Collared lemming

The collar lemmings ( Dicrostonyx ) are a genus of arctic voles, which are spread over Siberia, northern Canada and Alaska. Although they are very similar to the mountain Lemming in many ways, they are no longer counted for tribes Lemmini, as new research has given rise to the presumption that the Lemmini and the collar lemmings different origin and the similarities based on convergent evolution.

Features

Collar lemmings have a body length 10-15 cm, added only one to two centimeters long tail. The coat is gray in the summer depending on the type, beige or brown. In winter it is pure white. Collar lemmings are the only rodents with a white winter coat, as for other mammals ( arctic hare, ermine ) is also characteristic.

With the Lemmini collar lemmings have the stocky physique and stubby tail together, just as the Arctic habitat. Unique is the seasonal increase in the third and fourth claw of the front legs with them. These have in summer a normal size, grow in winter but considerably and become thicker and stronger. So they can dig in frozen earth, nor themselves.

Collar lemmings use in summer burrows, which they dig in the tundra soil. An up to six meters long tunnel leading to a nest chamber, which has a diameter of 15 cm and is padded with grass. In winter, the most Collar lemmings content with tunnels in the snow. Their food in summer grasses, flowers and fruit in winter bark, twigs and buds.

The white winter fur of the collar lemmings is used by some Inuit for the production of clothing, but has nationally irrelevant.

Species

Jarrell and Fredga recognized in 1993, the following three ways:

• Real collar or fork Lemming Lemming claws, Dicrostonyx torquatus, Siberian Tundra
• Northern collar lemming Dicrostonyx groenlandicus, Greenland, Nunavut, Northwest Territories, Yukon, Alaska
• Ungava collar lemming Dicrostonyx hudsonius, northern Quebec, the mainland of Newfoundland and Labrador

The number of species is controversial. Sometimes all collar lemmings a single species have been assigned; Wilson and Reeder, however, distinguish eleven species, besides those mentioned above, especially endemic species of Arctic islands.