Bison

Bison, largest terrestrial mammal in North America, where it is usually called buffalo although the bison and true buffalo are different species. The bison is characterized by a hump over the front shoulders; short, sharply pointed horns (in both sexes), which curve outward and upward from the sides of the massive head; and slimmer hindquarters. A mature bull of the North American bison is about 2 m (6y ft) high at the hump and 2.7 to 3.7 m (9 to 12 ft) long, and weighs 850 to 1,100 kg (1,800 to 2,400 lb); the female is smaller. The head, neck, forelegs, and front parts of the body have a thick coat of long, dark hair. The rear part of the body is covered with much shorter hair. An adult bull usually has a black beard about 30 cm (12 in) long.

Bison are usually found in groups, except for old, solitary bulls. Throughout most of the year, females with young form small bands, and immature bulls may stay with them. Mature males have their own groups. The bands may congregate in large herds in the spring or autumn to search for food or water. Bison grunts and snorts are audible at short distances. The roar of rutting bulls, audible at nearly 5 km (3 mi), is heard most often in the mating season, mainly July to September, when bulls go looking for cows and try to ward off rivals. Breeding bulls have little time to eat and lose more than 90 kg (200 lb) during the mating season. Gestation is eight to nine months, and a single yellow-red calf is born. After a few days the calf can keep up with the herd and follows its mother until the following spring.

The bison originated in Eurasia, where it was frequently preyed upon by palaeolithic hunters. The bison is one of the few members of its family to have crossed the Bering Strait land bridge in prehistoric times to North America, where two subspecies, the plains bison and the wood bison, survive. The European bison, or wisent, taller but lighter than the American bison, almost became extinct; they now exist in parks and zoos.

Until the 19th century, as many as 60 million bison lived on the Great Plains from Mexico into Canada, and some were found east of the Mississippi River. They were central to the existence of the Plains peoples (see Native Americans), who used them for food, hides, and bone implements; even the dried dung, called buffalo chips, was used as fuel. From 1830 to 1889, methodical destruction by encroaching white settlers, for sport and for hides, reduced this number to fewer than 1,000. Today, about 30,000 bison live in protected areas and on private ranches, and their numbers have increased substantially.

Scientific classification: Bison belong to the family Bovidae. The plains bison is classified as Bison bison bison, the wood bison as Bison bison athabasca, and the European bison as Bison bonasus.