The Grizzly Bear

Only available on StudyMode
  • Topic: Bears, Grizzly Bear, Bear
  • Pages : 17 (5715 words )
  • Download(s) : 125
  • Published : February 28, 2013
Open Document
Text Preview
The grizzly bear (Ursus arctos horribilis), also known as the silvertip bear, the grizzly, or the North American brown bear, is a subspecies of brown bear (Ursus arctos) that generally lives in the uplands of western North America. This subspecies is thought to descend from Ussuri brown bears which crossed to Alaska from eastern Russia 100,000 years ago, though they did not move south until 13,000 years ago.[1]

Except for cubs and females,[2] grizzlies are normally solitary, active animals, but in coastal areas, the grizzly congregates alongside streams, lakes, rivers, and ponds during the salmon spawn. Every other year, females (sows) produce one to four young (commonly two) which are small and weigh only about 500 grams (1 lb). A sow is protective of her offspring and will attack if she thinks she or her cubs are threatened.

Contents
[hide] 1 Name
2 Description
3 Range
4 Reproduction
5 Diet
6 Interspecific competition
7 Ecological role
8 Conflicts with humans
9 Protection
10 Conservation efforts
11 Hunting
12 See also
13 References
14 Further reading
15 External links

Name

The word "grizzly" in its name refers to "grizzled" or gray hairs in its fur, but when naturalist George Ord formally named the bear in 1815, he misunderstood the word as "grisly", to produce its biological Latin specific or subspecific name "horribilis".[3]

Description

Most adult female grizzlies weigh 130–200 kg (290–440 lb), while adult males weigh on average 180–360 kg (400–790 lb). The average total length in this subspecies is 198 cm (6.50 ft), with an average shoulder height of 102 cm (3.35 ft) and hindfoot length of 28 cm (11 in).[4] Newborn bears may weigh less than 500 grams (1.1 lb). In the Yukon River area, mature female grizzlies can weigh as little as 100 kg (220 lb). On the other hand, an occasional huge male grizzly has been recorded which greatly exceeds ordinary size, with weights reported up to 680 kg (1,500 lb).[5] Although variable from blond to nearly black, grizzly bear fur is typically brown in color with white tips.[6] A pronounced hump appears on their shoulders; the hump is a good way to distinguish a black bear from a grizzly bear, as black bears do not have this hump.

Range

Brown bears are found in Asia, Europe and North America giving them one of the widest ranges of bear species. The ancestors of the grizzly bear originated in Eurasia and traveled to North America approximately 50,000 years ago.[7] This is a very recent event in evolutionary time, causing the North American grizzly bear to be very similar to the brown bears inhabiting Europe and Asia.

In North America, grizzly bears previously ranged from Alaska to Mexico and as far east as the western shores of Hudson Bay.[7] In North America, the species is now found only in Alaska, south through much of western Canada, and into portions of the northwestern United States including Idaho, Montana, Washington and Wyoming, extending as far south as Yellowstone and Grand Teton National Parks, but is most commonly found in Canada.

In September 2007, a hunter produced evidence of grizzly bears returning to the Selway-Bitterroot Wilderness ecosystem, in Idaho and western Montana, by killing a male grizzly bear.[8]
Its original range also included much of the Great Plains and the southwestern states, but it has been extirpated in most of those areas.
The grizzly bear appears on the flag of California, though they are extinct in the state, the last one having been shot in 1922.[9]
In Canada, there are approximately 25,000 grizzly bears occupying British Columbia, Alberta, the Yukon, the Northwest Territories, Nunavut, Ontario and the northern part of Manitoba.[7] Combining Canada and the United States, grizzly bears inhabit approximately half the area of their historical range.[7] In British Columbia, grizzly bears inhabit approximately 90% of their original territory. There were approximately...
tracking img