Most small carnivores belong to the Mustelidae family. The mustelids are a diverse group, including otters, martens and badgers, which are adapted to aquatic, arboreal and subterranean lifestyles respectively. The world's largest and most successful mustelids live in the Americas, where they are found from the icy north to the humid tropics.

The fisher, or pekan, lives in the thick forests of North America. Despite its name, it feeds on small land animals, such as mice and porcupines. Fishers have no permanent dens, but take shelter in hollow trees, holes in the ground and even abandoned beaver lodges.

They are active during the day and night, and despite being expert climbers, spend most of their foraging time on the ground. When they come across suitable prey animals, they rush forward and kill them with bites to the back of the neck. Larger animals are killed with repeated bites to the face.

Fishers have dark fur that is coarser than that of most mustelids. Nevertheless, they are still hunted by humans for their fur.

Males seek out mates during the spring breeding season and litters are born about ten months later. As with many mustelids, the fertilized eggs do not begin to grow immediately inside the females. Their development is delayed for several months so that they are born at the right time of year. Unusually, births always take place in trees.

Distribution: Canada and northern United States.

Habitat: Conifer forest.

Food: Birds, rodents, carrion.

Size: 49 - 63 cm (19 - 25 in); 1.3 - 3.2 kg (2.75 - 7 lb).

Maturity: 1 - 2 years.

Breeding: 3 young born every spring.

Life span: 10 years.

Status: Lower risk.