The fisher, often mistakenly called a “fisher cat,” is a medium-sized mammal native to North America. Despite its common name, it is not a feline and rarely consumes fish. This agile predator belongs to the weasel family, Mustelidae, alongside animals like martens and wolverines.
Physical Characteristics and Taxonomy
The fisher has a long, slender body, short legs, and a bushy tail, often one-third of its total length. Its fur ranges from deep brown to black, often appearing grizzled with hoary-gold or silver guard hairs, particularly on its head and shoulders. Fishers have a pointed snout and small, rounded ears. Males are significantly larger than females, typically weighing 3.5 to 6.0 kilograms and measuring 90 to 120 centimeters, while females weigh 2.0 to 2.5 kilograms and are 75 to 95 centimeters long.
The fisher is classified as Pekania pennanti. It is closely related to, but larger than, the American marten. The origin of its common name is believed to stem from “fichet” or “fitch,” a European polecat whose pelt resembled the fisher’s, rather than any affinity for fish. Another theory suggests the name came from its habit of raiding traps baited with fish.
Habitat and Distribution
Fishers are widespread across the northern forests of North America, inhabiting areas from Nova Scotia to British Columbia in Canada, and extending south into the New England states, the Great Lakes region, and the Appalachian Mountains in the United States. Isolated populations also exist in the Sierra Nevada of California. They prefer dense coniferous or mixed forests with continuous tree cover, ideally over 80% canopy coverage, and avoid open landscapes. While they adapt to some disturbed areas, they show a clear preference for mature forest environments.
Diet and Hunting Behavior
Fishers are opportunistic carnivores with a varied diet, primarily consisting of small to medium-sized mammals such as snowshoe hares, squirrels, mice, voles, and rabbits. They also consume birds, insects, and eat carrion, fruits, and berries. A notable aspect of their diet is their ability to hunt porcupines, which few other predators attempt. The fisher repeatedly attacks the porcupine’s face, its only vulnerable area without quills, typically taking 20 to 35 minutes to subdue the animal.
They are agile hunters, climbing trees to pursue prey and hunting on the forest floor. Their anatomical adaptations include the ability to rotate their hind feet nearly 180 degrees, allowing them to descend trees head-first. Fishers rely on their keen sense of smell and acute hearing to locate prey, often stalking before pouncing with precision.
Behavior and Ecology
Fishers are largely solitary animals, associating with others mainly during the mating season. They are crepuscular, active at dawn and dusk, though they can be observed during the day. While excellent climbers, they spend most of their time on the forest floor, foraging around fallen trees and other natural structures. Fishers use various resting sites, including hollow trees, logs, stumps, and ground burrows.
While generally quiet, fishers produce vocalizations such as chuckles, growls, and hisses. Their calls are sometimes mistaken for those of other animals, like the red fox, which can create misconceptions about their presence. In their ecosystem, fishers play a role as predators, helping to regulate populations of their prey, including porcupines, which can impact forest health if their numbers are unchecked. Though they have a reputation for ferocity, fishers typically avoid human contact; aggression towards people is rare, usually occurring only when the animal feels threatened or provoked. Claims of frequent attacks on domestic pets are largely unsubstantiated, with studies indicating such occurrences are uncommon.