 GENERAL DESCRIPTION The humpback whale is a baleen whale and a rorqual whale that sings amazing songs. It performs complex and cooperative feeding techniques. The humpback has a bulky head with bumpy protuberances (tubercles), each with a bristle. Humpbacks are acrobats of the ocean, breaching and slapping the water. They live in pods and have 2 blowholes. The name humpback describes the motion it makes as it arches its back out of the water in preparation for a dive. SIZE Humpback whales grow to be about 52 feet (16 m) long, weighing 30-50 tons (27-45 tonnes). The females are slightly larger than males, as with all baleen whales. The four-chambered heart of the average humpback whale weighs about 430 pounds (195 kg) - about as much as three average adult human beings. SKIN, SHAPE AND FINS 
Humpbacks come in 4 different color schemes, ranging from white to gray to black
to mottled. There are distinctive patches of white on underside of the flukes
(tail). These markings are unique to each individual whale, like a fingerprint.
The humpback's skin is frequently scarred and may have patches covered with
diatoms. Humpback whales have 14-35 throat grooves that run from the chin to the navel. These grooves allow their throat to expand during the huge intake of water during filter feeding. They have small, round bumps on the front of the head (called knobs or tubercles), edging the jaws. Humpbacks have huge, mottled white flippers with rough edges that are up to one-third of its body length; these are the largest flippers of any whale. The humpback's genus, Megaptera, means "huge-wings," referring to its flippers. The flippers may have barnacles growing on them. The deeply-notched flukes (tail) are up to 12 feet (3.7 m) wide. Humpbacks have a small dorsal fin toward the flukes.
 MIGRATION Humpback whales take long seasonal migrations. They mate and calve in tropical waters during the winter and then travel to cold polar waters during the summer to feed. During the summer in the warm waters, adults do not eat, but live off their ayer of blubber (fat); the young calves feed on rich mother's milk. Humpbacks migrate at 3-9 mph (4.8-14 kph). They have incredible powers of endurance, travelling over 3,100 miles (5000 m) during each seasonal migration with almost no rest along the way. During migrations, they cover over 1,000 miles per month. REPRODUCTION Humpback whale breeding occurs mostly in the winter to early spring while near the surface and in warm, tropical waters. The gestation period is about 11-12 months and the calf is born tail first (this is normal for cetaceans) and near the surface in warm, shallow waters. The newborn instinctively swims to the surface within 10 seconds for its first breath; it is helped by its mother, using her flippers. Within 30 minutes of its birth the baby whale can swim. The newborn calf is about 14 feet long (4.3 m) and weighs about 2.5 tons (2.3 tonnes). Twins are extremely rare (about 1% of births); there is almost always one calf. The baby is nurtured with its mother's milk and is weaned in about 11 months. The mother and calf may stay together for a year or longer. Calves drink 100 pounds of milk each day. Humpback whales reach puberty at 4-7 years old, and maturity at 15 years. A calf is born to a female every 1-3 years. LIFE SPAN Humpback whales have a life expectancy of 45-50 years. POPULATION COUNT It is estimated that there are over 10,000-15,000 humpback whales world-wide. Humpback whales are an endangered species. CLASSIFICATION Humpback whales (Megaptera novaeangliae) are baleen whales (Suborder Mysticeti). They are one of 76 cetacean species, and are marine mammals.
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Humpbacks cooperate in hunting and have developed a method of rounding up highly
concentrated masses of prey that is called bubble-net feeding. The hunting
members of a pod form a circle 10-100 feet (3.1-31 m) across and about 50 feet
(1.5 m) under the water. Then the humpbacks blow a wall of bubbles as they swim
to the surface in a spiral path. The cylindrical wall of bubbles makes the
trapped krill, plankton, and/or small fish move to the surface of the water in a
giant, concentrated mass. The humpbacks then eat a large, hearty meal. 
Humpbacks are very acrobatic, often breaching high out
of the water and then slapping the water as they come back down. Sometimes they
twirl around while breaching. Breaching may be purely for play or may be used to
loosen skin parasites or have some social meaning. 
Spyhopping is another humpback activity in which the whale pokes its head out of
the water for up to 30 seconds to take a look around. 
Humpbacks also stick their tail out of the water into the air, swing it around,
and then slap it on the water's surface; this is called lobtailing. It makes a
very loud sound. The meaning or purpose of lobtailing is unknown, but may be
done as a warning to the rest of the pod. Humpbacks lobtail more when the seas
are rough and stormy. Slapping a fin against the surface of the water is another
unexplained humpback activity. 
Humpback whales breathe air at the surface of the water through 2 blowholes
located near the top of the head. They spout (breathe) about 1-2 times per
minute at rest, and 4-8 times per minutes after a deep dive. Their blow is a
double stream of spray that rises 10-13 feet (3.1-4 m) above the surface of the
water. 