The humpback whale (Megaptera novaeangliae) is a species of baleen whale. One of the larger rorqual species, adults range in length from 12–16 m (39–52 ft) and weigh about 36,000 kg (79,000 lb). Found.. Read more » in oceans and seas around the world, humpback whales typically migrate up to 25,000 km (16,000 mi) each year. Humpbacks feed in polar waters, and migrate to tropical or subtropical waters to breed and give birth when they fast and live off their fat reserves. Their diet consists mostly of krill and small fish.