American ermine

The American ermine has a body plan typical of weasels. It has short legs, a long body and neck, and a small triangular head with short round ears. It has a brown dorsum with a white venter (except during winter when the coat is fully white) and a short, black-tipped tail. The black coloring of the tail may serve to distract predators and divert attacks away from the body, which blends in more with its surroundings. American ermines are sexually dimorphic and males are 30% larger than females. == Taxonomy ==

The specific epithet, richardsonii, refers to Arctic explorer and naturalist Sir John Richardson. The American ermine was long considered conspecific with the stoat (M. erminea), but a 2021 study found it to be a distinct species, forming distinct genetic clades from erminea. The finding has been accepted by the American Society of Mammalogists. The Haida ermine (M. haidarum) is thought to be a hybrid species originating from ancient hybridization between M. erminea and M. richardsonii. == Distribution ==

The species is found throughout most of North America aside from most of Alaska (although it is found on some islands in southeastern Alaska), eastern Yukon, most of Arctic Canada, and Greenland, where it is replaced by M. erminea. It reaches the northern extent of its range in Ellesmere Island and a portion of eastern mainland Nunavut and ranges from here to cover almost all of western North America south to northern New Mexico, and eastern North America south to northern Virginia. It is absent from most of the Southeastern United States and the Great Plains. == Diet ==

Ermines are primarily nocturnal hunters, although they can also be seen frequently during the day. == Habitat and Breeding ==

Ermines are terrestrial and non-migratory, with an average home range of 12-16 hectares. Ermines live in hollow spaces in logs, under rocks or stumps, or in burrows and man-made structures. Sometimes, they will take over the nest of their prey and use their prey's fur as lining. == Predators ==

Some of the larger wild predators of ermines are minks, martens, fishers, bobcats, coyotes, and large owls and hawks. Occasionally a domesticated cat or dog may kill an ermine. Their small agile bodies help them evade these predators, while also allowing them to compete with their predators for food in more barren months. == Subspecies ==

About 13 subspecies are known: == Gallery ==

File:Stoat and chipmunks.png|American ermine surplus killing a family of chipmunks, as illustrated by Ernest Thompson Seton File:Frenataermineanivalis.png|Skulls of a long-tailed weasel (top), an American ermine (bottom left), and least weasel (bottom right), as illustrated in Merriam's Synopsis of the Weasels of North America File:American Ermine, FWG.jpg|Winter coat == References ==