Black (489 words) Essay Example For Students

Black (489 words) Essay BlackBearThere are 8 kinds of bears (Ursus) in the world but I chose the NorthAmerican Black bear (Ursus americanus). I will be covering general informationabout the bear such as their size, weight, color, food, etc., but I willconcentrate mainly on the hibernating cycle of the black bear. There are from400,000 to 750,00 black bears in North America, and they weigh from 130 to 660pounds 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 onits chest. Its feet are equipped with strong, highly curved claws. Theyreomnivores; eating nuts, berries, fruits, insects (especially ants), deer andmoose fawns, carrion and in coastal areas on spawning salmon. Their habitatincludes forests with occasional open areas such as meadows. They occupy all ofCanada starting from the tree line going south. They live in all provinces andterritories except Prince Edward Island, where heavy de-forestation has happenedand preferably away from brown bears (larger competitors). The only main riskfor black bears are poachers who sell their parts illegally to the Asianmedicinal market. In northern areas of Canada, the bear undergoes a remarkablemetabolic transformation as it prepares for hibernation. Hibernation is anenergy-saving process bears have developed to let them survive for long periodswhen there is insufficient food available to maintain their body mass. When t heystop eating and become increasingly lethargic, the bear will enter a cave; digout a den; or hole up in a dense brush pile, hollow log or tree cavity andhibernate. Right before it does this it starts to gain weight so it can survivethe long months ahead. It can gain as much as 30 pounds per week. The bearhibernates between four to seven months. When its in a hibernating state thebears heart rate drops from between forty to seventy beats per minute to onlyeight to twelve beats per minute. Its metabolism slows down by half, and itsbody temperature reduces by 3 to 7 degrees Centigrade (5 to 9 degreesFahrenheit). Also its body doesnt release any wastes like urea or solid fecalwaste but instead its recycled into usable proteins. During the hibernationperiod adult males and adolescent bears lose between 15% and 30% of their weightwhile a female cub with newborn loses as much as 40% of her weight. Most blackbears vacate their winter dens over a one to two month period starting in Aprilor May. Both the climatic conditions (snow cover and temperature) andphysiological factors such as the bears age, the status of its health and itsremaining fat reserves affect the time it comes out. Normally, adult malesemerge first. Females with newborn cubs are usually the last ones to leave theirden, and continue with their life cycle. BibliographyIonly 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