Humpback Whales

Megaptera is from the Greek, mega (big), and pteron (wing) which refers to the enormous flippers which are characteristic of this species. The specific name novaeangliae is Latin for "New England" because the first specimen to be scientifically described came from that area. Humpbacks are black dorsally and have variable combinations of black and white underneath. As with all rorquals, the ventral surface contains pleats which run longitudinally from the chin to the navel. The humpback's huge flippers, at one-third the body length, are proportionately larger than those of any other cetacean. On the head are numerous knobs called tubercles, each of which contains a single white hair. Humpbacks have a dorsal fin which varies considerably in shape and size, from very low to high and falcate. The underside of the tail has a pattern of black and white markings which is unique to each animal and is used by scientists to identify individuals. Adults average about 14 m, with a maximum recorded length of about 18 m. Females are about a meter longer than males. Maximum weight is 40-45 tons. The humpback is widely distributed in the waters of this continent. Throughout its worldwide range, the species makes a long migration from summer feeding grounds in high latitudes to tropical mating and calving areas in winter. Thus most African humpback populations are seasonal, coming to warm water areas in the region to breed. Known concentrations occur off the Cape Verde Islands (a now-small breeding population from the North Atlantic which was heavily exploited in the 19th century), off Madagascar, Mozambique and South Africa (a breeding stock which feeds in the Antarctic), off equatorial West Africa (breeding populations which may come from both hemispheres at different times of year), and off the Arabian Sea coast. The latter is an interesting group in that it appears to be the only population of the species in the world which remains in tropical waters year-round. Little is known about humpbacks off southwestern Africa, but they are almost certainly present ther during the austral winter. More is known about humpbacks than any other large whale, although African populations are generally poorly understood. Humpbacks make one of the longest migrations of any mammal (up to 5000 miles one-way). They feed on euphausids (krill) and various species of small schooling fish. Males sing long songs during the breeding season (and sometimes at other times) which are perhaps the most complex such vocalizations in the animal kingdom. Their purpose is probably primarily to attract mates, but they may also serve to maintain spacing among males. Males humpback also engage in highly aggressive competition for females in winter, with protracted and often spectacular fights being common. Humpbacks were heavily whaled, notably this century. Most populations were reduced by perhaps 95% of their original size notably in the Antarctic where almost a quarter million animals were killed. Today, most populations appear to be making a strong recovery, although little is known about the status of this species off Africa. Whaling for humpbacks occurred in this and the last century in various places, including South Africa, Madagascar, Congo, Gabon and the Cape Verdes. There is thought to be a continuing aboriginal whaling operation for humpbacks off the remote island of Pagalu (equatorial West Africa), but it is unlikely that this has significant impact on the population concerned. Humpbacks are often entangled in coastal fishing gear, including off Oma, but the magnitude of this problem in African waters is largely unknown.

African Marine Mamals