The stoat is entirely similar to the least weasel in general proportions, manner of posture, and movement, though the tail is relatively longer, always exceeding a third of the body length, though it is shorter than that of the long-tailed weasel. The stoat has an elongated neck, the head being set exceptionally far in front of the shoulders. The trunk is nearly cylindrical, and does not bulge at the abdomen. The greatest circumference of body is little more than half its length. The skull, although very similar to that of the least weasel, is relatively longer, with a narrower braincase. The projections of the skull and teeth are weakly developed, but stronger than those of the least weasel. The eyes are round, black and protrude slightly. The whiskers are brown or white in colour, and very long. The ears are short, rounded and lie almost flattened against the skull. The claws are not retractable, and are large in proportion to the digits. Each foot has five toes. The male stoat has a curved baculum with a proximal knob that increases in weight as it ages. Fat is deposited primarily along the spine and kidneys, then on gut mesenteries, under the limbs and around the shoulders. The stoat has four pairs of nipples, though they are visible only in females.
The dimensions of the stoat are variable, but not as significantly as the least weasel’s. Unusual among the Carnivora, the size of stoats tends to decrease proportionally with latitude, in contradiction to Bergmann’s rule. Sexual dimorphism in size is pronounced, with males being roughly 25% larger than females and 1.5-2.0 times their weight. On average, males measure 187–325 mm (7.4–12.8 in) in body length, while females measure 170–270 mm (6.7–10.6 in). The tail measures 75–120 mm (3.0–4.7 in) in males and 65–106 mm (2.6–4.2 in) in females. In males, the hind foot measures 40.0–48.2 mm (1.57–1.90 in), while in females it is 37.0–47.6 mm (1.46–1.87 in). The height of the ear measures 18.0–23.2 mm (0.71–0.91 in) in males and 14.0–23.3 mm (0.55–0.92 in). The skulls of males measure 39.3–52.2 mm (1.55–2.06 in) in length, while those of females measure 35.7–45.8 mm (1.41–1.80 in). Males average 258 grams (9.1 oz) in weight, while females weigh less than 180 grams (6.3 oz).
The stoat does not dig its own burrows, instead using the burrows and nest chambers of the rodents it kills. The skins and underfur of rodent prey are used to line the nest chamber. The nest chamber is sometimes located in seemingly unsuitable places, such as among logs piled against the walls of houses. The stoat also inhabits old and rotting stumps, under tree roots, in heaps of brushwood, haystacks, in bog hummocks, in the cracks of vacant mud buildings, in rock piles, rock clefts, and even in magpie nests. Males and females typically live apart, but close to each other. Each stoat has several dens dispersed within its range. A single den has several galleries, mainly within 30 cm (12 in) of the surface.
In Russia, It lives on the territory of the European north and in Siberia.
Methods of hunting permitted for use:
- using hunting dogs,
- ambush hunting,
- trapping (automatic trap)
Permitted hunting tools:
Hunting fire smooth-bore long-barreled arm, hunting firearm with a rifled barrel of caliber no more than 8 mm and a seating distance not more than 51 mm (including a caliber of 5.6 mm for a rim-fire cartridge); hunting firearm combined weapons (smooth-bore and rifted gun), including with rebarreling and auxiliary rifled barrels of 5.6 mm caliber for rim-fire cartridge; traps (automatic traps), including deadfalls of various types, mole traps, cherkans (wooden traps for animals living in lodges), gin traps, snares, and other analogues of automatic traps, as well as nets, cages, live traps and etc; cold bladed hunting weapon.
It is allowed to use a hunting pneumatic weapon with a muzzle energy of no more than 25 J for taking a chipmunk, ground squirrel, ground squirrel, hamster, water vole. Hunting for a lynx, badger, wolverine, hare and beaver using a hunting firearm with a rifled barrel of 5.6 mm caliber for a rim-fire cartridge is not performed.
The winter fur is very dense and silky, but quite closely lying and short, while the summer fur is rougher, shorter and sparse. In summer, the fur is sandy-brown on the back and head and a white below. The division between the dark back and the light belly is usually straight, though this trait is only present in 13.5% of Irish stoats. The stoat moults twice a year. In spring, the moult is slow, starting from the forehead, across the back, toward the belly. In autumn, the moult is quicker, progressing in the reverse direction. The moult, initiated by photoperiod, starts earlier in autumn and later in spring at higher latitudes. In the stoat’s northern range, it adopts a completely white coat (save for the black tail-tip) during the winter period. Differences in the winter and summer coats are less apparent in southern forms of the species. In the species’ southern range, the coat remains brown, but is denser and sometimes paler than in summe
A stoat fur is used for trimming fur products.