Smithsonian National Museum of Natural History, North American Mammals

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  Carnivora · Mustelidae · Mustela erminea

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Mustela erminea


Order: Carnivora
Family: Mustelidae

Click to see a 3-D view.
Image of Mustela erminea
Mustela erminea - summer coat depicted here; winter coat is white except for black tail tip
Click to enlarge. (101 kb)

Conservation Status: Least Concern.

Ermine are highly adaptable predators, easily invading small burrows to feed on voles, mice, and young rabbits. They also eat earthworms, frogs, and squirrels, climbing trees and swimming if necessary. Mother Ermine teach their young to hunt. Litters of 4 to 9 young are born in nests that are often located in rodent burrows. The newborns are blind and helpless, but in six weeks are almost adult-size. In the summer, the Ermine's coat is brown, but in the winter it is pure white except for the tip of the tail, which stays black. Ermine population density tends to fluctuate as rodent populations fluctuate.

Also known as:
Short-tailed Weasel, Stoat

Sexual Dimorphism:
Males are approximately twice the size of females.

Average: 272 mm males; 240 mm females
Range: 219-343 mm males; 190-292 mm females

Average: 80 g males; 54 g females
Range: 67-116 g males; 25-80 g females


Linnaeus, C., 1758.  Systema Naturae per regna tria naturae, secundum classis, ordines, genera, species cum characteribus, differentiis, synonymis, locis, Tenth Edition, Laurentii Salvii, Uppsala, 1:46, 823 pp.


Mammal Species of the World (opens in a new window).

Mammalian Species, American Society of Mammalogists' species account *
* PDF reader available here (opens in a new window).

Distribution of Mustela erminea

Image of Mustela erminea
Click to enlarge. (100kb)

Image of Mustela erminea
Mustela erminea (Ermine), Appalachian Trail
Click to enlarge. (321kb)