Megaptera novaeangliae. Megaptera novaeangliae. "Megaptera" means "great wing," referring to its huge pectoral fins. The word "novaeangliae" means "New England," where the first Humpback sighting was recorded. The Humpbacks begin arriving in Hawaii in November every year, after a 2,500-mile migration from Alaska. The young sub-adults appear to head the migration, while the cows and calves arrive later, around mid-January. After spending the winter in warm Hawaiian waters, this group is also the last to leave, waiting until late spring. Researchers have "guesstimated" the number of Humpbacks coming to Hawaii at between five and eight hundred. The calf, born in warm water, is 12 to 15 feet at birth and weighs in at 1 to 2 tons. The gestation period lasts up to 11 months. After birth, the calf consumes large amounts of the mother's rich milk and gains weight rapidly. The young calf swims closely to mom in those first few months, often perched just above her eye head or back with fins extended down for contact. Other than man, the Humpback knows few enemies, although attacks by sharks and killer whales have been recorded. They can reach 50 feet in length and weigh in the neighborhood of one ton per foot, with the female being larger than the male. Pectoral fins, for which the Humpback is known can reach 15 feet in length and the tail can measure up to 18 feet from tip to tip. No one knows the life span of the Humpback, but there is evidence that they live as long as we do (up to 70 years). Sexual maturity occurs at between five to nine years for the females, who have a 2 or 3 year breeding cycle, but annual calving has also been observed. Although Humpbacks live in all oceans of the world the different stocks have no inter-relation, The North Pacific group feeds in the cold waters of Alaska, and migrates to winter breeding grounds in either Hawaii, Mexico or the Western Tropical Pacific.