American Bison

The American Bison (Bison bison) is a bovine mammal, the largest terrestrial mammal in North America, and one of the largest wild cattle in the world. With their huge bulk, Wood Bison”“which are the largest subspecies in North America ““ are only surpassed in size by the massive Asian gaur and wild water buffalo, both of which are found mainly in India. The bison inhabited the Great Plains of the United States and Canada in massive herds, ranging from the Great Slave Lake in Canada’s far north to Mexico in the south, and from eastern Oregon almost to the Atlantic Ocean, taking its subspecies into account. Its two subspecies are the Plains Bison (Bison bison bison), distinguished by its smaller size and more rounded hump, and the Wood Bison (Bison bison athabascae), distinguished by its larger size and taller square hump.

The Bison is also commonly known as the American Buffalo, although it is only distantly related to either the Water Buffalo or African Buffalo.


Bison have a shaggy, dark brown winter coat, and a lighter weight, lighter brown summer coat. Bison can reach up to 6½ ft (2 meters) tall, 10 ft (3 meters) long and weigh 900 to 2,000 lb (450 to 900 kilograms). The biggest specimens on record have weighed as much as 2,500 lb (1140 kg). The heads and forequarters are massive, and both sexes have short, curved horns, which they use in fighting for status within the herd and for defense. Bison mate in August and September; a single reddish-brown calf is born the following spring, and it nurses for a year. Bison are mature at three years of age, and have a life expectancy of 18 to 22 years in the wild and 35 to 40 years in captivity.

One very rare condition results in the white buffalo, where the calf turns entirely white. It is not to be confused with albino, since white bison still possess pigment in the skin, hair, and eyes. White bison are considered sacred by many Native Americans.

Due to its size and the protection afforded by living in a herd, the bison have few enemies besides humans. Grizzly bears and packs of wolves may attempt to attack a young calf or sub adult, but only in the dead of winter when the herd cannot expend the energy to protect stragglers. A wolf pack can also take down an adult bison, but it typically takes at least 7 wolves to do so, and even then the wolves usually lose. The only threat, other than hunting by humans that leads to the depletion of wild bison is interbreeding with domestic bovines. In fact, only a small number of bison herds found in North America today are pure breed bison.

Native hunting

The American Bison is a relative newcomer to North America, having originated in Eurasia and migrated over the Bering Strait. About 10,000 years ago it replaced the Long-horned Bison (Bison priscus), a previous immigrant that was much larger. It is thought that the Long-horned Bison may have gone extinct because of a changing ecosystem and hunting.

Bison were a keystone species, whose grazing pressure was a force that shaped the ecology of the Great Plains as strongly as periodic prairie fires and which were central to the lifestyle of Native Americans of the Great Plains. But there is now some controversy over their interaction. What is not disputed is that before the introduction of horses, bison were herded into large chutes made of rocks and willow branches and then stampeded over cliffs. These bison jumps are found in several places in the U.S. and Canada, such as Head-Smashed-In Buffalo Jump. Large groups of people would herd the bison for several miles, forcing them into a stampede that would ultimately drive many animals over a cliff. The large quantities of meat obtained in this way provided the hunters with surplus, which they could trade with other cultures. A similar method of hunting was to drive the bison into natural corrals, such as Ruby site.

To get full use out of the bison, the Native Americans had a specific method of butchery, first identified at the Olsen-Chubbock archaeological site in Colorado.

Later when Plains Indians obtained horses, it was found that a good horseman could easily lance or shoot enough bison to keep his tribe and family fed, as long as a herd was nearby. The bison provided meat, leather, sinew for bows, grease, dried dung for fires, and even the hooves could be boiled for glue. When times were bad, bison were consumed down to the last bit of marrow.

19th century Buffalo hunts

Bison were hunted almost to extinction in the 19th century and were reduced to a few hundred head by the mid-1880s, from which all the present day’s managed herds are descended. One major cause was that hunters were paid by large railroad concerns to destroy entire herds, for several reasons:

  • The herds formed the basis of the economies of local Plains tribes of Native Americans for whom the bison were a primary food source; without bison, the Native Americans would be forced to leave or starve.
  • Herds of these large animals on tracks could damage locomotives when the trains failed to stop in time.
  • Herds often took shelter in the artificial cuts formed by the grade of the track winding though hills and mountains in harsh winter conditions. As a result the herds could delay a train for days.

Bison skins were used for industrial machine belts, clothing such as robes, and rugs. There was a huge export trade to Europe of bison hides

For a decade from 1873 on there were several hundred, perhaps over a thousand, such commercial hide hunting outfits harvesting bison at any one time, vastly exceeding the take by American Indians or individual meat hunters. The commercial take arguably was anywhere from 2000 to 100,000 animals per day depending on the season, though there are no statistics available. It was said that the Big 50s were fired so much that hunters needed at least two rifles to let the barrels cool off; The Fireside Book of Guns reports they were sometimes quenched in the winter snow. Dodge City saw railroad cars sent East filled with stacked hides.

As the great herds began to wane, proposals to protect the bison were discussed. Cody, among others, spoke in favor of protecting the bison because he saw that the pressure on the species was too great. But these were discouraged since it was recognized that the Plains Indians, often at war with the United States, depended on bison for their way of life. General Phillip Sheridan spoke to the Texas Legislature against a proposal to outlaw commercial bison hunting for that reason, and President Grant also “pocket vetoed” a similar Federal bill to protect the dwindling bison herds. By 1884, the American Bison was close to extinction.

Bison hunting today

Hunting of wild bison is legal in some states and provinces where public herds require culling to maintain a target population. In Alberta, where one of only two continuously wild herds of bison exists in North America at Wood Buffalo National Park, bison are hunted to protect disease free herds of public (reintroduced) and private herds of bison. In Montana a public hunt was re-established in 2005, with 50 permits being issued. The Montana Fish, Wildlife and Parks Commission increased the number of tags to 140 for the 2006/2007 seasons. Advocacy groups claim that it is premature to re-establish the hunt, given the bison’s lack of habitat and wildlife status in Montana.

One of the bison’s few natural predators is the wolf. Wolves will usually prey on the females and young and rarely will go for healthy bulls. Bears will also prey on the young of bison.

Buffalo trails

The first thoroughfares of North America save for the time-obliterated paths of mastodon or musk ox and the routes of the Mound Builders, were the traces made by bison and deer in seasonal migration and between feeding grounds and salt licks. Many of these routes, hammered by countless hoofs instinctively following watersheds and the crests of ridges in avoidance of lower places’ summer muck and winter snowdrifts, were followed by the Indians as courses to hunting grounds and as warriors’ paths; they were invaluable to explorers and were adopted by pioneers. Bison traces were characteristically north and south; there were, however, several key east-west trails, which were used later as railways. Some of these include the Cumberland Gap; along the New York watershed; from the Potomac River through the Allegheny divide to the Ohio River headwaters; and through the Blue Ridge Mountains to upper Kentucky. In Senator Thomas Hart Benton’s phrase saluting these sagacious path makers, the buffalo blazed the way for the railroads to the Pacific.