Weasel (Mustela nivalis)

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Head/body length: Males 194 - 217mm; Females 173 -183 mm.
Tail: Males 42 - 52mm; Females 34 - 43mm.
Weight: Males 106-131g, Females 55-69g.


Long slender body, short tail.. Fur ginger to russet brown, cream below.

General Ecology:

Widespread throughout Britain, The Weasels is smallest and probably most numerous carnivores. . Weasles live in a variety of habitats ranging from urban areas, lowland pasture and woodland, marshes and moors. Weasels do not favour and are less common in habitat which does not support their prey Eg dense woodland with poor ground coverand h.igher altitudes , Weasles are absent from Ireland and most off-shore islands

Weasels specialise in hunting small rodents and their numbers depend on the abundance of their prey. The weasel's small size enables it to search through tunnels and runways of mice and voles. Access to tunnels means weasels can hunt at any time of the day or year. They do not hibernate and can hunt even under deep snow. Additional prey such as birds, eggs and young rabbits may be taken, particularly if rodents are scarce.

Dens can be nests of former prey which are confiscated , often containing food remains from the accumulation of meals. In colder latitudes Nests are often lined with fur from prey.Weasel home ranges can be made up of a number of dens and resting places that are visited at various frequenceies

Home ranges vary in size but is ultimately dependent on the density and distribution of prey. Male and females live in separate territories, male ranges being larger. Resident animals of both sexes may defend exclusive territories at times when numbers are high and neighbours numerous. Spring time sees the male extending their territories in search of a mate


Probably only one litter, of 4-6 young are born per season. Young are weaned at 3-4 weeks and can kill efficiently at 8 weeks. Family groups split up at 9-12 weeks.

Weasels are small enough to be taken asprey by predators such as , hawks, owls, foxes, cats and even Mink have been known to eat them.


Weasels have no legal protection . In bad rodent years many weasels perish and few survivors breed. Local populations often experience extinctions. Weasels nevertheless are good at recolonising abandoned areas when conditions improve.