These stocky whales have extremely large heads, which can be over one-fourth of the body length. The mouthline is bowed and the rostrum is arched and very narrow when viewed from above. As is true for right and bowhead whales in general, there is no trace of a dorsal fin or ridge in the southern right whale. The flippers are fan-shaped, and the flukes are broad with smooth contours. All right whales have callosities on their heads, the largest of which is called the bonnet. The callosity patterns are individually-distinctive and are used by researchers to identify individuals.
Southern right whales are largely black, but some have white patches of variable shape and size on the belly and sometimes on the back. Color variants have been noted; these include blue-black, light brown, and nearly white individuals. In addition to those on the callosities, whale lice are common in creases and folds on the bodies of southern right whales.
Southern right whale adults reach up to 17 m in length; females grow larger than males. These animals can reach weights of at least 80 tons. Newborn animals are 4-5 m long.
The 200-270 baleen plates per side are narrow and long, up to 3 m in length. The plates tend to be dark gray to black (some can be nearly white) and have fine gray to black fringes. The blow of the southern right whale is relatively short and V-shaped, making this species identifiable at a distance, if seen from ahead or behind.
Can be Confused With
The southern right whale is the only whale in its range with a smooth, finless back and callosities; this should make misidentifications unlikely. From a distance the bushy, somewhat V-shaped, blows of humpback whales can be mistaken for those of right whales. At close range, the two species are unmistakable.
Southern right whales have a circumpolar distribution in the Southern Hemisphere, from approximately 20°S to 55°S, although they have been observed as far south as 65°S. They are migratory. In winter, the distribution is concentrated near coastlines. Major breeding areas are nearshore off southern Australia, New Zealand, southern South America, and South Africa, as well around several subantarctic islands. A few southern right whales have been sighted in Antarctic waters in summer.
Ecology and Behavior
Southern right whales have been well-studied on their winter breeding grounds, especially at Peninsula Valdes, Argentina, and in Australia and South Africa. Researchers have used callosity patterns to identify individuals on these grounds, and have learned much about the right whale's behavior, communication, and reproduction. Right whales often seem slow and lumbering, but can be surprisingly quick and active. They often breach, and slap their flippers and flukes on the surface. Southern right whales often raise their flukes on a dive.
Most of the breeding in Argentina takes place in August and September, but mating has been observed in most months of the year. Male right whales have huge testes and long penises, two characteristics predicted in species in which males compete for females primarily through sperm competition, rather than by direct aggression in shallow water.
Feeding and Prey
Surface and subsurface skim feeding is the rule in this species. Southern right whales prey on copepods and krill, apparently sometimes feeding near the bottom.
Threats and Status
After North Atlantic right whale stocks began to be reduced, European and American whaling activity shifted to the Southern Hemisphere. Heavy exploitation there left stocks badly depleted. Unauthorized catches by the Russians in the late 20th century added to the depletion. Fisheries interactions, as well as potential vessel disturbance and collisions, continue to threaten the southern right whale. Although there are only thought to be about 7,500-8,000 animals left, this species is not as seriously endangered as the northern species, and some populations appear to be recovering.
The IUCN classes the southern right whale as “Lower Risk/Conservation Dependent” while the United States Endangered Species Act classes them as “Endangered”.
Best, P.B., and J.L. Bannister, R.L. Brownell Jr., and G.P. Donovan (eds). 2001. Right whales worldwide status. Journal of Cetacean Research and Management, Special Issue 2, 309 pp.
Cummings, W.C. 1985. Right whales Eubalaena glacialis (Muller, 1776) and Eubalaena australis (Desmoulins, 1822). pp. 275-304 in S.H. Ridgway and R. Harrison, eds. Handbook of marine mammals, Vol. 3 The sirenians and baleen whales. Academic Press.
Rosenbaum, H.C., R. L. Brownell Jr., M.W. Brown, C. Schaeff, V. Portway, B.N. White, S. Malik, L.A. Pastene, N. J. Patenaude, C.S. Baker, M. Goto, P.B. Best, P.J. Clapham, P. Hamilton, M. Moore, R. Payne, V. Rowntree, C.T. Tynan, J.L. Bannister, and R. Desalle. 2000. World-wide genetic differentiation of Eubalaena: Questioning the number of right whale species. Molecular Ecology 9:1793-1802.