The humpback whale was first named by the German naturalist Georg Borowski in 1781. He assigned the Latin name Megaptera novaeangliae, meaning "big wing of New England"; the former was a reference to the humpback's long flippers, while the latter reflected the fact that the specimen he described came from New England, where humpbacks remain abundant today.
Size, shape and distinctive characteristics
Female humpback whales are on average about 1-1.5 m longer than males. Humpbacks attain a maximum length of 16-17 m, although 14-15 m is more typical for large adults. Humpback whales are most easily distinguished from other whales by their huge pectoral fins, which are a third the body length. The head contains numerous knobby protuberances known as tubercles, which may serve a sensory function. There are from 270 to 400 baleen plates on each side of the mouth; these are black, except the foremost plates are sometimes dull white or partly white. Unlike in other balaenopterids, the posterior margin of the tail is prominently serrated.
While all humpback whales are black on the dorsal side, the ventral coloration varies greatly from all white to all black, with significant differences among populations (for example, some Southern Hemisphere whales have extensive white which can extend far up onto the flanks). The underside of the tail has a pattern which is unique to each whale, and this feature has been extensively used worldwide to identify individuals and to follow them for years or even decades.
The humpback whale is found in all oceans. It has been observed in the Mediterranean Sea, but its occurrence there is generally considered rare. The species is commonly found in coastal or shelf waters throughout its range, although it frequently travels across deep water during migration.
Humpbacks are highly migratory. The whales spend spring, summer and autumn on feeding grounds in temperate or high-latitude waters, then migrate to breeding and calving areas in the tropics in winter, where they do not feed. These migrations can exceed 5,000 nautical miles one way, and as such are the longest recorded for any mammal. In summer, humpbacks have been observed as far north as latitude 79 deg in the North Atlantic, and they are found close to the ice edge in the Antarctic.
Distribution and population structure varies by ocean. In the Southern Hemisphere, there are seven recognized populations, which migrate in a broadly north-south fashion from Antarctic feeding grounds to wintering areas off continental or insular coastlines in the tropics. In the North Atlantic, there are six known feeding grounds, which are all relatively separate (whales from different feeding areas rarely mix in summer); however, most North Atlantic humpbacks migrate to a common wintering area in the West Indies. In the North Pacific, there are at least four major breeding areas, including Mexico (inshore and offshore), Hawai'i, and Asia (Japan, the Philippines and probably other unstudied areas). These are connected to various feeding grounds along the northern margin of the ocean, from California through British Columbia, Alaska and Russia.
The sole exception to the pattern described above is a small non-migratory population in the Arabian Sea, which both feeds and breeds in tropical and sub-tropical waters, and remains in this area year-round.
Ecology and Behaviour
Humpback whale groups are typically small and (except for mother/calf pairs) unstable, and individuals frequently change associates. Stable groups which remain together in feeding areas over weeks or even years have occasionally been recorded, but these represent an exception and their basis is not clear. No stable groups have been documented on the breeding grounds.
During the winter breeding season, males sing, probably primarily to attract females and to mediate interactions with other males. Males also engage in aggressive competition for access to potential mates; such "competitive groups" feature ramming, tail-slashing and other aggressive behaviors as other males attempt to displace the male closest to the central female.
Humpback whale songs consist of several themes which are sung in a generally invariant order, the entire song lasting from a few minutes to half an hour. Singers, who are always male and are usually alone, will sometimes sing continuously for hours or even days. All of the whales in a given population sing the same song. However, the song changes progressively, yet all singers somehow keep up with the changes. What drives the change is unknown, but most observers assume that sexual selection plays a key role. Singing is virtually ubiquitous in the species' breeding range in winter, but it has often been recorded on the feeding grounds, as well as on migration.
Foraging humpback whales are unique in that they frequently use bubbles to trap or corral prey. Bubble structures in the form of nets, clouds or curtains are commonly observed in all studied populations, notably when whales are feeding on schooling fish. Such behaviors are often individually specific, and vary among populations.
Diving behavior varies by time of year. In summer, dives lasting < 5 min are the rule, and dives exceeding 10 min are unusual. In winter, dives average 10-15 minutes, and dives of more than half an hour have been recorded. Nothing is known for certain about sleep in mysticetes, although it is often assumed that, like some dolphins, they rest one hemisphere of the brain at a time (essential for a voluntary breather).
Humpback whales are well known for their aerial behavior, which includes breaching (leaping out of the water), flippering (slapping one or both pectoral fins on the water surface) and lobtailing (slamming the tail down on the water). The purpose of these behaviors is not well understood. However, it is clear that they perform different functions in different contexts, since they are performed at all times of year and by both lone whales and animals in groups. For example, it has been suggested that breaching serves multiple purposes ranging from signalling position to excitement or (in calves) play.
Humpback whales are born in tropical waters in winter, and average about 4.3 m long at birth. The peak birth months in Southern and Northern Hemisphere populations are early August and early February, respectively. As in most baleen whales, reproduction in humpback whales is strongly seasonal. Females come into oestrus during winter, and males exhibit a marked increase in sperm production at this time.
At the end of winter, calves follow their mothers to a high-latitude feeding ground, and they will nurse for up to a year before separating and becoming independent; at this point, such yearlings are typically 8-10 m long. Both males and females reach sexual maturity at ages varying from about four to 10 years, with significant differences in this parameter among populations. Females given birth at intervals of two or three years, although a minority can be simultaneously pregnant and nursing (resulting in a one-year interval between births).
There is dispute about the life expectancy of humpback whales, but at a minimum they live for about 50 years, and it is possible that longevity could greatly exceed this. Data on life expectancy came largely from animals killed by whaling (obviously not a natural death). There is disagreement regarding the method of determining age in dead whales, which depends upon exmaination of a laminar "plug" in the ear that features annual growth layers. The key issue is the number of growth layers that are added each year; these days, most scientists accept that humpbacks add one pair of layers per year, which would suggest that the maximum life expectancy of this species exceeds 90 years. However, more data are needed from stranded dead animals to confirm this.
Humpback whales feed on a variety of prey, including krill and several species of small schooling fish. In the Antarctic, krill is the almost exclusive prey, while in other areas of the world the whales will take (as well as krill) herring, sand lance, capelin, menhaden and occasionally other fish species. Like all baleen whales, humpbacks have a huge mouth but a very small gullet, and therefore are quite limited in the size of the prey they can consume.
All populations of humpback whales are listed as "least concern" by IUCN with the exception of that from Oceania in the South Pacific, which has "endangered" status.
The single largest conservation issue for humpback whales in the recent past has of course been commercial whaling. In the 20th century alone, more than 200,000 humpbacks were killed by whalers in the Southern Hemisphere. Of this number, more than 45,000 were taken illegally by the USSR, with a staggering 25,000 whales killed by the Soviets in the Antarctic south of Australia and New Zealand in just two whaling seasons (1959/60 and 1960/61). In the Northern Hemisphere, it is estimated that about 30,000 humpbacks were killed in the North Atlantic, and some 25,000 in the North Pacific.
Today, the recovery status of humpback whale populations varies cnsiderably, although most appear to be making a strong comeback. Known exceptions include the whales in Oceania, and a small, isolated population in the Arabian Sea which is unique in that it is non-migratory and remains in tropical/sub-tropical waters year-round. In addition, humpback whales are today very rarely observed at South Georgia in the South Atlantic, where they were highly abundant prior to industrial whaling; it is posisble that this population was extirpated, and that the whales' "cultural memory" of the existence of this habitat has been lost.
Today, the largest conservation issues for humpback whales are entanglement in fishing gear, ship strikes, and noise pollution. While whales from most populations have varying levels of industrial contaminants in their tissues, the impact of such chemical pollution is currently unknown.
Baker, C. S., and L.M. Herman. 1984. Aggressive behavior between humpback whales (Megaptera novaeangliae) wintering in Hawaiian waters. Canadian Journal of Zoology, 62:1922-1937.
Borowski, G.H. 1781. Gemeinnüzzige Naturgeschichte des Thierreichs. Gottllieb August Lange, Berlin, vol. 1:21.
Brodie, P.F. 1975. Cetacean energetics: an overview of intraspecific size variation. Ecology, 56:152-161.
Calambokidis, J., Falcone, E.A., Quinn, T.J., Burdin, A.M., Clapham, P.J., Ford, J.K.B., Gabriele, C.M., LeDuc, R., Mattila, D., Rojas-Bracho, L., Straley, J.M., Taylor, B.L., Urbán R., J., Weller, D., Witteveen, B.H., Yamaguchi, M., Bendlin, A., Camacho, D., Flynn, K., Havron, A., Huggins, J. and Maloney . 2008. SPLASH: Structure of Populations, Levels of Abundance and Status of Humpback Whales in the North Pacific. Final report for Contract AB133F-03-RP-00078 , available from cascadia Research, Olympia, WA.
Clapham, P.J. 2000. The humpback whale: seasonal feeding and breeding in a baleen whale. In: Mann, J., Tyack, P.L., Connor, R., & Whitehead, H. (eds.) Cetacean Societies. University of Chicago Press, pp. 173-196.
Clapham, P. & Baker. C.S. 2008. Modern whaling. In: Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (eds.) Encyclopedia of Marine Mammals, pp. 1239-1243. Academic Press, San Diego.
Clapham P.J. and C.A. Mayo. 1990. Reproduction of humpback whales, Megaptera novaeangliae, observed in the Gulf of Maine. Reports of the International Whaling Commission, Special Issue 12:171-175.
Clapham, P., Mikhalev, Yu., Franklin, W., Paton, D., Baker, C.S., Ivashchenko, Y.V. & Brownell, R.L. Jr. 2009. Catches of humpback whales by the Soviet Union and other nations in the Southern Ocean, 1947-1973. Marine Fisheries Review 71: 39-43.
Clapham, P.J., and P.J. Palsbøll. 1997. Molecular analysis of paternity shows promiscuous mating in female humpback whales (Megaptera novaeangliae, Borowski). Proceedings of the Royal Society of London Part B, 264:95-98.
Clapham, P.J., P. J. Palsbøll, D. K. Mattila, and O. Vásquez. 1992. Composition and dynamics of humpback whale competitive groups in the West Indies. Behaviour, 122:182-194.
Clapham, P.J. et al. 1993b. Seasonal occurrence and annual return of humpback whales in the southern Gulf of Maine. Canadian Journal of Zoology, 71:440-443.
Clark, C.W. & Clapham, P.J. 2004. Acoustic monitoring on a humpback whale (Megaptera novaeangliae) feeding ground shows continual singing into late spring. Proceedings of the Royal Society of London B 271: 1051-1057.
Herman, L. M. 1979. Humpback whales in Hawaiian waters: a study in historical ecology. Pacific Science, 33:1-15.
Herman, L.M., and R. C. Antinoja. 1977. Humpback whales in the Hawaiian breeding waters: population and pod characteristics. Scientific Reports of the Whales Research Institute, 29:59-85.
Jurasz, C.M., and V.P. Jurasz. 1979. Feeding modes of the humpback whale, Megaptera novaeangliae, in southeast Alaska. Scientific Reports of the Whales Research Institute, 31:69-83.
Katona, S.K., and H. P. Whitehead. 1981. Identifying humpback whales using their natural markings. Polar Record 20:439-444.
Klinowska, M. 1986. Diurnal rhythms in Cetacea: a review. Reports of the International Whaling Commission, Special Issue 8:75-88.
Larsen, A. H., J. Sigurjónsson, N. Øien, G. Vikingsson, and P. J. Palsbøll. 1996. Population genetic analysis of mitochondrial and nuclear genetic loci in skin biopsies collected from central and northeastern North Atlantic humpback whales (Megaptera novaeangliae): population identity and migratory destinations. Proceedings of the Royal Society of London Part B, 263:1611-1618.
Lien, J. 1994. Entanglement of large cetaceans in passive inshore gear in Newfoundland and Labrador (1979-1990). Reports of the International Whaling, Special Issue 15:149-157.
Matthews, L. H. 1937. The humpback whale, Megaptera nodosa. Discovery Reports, 17:7-92.
Mattila, D. K., L. N. Guinee, and C. A. Mayo. 1987. Humpback whale songs on a North Atlantic feeding ground. Journal of Mammalogy, 68:880-883.
McSweeney, D. J., K. C. Chu, W. F. Dolphin, and L. N. Guinee. 1989. North Pacific humpback whale songs: a comparison of southeast Alaskan feeding ground songs and Hawaiian wintering ground songs. Marine Mammal Science, 5:116-138.
Mikhalev, Y.A. 1997. Humpback whales Megaptera novaeangliae in the Arabian Sea. Marine Ecology Progress Series, 149:13-21.
Mobley, J. R., and L. M. Herman. 1985. Transience of social affiliations among humpback whales (Megaptera novaeangliae) on the Hawaiian wintering grounds. Canadian Journal of Zoology, 63:763-772.
O'Shea, T. J., and R. L. Brownell, Jr. 1994. Organochlorine and metal contaminants in baleen whales: a review and evaluation of conservation implications. Science of the Total Environment, 154:179-200.
Palsbøll, P.J., Allen, J., Bérubé, M., Clapham, P.J., Feddersen, T.P., Hammond, P., Jørgensen, H., Katona, S., Larsen, A.H., Larsen, F., Lien, J., Mattila, D.K., Sigurjónsson, J., Sears, R., Smith, T., Sponer, R., Stevick, P. & Øien, N. 1997. Genetic tagging of humpback whales. Nature 388: 767-769.
Payne, R. S., and L. N. Guinee. 1983. Humpback whale, Megaptera novaeangliae, songs as an indicator of "stocks". In Communication and behavior of whales (R.S. Payne, ed.). AAAS Selected Symposia Series, Westview Press, Boulder, Colorado, 76:333-358.
Payne, R.S., and S. McVay. 1971. Songs of humpback whales. Science, 173:585-597.
Rasmussen, K., D.M. Palacios, J. Calambokidis, M.T. Saborio, L. Dalla Rosa, E.R. Secchi, G.H. Steiger, J.M. Allen, and G.S. Stone. 2007. Southern Hemisphere whales wintering off Central America: insights from water temperature into the longest mammalian migration. Biology Letters 3:302-305.
Rosenbaum, H. et al. 1995. Variations in ventral fluke pigmentation of humpback whales, Megaptera novaeangliae, worldwide. Marine Ecology Progress Series, 124:1-7.
Stevick, P.T., Allen, J., Clapham, P.J., Katona, S.K., Larsen, F., Lien, J., Mattila, D.K., Palsbøll, P.J., Sears, R. Sigurjónsson, J., Smith, T.D., Vikingsson, G., Øien, N. & Hammond, P.S. 2006. Population spatial structuring on the feeding grounds in North Atlantic humpback whales. Journal of Zoology, London 270: 244-255.
Stevick, P.T., Allen, J., Clapham, P.J., Friday, N., Katona, S.K., Larsen, F., Lien, J., Mattila, D.K., Palsbøll, P.J., Sigurjónsson, J., Smith, T.D., Øien, N. & Hammond, P.S. 2003. North Atlantic humpback whale abundance and rate of increase four decades after protection from whaling. Marine Ecology Progress Series 258: 263-273.
Stone, G. S., L. Florez-González, and S. Katona. 1990. Whale migration record. Nature, 346:705.
True, F. W. 1904. The whalebone whales of the western North Atlantic. Smithsonian Institution Press, Washington, District of Columbia, 332 pp.
Tyack, P. 1981. Interactions between singing Hawaiian humpback whales and conspecifics nearby. Behavioral Ecology and Sociobiology, 8:105-116.
Tyack, P., and H. Whitehead. 1983. Male competition in large groups of wintering humpback whales. Behaviour, 83:1-23.
Weinrich, M. T. 1991. Stable social associations among humpback whales (Megaptera novaeangliae) in the southern Gulf of Maine. Canadian Journal of Zoology, 69:3012-3019.
Weinrich, M.T., and A. E. Kuhlberg. 1991. Short-term association patterns of humpback whales (Megaptera novaeangliae) groups on their southern Gulf of Maine feeding grounds. Canadian Journal of Zoology, 69:3005-3011.
Whitehead, H.P. 1983. Structure and stability of humpback whale groups off Newfoundland. Canadian Journal of Zoology, 61:1391-1397.
Whitehead, H.P. 1985. Humpback whale breaching. Investigations on Cetacea, 17:117-155.
Yablokov, A.V. 1994. Validity of whaling data. Nature, 367:108.