The Least Weasel, also known as the common, dwarf, pygmy, or mouse weasel (Mustela nivalis) is the smallest of all species of the Carnivora order, making it the smallest true carnivore. Least Weasels are found through much of the Palearctic and Nearctic regions of the Northern Hemisphere including Alaska, Canada, northern United States, Britain, continental Europe, northern Asia and Japan. They are absent from Ireland, the Arabian Peninsula, and Greenland. They have been introduced into New Zealand.
Ten Facts about Least Weasel
- The least weasel is commonly found in meadows, marshes, farmlands, prairies, semi-deserts and grassy fields, yet tends to avoid woodlands, sandy deserts and open spaces.
- The least weasel has a long, slender body with short, fine underfur and longer guard hairs. It possesses a flat, narrow head, with black eyes and round ears. It has short limbs with its feet having five fingers with sharp claws.
- Males are larger than females:Total length of males: 18-25 cm (7.1-9.8 in); females: 16.5-18 cm (6.5-7.1 in).
- Weight is weight of males: 40-55 g (1.4-1.9 oz); females: 30-50 g (1.1-1.8 oz).
- Small rodents make up the majority of the least weasel's diet. On average, this small carnivore must consume half of its body weight every day to survive. This is about two deer mice or one meadow vole each day.[2] When rodents are not readily available, the least weasel will eat birds' eggs, nestlings, insects, and lizards.
- Male least weasels reach sexual maturity at eight months, while females reach maturity at four months.[2] Males are sexually active throughout the year but most breeding occurs in spring and late summer.
- The gestation period is 35 days. Females care for and nurse their young until they become independent.
- Litters may range from 1-6 and the young are born wrinkled, pink, naked, blind and deaf.[4] At 11 days, the young are covered with a fine white body hair, and by 18 days they have brown hair on their backs with white bellies.
- It spends its time, day and night, hunting, feeding, and sleeping.[2] When the least weasel hunts, it watches its prey's movements before attacking.
- Both male and female least weasels have body diameters no larger than their prey, which allows them to to follow their prey into burrows, tunnels, and matted grass.
