The American ermine or American stoat (''Mustela richardsonii'') is a species of

mustelid The Mustelidae (; from Latin , weasel) are a diverse family of carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the suborde ...

native to most of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

refers to Arctic explorer and naturalist John Richardson.

Description

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.

Taxonomy

It was long considered conspecific with the

stoat The stoat (''Mustela erminea''), also known as the Eurasian ermine or ermine, is a species of mustelid native to Eurasia and the northern regions of North America. Because of its wide circumpolar distribution, it is listed as Least Concern on th ...

(''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 American Society of Mammalogists (ASM) was founded in 1919. Its primary purpose is to encourage the study of mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence ...

. 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 Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

(although it is found on some islands in southeastern Alaska), eastern

Yukon Yukon () is a Provinces and territories of Canada, territory of Canada, bordering British Columbia to the south, the Northwest Territories to the east, the Beaufort Sea to the north, and the U.S. state of Alaska to the west. It is Canada’s we ...

, most of

Arctic The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, and

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

, where it is replaced by '' M. erminea''. It reaches the northern extent of its range in

Ellesmere Island Ellesmere Island (; ) is Canada's northernmost and List of Canadian islands by area, third largest island, and the List of islands by area, tenth largest in the world. It comprises an area of , slightly smaller than Great Britain, and the total ...

and a portion of eastern mainland

Nunavut Nunavut is the largest and northernmost Provinces and territories of Canada#Territories, territory of Canada. It was separated officially from the Northwest Territories on April 1, 1999, via the ''Nunavut Act'' and the Nunavut Land Claims Agr ...

and ranges from here to cover almost all of western North America south to northern

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

, and eastern North America south to northern

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

. It is absent from most of the

Southeastern United States The Southeastern United States, also known as the American Southeast or simply the Southeast, is a geographical List of regions in the United States, region of the United States located in the eastern portion of the Southern United States and t ...

and the

Great Plains The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...

Diet

In North America, where the

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of Resource (biology), resources an ...

for rat- and rabbit-sized prey is taken by the larger

long-tailed weasel The long-tailed weasel (''Neogale frenata''), also known as the bridled weasel, masked ermine, or big stoat, is a species of weasel found in North America, North, Central America, Central, and South America. It is distinct from the Stoat, short-t ...

(''Neogale frenata''), the American ermine preys on mice, voles, shrews, young cottontails, chipmunks, deer mice, jumping mice, and house mice. Usually the ermine kills by biting at base of skull. Small birds, frogs, small fish, and earthworms are other types of prey for ermines.Ahlborn, G. “Life History Account for Ermine.” Life History Accounts for Species in the California Wildlife Habitat Relationships (CWHR) System, 1988.

Habitat

Ermines live and find cover from predators in hollow spaces from logs, burrows and man made structures. Ermines sometimes den within their prey's nest and use their skin and fur as a lining for their den.

Breeding

They breed in dense parts of the forest. The season for breeding is late springtime to the summer from July to August. The males mature in a year while the females only take three to four weeks to mature. The females carry a litter of four to seven babies for 255 days then gives birth.

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:

Relationships with humans

The fur of ermine was valued by the

Tlingit The Tlingit or Lingít ( ) are Indigenous peoples of the Pacific Northwest Coast of North America. , they constitute two of the 231 federally recognized List of Alaska Native tribal entities, Tribes of Alaska. Most Tlingit are Alaska Natives; ...

and other

indigenous peoples of the Pacific Northwest Coast The Indigenous peoples of the Americas, Indigenous peoples of the Pacific Northwest Coast are composed of many nations and tribal affiliations, each with distinctive cultural and political identities. They share certain beliefs, traditions and prac ...

. They could be attached to traditional regalia and cedar bark hats as status symbols or made into shirts.

Gallery

File:Stoat and chipmunks.png, American ermine surplus killing a family of

chipmunk Chipmunks are small, striped rodents of subtribe Tamiina. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia. Taxonomy and systematics Chipmunks are classified as four genera: '' ...

s, as illustrated by

Ernest Thompson Seton Ernest Thompson Seton (born Ernest Evan Thompson; August 14, 1860 – October 23, 1946) was a Canadian and American author, wildlife artist, founder of the Woodcraft Indians in 1902 (renamed Woodcraft League of America), and one of the foun ...

File:Frenataermineanivalis.png, Skulls of a

(top), an American ermine (bottom left), and

least weasel The least weasel (''Mustela nivalis''), little weasel, common weasel, or simply weasel is the smallest member of the genus ''Mustela,'' Family (biology), family Mustelidae and Order (biology), order Carnivora. It is native to Eurasia, North Ame ...

(bottom right), as illustrated in

Merriam Merriam can refer to: People * Alan P. Merriam (1923–1980), American ethnomusicologist * Charles Edward Merriam (1874–1953), American political scientist *Charles W. Merriam (1877–1961), American insurance businessman and politician * Clinton ...

's ''Synopsis of the Weasels of North America'' File:American Ermine, FWG.jpg, Winter coat

References

Bibliography

* * {{Taxonbar, from=Q41085321 Weasels Mammals of Canada Mammals of North America Taxa named by Charles Lucien Bonaparte Mammals described in 1838 Taxobox binomials not recognized by IUCN