Foto de stock - Adult humpback whales Megaptera novaeangliae surfacing near the Lindblad Expedition ship National Geographic Explorer near the Antarctic Peninsula One of the larger rorqual species, adults range in length from 1216 metres 4050 ft and weigh approximately 36,000 kilograms 79,000 lb The humpback has a distinctive body shape, with unusually long pectoral fins and a knobbly head It is an acrobatic animal, often breaching and slapping the water Males produce a complex whale song, which lasts for 10 to 20 minutes and is repeated for hours at a time The purpose of the song is not yet clear, although it appears to have a role in mating Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 kilometres each year Humpbacks feed only in summer, in polar waters, and migrate to tropical or sub_tropical waters to breed and give birth in the winter During the winter, humpbacks fast and live off their fat reserves The species´ diet consists mostly of krill and small fish Humpbacks have a diverse repertoire of feeding methods Humpback whale populations here are severely depleated from over fishing during the 20th century modern era whaling efforts A 2007 study identified seven individual whales wintering off the Pacific coast of Costa Rica as those which had made a trip from the Antarctic of around 8,300 km Identified by their unique tail patterns, these animals have made the longest documented migration by a mammal