HUMPBACK WHALE

Humpback whale (Megaptera novaeangliae) breaching. (Megaptera novaeangliae, or M. nodosa), baleen whale, the only species of the genus Megaptera, belonging to the family Balaenopteridae. The humpback is a thickset whale that usually attains a length of about 12 to 16 m (40 to 52 feet). It is black, with a variable amount of white below, and is distinguished by its very long, narrow pectoral finsscalloped on the forward edgeand by large knobs, each associated with one or two hairs, on its head and jaws. The dorsal fin is small and set far back, and there are about 20 lengthwise grooves on the throat and chest. Humpback whale surfacing, showing blowholes. The humpback lives along the coasts of all major oceans, occasionally swimming close inshore or even into harbours and up rivers. It migrates between polar oceanic waters in summer and tropical or subtropical breeding grounds in winter. Its diet consists of shrimplike crustaceans, small fish, and plankton, which it strains out of the water by means of its baleen. The humpback is one of the most acrobatic of all whales. On occasion it may perform a somersault by leaping from the water belly up, arching backwards, and plunging headfirst back into the water with a loud slapping sound. When making deep dives, it hunches its back and rolls steeply forward, bringing its tail vertically clear of the water. The humpback is also probably the most vocal of all whales, making a great variety of sounds which it strings together to form a song that may last from 5 to 35 minutes. The sounds range from moans and cries to groans and snores. The songs themselves vary among groups of whales in different areas of the ocean, and the songs undergo gradual but distinctive changes from year to year. The humpback whale is commercially valuable and was much reduced in numbers by overhunting in the early and mid-20th century. Protected worldwide since the mid-1960s, it is listed as an endangered species in the Red Data Book.