Stoat and weasel
These species are more numerous than any other Scottish carnivore, though the stoat is the more abundant of the two.
The stoat (Mustela erminea) and the weasel (Mustela nivalis) are widespread and abundant. Gamekeepers routinely control both species, but they seem able to maintain healthy populations.
Both species habitually enter the tunnels of their prey. Their size difference affects the range of prey they can take.
Weasels are well suited to following field and bank voles along their runs and burrows, including tunnels formed beneath snow.
Stoats can only enter wider burrows such as those of the rabbit, rat and water vole. As rabbits form the bulk of the stoat’s diet, the distribution and population densities of prey and predator are closely related. Stoats are incredibly agile and will also climb trees and walls to reach birds’ nests.
More about the stoat
These very successful hunters are found across mainland Britain and can use a wide variety of habitats.
The stoat usually has a chestnut body with white underparts and a black-tipped tail. In colder climates, its winter coat is white (except for the tail tip) – and is known as ermine. A stoat may be up to 30cm long from nose to tail.
Stoats can travel up to 2km in a single hunting expedition of a few hours – and even further if food is scarce. They can reach speeds of up to 20 miles an hour and rely on their acute sense of smell to locate prey.
In winter, stoats are almost wholly nocturnal and are rarely seen. They travel as little as possible in colder months to conserve energy. Stoats are much more active during daylight hours in summer.
Stoats occasionally make dens in buildings, but this behaviour seems to be much less common than it is among pine martens.
Stoats are solitary animals, with males and females living in separate territories. Mating occurs in early summer, with the male travelling to a female. The development of the fertilised egg is delayed for around 9 months, and 6 to 12 kits are born in spring. Most females will only have one litter in a lifetime.
Young stoats begin to hunt with their mother at 8 weeks of age.