Thursday, June 23, 2011

Fauna of Taiga


The boreal forest, or taiga, supports a large range of animals. Canada's boreal forest includes 85 species of mammals, 130 species of fish, and an estimated 32,000 species of insects. Insects play a critical role as pollinators, decomposers, and as a part of the food chain. Many nesting birds rely on them for food. The cold winters and short summers make the taiga a challenging biome for reptiles and amphibians, which depend on environmental conditions to regulate their body temperatures, and there are only a few species in the boreal forest. Some hibernate underground in winter.

The taiga is home to a number of large herbivorous mammals, such as moose and reindeer/caribou. Some areas of the more southern closed boreal forest also have populations of other deer species such as the elk (wapiti) and roe deer. There is also a range of rodent species including beaver, squirrel, mountain hare, snowshoe hare, and vole. These species have evolved to survive the harsh winters in their native ranges. Some larger mammals, such as bears, eat heartily during the summer in order to gain weight, and then go into hibernation during the winter. Other animals have adapted layers of fur or feathers to insulate them from the cold.


A number of wildlife species threatened or endangered with extinction can be found in the Canadian boreal forest, including woodland caribou, American black bear, grizzly bear, and wolverine. Habitat loss, mainly due to logging, is the primary cause of decline for these species.

Due to the climate, carnivorous diets are an inefficient means of obtaining energy; energy is limited, and most energy is lost between trophic levels. Predatory birds (owls and eagles) and other smaller carnivores, including foxes and weasels, feed on the rodents. Larger carnivores, such as lynx and wolves, prey on the larger animals. Omnivores, such as bears and raccoons are fairly common, sometimes picking through human garbage.

More than 300 species of birds have their nesting grounds in the taiga. Siberian Thrush, White-throated Sparrow, and Black-throated Green Warbler migrate to this habitat to take advantage of the long summer days and abundance of insects found around the numerous bogs and lakes. Of the 300 species of birds that summer in the taiga only 30 stay for the winter. These are either carrion-feeding or large raptors that can take live mammal prey, including Golden Eagle, Rough-legged Buzzard (also known as the Rough-legged Hawk), and Raven, or else seed-eating birds, including several species of grouse and crossbills.

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