, owls, coyotes, bobcats, and black bears. Breeding occurs in March and April with delayed implantation and birth 51 weeks after mating. Fisher have one litter a year, with 1 to 5 kits. Both sexes are sexually mature at one year of age.
