Lemmings are small rodents that live in the forest-tundra and tundra of North America and Eurasia. There are several types of these animals. Thus, the Siberian lemming is common in Kamchatka and many Arctic islands, along the tundra of the Arctic.
In this article we will learn more about these animals: what they eat, how they look, live and reproduce.
Distribution
This lemming lives in the tundra of Eurasia from the interfluve of the Northern Dvina and Onega to the lower reaches of the Kolyma. It also inhabits such islands as Bely, Vaigach, Novosibirsk, Wrangel. Basically, the southern border of the range coincides with the northern part of the forest-tundra. Isolated individual populations were recorded in the swampy taiga of the Kolyma Lowland.
Geographic variability
It should be noted that the mainland forms showed a decrease in size depending on the direction. So, the lemming in the tundra in the west lives the largest, decreases in the east direction. At the same time, brownish-buffy shades are replaced in color by black tones extending to the cheeks, sides, and also the lower part of the body, while the dark dorsal stripe disappears. Winter color turns gray andbrightens. In the animals of the New Siberian Islands, it is almost pure white. It should also be noted that island forms are much larger than mainland ones.
Appearance
Lemming is an animal that is a short-tailed small rodent: its body length is up to 18 cm, and its tail is up to 17 mm. It reaches a weight of 130 g, while males are 10% heavier than females. The general tone of the animal is reddish-yellow with a slight admixture of brownish and gray tones. A thin black stripe runs along the spine from nose to tail. Sides and cheeks of a bright rusty shade; fawn-whitish belly, occasionally with an admixture of yellow. There are dark blurry stripes in the area of the ears and eyes.
A black spot on the rump is typical for animals from about. Wrangel and the New Siberian Islands. Winter fur is dimmer and lighter than summer, occasionally almost white, with a thin stripe on the back of a light brown hue. Mainland subspecies are somewhat smaller than mainland ones; the gradual disappearance of the strip and a decrease in size is observed in the east direction. The diploid number of chromosomes is 50.
Reproduction
Siberian lemming is very prolific. So, the female throws from 3 to 5 cubs 6 times a year. Periodically, they multiply simply in huge numbers. In this case, there is a lack of food, after which the animals make mass migrations, while moving in a straight line, like locusts, and devouring everything they can gnaw.
What do lemmings eat?
They mainly eatsedge, sometimes twigs of shrubs. On occasion, they also eat berries, insects, and gnaw on deer antlers dropped by animals earlier. If you find out what lemmings eat in winter, it is worth noting that sometimes they gnaw moss and moss in areas of about a meter and a half. When the snow is compacted, they often come to the surface of the earth.
Lifestyle
Together with narrow-skulled voles and ungulate lemmings, it is one of the most common rodent species in the tundra. It reaches its largest abundance in polygonal, hummocky and flat tundra with a well-developed sedge-moss cover. There is a lemming, the photo of which is presented in this article, in the valleys of lakes and rivers, in the low-mountain and foothill sedge-shrub tundra, in wetlands. Penetrates through the swamps into the forest zone.
Mandatory conditions for the habitat of the animal is the availability of food and convenient places for the construction of holes (peat and soil mounds, moss and sphagnum pillows). In the polygonal tundra (with a microrelief in the form of large polygons, which are broken by frost cracks), the lemming (a photo of the animal can be seen in this article) lives in the cracks of the peat layer, while using them for fast movement.
A characteristic feature of the way of life of animals is living under the snow most of the year. In winter, they are tied to various areas with a snow cover of 0.5-1 m: stream beds, river banks, drying tundra lakes, and swampy lowlands. They make passages under the snow, build spherical nestsfrom various plant rags and dig snow chambers. In winter, the Siberian lemming lives crowded.
During the melting of snow, water floods the settlements of animals, and they move to the thawed patches, and then to the summer habitats. There, simple burrows are dug on small elevations. They also occupy various natural hiding places. Surface passages are laid to the aft areas. In adult females in the snowless period, territoriality is well expressed; juveniles and adult males roam the territory rather randomly, lingering in various temporary shelters.
Numbers
It should be noted that the number of animals varies greatly: sometimes they are almost impossible to meet, periodically (once every 5 years) animals scurry around, are not at all afraid of humans, and are quite aggressive. In these years, the number of ungulate lemmings also increases in the same places, while the number of bank voles in the forests.
Siberian lemming at this time floods the mountain valleys and villages, sometimes trying to swim across the bays and rivers and as a result die en masse. With a large population, rodents do not settle in colonies and are aggressive towards each other. In this case, migrations may appear to be organized movements, although each lemming actually moves on its own, and only external obstacles sometimes make them gather together.
