• In captivity they have lived more than 20 years.
• Calves are born reddish.

The American bison’s typical lifespan ranges from 25 years and 2 months to 41 years and 11 months, although the maximum recorded lifespan is 33 years and 6 months, with a theoretical lifespan between 16 years and 9 months and 33 years and 6 months. The species reaches sexual maturity between 1 year and 11 months and 3 years and 2 months of age; its eyes open at birth, and it begins to walk immediately. The embryo develops within the mother and receives nourishment from her. The young, called calves, are in the calf stage, feeding on their mother’s milk and growing rapidly for a duration of 6 to 9 months. Following this, the species enters the adult stage, lasting from 4 to 25 years, during which it lives independently and can reproduce.