Every fall, more than 10,000 humpback whales migrate from the north Pacific Ocean to the Hawaiian Islands (smart whales!). That journey of over 3,000 miles brings them to warmer, shallow waters to breed. Some mate during this time, with “competition pods” of males pursuing a female. They will bump into one another and jockey for position close to her, attempting to become her primary escort. Ultimately the female will mate with several males for a better chance of getting pregnant. Once she is, the gestation time is about 11 months.
For females returning to Hawaii already pregnant, it is a safe place for them to give birth because there are few predators in the shallow waters. In addition, the newborn calves have no blubber, so the warm water is essential. When born, the calves are 12-15 feet long and weigh 1-2 tons. By comparison, adult humpbacks can weigh as much as 40 tons and grow to 60 feet long.
A mother whale nurses her baby with as much as 100 gallons of milk per day. In addition, she prepares her baby and helps it grow stronger before the long migration back north in the spring. She also teaches the baby how to breach, which, in addition to slapping their fins and flukes, is how humpback whales communicate with other humpbacks. The mother does all this without eating for months.
That’s right, the whales do not eat while in Hawaii because the tropical water have much less food available. Instead, they live off the stores of blubber they built up while in the cooler productive waters up north. They return to the North Pacific in the spring, where they feed on an abundance of krill, plankton, and small fish.
No matter what ocean (because humpbacks live in oceans around the world), if you have a chance to see whales, do it…they are an extraordinary sight to behold.