Species Spotlight: American Bison

November 12, 2009, 12:06 pm
Perhaps no other animal symbolizes the West as dramatically as the American bison, which has roamed the North American Continent from the Great Slave Lake in northern Canada, south into Mexico and from coast to coast for millions of years. Bison are part of the family Bovidae, to which cattle and goats belong. Often referred to as buffalo, this name is in fact a misnomer as they are not in the same family that includes “true” buffaloes—Asian and African buffalo. One of the physical differences between the old world buffalo and the American bison is the large shoulder hump of the bison. This hump, along with a broad, massive head, short, thick neck and small hindquarters give the animal its rugged appearance.

In 1800, the 40 million bison roamed the plains foraging for grass and sedge, forming the backbone of the American Indian economy. The bison sustained a way of life, providing food, clothing, shelter and fuel. By 1883, there were no wild bison in the United States. The majority of the 40 million animals were killed in a 55-year period, beginning in 1830. By 1900, there were fewer than 600 left in North America. The extermination of the species marked the end of American Indian independence, as no resource could replace the buffalo to support tribes’ economic infrastructure. Many people denounced the slaughter, but few did anything to stop it. With fortuitous foresight, the American Bison Society was formed in 1905 to secure the survival of this species. With the help of captive breeding and reintroductions to the wild, the American bison population is now relatively secure, with more than 500,000 animals, all of which descended from a handful of survivors saved by a small group of dedicated conservationists.

There are two distinct subspecies of bison—the Plains Bison (Bison bison bison), smaller in size and with a more rounded hump, and the Wood Bison (Bison bison athabascae), which is the larger of the two and with a taller, square hump.

Bison are the largest land mammals in the Americas. The distinct dark brown coat is long and shaggy on the forequarters, covering its front legs, neck, and shoulders. Calves are ruddy at birth, but generally change to dark brown by 6 months of age.  Males may be up a third larger than females. The shoulders are massive and humped with the head carried low. Both sexes possess horns (not antlers) that arch backwards, outwards and then upwards, curving in slightly to form blunt tips.

Despite their size, bison are incredible athletes, able to run at speeds of up to 50 kmph/30 mph, jump 6 to 8 feet high, and swim rivers more than 1 km/0.6 miles wide. During the breeding seasons males will bellow - a sound which may carry up to 5 kilometers / 3 miles.

Body Length: Up to 12.5 feet/380 cm
Shoulder Height: Up 6.5 feet/195 cm

Weight: Adult males can weigh more than 2,000 pounds though they average between 545-818 kg/1,200-1,800 pounds. Females are typically a third smaller than males.

Park Habitat:

Native to the Badlands, bison were extirpated from this area by the 1880s. In 1963, bison were reintroduced into the Sage Creek basin. Due to a fear of the disease brucellosis, Badlands bison are not a free-ranging herd and are contained within 64,000 acres to keep them from mingling with surrounding cattle herds (though no Badlands bison have ever tested positive for brucellosis, a disease that causes the death of calves during the birth process.) While you’ll see an occasional bison along the park road, the best place to see them is along the unpaved Sage Creek Rim Road.

Bison graze on prairie grasses and sedge common to their prairie and wooded habitat.  In the winter, bison will paw away in deep snow to reach the dried shrubs, lichen and moss trapped underneath.

Interesting Fact:
Many sources assert that the nickname for the U.S. 10th Cavalry Regiment of the United States Army—the Buffalo Soldiers—was given to them by the Comanche tribe out of respect for their fierce fighting ability.

There are several other parks where the buffalo roam, including:

Theodore Roosevelt National Park

Capitol Reef National Park - reintroduced

Grand Teton National Park

Wind Cave National Park - reintroduced

Wrangell-St. Elias National Park - introduced

Yellowstone National Park