Average life span of bison is about 20-25 year. In nature, they have virtually no enemies. In some forest areas, wolves occasionally attack bison. In the case of attack predators, females are surrounded by young growth and run ahead, and males cover the herd from the rear. Sometimes, to protect against wolves, bison enter the water.
Breeding season for buffalo lasts from May to September. During this period, the herds form large clusters, the males join the groups of females and start fierce fighting among themselves. Bulls converge with their noses to the nose and start to butt, resting their foreheads. From the side of their movement they look heavy and slow, but in reality they are full of strength. The rival, who did not dodge, the bison is capable of causing serious wounds, sometimes with a fatal outcome.
Pregnancy lasts 9 months, before giving birth, the cow leaves the herd and calves in a secluded place. Occasionally the female can give birth in the herd, in this case the relatives show interest in the newborn and licks it with tongues. Sexual maturity of bison reach in 3-5 years.