Bison

The bison is the largest land animal in North America. An adults they weigh 900 to 2000 pounds, depending on their gender. They are six to six and a half feet tall at the shoulder. They should not be confused with buffalo that are found only in Asia and Africa.

In the eighteenth century between twenty and thirty million bison roamed the North American plains and woods. By the late nineteenth century there were about one thousand bison left. This reduction in population caused a genetic bottleneck. This means that the bison were at risk for inbreeding because of a lack of diversity.

Bison start their life, after 285 days of gestation, living in a group of about twenty females and calves. They nurse for seven months. They start out with light brown fur that turns chocolate brown as they mature. When males turn three they leave and live alone or with other male adults.

The bison live in conservation herds and on ranches where they are bred with cattle for eating. Cross breeding dilutes the bison genes. The herd that lives in Yellowstone National Park is genetically pure. Staying in Yellowstone is a problem in the winter when the bison do not find enough grasses, berries and sedges to eat. That leads to their enemy, the Montana rancher.

Ranchers have an irrational fear that bison give their cattle brucellosis even though none of the herd has the disease. When the bison would try to leave to graze on public land in Montana, the ranchers would haze them back or kill them! Last year, for the first time, the bison were allowed to graze in Montana under the Interagency Bison Management Plan as part of a joint effort between the Federal government and the State of Montana. The future remains uncertain for the bison. _