Common Name: Ermine
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Mustela
Species: Mustela erminea

photo M. Noonan

Ermine Taxonomy/Description

Ermine belong to the weasel family, Mustelidae, which they share with minks, otters, badgers, wolverines, and otters, in the Mammalian Order Carnivora. Its scientific name is Mustela erminea, which means "weasel ermine".

The ermine has a long, slender body and short legs. This animal’s coat coloration changes throughout the year. There are two color phases. During the winter months, the ermine is completely white, with the exception of a black tip of fur on its tail. The ermine’s coat color of the summer is generally a rich brown dorsally, and yellow ventrally. The black tipped tail fur is still present. The ermine is 7-14 inches long and weighs. Males are usually twice as large as females. Ermines weigh approximately one to five ounces.

Ermine Habitat/Diet

The ermine’s range includes temperate Eurasia and North America. This species inhabits a variety of habitats across central North America as well, with the exception of the Great Plains. Meadows bordering forests, marshes and riparian woodlands are preferred by this species. Burrows are lined with vegetation and are often old rodent burrows.

Ermines eat a variety of other animals. Rabbits and smaller mammals are their preferred prey. However, ermines will occasionally eat birds, eggs, insects, amphibians and small reptiles.

photo M. Noonan

Ermine Behavior/Reproduction

Ermines are solitary, associating only during mating season. Breeding takes place in late spring or early summer. Delayed implantation prevents the young from developing until 8-9 months later. Once implantation occurs, the gestation period is about 9 months. A female gives birth to one litter of 4-9 offspring. They are born altricial. This means the baby ermines are born relatively undeveloped, requiring large amounts of parental care. The young are cared for extensively, growing very fast. They are able to hunt alongside their mother by 8 weeks of age. Full size is not reached until 6 weeks, but sexual maturity is achieved at 60-70 days old. Ermine may live to 7 years of age, but usually do not live past 2 years in the wild.

Ermine Conservation

Ermines are not endangered. Some areas allow humans to trap ermine. However, as with all species, monitoring destructive human interactions with the environment, such as pollution and habitat destruction, are beneficial to this species.

Content provided by Canisius College students under the direction of Michael Noonan, PhD.