Fishers live in similar habitat, have similar tracks and are darker in color than pine martens. Stone martens are non-native species and are also about the size of the male pine marten. Marten are rather solitary creatures except during the mating season. Mating pairs are temporary and the males may have several mates at the same time. May. Home ranges of the marten vary in size in response to population levels and food availability.
Martens prey on small mammals, particularly mice and voles.
The marten's diet can also include insects, various fruits and nuts, and passerine birds. As a species, pine martens are not endangered in the U.S. or Canada. In some parts of their range, however, martens have been extirpated or are endangered. In 1972, pine martens were placed on the Wisconsin Endangered Species List . Only through recent efforts to introduce martens from other parts of North America has a population been reestablished in Wisconsin.