Birds will perch on the backs of bison, looking for insects disturbed by their grazing.
NPS Photo / Kim Acker
Perhaps no other animal symbolizes the West as dramatically as the American bison. In prehistoric times millions of these animals roamed the North American Continent from the Great Slave Lake in northern Canada, south into Mexico and from coast to coast. No one knows how many bison there were, but the naturalist, Ernest Thompson Seton, estimated their numbers at sixty million when Columbus landed. They were part of the largest community of wild animals that the world has ever known. The National Park Service has played an important part in returning the bison to the Great Plains.
Bison or Buffalo?
In North America, both “bison” and “buffalo” refer to the American bison (Bison bison). Generally, “buffalo” is used informally; “bison” is preferred for more formal or scientific purposes. Historians believe that the term “buffalo” grew from the French word for beef, “boeuf.” Some people insist that the term “buffalo” is incorrect because the “true” buffalo exist on other continents and are only distant relatives.
Another name for these animals is “tatanka.” Tatanka is the Lakota word for bison. Bison are incredibly important in Lakota culture; the Lakota are traditionally nomadic and would have spent their lives following bison before Euro-Americans settled the West. Another word for bison in Lakota is “pte.” The Lakota are sometimes known as pte oyate, meaning “buffalo nation.”
Cows (left) are smaller and have less hair on their heads. Bulls (right) are much larger, more muscular, and have thicker hair on their heads and forelegs.
NPS Photo
Description
Bison are the largest land-dwelling mammal in North America. Males (2,000 lbs/900 kg) are larger than females (1,100 lbs/500 kg) and both are generally dark chocolate-brown in color, with long hair on their forelegs, head, and shoulders, but short, dense hair (1 in/3 cm) on their flanks and hindquarters. Calves of the year are born after 9 to 9-½ months of gestation. They are reddish-tan at birth and begin turning brown after 2-½ months. Both sexes have relatively short horns that curve upward, with male’s averaging slightly longer than those of adult females.
All bison have a protruding shoulder hump. Large shoulder and neck muscles allow bison to swing their heads from side-to-side to clear snow from foraging patches, unlike other ungulates that scrape snow away with their front feet. Bison are agile, strong swimmers, and can run up to 35 miles per hour (55 kph). They can jump over objects about 5 feet (1.5 m) high and have excellent hearing, and sense of smell.
In the spring, bison shed their winter coat and may use wallows, park signs, trail markers, and fence posts to help remove itchy loose fur.
NPS Photo
Behavior
The best description of a bison's temperament is unpredictable. They usually appear peaceful or unconcerned, yet they may attack without warning. To a casual observer, a grazing bison appears slow and lumbering, but they can outrun and out-maneuver humans.
Males (bull) weighs up to 2,000 pounds, females (cow) weighs up to 1,000 pounds. They may live 12–15 years, a few live as long as 20 years.
Other activities of the bison include rubbing, rolling, and wallowing. Wallowing creates a saucer-like depression called a wallow. This wallow was once a common feature of the plains; usually these wallows are dust bowls without any vegetation.
The sounds they make range from a pig-like grunt to an aggressive bellow.
Always stay at least 25 yards (23 m) away from bison. Give bison space when they are near a trail or in a developed area. If need be, turn around and go the other way to avoid interacting with a bison in close proximity. Approaching bison threatens them, and they may respond by putting up their tail, bluff charging, head bobbing, pawing, bellowing, or snorting. These are warning signs that you are too close and that a charge is imminent. Do not stand your ground. Immediately walk or run away from the animal.
Calves stay with their mothers until they are about one year old.
NPS Photo
Reproduction
The rut, or mating, season lasts from late June through early September with peak activity in July and August. At this time, the older bulls rejoin the herd and fight each other for breeding rights. The herd is very restless during the rut and this is when they are most dangerous.
Calves, born about nine months later in April or May, generally weigh 30 to 70 pounds. They have reddish-brown fur and do not have the conspicuous hump of the adult. After a few months, the fur begins to change to chocolate brown and the hump begins to develop.
Cultural Significance and Conservation
Wind Cave, also called Oniya Oshoka or Maka Oniye, is a significant place in the Lakota tradition. In Lakota oral tradition, not only were the first humans born from the cave, but the first bison came from the cave as well. This oral tradition highlights the close connection that plains tribes had, and continue to have, with bison.
In 1800, it was estimated there were 40 million bison, by 1883, there were few wild bison in the United States - most were in Yellowstone National Park. By 1900, there were less than a thousand left in North America. The majority of the forty million animals were killed in a fifty-five year period, beginning in 1830. Many people denounced the slaughter; few did anything to stop it. Fortunately, a small, devoted group of conservationists managed to save a few hundred.
In 1913, the American Bison Society sent 14 bison from the New York Zoological Gardens (now the Bronx Zoo) to Wind Cave. An additional six bison were sent to the park in 1916 from Yellowstone National Park. It is from these bison that Wind Cave's herd is descended from.
During mating season, known as the rut, male "bellows" are commonly heard. These bellows have been compared as to revving up an old Chevy truck! It is believed that these bellows announce the male's presence and establish dominance within the herd.
