Norway Lemming (Lemmus lemmus)

 

Class: Mammalia
Order: Rodentia
Family:    Muridae
Size:    Length: 3.9 to 5.9 inches (10 to 15 cm)
Weight: 5 to 7 ounces (142 to 198 g)
Diet: Leaves, grasses, bark, berries, roots, green plants and mosses
Distribution: Scandinavia and northwest Europe
Young:  5 to 12, several times a year
Animal Predators:  Snowy owls, grey owls, buzzards, gyrfalcons, skuas, wolverines, ermines and arctic foxes
IUCN Status: No special status
Terms: No special terms
Lifespan: 1 to 2 years in the wild and up to 3 years in captivity

 

Facts/Trivia:

       Some females bear only female offspring.

       The belief that lemmings go on a suicide march to the sea, where they drown, is untrue.

       Lemmings have waterproof fur, enabling them to survive cold northern temperatures.

Description

Norway lemmings are colourful little animals with patches of black, tan and reddish-brown fur. Lemmings do not hibernate during winter, and their fur grows thicker to compensate for the cold weather. They have sharp teeth, small ears and a short tail. Their belly and legs are cream coloured.  

 

Habitat

Norway lemmings live in Norway, Sweden, Finland and extreme northwest Europe, in northern alpine and the open, swampy flatlands of the tundra.

 

Feeding Habits

Their diet consists of leaves, grasses, bark, berries, roots, green plants and mosses.

 

Reproduction

Norway lemmings can reproduce all year round and may have several litters per year, each consisting of five to 12 young. However, when food is scarce due to overpopulation, reproduction slows down. Some females and males mate for life, while others have several mates. The female gives birth 16 to 28 days after conception, and will nurse the newborns for 16 days. The female cares for the young without any assistance from the male. Young females can mate at the age of two weeks, while males become sexually mature at seven weeks of age. 

 

Behaviour

Every three to four years, the population of lemmings increases to the point where they feel the need to migrate in a desperate search for food sources. Although lemmings can swim, they sometimes try to cross bodies of water that are too deep and too wide to swim across (for example, the sea) and so they drown in large numbers, because they can only swim for 15 to 25 minutes before becoming exhausted. Although all lemmings experience this population spurt, Norway lemmings are the only ones who migrate as a result. They build burrows during the summer lined with grasses and many will gather in winter to snuggle together for warmth. They rarely appear above the snow, usually remaining between the soil and the snow where the temperature is not as cold. Lemmings are active both day and night, taking only short naps at various intervals in between feeding.

 

Conservation

Norway lemmings are not a conservation concern at this time.

 

Sources

http://animaldiversity.ummz.umich.edu/accounts/lemmus/l._lemmus$narrative.html

http://www.cws-scf.ec.gc.ca/hww-fap/lemming/lemming.html

http://mbgnet.mobot.org/sets/tundra/animals/lemm.htm

http://www.nature.com/nsu/000601/000601-10.html

http://www.bartleby.com/65/le/lemming.html

http://www.americazoo.com/goto/index/mammals/177.htm

http://www.essaynow.com/new/Science/Lemmings+and+the+Myths.asp

Norwegian Lemming Wildlife Fact File, IM Pub, US

Vaughan, T., Ryan, J. and Czaplewski, N. (2000). Mammalogy, Fourth Edition. Orlando: Saunders College Publishing