The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook American Heritage Coll. This carnivorous, largely arboreal mammal is found in hardwood forests of Canada, the extreme N United States, and mountain ranges of the W United States.
Fishers have dark brown fur shading to black and frosted with white-tipped hairs.
Active both by night and by day, on the ground and in trees, the fisher makes its den in a hollow tree or a hole in the ground. It feeds on small mammals, birds, carrion, and fruits. Despite its name, it does not catch fish, although it will eat them. It is one of the few animals that eats porcupines, which it attacks by striking at the unprotected underparts. Once considered threatened with extinction, fishers are now increasing in numbers.