The Siberian weasel or kolonok (Mustela sibirica), is a medium-sized weasel native to Asia, where it is widely distributed and inhabits various forest habitats and open areas. It is therefore listed as Least Concern on the IUCN Red List.
The Siberian weasel has a long, stretched out body with relatively short legs. Its head is elongated, narrow and relatively small, and its short ears are broad at the base. Its tail is half the length of its body. Its winter fur is very dense, soft and fluffy, with guard hairs reaching 3–4 cm in length. The underfur is dense and loose fitting. Siberian weasels are monotone in colour, being bright reddish-ocherous or straw-red, though orange or peach tones are sometimes noticeable on the skin. These tones are especially bright on the back, while the flanks and underbelly are paler. A dark, coffee-brown mask is present on the face. Their tails are more brightly coloured than the back, and are fluffier than those of other members of the genus. The lips and chin are white or slightly ochreous. The front of the muzzle is darker than the remaining parts of the head. Its skull is in several respects intermediate in form between that of the stoat and the mink; it is longer and larger than that of the stoat, but is somewhat more flattened than the mink's. Adult males are 28–39 cm (11–15 in) long, while females reach 25–30.5 cm (9.8–12.0 in). The tail in males reaches 15.5–21 cm (6.1–8.3 in) in length, while that of females reaches 13.3–16.4 cm (5.2–6.5 in). Males weigh 650–820 g (23–29 oz), while females weigh 360–430 g (13–15 oz). Exceptionally large individuals were sighted in the Baraba steppe.
The Siberian weasel builds its nest inside fallen logs, empty stumps, brushwood piles and exposed tree roots. It also uses and enlarges the dens of other species. The length of its burrows ranges from 0.6–4.2 m (2 ft 0 in – 13 ft 9 in) and 0.2–1.3 m (7.9 in – 4 ft 3.2 in) deep. Adults have a permanent burrow and up to five temporary shelters, which may be separated from each other by several kilometres. They build a nesting chamber in the middle or end of the burrow and line it with bird feathers and rodent hair.
The Siberian weasels ranges from the Himalayas in Pakistan, India, Nepal and Bhutan to northern Myanmar, northern Thailand, Laos, Taiwan, China, and North Korea. In Russia, it occurs in the Kirov Province, Tataria, from the western Urals through Siberia to the Russian Far East. It has been introduced to Honshu, Shikoku and Kyushu islands.
Siberian Weasel (Mustela sibirica) - Shianghai China - seen commonly but never successfully by myself. I decided to include images by another - Images by Ned Kelly.