Lemming, stocky northern RODENT
related to VOLES
. About l6 species occur worldwide; best known of the 7 Canadian species are brown and collared lemmings (Lemmus sibiricus
and the Dicrostonyx groenlandicus complex
, respectively) from the ARCTIC ARCHIPELAGO
and mainland TUNDRA
W of HUDSON BAY
, and LABRADOR
collared lemmings (D. hudsonius
) from the UNGAVA PENINSULA
and Labrador. The northern and southern bog lemmings (Synaptomys borealis
and S. cooperi
) are uncommon.
Lemmings rarely exceed 90 g and 15 cm in length. Their extremities are hidden by, or barely extend beyond, their long brown or grey fur. Collared lemmings are the only rodents that molt to a camouflaging white for winter.
Lemmings eat WILLOWS
and herbaceous PLANTS
. They are intermittently active day and night, and during winter forage beneath insulating snow.
Reproduction and Development
Lemmings breed rapidly and every 3-5 years reach peak densities of 60-125 per hectare. Subsequent population declines involve cessation of breeding and massive die-offs, but are not caused by predators, disease, starvation or stress from overcrowding.
Lemming populations are self-regulating: genetically determined behaviours (aggressiveness and tendency to disperse) change with population density and influence the cycle. Although some Canadian lemmings emigrate from crowded areas and some accidentally drown, they do not make spectacular suicide marches to the sea, as related in folklore.
Lemmings are the main food for arctic carnivores, including valuable fur-bearing arctic FOXES
Lemmings do not make spectacular suicide marches to the sea, as related in folklore (artwork by Claire Tremblay).
DONALD A. SMITH
Links to Other Sites
See a description of the natural history and typical habitat of lemmings in Canada. From the "Hinterland Who's Who" website. Also includes video clips, summaries of related conservation issues, and educational resources.
Canadian Biodiversity Website
A great information source for all budding biologists. Learn about biodiversity theory, natural history, and conservation issues. From McGill’s Redpath Museum.