A lemming that turns white
Most Arctic rodents stay some shade of brown or gray year-round, relying on cover rather than a coat that matches the season. The northern collared lemming is the exception. Come winter, its coat molts to solid white, and the two middle claws on each front foot enlarge and split into a thick, shovel-like double claw used for tunneling through snow and frozen ground. No other rodent native to North America does both. In summer, once the white coat and enlarged claws shed, the same animal looks like an ordinary grizzled gray-brown lemming, thicker-bodied and shorter-tailed than the voles sharing its tundra range.
Mostly a creature of the dark
Where several tundra rodents split their activity across day and night, the collared lemming leans hard toward nocturnal. Alaska’s near-continuous summer daylight makes “night” a relative concept at these latitudes, but the pattern still shows up in when the species is most active. That nighttime habit likely helps it avoid some of the daytime aerial predators that hunt by sight.
A short breeding season with real stakes
A female’s gestation lasts about three weeks, and she can produce more than two litters across a single summer, each with several pups. Young grow fast. Females can breed within about six weeks of birth, letting a population turn over quickly. That speed matters because the list of animals hunting a collared lemming is long. Snowy owls and peregrine falcons both take them from above, and even arctic ground squirrels, normally seed-and-plant eaters, have been documented preying on lemmings when the opportunity arises.
Tundra, and grazing close to the ground
The species sticks to open tundra, grazing on the grasses, sedges, and other low plants that make up the bulk of an herbivore’s diet at this latitude. Its shovel-clawed winter digging isn’t just about staying warm. It also opens up access to buried vegetation and moss once snow has locked the surface away, letting the lemming keep feeding through months when most of the landscape looks dead.
