The Arctic lemming (''Dicrostonyx torquatus'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

in the family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has m ...

. Although generally classified as a "least concern" species, the

Novaya Zemlya Novaya Zemlya (, also , ; rus, Но́вая Земля́, p=ˈnovəjə zʲɪmˈlʲa, ) is an archipelago in northern Russia. It is situated in the Arctic Ocean, in the extreme northeast of Europe, with Cape Flissingsky, on the northern island, ...

subspecies ''(Dicrostonyx torquatus ungulatus)'' is considered a

vulnerable species A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, ...

under Russian nature conservation legislation (included in Red Book of Russian Federation since 1998).

Biology

It is found only in the

Arctic The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...

biome A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...

s in the

Russian Federation Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

, and it is the most common mammal on

Severnaya Zemlya Severnaya Zemlya (russian: link=no, Сéверная Земля́ (Northern Land), ) is a archipelago in the Russian high Arctic. It lies off Siberia's Taymyr Peninsula, separated from the mainland by the Vilkitsky Strait. This archipelago s ...

. Specimens were once found in England, but they are now

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

. For the most part, lemmings of the genus ''Lemmus'' can coexist with those of genus ''Dicrostonyx''. Arctic lemmings migrate when population density becomes too great, and they resort to swimming 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 among 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 to consist of 86% dicotyledons, 14% monocotyledons, and less than 1% mosses. The diet of a family of lemmings consists mostly of Saliceae, although

Poaceae Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

are also in their diet. They are a well studied example of a cyclic predator−prey relationship. Terns in the Arctic target lemmings that move in groups; after attacks, lemmings seek shelter in holes or elsewhere out of the terns' territory to avoid additional attacks.

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

External links

* {{Taxonbar, from=Q305615 Dicrostonyx Mammals of the Arctic Mammals of Russia Endemic fauna of Russia Arctic land animals Mammals described in 1778 Taxonomy articles created by Polbot