Southern Right Whale

Like other right whales, the southern right whale is readily distinguished from others by the callosities on its head, a broad back without a dorsal fin, and a long arching mouth that begins above the eye. Its skin is very dark grey or black, occasionally with some white patches on the belly. The right whale's callosities appear white due to large colonies of cyamids (whale lice). It is almost indistinguishable from the closely related North Atlantic and the North Pacific right whales, displaying only minor skull differences. It may have fewer callosities on its head than North Atlantic and more on its lower lips than the two northern species. The biological functions of callosities are unclear, with proposed purposes including protection, identification, and use in mating.

The global population of southern right whales was estimated at 13,611 in 2009. An estimate published by National Geographic in October 2008 put the southern whale population at 10,000. A population estimate of 7,000 followed a March 1998 IWC workshop. Researchers used population data from three surveys of adult females in the 1990s (Argentina, South Africa and Australia). They extrapolated to include the population of unsurveyed areas, and used known male-to-female and adult-to-calf ratios to estimate and include numbers of males and calves. Recovery of the overall population size of the species is predicted to be at less than 50% of its pre-whaling state by 2100 due to heavier impacts of whaling and slower recovery rates. Since hunting ceased, the population is estimated to have grown by 7% a year.

The only known predator of the southern right whale is the killer whale, There have been cases of adult killer whales hunting a southern right whale calf in Golfo San Jose, Argentina in 1986, and of killer whales hunting a newborn southern right whale in Balneario Quintão, off the northern coast of Rio Grande do Sul, Brazil, in July 2008.

Like other right whales, they are rather active on the water surface and curious towards human vessels. Southern rights appear to be more active and tend to interact with humans more than the other two northern species. One behaviour unique to the southern right whale, known as tail sailing, is that of using their elevated flukes to catch the wind, remaining in the same position for a considerable amount of time. It appears to be a form of play and is most commonly seen off the coast of Argentina and South Africa. Some other species such as humpback whales are also known to display. Right whales are often seen interacting with other cetaceans, especially humpback whales and dolphins. There have been records of southern rights and humpbacks thought to be involved in mating activities off Mozambique, and along Bahia, Brazil.

Southern right whales display strong maternal fidelity to their calving grounds. Calving females are known to return to calving grounds at 3-year intervals. The most commonly observed calving interval is 3 years, but intervals can range from 2 to 21 years. Calving takes place between June and November in calving grounds between 20 and 30° S.

In Australia, southern right whales have shown a preference for calving grounds along coastlines with high wave energy, such as the Head of the Bight. Here, the sound of breaking waves may mask the sound of the whales' presence, and so protect infants and calving cows from predators such as killer whales. Deep waters alongside shallower calving grounds may serve as training grounds for calves to build up their stamina ahead of migration.

The southern right whale, listed as "endangered" by CITES, is protected by all countries with known breeding populations (Argentina, Australia, Brazil, Chile, New Zealand, South Africa and Uruguay). In Argentina, it is considered a "Natural Monument" under national law Nº 23094, with all whales sighted on Argentine waters under legal protection. In Brazil, a federal Environmental Protection Area encompassing some 1,560 km2 (600 mi2) and 130 km (81 mi) of coastline in Santa Catarina State was established in 2000 to protect the species' main breeding grounds in Brazil and promote regulated whale watching. The southern right whale is listed on Appendix I of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) as this species has been categorized as being in danger of extinction throughout all or a significant proportion of their range.