Reproduction Reproduction A. Sexual maturity. Estimates of sexual maturity in baleen whales range from 3 to 10 years depending on the species. This information is not known for all species. Sexual maturity is often reached at a particular body size and is reported as length.
Males display a seasonal reproductive cycle which correlates with a winter estrus in females.
B. Mating activity. In right, bowhead, and gray whales, breeding behavior includes several males and one female. Breeding groups may engage in pre-mating activity for more than an hour. The female may allow the largest and most aggressive male to mate with her, or she may flee or roll away. A female may mate with more than one male in a single breeding season.