Stoat  (Mustela erminea)

The stoat is classified as Least Concern (LC) on the IUCN Red List (1). Listed under Appendix III of the Bern Convention, and classified as a species of conservation concern under the UK Biodiversity Action Plan (3).

Stoats (Mustela erminea) are elusive predators, with long, slender bodies and short legs (2). The pelage is reddish to ginger in colour with white or cream underparts (2). Some individuals turn either partially or fully white in winter (2). The tail has a black tip, a feature that allows stoats to be distinguished from weasels (2). The head, which is supported by a fairly long neck, is triangular in shape, and features bright black eyes, long whiskers and round ears (4). Male stoats are much larger than females (4). At birth the kits are covered with fine white hair, and a dark 'mane' of fur forms around the neck after the third week (4).

Widespread and common throughout mainland Britain and Ireland (5), and occurs on a number of the larger islands around the UK (5). The stoat is found throughout north temperate and cold parts of Eurasia and North America (4).

You can view distribution information for this species at the National Biodiversity Network Gateway.

The stoat inhabits a range of habitats including open moor, woodland, farmland and marsh (5).

The stoat is a carnivore, and a very skillful predator (4), typically feeding on birds and small mammals, particularly rabbits and small rodents, even taking prey as large as rats and grey squirrels (6). They hunt in a zigzag pattern, making use of features such as walls and hedgerows to provide cover, probing crevices and holes, and often standing alert on the hind legs to look around (4). Their exceptionally keen senses help them to locate prey; they try to get as close as possible to their target, before rushing in and dispatching it with a swift bite to the back of the neck (4). Males (dogs, bucks, jacks or hobs) (7) and females (bitches, does, or jills) (7) live in separate territories, which they defend against individuals of the same sex (2). In spring, males set off to search for females (2). Mating occurs in early summer, but births do not occur until the spring of the following year, as development of the fertilised egg is delayed (2) for eight to nine months (4). Between 6 and 12 blind, helpless kits are born per litter (2); after about eight weeks the young stoats begin to hunt alongside their mother (4). Females are able to mate before they are fully weaned at just 60 to 70 days of age, whereas males are unable to breed until they reach at least 2 years of age (4). Females typically stay within or close to the area of birth, and males disperse and establish large territories that overlap several female ranges (4). Predators of stoats include owls, larger carnivores and hawks (2). The average life expectancy of a stoat is just 1.5 years (5).

Stoats are controlled by gamekeepers because they prey on gamebirds (5). Historically they were trapped extensively for their winter fur (ermine). At present, competition with foxes, declines of farmland bird populations, habitat loss (5) and the effects of rodenticides (6) may all be affecting stoats (5). Although the current status of stoats in the UK is unclear, it is apparent that the population has not shown an increase following the post-myxamatosis recovery of rabbit populations (7). This fact is cause for concern regarding the conservation status of this species (7).

Research is currently being carried out to determine whether the populations of weasels and stoats, our smallest carnivores are in decline (7).

There may be further information about this species available via the National Biodiversity Network Gateway.

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the stoat, visit:

• BBC Wildlife Finder:
  http://www.bbc.co.uk/nature/species/Stoat