Related Biomes
Collared Lemming
Collared lemming, Dicrostonyx sp.
Three species of collared lemming have been identified in North America, the nearctic collared lemming (Dicrostonyx groenlandicus), the Ungava collared lemming (Dicrostonyx hudsonius), and Richardson's collared lemming (Dicrostonyx richardsoni). However, these species can be difficult to distinguish on the basis of isolated teeth and only D. richardsoni has been identified through aDNA (Fulton et al. 2013). For that reason, the unspecified genus, Dicrostonyx, is discussed here.
Greenland collared lemming. Photo by Kevin Pietrzak, and used under the Creative Commons License.
Length: 13-16 cm (5.1-6.3 in)
Weight: 45-113 g (1.6-4.0 oz)
Physical Description:
The collared lemming has a short, round body covered with thick grey fur and thin black stripes along the head and back. In the winter, they molt to a completely white coat. These rodents have small ears and tails and strong claws for digging. The claws on their front toes are especially well-suited to breaking through snow and ice.
Nearctic and Ungava collared lemmings inhabit elevated, dry tundra and alpine habitats. They currently are found in the open tundra of the Arctic. Richardson's collared lemmings however, occupy a more temperate tundra environment. Modern populations of D. richardsoni are found west of the Hudson Bay, Canada. The latter species has been identified through aDNA studies in cave deposits from the South Dakota Black Hills dating to the last glacial maximum (Fulton et al. 2013).
These animals are herbivores who feed on grasses, sedges and berries in the summer, and willow buds and bark in winter (Banfield 1974; Burns 2004). They prefer willow leaves and forbs, and in some areas will leave clumps of willows stripped bare of leaves, particularly during periods of high population density.
Unlike many northern rodents, the collared lemming is active year round. These animals dig burrows under ground, but above the permafrost, and create runways through surface vegetation. During the winter, they survive in passages excavated under deep accumulations of snow.
A recent analysis of terminal Pleistocene collared lemming localities found that these animals were distributed along the southern margin of the ice sheets (Burns 2004). Collared lemming remains have been recovered from localities as far south and east as West Virginia and Pennsylvania and as far south and west as central Idaho, as well as from the front range of Wyoming, southern Montana, north central Nebraska, northeastern Iowa and southwestern Wisconsin.
As the continental ice sheets retreated northward towards the end of the late Pleistocene and into the Holocene, collared lemmings followed their preferred tundra habitat north to their current Arctic distribution.
Collared lemming remains have been recovered from Prairieburg and Elkader in northeastern Iowa and Moscow Fissure in southwestern Wisconsin, and possibly from Conklin Quarry in eastern Iowa. These sites are almost 18 degrees of latitude south of its present distribution in the Arctic and are located along the former margins of the late Pleistocene continental ice sheets.
- Although large groups of lemmings do embark on mass migrations from time to time, there is no evidence that they actually throw themselves into the sea to drown en masse, as the popular legend proposes (MacDonald 2006).
- Collared lemmings are the only rodents that molt to a completely white coat in winter (MacDonald 2006).
Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Ontario.
Burns, J. A. 2004. Late Pleistocene Lemmings (Lemmus Trimucronatus and Dicrostonyx Groenlandicus; Muridae: Rodentia) from Alberta, Canada. Journal of Mammalogy 85(3):379-383.
Fulton, T. L., Norris, R. W., Graham, R. W., Semken, H. A., & Shapiro, B. (2013). Ancient DNA supports southern survival of Richardson's collared lemming (Dicrostonyx richardsoni) during the last glacial maximum. Molecular ecology (9), 2540-2548.
Macdonald, D. W. (editor). 2006. The Princeton Encyclopedia of Mammals. Princeton University Press, Princeton, NJ.
Related Animals:
