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Brief Summary

    Norway lemming: Brief Summary
    provided by wikipedia

    The Norway lemming, also Norwegian lemming (Lemmus lemmus) is a common species of lemming found in northern Fennoscandia. It is the only vertebrate species endemic to the region. The Norway lemming dwells in tundra and fells, and prefers to live near water. Adults feed primarily on sedges, grasses and moss. They are active at both day and night, alternating naps with periods of activity.

Comprehensive Description

    Lifespan, longevity, and ageing
    provided by AnAge articles
    Maximum longevity: 3.3 years (captivity) Observations: One specimen lived at least 3.3 years in captivity (Richard Weigl 2005).
    Norway lemming
    provided by wikipedia

    The Norway lemming, also Norwegian lemming (Lemmus lemmus) is a common species of lemming found in northern Fennoscandia. It is the only vertebrate species endemic to the region. The Norway lemming dwells in tundra and fells, and prefers to live near water. Adults feed primarily on sedges, grasses and moss. They are active at both day and night, alternating naps with periods of activity.

    Description

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    Lemming

    The Norway lemming has a bold pattern of black and yellow-brown, which is variable between individuals. It grows to a size of 155 mm. The tail is very short (10 – 19 mm). It weighs up to 130 g. The dental formula is 1/1, 0/0, 3/3.[3]

    Behavior

    The Norway lemming has a dramatic three- to four-year population cycle, in which the species' population periodically rises to unsustainable levels, leading to high mortality, which causes the population to crash again.

    The Norway lemming spends the winter in nests under the snow. When the spring thaws begin and the snow starts to collapse, they must migrate to higher ground, where the snow is still firm enough for safety, or, more commonly, to lower ground, where they spend the summer months.[citation needed] In autumn, they must time their movement back to sheltered higher ground carefully, leaving after alpine snow cover is available for their burrows and nests, and before the lowlands are made uninhabitable by frost and ice.

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    Drawing of Norway lemming

    When the seasons are particularly good (short winters without unexpected thaws or freezes, and long summers), the Norway lemming population can increase exponentially: they reach sexual maturity less than a month after birth, and breed year-round if conditions are right, producing a litter of six to eight young every three to four weeks.[citation needed] Being solitary creatures by nature, the stronger lemmings drive the weaker and younger ones off long before a food shortage occurs. The young lemmings disperse in random directions looking for vacant territory. Where geographical features constrain their movements and channel them into a relatively narrow corridor, large numbers can build up, leading to social friction, distress, and eventually a mass panic can follow, where they flee in all directions. Lemmings do migrate, and in vast numbers sometimes, but the deliberate march into the sea has yet to be verified.

    According to genetic research,[4] the Norwegian lemming survived the Pleistocene glaciation in western Europe, inhabiting various refugia which were not covered by ice. Alternatively, some researchers have contended the Norwegian lemming populations had arisen from ancestors of the present-day brown lemming (Lemmus sibiricus), moving in after glaciers receded.

    References

    1. ^ Henttonen, H. (2008). "Lemmus lemmus". IUCN Red List of Threatened Species. Version 2008. International Union for Conservation of Nature. Retrieved 5 June 2009..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} Database entry includes a brief justification of why this species is of least concern.
    2. ^ IUCN (International Union for Conservation of Nature) 2008. Lemmus lemmus. In: IUCN 2014. The IUCN Red List of Threatened Species. Version 2014.3. http://www.iucnredlist.org. Downloaded on 22 March 2015.
    3. ^ MacDonald, David; Priscilla Barret (1993). Mammals of Britain & Europe. 1. London: HarperCollins. pp. 241–242. ISBN 0-00-219779-0.
    4. ^ Fedorov, V.B. & Nils Christian Stenseth (2001). Glacial survival of the Norwegian lemming (Lemmus lemmus) in Scandinavia: inference from mitochondrial DNA variation. Proceedings of the Royal Society: Biological Sciences, 268(1469):809-814. [1]

Distribution

    Distribution
    provided by Animal Diversity Web

    Norway, Sweden, Finland, extreme north west Europe.

    Biogeographic Regions: palearctic (Native )

Morphology

    Morphology
    provided by Animal Diversity Web

    Other Physical Features: endothermic ; bilateral symmetry

    Average mass: 70 g.

    Average basal metabolic rate: 1.071 W.

Habitat

    Habitat
    provided by Animal Diversity Web

    Alpine, tundra, steppe, temperate grasslands, scrub, open forest, rocks.

    Terrestrial Biomes: tundra ; savanna or grassland ; mountains

Trophic Strategy

    Trophic Strategy
    provided by Animal Diversity Web

    Herbivorous, diet consisting largely of berries, leaves, grasses, bark, lichens, roots, green part of plants, bulbs, mosses, pine needles. Forage both day and night. Graze and dig for roots.

Behavior

    Behavior
    provided by Animal Diversity Web

    Perception Channels: tactile ; chemical

Life Expectancy

    Life Expectancy
    provided by Animal Diversity Web

    Average lifespan
    Status: captivity:
    2.0 years.

Reproduction

    Reproduction
    provided by Animal Diversity Web

    Gestation 16- 28 days. Reach sexual maturity early (females: 2-3 weeks old, males: 6-8 weeks old). Very fecund. Breed in summer and winter. Length of breeding season varies. Mated female may fail to conceive or may abort if exposed to a strange male. Litter size may vary from 1-12 or more litters per year. Some females genetically programmed to bear only female offspring.

    Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual

    Average birth mass: 3.8 g.

    Average gestation period: 19 days.

    Average number of offspring: 7.

    Average age at sexual or reproductive maturity (male)
    Sex: male:
    44 days.

    Average age at sexual or reproductive maturity (female)
    Sex: female:
    24 days.

Conservation Status

    Conservation Status
    provided by Animal Diversity Web

    Many live in areas of little agricultural importance to humans. Not pests. Not endangered. Highly varying population density (see "Other Comments"). Clearing of forests by humans has increased habitat.

    IUCN Red List of Threatened Species: least concern

Benefits

    Benefits
    provided by Animal Diversity Web

    Some harbor vectors of disease, such as plague.

    Benefits
    provided by Animal Diversity Web

    Social behavior studied by many.

Other Articles

    Untitled
    provided by Animal Diversity Web

    So-called "Suicidal March to the Sea" about every 3-4 years. Populations "cycle," increasing greatly approximately every 3-4 years. When this happens, lemmings may migrate in large numbers from densely populated areas in the mountains down to birch forests, searching for food. Encountering natural obstacles, including bodies of water, causes panic and a "flight response." This behavior sometimes takes them into the sea, and large numbers may die. So, they may die in this individual quest for food, but they aren't committing suicide for the sake of the rest of the population.

    Predators of the lemming include the snowy owl, grouse buzzard, ermine, and arctic fox.