Long slender body with short legs. Medium-short tail (length 95-140mm) always
with a black tip. Fur reddish brown to ginger above, white to cream below. Some
animals turn white or partially white in winter.
Head/body length: Males 275-312 mm; females 242-292 mm.
Weight: Males 200-445g; females 140-280g.
The stoat occurs throughout Britain and Ireland, living in any habitat at any altitude with sufficient ground cover and food. The stoat's presence on offshore islands depends upon prey availability.
Stoats feed mainly on small mammals, especially rabbits and water voles where these are abundant. Small rodents are also taken, supplemented by birds, eggs, fruit and even earthworms when food is scarce. Stoats don't like to be out in the open and so tend to hunt along ditches, hedgerows and walls or through meadows and marshes. They search each likely area systematically, often running in a zig-zag pattern. All but the largest prey is killed by a single bite to the back of the neck.
The nests of former prey are taken over as dens which may be lined with rodent fur in colder climates. Within its territory the resident stoat will have several dens which it uses periodically.
Male and female stoats live separately, marking their territories with scent. These animals will defend their territory against intruders of the same sex, but in spring the males' system breaks down as they range widely in search of females.
Although females (including that year's kits, which may be only 2 - 3 weeks old) are mated in early summer, they do not give birth until the following spring because implantation is delayed for 9 - 10 months and gestation is only 4 weeks. Between 6 and 12 young are born - blind, deaf and barely furred. The female feeds them for up to 12 weeks, by which time they are developing into efficient hunters.
Food shortage is probably the main cause of death for young stoats but, at any age, they are occasionally taken by owls, hawks or larger carnivores. There is little competition for food between stoats and weasels. The stoat is much more aggressive and can handle larger prey, but the weasel is an excellent 'tunnel-hunter', reaching small rodents which the stoat cannot.
Stoats are sometimes called 'weasels' in Ireland, where the true weasel does not occur.
For many years gamekeepers and poultry farmers have attempted to control stoats. An animal getting into a shed or pen can kill every bird it holds. Such frenzied attacks are typical behaviour for many small carnivores faced with abundant 'prey'. Trapping is less intensive than it used to be (stoats were also taken for their skins, especially when in ermine) but it appears that this had little long-term effect on numbers as natural mortality is usually quite high in stoat populations.
Stoats are legally protected in Eire but not in the United Kingdom.
How can I tell a stoat from a weasel?
A stoat is larger than a weasel and its tail is proportionately longer ( 9-14cm for a stoat; 3-5cm for a weasel). The stoat's tail always has a black tip. Also, the dividing line between upper and lower body colour is straight on a stoat but irregular on a weasel. British weasels do not turn white in winter.
What makes the stoat go white in winter?
The shortening days of autumn bring on the moult from summer to winter coat. In northern populations the winter fur is white (known as ermine), whilst further south the colour change may be incomplete or not occur at all. In some areas certain animals turn white but others do not. Also, more females go white than males. The tip of the stoat's tail always stays black.
Do stoats hunt in packs?
In the autumn a female and her numerous young may go out hunting together, giving the impression of a 'pack'.
Does myxomatosis in rabbits affect stoats?
The disease cannot be passed from an infected rabbit to a stoat and where local outbreaks have killed many rabbits stoats will switch temporarily to other food. However, British stoat populations were severely reduced after myxomatosis wiped out nearly all the country's rabbits in the 1950's.
Is it true that you can attract stoats by making squeaking noises?
Stoats, and weasels, are particularly curious animals. They may come closer to investigate squeaking noises especially if they sound like the squeal of a rabbit in distress. Try standing still and sucking hard on the back of your hand.
Corbet, G.B. & Harris, S. (1991) The Handbook of British Mammals. (3rd edn.). Blackwell, Oxford.
King, C. (1989) The Natural History of Weasels and Stoats. Christopher Helm, London.
Sleeman, P. (1989) Stoats, Weasels, Polecats and Martens. Whittet Books, London.