Stoat

Mustela erminea

Group: Predators & furbearers
Size class: Small (under 10 kg)
Family: Mustelidae

Range

Europe
North America
Arctic

Habitat

Farmland
Tundra

Range

Countries it is found in

47 countries

Afghanistan
Austria
Belarus
Belgium
Bosnia & Herzegovina
Canada
Croatia
Czechia
Denmark
Estonia
Finland
France
Georgia
Germany
Hungary
India
Ireland
Isle of Man
Italy
Japan
Kazakhstan
Kyrgyzstan
Latvia
Liechtenstein

Range from:ASM Mammal Diversity Database, GBIF occurrence records — read 2026-08-05

Chapter 01

Overview

The stoat (Mustela erminea), also the Eurasian ermine, is a mustelid native to Eurasia and the northern parts of North America. Its wide circumpolar distribution puts it at least concern on the IUCN Red List. The name ermine is used especially of the pure white winter coat, and of the fur: it was used by Catholic monarchs in the 15th century, sometimes as the mozzetta cape, and has long been used on the ceremonial robes of members of the House of Lords. Formerly treated as a single very widely distributed species, M. erminea was split in a 2021 study into three: M. erminea proper in Eurasia and Alaska, M. richardsonii across most of North America, and M. haidarum on several islands off the Pacific Northwest coast. In Europe it is found as far south as 41°N in Portugal and on most islands except Iceland, Svalbard, the Mediterranean islands and some small North Atlantic islands. Its vertical range runs from sea level to 3,000 m.

Chapter 02

Behaviour

Mating occurs in the northern hemisphere between April and July. In spring the male's testes enlarge, accompanied by rising plasma testosterone; spermatogenesis takes place in December, and males are fertile from May to August, after which the testes regress. The female is usually in heat only briefly, triggered by changes in day length, and copulation can last as long as an hour. Stoats are not monogamous, and litters are often of mixed paternity. They undergo embryonic diapause — the embryo does not implant in the uterus immediately, which is what stretches the interval between mating and birth. Mouse-like rodents predominate in the diet, but the stoat regularly takes larger rodents and lagomorphs, including individuals far larger than itself. In Russia its prey includes water voles, common hamsters and pikas, which it overpowers in their burrows. Small birds, fish and shrews are of secondary importance, and amphibians, lizards and insects rarer still. It also takes lemmings. In Great Britain rabbits are an important food source.