Behaviour
Humpback whales live in groups. They migrate seasonally from the tropics to the northern feeding grounds. In the tropics, they are found in dense aggregations on shallow banks. They are usually deep oceanic migrators between their feeding and breeding grounds; the vast majority of humpbacks do not come into coastal waters until they are ready to breed.
Breeding usually takes place once every two years, but it may occur twice every three years. Migration is largely connected with the two functions of feeding and reproduction. Pairing and mating take place in the warmer waters. Calves are born in the warm tropical waters and subtropical waters of each hemisphere. Newborns are usually 4 to 5 m long, and are suckled by their mothers for about 5 months. The females' milk is highly nutritive, containing high amounts of fat, protein, lactose and water. There is no parental investment on the part of the males.
There is no direct evidence of territoriality. However, there are some types of preferred area sentiments by individuals or groups. This is supported by the seasonal returns to the same feeding and breeding grounds of most humpbacks.
Swimming speed may reach 27 km per hour and during migration, it may reach 3.8 to 14.3 km per hour. Whales with calves swim the slowest, whereas lone whales travel faster than those in groups.
Humpbacks dive 6 to 7 m for 15 to 20 minutes. During diving, blows are not regular and flukes are not lifted as the whale submerges. In longer dives, the flukes are lifted and the animal surfaces between dives for about 4 minutes, while blowing regularly.

Food Habits
Like minke whales and fin whales, humpbacks are generalized feeders. They are highly mobile and opportunistic. Humpbacks feed upon plankton, the plant and animal life at the surface of the ocean's water, or upon fish in large patches or schools. Because of this, humpbacks are classified as "swallowers" and not "skimmers." They do eat commercially exploited fishes. Feeding by humpbacks takes place during the summer.
Humpbacks near Australia and in the Antarctic feed on euphausiids. Typically, these whales take both food and water into their mouths. Large volumes can be accommodated because the ventral grooves in the throat allow for expansion. Once the mouth is full, it is closed and the water is pressed out. Meanwhile, the food is caught in the baleen plates and is then swallowed. This process is aided by the internal mechanism of rorqual feeding - the tongue.

Conservation Status
Humpbacks have historically had incredible economic importance to humans. They were one of the nine species hunted intensively by whalers. They were at times the most important constituent of the catch of modern whalers. Their oil was in demand as a kind of burning oil for lamps and as a lubricant for machinery. Whale oil was also used as a raw material for margarine and as a component of cooking fat. Whale meat was processed for human consumption and made into animal feed. Meal made from whale bones was used as fertilizer.
However, these animals are no longer hunted extensively. They do continue to have some economic impact, as eco-tourism and whale sighting tours are quite popular in appropriate coastal areas. Currently, there are an estimated 6,000 humpbacks in the earth's waters, with possibly 1,000 to 3,000 more.
Humpback whales received some protection in 1985 when the International Whaling Commission instituted a moratorium on commercial whaling. In the early part of the twentieth century, during the modern whaling era, humpback whales were highly vulnerable due to their tendency to aggregate on the tropical breeding grounds and to come close to the shore on the northern feeding grounds.
In order to combat the problem of depletion, catching humpback whales was prohibited in the Antarctic in 1939, although that plan was abandoned in 1949. In the southern hemisphere, hunting was banned in 1963. In the North Atlantic, hunting was banned in 1956. Finally hunting was banned in the North Pacific in 1966.