Blue whales begin mating between 5-10 years of age. Females are pregnant for about 11 months and females get pregnant approximately every two to four years. Calves can gain 200 lbs. Mother and calf form a very close bond, with the baby often swimming close to its mother. It is believed they live past 50 years old.
Blue whales die of natural causes and are sometimes preyed upon by packs of killer whales .
Today blue whale hunting is illegal in the United States. Blue whales may also be harmed by pollution, ship strikes, or entanglement in fishing gear. Books and the world wide web are excellent places to learn more about marine mammals. Books Leatherwood, Stephen. Reeves, Randall R. Foster, Larry.