Unlike cattle, bison can produce calves for 20 years or more.

  • Female bison breed when they are two years old and have their first calves when they are three.
  • Cows can live to be 20-25 years old, having a calf each year under the right conditions.
  • The gestation period for the American Buffalo is 9 1/2 months. Under normal conditions, cows have their calves from mid-April through June. Cows generally have one calf per year, but twins very rarely occur.
  • The calves are very small when born, normally weighing between 25-35 lbs. Although small, these little critters are very tough and are up walking and running with their mothers within a couple of hours.
  • Cows are very protective of their young. They leave the herd to have their calves and then remain away from the herd for a period between 6 hours to several days.
  • Bison calves are normally weaned when they are around 6 months old. At that time the females generally weigh around 350 lbs and males weigh approximately 425 lbs.
  • Under range conditions, bison cows seldom have calving problems.
  • The bull to cow ratio for bison is approximately one bull per 15 cows.
  • Buffalo have not been successfully artificially inseminated on a consistent basis.