The northern red-backed vole does not hibernate, but remains active all winter, feeding on the seeds, nuts, and roots that it gathered during warmer weather.
In the tundra, where it is also found, it tends to be larger, with a redder pelage than here in the boreal forest.
Once the snow has melted, the population of Clethrionomys rutilis is made up entirely of those born the year before, but within about eight weeks, the first of the young are starting to breed.
By the end of summer, all those born the year before have died.
Its abundance makes the northern red-backed vole popular prey for weasels and other small carnivores, as well as predatory birds.
Another name for it is the polar red-backed vole, and Laplanders call it the squirrel mouse.
Name: Northern Red-Backed Vole (Clethrionomys rutilus)
Family: Muridae (Rats and Mice)
Range: Northern North America and Eurasia
Habitat: Coniferous forest to tundra
Diet: Leaves, shoots, fruits, berries, nuts, seeds, bark, roots, lichens, fungi, and insects
Head and Body Length: 4 to 5 inches (11 to 12 cm)
Tail Length: 1.1 to 1.4 inches (2.8 to 3.6 cm)
Weight: 0.7 to 1.3 ounce (20 to 40 g)
Life Cycle: Mating May to September; gestation 17 to 19 days, four to nine young born; two to five litters per year
Description: Chestnut brown stripe along back; yellowish-brown face and sides; dark gray to pale underparts; long, soft fur in winter; short, coars fur in summer
Conservation Status: Common