14 June 2007

Mountain Caribou




There are three main types of caribou in Canada. They are called “woodland caribou” if they live in the forest, “barren-ground caribou” if they live in the arctic tundra, and “mountain caribou” if they live in mountainous regions. Caribou have large hooves, which are about as wide as they are long and the dew claws (the back part of the hooves) touch the ground when walking. These large round hooves allow the caribou to distribute their weight more evenly and walk on packed snow. Caribou are the only member of the deer family in which both sexes have antlers, Males shed their antlers following the fall breeding season (young males retain their antlers longer than mature males). Pregnant females shed their antlers soon after the calves are born in the spring. Non-pregnant females shed their antlers during the winter. They are considered one of the most endangered mammals in North America.

Life Cycle
Baby mountain caribou are born in May, and stay with their mom for at least one year. They can run faster than a adult human when they are only one day old. Male caribou live about 7 to 8 years. Females live slightly longer, to 10 or more years. These are very general numbers. Every animal faces its own set of situations that lead to a shorter or longer life. If a caribou lives in a herd that is in decline (getting smaller over the years), it probably will have a shorter life than a caribou in a healthy, or expanding herd. Also, many caribou die within the first year after they are born, and never reach adult age.

Diet
During approximately 6 months of the year, mostly during the winter months, caribou subsist only on a diet of arboreal (i.e. growing on tree branches) lichens. This is unique within the deer family. During the non-winter months, caribou also forage on shrubs, grasses and sedges.

Threats
Logging causes problems not only because it destroys their habitat, but also because moose and deer move into logged areas to eat grass and brush that grows in clear cuts. Wolves and cougars then move in to hunt the moose and deer. The wolves and cougars find the mountain caribou and chase them into the clear cuts. Caribou can’t move around very well in clear cuts so they make an easy catch. Snowmobiles and skiers also present challenges with the noise and
increased activity. It can kill caribou by forcing them to abandon their habitat. It is believed that increased human access into caribou habitat, changes in the balance of predators, poaching, and early logging in sensitive habitat may have contributed to their decline.

Facing Extinction
Scientists believe that at least 10,000 mountain caribou existed historically in BC, but the exact number may have been even larger. Today only 1,670 mountain caribou remain. The number of mountain caribou is decreasing because both their low-elevation (summer) and high-elevation (winter) forest homes are being logged. After decades of logging, the low-elevation old growth forests are almost gone.

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