Weasel
- In autumn, the least weasel, except in some southern parts of its range, replaces its summer brown coat with a purely white winter fur. The density of the fur is the same in summer and winter, but summer hairs are shorter and finer than winter ones.
- The least weasel becomes sexually mature at 3 months and can reproduce year-round during years of abundance of rodents.
- The least weasel hunts venomous snakes, including vipers, and other small animals. It is agile and bold, hunting both day and night.
Age
The dwarf weasel, or least weasel, undergoes several distinct developmental stages; during the embryonic stage, the developing offspring receives nourishment from the mother. The young open their eyes between three weeks and one month and one week of age, and begin walking at one month and one week old. The infant stage lasts from one day to two months, where the young live in a den, drink their mother’s milk, and grow rapidly. The species reaches sexual maturity between three and five months of age. The adult stage begins at three months and lasts up to two years and nine months. A typical lifespan ranges from nine years and seven months to fifteen years and eleven months; the maximum lifespan is also from nine years and seven months to fifteen years and eleven months, while the theoretical lifespan extends from four years and seven months to nine years and one month.
Phenotype
Cub: fur — Soft and short fur is colored brown on top and white below. Cub: Number of teeth — Milk teeth, which are later replaced by permanent sharp teeth. Adult: fur — aY3EKvsBdrA. Adult: fur — In cold areas, the fur is completely white to hide in the snow. Adult: Body size — A long and very flexible body allows climbing into narrow burrows of rodents. Adult: Number of claws — Sharp claws help to cling to the ground and prey. Adult: Number of tails — A short tail without a black tip at the end. Adult: Number of teeth — Sharp teeth with which the predator kills prey by biting in the head or neck.
Physiology
The dwarf weasel, also known as the least weasel, exhibits a body height ranging from 1.7 to 3.25 meters, and a body length from 13 to 26 centimeters; its mass varies from 130 to 179 grams. During the embryo stage, the body mass is between 1 and 5 grams. The young, in the infant stage, have a body mass from 2 to 25 grams and a body length from 5 to 12 centimeters. Adult individuals weigh from 40 to 100 grams, with a body length from 13 to 18 centimeters.
Habitat
The dwarf weasel occupies habitats at elevations up to 3 kilometers above sea level and is found in temperate mixed forests with warm summers and many oak, birch, and maple trees; flooded meadows where water frequently covers the ground and there is abundant grass; temperate steppes with plentiful grass and few trees, experiencing rainfall; taiga characterized by cold winters and numerous coniferous trees such as spruce and pine; and tundra with very cold temperatures, a short summer, sparse trees, and an abundance of moss. The species’ landscape includes terrestrial environments, forests on land, and grassy areas on land. The climate varies, including cool summers with temperatures between 15 and 20 degrees Celsius, consistently high humidity with frequent rainfall, and conditions where there is plentiful rain, a cool summer, and snow in winter; tundra experiences very cold temperatures and a short summer with sparse trees and abundant moss; and areas with warm and pleasant summers accompanied by abundant rainfall.
Shelter
The dwarf weasel, or least weasel, inhabits underground burrows, dense grass, or areas beneath rocks. The species utilizes a dug underground tunnel or chamber for shelter and nesting. These shelters serve multiple purposes, including reproduction, rest, and protection from the sun.
Geography
The dwarf weasel occupies the biogeographical realms of Nearctica and Palearctica. It inhabits Celtic broadleaf forests, broadleaf forests of Western Europe, coniferous forests of the Qilian Mountains, Balkan mixed forests, Baltic mixed forests, and European Atlantic mixed forests.
Feeding
The dwarf weasel is a predator that feeds on small animals, actively hunting and pursuing prey in shelters. Its diet consists of mice, voles, shrews, small birds, eggs, and other small mammals, including rodents, bats, lagomorphs, and hamsters. The species hunts its prey skillfully, killing with a bite to the back of the neck and consuming it immediately or hiding the remains. The hunting strategy involves active pursuit. Daily food intake ranges from 20 grams to 60 grams; young weasels consume milk. The species’ prey also includes rodents, lagomorphs, bats, and other mammals.
Reproduction
The weasel is a species inhabiting and developing on land, outside of water bodies, reproducing through viviparity, with offspring being born live on land, not hatching from eggs or spawn; embryonic development occurs rapidly, taking only 1 week. A female gives birth to from four to eight offspring, which are born blind and without fur, and the mother cares for them in a den located in an underground nest. The reproductive interval is from 2 to 5 months, and maturity occurs at an age of from 3 to 5 months. The litter size can be from 4 to 10, and eggs, spawn or offspring develop in a terrestrial nest built on the ground or close to it. Reproduction always occurs through homogamy, with fertilization and without alternation of generations, with only the mother exhibiting parental care for the offspring.