The Boreal Life Zone is often subdivided into Hudsonian and Canadian belts which are nearly coextensive with Subarctic and Boreal forest regions which have already been discussed. Zoologic associations, however, are fairly constant throughout this vast area. There are some species, however, with a more restricted or even local habitat.
The moose (Alces americana) ranges north to the limit of trees and is found all the way from Yukon to Nova Scotia, but is not found in Newfoundland. Primarily a browser, its food is obtained from shrubs and low growing trees to a height of about seven feet. In summer they feed extensively upon aquatic vegetation in lakes, ponds and the stillwaters of northern streams. In winter they band together in "yards" where coniferous growth is plentiful. The woodland caribou (Rangilet caribou) was also originally found throughout these zones but is now found rather sparingly through the northern portion of the range. The wood buffalo (Bison bison athabascae) was formerly found as far north as Great Slave Lake but is now confined to the Wood Buffalo Park. Here also are large numbers of plains buffalo (Bison bison). The mule deer (Odocoileus hemionus) is also found in the park.
The black bear (Ursus americanus), the timber wolf (Canis lupus), the coyote (Canis latrans), the Canada lynx (Lynx canadensis), the common fox (Vulpes fulva), are among the larger carnivorous animals. Smaller ones include the northern skunk (Mephitis hudsonica), the otter (Lutra canadensis), the marten (Martes americana), the fisher (Martes pennanti), the mink (Mustela vison) and various weasels (Mustela spp.)
The rodent population includes the porcupine (Erethizon dorsatum), the red squirrel (Tamiasciurus hudsonicus), the eastern chipmunk (Tamias striatus), the western chipmunk (Eutamias minimus) and the meadow mouse (Microtus pennsylvanicus). Two larger rodents of aquatic habitat characterize this zone almost as well as the moose and black bear: the beaver (Castor canadensis) and the muskrat (Ondatra zibethica). Badly depleted in many parts of its range, the beaver is now staging a comeback under present trapping regulations. The effect of the beaver upon the landscape is considerable; creating ponds, bogs and meadows throughout the northern forest, he maintains the habitat of his choice. The snowshoe rabbit or varying hare (Lepus americanus) in its various forms is found throughout the Boreal Forest. It is an important source of food for some of the valuable carnivorous furbearing animals and is also eaten by the Indians. The population of these animals shows great fluctuation during an approximate ten-year cycle, with a consequently similar effect upon the numbers of lynx and other furbearers which prey upon them.
Many species of fish inhabit the lakes throughout the glaciated Canadian Shield. Among them are several species of whitefish (Coregonus), pike (Esox lucius), yellow pickerel (Stizostedion vitreum), lake trout (Cristivomer namaycush) and tullibee (Leucichthys lucidus).
This is also the breeding ground of dozens of species of birds. Characteristic of the northern or Hudsonian zone are the fox sparrow (Passerella iliaca) and the pine grosbeak (Pinicola enucleator); the Canadian zone may be represented by the brownheaded chickadee (Penthestes hudsonicus), hermit thrush (Hylacichla guttata), Canada jay (Perisoreus canadensis) and the three-toed woodpecker (Picoides trydactylis). Around the lakes are found such fisheaters as the osprey (Pandion haliaetus) and the kingfisher (Megaceryle alcyon).