Grizzly bear is a subspecies of a brown bear, which can be found in Alaska and Western Canada. Isolated populations of grizzly bears can also be found in northern Idaho, western Montana, in north-western Wyoming and North Cascade Mountains (Washington State). In all ecosystems in which grizzly bears live, they play an important role and significantly affect their functioning. Due to being omnivorous, these bears are included in the food chain at various levels.
Despite the fact that the diet of this species is dominated by vegetable food, grizzly bears are the largest land predators in the territories where they live. These animals are able to kill almost all kinds of mammals, from rodents to moose (National Geographic). Although, in accordance with National Geographic, Grizzly bears eat mostly berries, leaves and roots, hoofed animals (red deer, roe deer, moose, caribou, etc.) also have a great value in their nutrition. Grizzly bears can significantly affect the mortality of young ungulates during their first months of life.
Fish, especially salmon, also plays a crucial role in the diet of grizzly bears. Bears gain fat for winter by extensively eating fish, both living (which has not spawn) and dead one. In the first case bears control the number of fish that reaches the spawning grounds, and in the second they function as “cleaners” making the bodies of water free from the rotting corpses. While eating fish, the grizzly bears perform an important function of the transfer of substances from the sea to the land, thus being a unique link between the terrestrial and aquatic ecosystems (Ben-David, Titus and Beier 471).
Grizzly bears perform the function of medical orderlies, killing sick animals, and thus precluding the disease from spreading to other animals. If they disappear, many herds of animals may become extinct because if one animal becomes ill, the epidemic will go around the entire herd. This, in its turn, may lead to extinction of other animals to which those herds were the main source of nutrition. It is important to remember that in nature everything is interconnected and even inconsiderate changes in the population of one species with time may lead to very significant and devastating changes in the entire ecosystem.
Although grizzly bears are big and strong, and can easily kill almost any enemy, they are currently in danger of extinction; such danger is high in the United States and it is critically high in Canada. In Mexico grizzly bears have already disappeared, although in the past they inhabited a vast area from Alaska to Texas and Mexico.
It is believed that the decrease in population of the grizzly began during the Spanish colonization of the Americas. With the appearance of the Europeans and the growth of large-scale settlements, the usual habitats of grizzly bears began to decline steadily. Indians considered these bears a totem animal, and they played an important role in the mythology of many peoples. However, even Indians hunted grizzly bears using their meat for food, furs for clothing and claws and teeth as decorations. For immigrants from Europe, the bear became a competitor in the process of obtaining food and represented a potential threat to life that led to its mass extermination (Brownbear.org).
Currently, the largest population of grizzly bears inhabits the area of Yellowstone National Park (Nps.gov.). In this National Park the scientists decided to try the reverse process and undertook a study of the reaction of this specific ecosystem to artificial settlement of previously extinct animals and, in particular, the large predators such as grizzly bears. The total number of this species is estimated today as 50,000 individuals.
Works Cited:
Ben-David, Merav, Kimberly Titus, and LaVern R Beier. “Consumption Of Salmon By Alaskan Brown Bears: A Trade-Off Between Nutritional Requirements And The Risk Of Infanticide?”. Oecologia 138.3 (2004): 471. Print.
Brownbear.org. “Brown Grizzly Bear Endangered And Close To Being Extinct”. Brownbear.org., 2016. Web. 23 July 2016.
National Geographic. “Grizzly Bears, Grizzly Bear Pictures, Grizzly Bear Facts”. National Geographic. N.p., 2016. Web. 22 July 2016.
Nps.gov. “Grizzly Bears & The Endangered Species Act - Yellowstone National Park (U.S. National Park Service)”. Nps.gov., 2016. Web. 23 July 2016.
