Humpback whale

Humpback whale
Humpback whale (Photo: Dave and Fiona Harvey)
Humpback under waterHumpback whale fluke (Photo: Sarah Robinson)Humpback whale breachingA humpback whale points its upper body straight up out of the ocean in a behaviour known as spyhopping
Humpbacks are one of the most active whales in terms of behaviour – they frequently breach, slap their tails and fins on the water surface, and males engage in vigorous, even violent competition for mates on their breeding grounds.

Scientific name: Megaptera novaeangliae

Physical description and related species

Unlike their 'cousins' the blue, sei and minke whales, humpbacks (Megaptera novaeangliae) are not slender and graceful - they tend to be quite stout and stocky, with exceedingly long pectoral fins (their 'arms'). They are much slower swimmers than these other species.

Humpback whales grow to about 15 m, and 40 tonnes in weight. Like all baleen whales, females are slightly larger than males.

Distribution

It is now thought that many female humpbacks, those who are not engaged in breeding activities in a given year, probably remain somewhere in the Southern Ocean to feed, build up their fat reserves for the following seasons migration and mating. On migration, humpbacks may not feed for as much as eight months of the year.

Humpbacks are known to have the longest annual migration of any mammal. They travel from the Antarctic Peninsula south of Cape Horn, across the Equator to Columbia or even Mexico.

Threats

Because they were slow and fat, humpback whales were targeted by whalers well before the faster blues, fins, etc, and were killed by open boat whalers with hand harpoons in the 19th century. However, they survived in numbers until the 1950s and 1960s when illegal whaling reduced their numbers to near-extinction.

Nevertheless, they now seem to be recovering well after whaling ceased, and their numbers are increasing in many areas of the world. The populations, which breed in Australian waters, have doubled in the last ten years.

Conservation status: least concern

Breeding

Humpback breeding areas are fairly well known (unlike those of most other baleen whales). In Australia they breed inside the Great Barrier Reef on the East Coast and on the Northwest Shelf, along the west Kimberly coast. They migrate close to the shore, and at the right times of the year can be easily seen as they travel past.

Diet and feeding

Humpback whales feed in Antarctic waters on krill of various kinds, but also eat small fish and plankton during their migration south from their breeding areas.

Whale song

Humpbacks communicate among themselves with their famous and beautiful song. A song is usually quite short, less than ten minutes, but can be repeated many times, sometimes for hours without stopping. It is thought to be mainly a method for mature males to advertise themselves to females as sexual partners.

This page was last modified on 12 August 2010.