To conserve heat, the mammals that do
live in the boreal forest tend to be large: moose, which are the largest type of deer, wolverines, which are the largest weasel, and
the largest species of grouse all live in boreal forests. Aside from these very large, conspicuous animals, many of the mammals in these
forests are either rodents, including porcupine and squirrels, or small insect-eaters such as shrews. Common birds include jays and
ravens, grouse, and crossbills. In the summer, large flocks of songbirds migrate north to the boreal forests.
Snowshoe hare can be extremely numerous in
the boreal forest, though their populations change dramatically from year to year with the amount of available food. In turn, the populations
of carnivores such as lynx change with the number of snowshoe hare. Both of these animals are specially adapted for the particular
characteristics of boreal areas: the snowshoe hare have brown fur in the summer, but change color with the seasons and are white in
winter to blend in with the snow; the lynx have very wide paws so they can run on top of the snow, which makes it easier for them to catch
snowshoe hare. The hares feed on bark and leaves, and sometimes girdle small trees.