|
The Canadian Black Bear
There are 8 kinds of bears (Ursus) in the world but I chose the North American Black bear (Ursus americanus). I will be covering general information about the bear such as their size, weight, color, food, etc., but I will concentrate mainly on the hibernating cycle of the black bear.
There are from 400,000 to 750,00 black bears in North America, and they weigh from 130 to 660 pounds with a body length of 50 to 75 inches. Their colors vary from black, chocolate brown, cinnamon brown, pale blue (known as glacier bears) to white. Black bears will often have a brown muzzle and may have a lighter color patch on its chest. Its feet are equipped with strong, highly curved claws. Theyre omnivores; eating nuts, berries, fruits, insects (especially ants), deer and moose fawns, carrion and in coastal areas on spawning salmon. Their habitat includes forests with occasional open areas such as meadows. They occupy all of Canada starting from the tree line going south. They live in all provinces and territories except Prince Edward Island, where heavy de-forestation has happened and preferably away from brown bears (larger competitors). The only main risk for black bears are poachers who sell their parts illegally to the Asian medicinal market.
In northern areas of Canada, the bear undergoes a remarkable metabolic transformation as it prepares for hibernation. Hibernation is an energy-saving process bears have developed to let them survive for long periods when there is insufficient food available to maintain their body mass. When they stop eating and become increasingly lethargic, the bear will enter a cave; dig out a den; or hole up in a dense brush pile, hollow log or tree cavity and hibernate. Right before it does this it starts to gain weight so it can survive the long months ahead. It can gain as much as 30 pounds per week. The bear hibernates between four to seven months. When its in a hibernating state the bears heart rate drops from between forty to seventy beats per minute to only eight to twelve beats per minute. Its metabolism slows down by half, and its body temperature reduces by 3 to 7 degrees Centigrade (5 to 9 degrees Fahrenheit). Also its body doesnt release any wastes like urea or solid fecal waste but instead its recycled into usable proteins. During the hibernation period adult males and adolescent bears lose between 15% and 30% of their weight while a female cub with newborn loses as much as 40% of her weight. Most black bears vacate their winter dens over a one to two month period starting in April or May. Both the climatic conditions (snow cover and temperature) and physiological factors such as the bear's age, the status of its health and its remaining fat reserves affect the time it comes out. Normally, adult males emerge first. Females with newborn cubs are usually the last ones to leave their den, and continue with their life cycle.
Bibliography
I only used the web to find information and these are the sights I visited:
http://www.nature-net.com/bears/black.html
http://www.bearden.org
Word Count: 500
|
|
|
|
