Stoat

The Stoat (Mustela erminea, also called the Eurasian ermine or ermine) is a small, slim mustelid found across Eurasia and the northern parts of North America. Because its range is so wide, it is listed as Least Concern on the IUCN Red List.

Stoats have a long neck, a nearly cylindrical body, short rounded ears, round black slightly protruding eyes and very long whiskers. The tail is always longer than a third of the body length and ends in a black tip. Males are roughly 25% larger than females. Males average about 258 g and measure roughly 19-33 cm in body length, while females weigh under 180 g and measure about 17-27 cm.

In summer the fur is sandy-brown on the back and head and white below. In the northern part of the range the coat turns completely white in winter, apart from the black tail-tip, and this white coat is the ermine. In southern areas the winter coat stays brown, though it is denser and sometimes paler.

The Stoat's direct ancestor was Mustela palerminea, a common carnivore in central and eastern Europe in the Middle Pleistocene. Its story began 5-7 million years ago, when northern forests gave way to open grassland and small burrowing rodents multiplied. The ancestors were larger than today's Stoat and shrank as they exploited this new food source.

Stoats first arose in Eurasia and thrived during the Ice Age, as their small size and long body let them work beneath snow and hunt in burrows. Fossil remains have been found in Denisova Cave. A 2021 study split the old wide-ranging species into three, with the Stoat proper living in Eurasia and Alaska.

Stoats have long been prized for their fur. Ermine was used by Catholic monarchs in the 15th century and has long trimmed the ceremonial robes of the UK House of Lords. Stoats were introduced to New Zealand in the 1880s to control rabbits and hares, with devastating effects on native birds. They have also been present in Orkney since 2010, where a large trapping project began in 2018.

Stoats are opportunistic predators that move quickly and check every burrow and crevice. Mouse-like rodents dominate the diet, but they also take larger prey such as rabbits, plus small birds, fish, shrews and, more rarely, amphibians, lizards and insects. In Britain, rabbits are an important food. Stoats climb trees to reach birds' nests and eat about a quarter of their body weight daily. Small prey die from a bite to the back of the neck, and surplus kills are often cached for later.

They do not dig their own burrows but use those of the rodents they kill, lining the nest with prey fur. Dens can also be in stumps, tree roots, brushwood, haystacks, rock piles and even magpie nests. Males hold larger territories that cover smaller female ones, and both sexes scent-mark with urine, droppings and glandular secretions.

Stoats are usually silent. Kits chirp, adults trill before mating, and a nervous Stoat hisses, adding sharp barks, shrieks and prolonged screeching when aggressive. When attacked or aggressive they release a strong musky odour from the anal glands.

Females mate in summer, but the embryos stay dormant for nine to ten months, so young are born the following spring after about 300 days. Males play no part in rearing the young.

Wild Stoats are prone to a range of parasites. The nematode Skrjabingylus nasicola is particularly threatening, as it erodes the bones of the nasal sinuses and lowers fertility. Fleas, ticks, lice and mites are also recorded, as are other worms.

Tuberculosis has been recorded in Stoats in the former Soviet Union and New Zealand, and symptoms of mange have been seen. They are largely resistant to tularemia.

In the wild, Stoats are preyed on by red foxes, various birds of prey including owls, buzzards and golden eagles, and grey herons. A severe winter can lead females to reabsorb their litters.

This is general awareness only, not veterinary advice. If you find an injured or unwell wild animal, contact a vet or a wildlife rescue.

What is a stoat?

It is a small, slim, meat-eating mustelid found across Eurasia and northern North America. It is also called the ermine, especially in its white winter coat.

Is a stoat the same as an ermine?

They are the same animal. The name ermine is used especially for the pure white winter coat or the fur made from it. In North America it is called a short-tailed weasel.

How can you tell a stoat from a weasel?

The Stoat's tail is relatively long, always over a third of its body length, and has a black tip. Its skull and teeth are also a little stronger than those of the least weasel.

Do stoats turn white in winter?

In the northern part of their range they do, keeping only the black tail-tip. In southern areas the coat stays brown, though it is denser and sometimes paler.

Do stoats really dance to hypnotise rabbits?

They reputedly mesmerise prey with a dance, but this behaviour could be linked to Skrjabingylus infections.

A male Stoat is called a dog, hob or jack, and a female is a jill. A group is called a gang or a pack.

Stoats moult twice a year, with a slow spring moult and a quicker autumn one, triggered by day length.

Kits are born blind, deaf and toothless, and females can be mated while still only a few weeks old.

The Stoat inspired the mascots Tina and Milo at the Milano Cortina 2026 Winter Games.

Ermine traditionally trims the ceremonial robes of UK peers and the academic hoods of Oxford and Cambridge, though rabbit or fake fur is now often used. Leonardo da Vinci's Lady with an Ermine shows one being held.