what is the gestation period of a blue whale
1 Blue whales give birth after 11 â 12 months of pregnancy and it is estimated that female whales give birth every 2 â 3 years.  killer whale have a pregnancy period of 15 â 18 months, however it is believed that the average pregnancy period is about 17 months. (Females killer whales give birth every 3 â 5 years).