Bison bulls may weigh a ton, cows top out around 1,100 pounds and calves weigh about 65 pounds when born. Bison can run at 35 MPH for long distances. Bison can live up to 40 years in captivity. Formerly, their only natural enemies were wolves and grizzly bears. Bison will use their massive heads to push the snow aside in winter to reach the grass beneath.
Late summer is an important time for bison.
That is the season of rut, when the dominant bison bulls must re-establish their right to sire next year's calves. There is much jousting and posturing between the dominant bulls and the lesser rival bulls and that keeps things hopping in the herd. The calves, typically a single birth and occasionally twins, will be born in late spring. The calves are a tawny brown color and can run with the herd within a few hours after birth. The bison was chosen as the State Animal of Kansas in 1955.