Bird Families

Long-tailed weasel


The long-tailed weasel (Latin Mustela frenata) belongs to the Mustelidae family. Her ancestors appeared on the American continent already in the early Pleistocene epoch about 2 million years ago. Their fossils were found in Kansas (USA).

The immediate ancestor is Mustela rextroadensis, which lived in the late Pleistocene and died out about 20 thousand years ago.

The long-tailed weasel is distinguished by its aggressive character and is not afraid to engage in a fight with an enemy that is much larger than it. In self-defense, she can attack a person and inflict rather painful bites.

This animal effectively inhibits the growth of the population of rodents and rabbits. Its fur is used to make fur products, but has no industrial value.

The species was first described in 1831 by the German zoologist Martin Heinrich Lichtenstein.


The habitat is in North and Central America. Several subspecies are also found in the northwest of South America. The range extends from southern Canada through the United States to Mexico, Bolivia and Guyana.

Long-tailed weasels inhabit various biotopes. Most often they settle on the outskirts of woodlands near the banks of rivers and lakes. The animals categorically avoid dense forests and completely desert regions. They are found in the temperate, subtropical and tropical climates.

There are over 40 subspecies. The nominative subspecies is distributed in the state of Texas and eastern Mexico.


The long-tailed weasel is solitary. Individuals of the opposite sex are found only during the mating season, but after mating they part. The male's home grounds overlap with the hunting grounds of several females. Animals of the same sex, as a rule, show aggression towards each other.

Activity can occur at any time of the day. The animals start looking for food as hunger sets in. When hunting, they primarily rely on a developed sense of smell and hearing, vision plays a secondary role. They kill their victim with a bite in the throat.

Despite their short legs, long-tailed weasels run well and quickly.

They climb trees perfectly and are able to overcome water obstacles by swimming. In winter, they cut long tunnels under the snow.

Nimble predators successfully hunt in water, on land and trees. Communication between them takes place using smells and sound signals. They emit sounds in the 200-500 Hz and 750-1000 Hz ranges.

The animals rest in underground shelters or under stones, making a bed of grass and wool. Less often, they hide in the hollows of trees.


The long-tailed weasel is a carnivore. Most often, she goes hunting at dusk and hunts throughout the night until the early morning. Its victims are mammals that do not exceed the size of a hare. Most often these are mice, voles, rats, squirrels and American rabbits (Sylvilagus).

During the starvation period, the predator also begins to hunt birds, amphibians, reptiles, and even insects. Due to the high energy consumption, she has to eat every day. The animal eats food in the amount of about 40% of its body weight per day. Females hunt small animals, and males prefer to lie in wait for rabbits.

In late summer and autumn, ripe berries and fruits complement the diet.


Sexual maturity occurs at the age of 6-12 months. The mating season begins in spring and lasts until mid-summer. Males usually mate with several females.

Egg development stops shortly after mating. The embryonic development of the fetus resumes in the early spring of the following year.

As a result, the total duration of pregnancy can range from 205 to 337 days. Pure embryonic development takes about 30 days.

The female gives birth to 4-5, maximum 6 cubs. Childbirth takes place in a prearranged nest and lasts only 7-10 minutes. The peak of fertility is observed from the end of April to the second half of May.

Babies are born blind and naked. They weigh about 3 g. Their eyes open in the fourth or fifth week. The hair grows back in the second week.

At the age of one and a half months, milk feeding stops, after which the cubs switch to solid food. In the sixth week, they can already kill their first victim on their own.

From that moment on, they go out in search of food with their mother and diligently study the methods of hunting. At 2 months of age, adolescents move to an independent existence. By the age of one, no more than 30% of long-tailed weasels survive.


The body length of adults is 28-42 cm, and the fluffy tail is 12-30 cm. Males weigh 160-450 g, and females 80-250 g. Fur is thick and very soft. The upper body is dark brown or cinnamon colored. The lower part is lighter. Its color can range from cream to tan.

Molting occurs twice a year. In spring it lasts 20-35 days, and in autumn 40-70 days. In winter, the coat becomes denser, and in northern populations it acquires a whitish tint, which serves for camouflage in the snow. The fur consists of an undercoat that reliably protects against cold and moisture, as well as coarser covering hair.

The head is very narrow and slightly separated from the neck. Small, round ears are located far behind the head. In the area of ​​the muzzle there are long tactile hairs (vibrissae), which serve for orientation in space.

The slender, flexible body is supported by short but strong limbs. The fingers are armed with sharp claws. Females have 5 pairs of nipples. There are 34 teeth in the oral cavity.

The long-tailed weasel has a lifespan of about 9 years.