Grizzly Bear. History and Identification. Characteristics

When the Lewis and Clark expedition, sent out to explore the Louisiana Purchase, arrived at the foothills of the Rocky Mountains, the Indians they encountered told tales of a great bear, an animal of tremendous strength, great shyness, and unusual ferocity. Even then, the "facts" were influenced by legends born of fear.

As late as 1857 even the naturalists and hunters believed Ursus horribilis to be the only member of the grizzly family. Since then, zoologists have made careful studies of this animal, and C. Hart Merriam made the initial extensive break down by species. His record included about 30 recognizable species and sub-species, but present authorities believe there are about half that number.

A Toklat (Alaskan) Grizzly . The typical "hump" is clearly shown

Despite the existence of many different species, each of the subdivisions remains aloof from the others, and although some zoologists have written to the contrary there is no evidence of habitual interbreeding. It does occur, in isolated cases, and the hybrids in most instances are the result of breeding while in captivity and are not representative of the animal in its natural habitat.

Due to the wide distribution of the animal in the West and North, details on the different species and their ranges will be listed under " Range and Distribution."

History. The American grizzly, defined as the "king of North American game animals," dates back to the Pleistocene Age. Through the years he has changed in numbers and in size. In the early days his range covered the greater part of western North America, from northern Mexico northward and into western Canada.

He was especially numerous among the foothills of the Rockies and its bordering plains. T h e sweep of civilization drove him from these plains to isolated pockets in the mountains. A s the varied species which ranged the plains were reduced in numbers and forced to the mountains, several species were crowded into one range.

Changes in climatic conditions through the ages brought about a slow change in the size of the bear. On the plains he had easy access to food, there were few enemies, and the climate was temperate. This resulted in his attaining maximum growth. The struggle for existence which has been his lot for the past 50 years has reduced both his life span and his size and has resulted in a lengthening of his period of hibernation.

Both the hunter and the zoologist have found it difficult to differentiate between the aggressive grizzly and the mild big brown bear, and there has been considerable confusion. Only in recent years has there been even a partial clarification of the differences in these species. A typical grizzly differs from a typical brown bear in color, claws, skull, and teeth. The brown bear is more uniform in color, has a darker pelage, and shows less admixture of the silver-tipped hairs. Also, the brown has shorter claws and a more massive skull. (See diagram of footprints.)

The strength and courage of the grizzly are the features which make him the most sought-after animal, and it has been necessary to protect him from hunters in several areas in order to insure his existence. The larger national parks, such as Mount McKinley and Yellowstone, have proved to be the most certain refuges for this bear, for in them he is permitted to live and thrive in a natural habitat.

Identification. Because of the many species, it is difficult to describe a "typical " grizzly. His coloration may vary from almost black to a light cream, although the average grizzly has the coloration his name implies — grizzled: a dark brown undercoat with grayish, silvery tips to the hairs. While a cub he has a characteristic white collar around his neck, which he loses at the age of three.

By the time he has reached this age he has gained maturity in size but not in strength. His skull, which is used as a means of identification by zoologists, is still changing at this age, and he does not reach full maturity until about seven years old. An average lifetime is 25 years, but unconfirmed records indicate that some have lived to be 50 years of age.

The track of an average mature grizzly will measure about 61/2 to 7 inches in width and from 12 to 14 inches in length. T h e length varies with species and with individual members of a species. Though the typical adult male weighs 500 pounds, a most unusual kill was reported in 1908 in Colorado. This bear weighed approximately 1800 pounds, and the hide measured 11 feet 7 inches in width and 12 feet 6 inches in length. This kill has not been confirmed.

As a result of the inability of zoologists to establish a definite line between the grizzly and the brown bear in Alaska (See page 17) records are differentiated along an arbitrary geographical line. The record grizzly bear was a male killed in 1954 by F. Nygaard at Rivers Inlet, British Columbia . The skull of this bear measured 16 5/8 by 10 inches.

While the grizzly has poor vision, his sense of smell and his hearing are very acute. In many instances hunters have worked up-wind in stalking a grizzly, only to find, on arriving at the place where he had been spotted, that he had departed in great haste in another direction. His actual vision is not so poor as many believe, but the fact that his eyes are set very close together makes his field of vision extremely limited. He sees very well directly ahead, but badly at even slight angles. Often, when surprised, he will swing his head from side to side and often turn in a complete circle in an effort to locate the enemy he senses to be near.

Drawing showing small brain area of bear , dotted line indicating thickness of skull

Characteristics. By nature, the grizzly is a peaceful individualist, desiring only to be left alone, but he will fight viciously to maintain his solitary way of life. Because of his great size and strength, he requires a vast quantity of food; consequently he finds it necessary to protect a wide range against constant challenge by other animals. One sweep of his huge paw is capable of crushing the skull of a range bull, and he can mangle a man or beast as thoroughly as a lion with his almost straight claws.

He flips over a boulder that a strong man would find difficult to move by an apparently effortless sweep of one paw. One of his enemies, the black bear, finds his only safety from his big cousin by climbing a tree. The grizzly though able to climb during his cub days, is unable to get up a tree when he reaches maturity because of the stiffening of his wrists.

In the spring the grizzly drops down to the foothills where he feeds on green grass, rock-chucks, gophers, and mice, but with the arrival of warm weather he retires to the shade of mountain forests, where his major diet is made up of roots, nuts, and berries. Like other members of the bear family he is omnivorous, but is a vegetarian by preference. He is not above eating the kill made by another animal, and is an avid fish-eater.

The early farmers and cattlemen found him a ruthless enemy and a pest, and his inroads on stock were severe in many instances. While he lived on the plains he did not begin his hibernation until mid-December, and often emerged from his den in March. Driven to the mountains, however, he often dens up late in October remaining until April.

Footprints of the bear family

Range and Distribution. A n inventory completed by the World Wild life Fund in 1964 indicates a continental population of around 36,000, about half of which live in western Canada . Alaska has between 17,000 and 18,000. South of Canada the grizzly is a threatened species. Wyoming has between 100 and 200, Montana 350, Idaho 50, and Colorado and Washington about ten each. Most of the survivors find refuge in Yellowstone and Glacier National Parks.

A breakdown of the range of this bear, by species, is as follows:

Food is the driving force which guides his selection of range, and his size and strength permit him to select a large one and hold it against the invasion of all animals but man and his repeating rifles. He changes his habitat with the seasons. In the spring he goes to the lower ground and feeds, when opportunity offers, on grasses, cattle, and game; in the early summer he favors the rolling hills with their quamash and Indian turnip; in the late summer he prefers the berry growth along the river flats, and in the fall he moves to the pine woods.

Each spring, after winter winds and snow have erased his signs, he renews his "mark" on the trees bordering his range by rearing to his full height and stretching himself against a tree trunk, where he rubs his itching skin. This not only aids in the removal of his heavy winter coat b u t identifies that area as "his."

Breeding. June of every other year is the mating period for the female grizzly. The cubs, normally twins, but occasionally triplets or quadruplets, are born in late January or early February while the mother is in hibernation. Despite the great size of the mother, these cubs weigh but a few ounces when born.

Mother Grizzly and Cubs, checking up on an intruder

The female is a gentle, wise mother, carefully instructing her cubs in all the tricks of eating and living, and guarding them with a savagery which few other animals dispute. Few of the predators that prey on the young of other animals are inclined to annoy the grizzly cub.

 






Date added: 2022-12-11; views: 540;


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