Arctic lemming

Arctic lemming
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Cricetidae
Genus:	Dicrostonyx
Species:	D. torquatus
Binomial name
Dicrostonyx torquatus (Pallas, 1778)

The Arctic lemming (Dicrostonyx torquatus) is a species of rodents in the family Cricetidae.

Biology

It is found only in the Arctic biomes in Russia. Specimens were once found in England, but they are now extirpated. For the most part, lemmings of the genus Lemmus can co-exist with those in the Dicrostonyx genus. Arctic Lemmings are known to migrate when population density becomes too great and they will resort to swimming while in search of a new habitat. The disappearance of lemmings and the lemming cycles in the Arctic have shown that they are the causes of fluctuations in local breeding between geese and waders. Recovery of Lemmings after years of low density is associated with a period of successful breeding and maintenance of their young in the snow.

The diet of the Arctic Lemming has been studied and it has been found that their diet primarily consists of 86% dicotyledons, 14% monocotyledons, 1<%mosses. The diet of a family of lemmings would be mostly Saliceae. Poaceae is also in their diet.

They are a well studied example of a cyclic predator prey relationship. Terns in the Arctic would target lemmings that would move in groups and they would use their bills to attack lemmings and, after the attack, lemmings would either seek shelter in a hole or somewhere that was out of the tern's territory in order to avoid another attack.

Environment

During the winter, Arctic Lemmings make nests in order to help maintain thermoregulation, maintaining their young, and aids in their survival against predators. One of their predators is the Arctic Fox and they would find that it difficult to hunt lemmings on account of the fact that they would burrow themselves deep within the snow. The fox would then have to dig through the snow in order to reach them. Unfortunately, when snow is scarce and there isn't much for the lemmings to make a nest or burrow in, there would be periodic disappearances of lemmings because of hunting by other predators and their inability to protect themselves.

References

• Musser, G. G. and M. D. Carleton. (2005). Superfamily Muroidea. pp. 894–1531 in Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore.