Killer whales, also called orcas, are conceived via sexual reproduction between a sexually mature bull and a cow in estrus. The gestation period is approximately 17 months, at the conclusion of which a calf typically measuring 8 feet long is born to the cow.
The calf is weaned from its mother after one year. After this time, the calf is integrated into the pod, a family group of killer whales consisting of up to 40 individuals. The point of sexual maturity varies between male and female killer whales; males reach maturity at approximately 22 feet long, and females reach maturity at approximately 16 feet long. Although both male and female killer whales can live in the pod, breeding typically occurs between members of different pods to maintain genetic diversity.