Fishers are not just people who like to fish; they are also a small mammal related to badgers and minks. All are members of the weasel, or Mustelidae, family.

In Montana, fishers live in the thick forests in the northwestern corner of the state. Their fur is dark brown to black and they have long tails. The females, weighing around 4 pounds, are much smaller than the males, which can grow up to 12 pounds.

It’s believed fishers got their name because they were similar to a European animal called a polecat. Polecats were also called a fitch, fitchet or fitchew. Fishers are meat eaters, but are not known for eating fish.

Fishers are good tree climbers with claws that retract, like a cat’s. Their back feet also can swivel backward to help them climb down trees head first. This is one way that they attack porcupines—climbing down toward the prickly porcupine’s face where there are no sharp quills. Fishers are one of the few animals that target porcupines for food. They also eat mice, hares and raccoons.

The animals were believed to have all been killed in Montana by the 1930s, caught by trappers for their fur. So biologists captured fishers from other places and, in 1959 and 1960, put them in three northwestern Montana counties where they seem to be doing OK, according to Montana Fish, Wildlife & Parks’ Field Guide.

Some Oregon State University scientists were curious about how introducing fishers to a forest might affect similarly sized animals like grey foxes and ring-tailed cats, which are members of the raccoon family. So they set up an experiment and found that even though fishers may be small, they are pretty feisty and became the main meat eaters, outcompeting foxes and ringtails.

— Brett French,