The American bison (commonly known as the buffalo) has a massive body, humped shoulders, and pointed horns that curve up and in. In winter, its coat is dark brown and shaggy.
RANGE: Canada, USA
STATUS: Lower risk: conservation dependent, IUCN Endangered, ESA (subspecies athabascae)
In the spring, this coat is shed and replaced by one that is short and light-
relatively short tail is 12 to 35 inches (31 to 89 centimeters) long and ends in a tuft of hair. The American bison species is divided biologically into two subspecies: the plains bison (Bison bison bison) and the wood bison (Bison bison athabascae). The main physical difference between the two is the color of the hair on the shoul ders. On the plains bison, this hair is lighter in color than the hair on the rest of its body. The difference in hair color on the wood bison is not so pronounced.
The bison is a fast runner and good swimmer, and has a keen sense of smell. It is active during both day and night, feeding on prairie grasses and sedges (grasslike flowers). Bison usually travel in herds, although some males (bulls) tend to be solitary. Mating season lasts from June to September. The gestation (pregnancy) period of the female American bison is about 285 days. The calves, which are reddish-
Habitat and current distribution
In the United States in the early years of the twenty-
History and conservation measures
American bison once ranged from Alaska and western Canada into the United States and northern Mexico. Scientists have estimated that in the early nineteenth century more bison—60,000,000 total—than
humans existed in North America. These large animals were an essential part of the culture of many Native American people, who depended on the American bison for food and clothing. As American and European settlers moved west during that century, the number of bison began to decline. The animals were hunted for their hides, meat, and tongues, which were considered a delicacy. They were shot from trains for sport. And as part of the American government’s strategy to subdue Native Americans, bison were slaughtered by the millions. By the late nineteenth century, only a few hundred of each subspecies remained in the wild.
In 1902, the American government placed a herd of some 40 captive and wild plains bison under protection in Yellowstone National Park. This herd grew into the one that exists in the park today. In 1922, the Canadian government established Wood Buffalo National Park to protect the last surviving wood bison. Unfortunately, plains bison were shortly afterward released into the park, where they mated with the wood bison. The resulting offspring were a hybrid, or genetic mixture, of the two subspecies. In the late 1950s, a small herd of genetically similar wood bison were located in the park. Although scientists allowed these animals to breed only with each other, no one is certain whether any genetically pure wood bison currently exist.
Beginning in 1990, Montana Department of Livestock workers shot plains bison that wandered outside of the boundaries of Yellowstone National Park. Even though the animals are protected within the park, a state-