Photodisc Blue/Getty Images |

The fisher is primarily nocturnal, but will occasionally venture out during the day. Usually it spends the day sleeping inside hollow trees or logs.

It is aggressive and will eat just about anything it can kill, especially small mammals, birds, fish, and insects.


It is one of the few carnivores that preys on porcupine. When the porcupine takes refuge in trees, the fisher follows.

Because it is able to descend trees head-first, the fisher attacks the porcupine from above, biting its face — one of the few places without spines — and avoiding its quills.

It may gorge itself for two days on the carcass of one porcupine.

Animal Facts

Name: Fisher (Martes pennanti)

Family: Mustelidae (Mustelids)

Range: Canada and northern United States

Habitat: Coniferous forest

Diet: Rabbits, hares, rodents, porcupines, squirrels, birds, shrews, fruits, truffles, and carrion

Head and Body Length: 20 to 27 inches (50 to 70 cm)

Tail Length: 12 to 16 inches (30 to 42 cm)

Weight: 3 to 8 pounds (1.5 to 8 kg)

Life Cycle: Mating March to May, implantation delayed until January to March; gestation about 30 days, one to six young born

Description: Medium to dark brown coat; gold to silver on head, shoulders, legs, and tail; slender body; short legs; retractable claws; bushy tail

Conservation Status: Not listed by the IUCN.