The American marten (Martes americana), also known as the American pine marten, is a species of North American mammal, a member of the family Mustelidae. The species is sometimes referred to as simply the pine marten. The name "pine marten" is derived from the common name of the distinct Eurasian species, Martes martes. It is found throughout Canada, Alaska, and parts of the northern United States. It is a long, slender-bodied weasel, with fur ranging from yellowish to brown to near black. It may be confused with the fisher (Pekania pennanti), but the marten is lighter in color and smaller. Identification of the marten is further eased by a characteristic bib that is a distinctly different color than the body. Sexual dimorphism is pronounced, with males being much larger. The diet is omnivorous and varies by season, but relies chiefly on small mammals like voles. They are solitary except during the mid-summer breeding season. Embryonic implantation is delayed until late winter however, with a litter of 1–5 kits born the following spring. Young stay with the mother in a constructed den until the fall, and reach sexual maturity by one year old. Their sable-like fur made them a thoroughly trapped species during the height of the North American fur trade. Trapping peaked in 1820, and populations were depleted until after the turn of the century. Populations have rebounded since, with them being considered a species of least-concern by the IUCN; however, they remain extirpated from some areas of the Northeast, and of the 7 subspecies, one is threatened. The American marten is broadly distributed in northern North America. From north to south its range extends from the northern limit of treeline in arctic Alaska and Canada south to New York. From east to west, its distribution extends from Newfoundland to western Alaska, and southwest to the Pacific coast of Canada. In Canada and Alaska, the American marten's distribution is vast and continuous. In the northeastern and midwestern United States, American marten distribution is limited to mountain ranges that provide preferred habitat. Over time, the distribution of American marten has contracted and expanded regionally, with local extirpations and successful recolonizations occurring in the Great Lakes region and some parts of the Northeast.