- Education and Science»
- Life Sciences
The bison is a genus of large wild cattle once numerous in North America and Europe but brought close to extinction by man's senseless slaughter of the animals. Two species still exist in zoos and protected herds: the American bison, or "buffalo" (Bison bison), and the European bison, or wisent (Bison bonasus).
The adult bison is characterized by a large head, heavy forequarters and relatively light hindquarters, and a hump (larger in American bison, and larger in the male animal) on the withers and back. The hump is formed by long spinous extensions of the thoracic vertebrae; the powerful muscles and ligaments that support the heavy head arise from these spines. Dark shaggy fur covers the hump and head, and there is usually a beard. The skull above the eye sockets is very broad, and short upcurved horns grow from the sides of the skull in both male and female bison. The animals have 14 pairs of ribs as compared to the 13 pairs in domestic cattle, and there are other structural differences.
Bison evolved in Eurasia during the Pleistocene epoch and entered North America somewhat later during the same epoch by means of the Bering Strait land bridge existing at that time. About 18 species evolved in all, with various characteristic shapes and sizes; a fossil with a horn spread of over 10 feet (3 meters) is known. The two remaining species breed readily with each other and less rapidly with other kinds of cattle. Hybrids of bison and domestic cattle are called cattalo; the hybrids are often fertile.
The American Bison
There are two subspecies of American bison (although some scientists say that the differences are too slight for separate classification). One, the plains bison, roamed most of the United States east of the Sierra Nevadas, except for the Great Lakes region, Florida, New Jersey, and New England. In Canada it inhabited Manitoba, Saskatchewan, and eastern Alberta. Herds of plains bison may have entered northern Mexico as well. The other subspecies, the wood or mountain bison, was found in the Rocky Mountains from Colorado to subarctic Canada; pre-historically it ranged as far as central Alaska.
A large male American bison may stand from 5 feet 6 inches to 6 feet high, be 9 feet long, and weigh from 2,000 to 2,800 pounds. The females (as with all bison) are considerably smaller. Gestation is about nine months, and there is usually a single calf. The average life-span is about 20 years.
The wood bison is larger than the plains bison, has darker and silkier hair, and is somewhat warier and more unapproachable. Like the wisent, the wood bison inhabited forested and mountainous regions where restricted pasturage limited the size of the herds. Wood Buffalo National Park, in Alberta and the Mackenzie district of Canada, is the last remaining locality of wild wood bison. Several thousand plains bison were transferred to this park from Wainwright Buffalo Park in the 1920's. The herds hybridized freely, so it was thought that the wood bison had become extinct as a separate form. However, a group of purebred wood bison were discovered in a remote section of the park in 1957.
Life of the Plains Bison
The plains bison was notable for its gregariousness. With enormous areas available for exploitation without much competition before the land was settled by man, the bison population was free to increase to vast numbers. The herds contained thousands of small bands; a typical band consisted of a patriarchal old bull, as many cows as he could collect and keep, younger adult bulls, and young bison of various ages. The herding process protected the plains bison against predators such as pumas, wolves, and bears, which were always around to seize stray young or feeble members of the band. When attacked by other animals, the band would quickly form a protective circle with bulls on die outside and cows and young in the center.
The sexes remained together throughout the year. Bulls fought furiously for supremacy of their bands during the mating season, which lasted from July to October. At other times the animals generally appeared docile and sluggish, but their behavior was unpredictable. Some individuals panicked easily, and an alarm might cause an entire herd to stampede; other bison stood by in apparent apathy toward or defiance of human intruders. Despite their clumsy appearance, bison could swim well and manage mountain slopes with ease.
Neither the small bands nor the larger herds were necessarily permanent units. Reports of huge permanent migrating herds are especially doubtful. Instead of regular migrations there were local and seasonal shifts for water, food, or escape from summer heat. The bison did not necessarily take the easiest route from place to place, particularly when crossing streams. The so-called buffalo trails were really crooked, haphazard paths, so numerous that a seemingly continuous route could easily be picked out from among them. This was especially true in the Midwest, where the connecting of many short trails between feeding grounds and nearby streams (with their predominantly east-west course) gave rise to the belief that the animals made an annual north-south migration.
Slaughter of the Herds
For many of the Western Indians the bison provided their one real industry. The Indians wasted little of a kill; food, fuel, clothing, shelter, tools, and glue were obtained from the body and hide of the animal. It was probably unavoidable that the bison eventually would be eliminated from areas as they came to be settled, but white hunters were frugal at first. Unfortunately, the apparent limitless-ness of the herds soon led to waste and thoughtless slaughter, and by 1800 the bison was extinct east of the Mississippi. The same practices were followed in the Red River region of Canada about 1820, when it was realized that bison meat and hide were marketable on a large scale. Hundreds of hide hunters, meat packers, and tongue picklers began to exploit the Canadian plains bison, which became extinct by 1880.
Bison hunts in the United States began in earnest with the opening of the Union Pacific and Kansas Pacific railways about 1865. At that time the United States bison population was divided into two parts- whether resulting from or coincident with the building of the railroads is not clear. Between 1870 and 1875 the southern herd was eradicated; the northern herd was destroyed mainly between 1880 and 1885. Probably the major excuse for this carnage was a military-political one, an outcome of the Indian wars begun in 1862 as the Indians tried to resist the encroachments of the white man. Encouraged by the propaganda of government officials, who said that the Indian could best be "civilized" by exterminating the bison, thousands of hunters slaughtered the herds without mercy, sometimes in the most inhumane manner and usually with little pretense of frugality or of true sport. By 1900 some 50 million plains bison had been killed, bringing the native wild herds to near extinction.
The wisent differs from the American bison in several respects. The head of the wisent is smaller and is carried higher. The spines forming the hump are shorter, and the hump does not extend as far back as in the bison. The wisent's body and legs are longer, with smaller forequarters and larger hindquarters, but the maximum body weight is less. A large male wisent may stand from 6 feet to 6 feet 2 inches high, be 10 feet long, and weigh from 1,800 to 2,000 pounds.
In general, the appearance of the wisent is more oxlike and less imposing than that of the bison. The coat is less shaggy and more evenly distributed in length and has a lighter, predominantly chestnut, color; the tail is longer and hairier. Gestation is about nine months, and a single birth is usual; the lifespan is about 30 years. Herd size in the wild was limited to about 50 individuals; they fed on grasses, ferns, leaves, and bark.
Two distinct populations of wisent existed until the 20th century, one in the Bialowieza Forest of Poland and the Soviet Union, and the other on the northern slopes of the Caucasus Mountains. The former were exterminated in the wild by 1918 and the latter by 1927. The Caucasus wisent is said to have differed from the Lithuanian in having certain of the characteristics of the American bison; apparently only hybrid Caucasus wisents have survived. The two populations are generally considered as subspecies (although again, some scientists hold that the differences were too slight for classification and were due to habitat alone). The International Society for the Preservation of the Wisent has saved the Lithuanian subspecies from extinction by careful breeding from several small, privately owned herds. More than 200 of the animals now exist, and a herd of wisents has been released in the Bialowieza Forest to live in a wild state.
Through the determined efforts of various individuals and zoos, a few hundred bison still were alive in 1900. Most of the specimens were privately owned, but a small wild herd lived in Yellowstone National Park and a somewhat larger one in Canada. The American Bison Society, formed by conservationists in 1905, did much to build up a few more herds and to save the bison from utter annihilation. The National Bison Range in Montana and the Wichita Game Preserve in Oklahoma were established to protect the herds.