Stoat (Mustela erminea)

The Stoat is a small carnivore closely related to the smaller Weasel. It can be identified by a distinctive black tip to its tail. It is an attractive animal with a long slim body, sort legs and white belly with chestnut brown fur which can turn completely white in winter cold environments with the exception of the black tail tip. This white fur is known as ermine to the fur trade and was traditionally used in the UK for ceremonial clothes for royalty. Females are more likely to turn white than males and if you see a white animal it is definitely a Stoat as weasels don’t turn white. Males are larger than females with males being around 30cm long and weighing up to 450grams and females being at least 2 cm shorter and up to 300grams lighter.

Prey

The stoat is primarily (but not exclusively) a carnivore, hunting mainly at night and prone to scavenging anything edible.  It is a ferocious hunter taking rats, mice, voles and shrews, young rabbits, grass snakes, slow-worms and the occasional fish. The wide variety of diet has helped the species to be successful and bird’s eggs, berries, insects and scraps are also on the menu.

Agile and fast, Stoats are good climbers and strong swimmers crossing rivers and climbing trees to find prey often taking young birds in nests or tackling prey many times their size. They hunt in a methodical zigzag pattern avoiding being in open ground for long due to airborne predators they use walls, ditches and hedges for cover. Most prey is killed by a single bite to the back of the neck severing the spinal cord.  Females will go out hunting with their young which can be numerous which has given rise to the false idea that Stoats hunt in packs. Despite this they are not aggressive animals and can be very curious if one darts in front of you it can often be attracted back to have another look by jangling keys, or making a whistling/sucking sound on the back of your hand, they have excellent hearing but not so good eyesight.  It was thought that stoats could catch myxomatosis from rabbits but this is not the case although a fall in rabbit population affects the stoat population as rabbits form a large part of their diet.

They have several natural predators including birds of prey, foxes and owls and are often shot by game keepers to protect game birds, it is protected by law in Ireland but not in the UK. The trapping of stoats for their fur had little effect on the population as mortality is fairly high with shortage of food being the main killer of young stoats. They don’t compete for the same food as weasels as the stoat takes far larger prey whereas the weasel is a better tunnel hunter.

Habitat

Stoats are found all over Britain and Ireland (where it is sometimes called a Weasel as true Weasels are not found in Ireland). They are adaptable and will live anywhere with suitable prey and ground cover from woodland to some urban examples. Nests are often the homes of former prey which the stoats line with rodent fur in colder areas; a stoat will have several dens in its territory and move between them regularly, common nest sites are mole hills/ tunnels, hollows in trees and holes in walls and embankments. Males and females scent mark and live separately except in breeding season.

Breeding

Stoats mate in late May early June but interestingly implantation is delayed until spring the next year (a 10 month gap!) and gestation is then about 30 days.  A litter of Kit’s (young stoats) is between 6 and 12 and they are born naked , blind and deaf, they are weaned in about 5 weeks and stay with the mother for about 12 weeks in total often hunting with her as they get older as mentioned earlier, the male stoats are not involved. The UK stoat population is estimated at 450,000 before the breeding season.