Undoubtedly the best place to spot these Cetaceans from land is De Kelders, near Gansbaai. From June each year large numbers of Southern Right whales, Eubalaena australis, arrive in Walker Bay to give birth and mate. This bay seems to have the perfect conditions for these gentle giants. Dozens can be seen close up from vantage points along the cliff path. Humpback whales, Megaptera novaeangliae, also pay a visit here on their long migration path, and stay to recoup before continuing north. Bryde’s whales, Balaenoptera brydei, can be seen blowing off shore right throughout the year along with sometimes hundreds of dolphins torpedoing across the bay.
Southern right whales are migratory whales which travel between the sub-Antarctic and the southern coastlines of South America, South Africa and Australia. They spend approximately half of the year in the sub-Antarctic regions where feeding is their main objective. Following their time spent stocking up on food reserves, the Southern right whales migrate north between 3000-4000km to their mating and breeding grounds. These whales are most commonly found along the coastlines in South Africa between July and December.
Southern right whales are 14-16m in length that can weigh between 40-60 tonnes. lacking a dorsal fin, unlike most large whales. One of the most distinguishing features of the Southern right whales is the scattering of “callosities” on their head. These callosities are rough patches of skin on which barnacles and whale lice live. Each whale has a unique pattern of these callosities on their head, and the patterns are a useful as mechanisms for individual identification (either visually or by examining photos). When born, calves average between 4-6m in length and 1 ton in weight. The whales have large square-shaped black flippers and a large tail fin that can reach 7m in width. Approximately 4% of Southern right whales are born mostly white in colour; this colour typically becomes a grey/brindle colour in adults. When southern right whales are sighted, either at sea or from the coast, their identity is often facilitated by their ” V” shaped blow, due to the positioning of their two blowholes.
These whales got their name historically from early whalers, who determined that these were the “right whales” to hunt, both for commercial value, but also for their ease of hunting. Southern right whales have a relatively slow average swim speed (4-6km/hour), they tend to spend a significant amount of their time at the surface of the water, they would float when dead and many of their calving and mating grounds are close to the coastlines. Now they are considered the “right” whales to watch, again due to their fondness of the coastlines, and for their slow swimming speeds.
Feeding is only thought to occur while the whales are in the sub-Antarctic region. The main food source for Southern right whales is small plankton called copepods. Although each copepod is very small in size, they tend to aggregate in dense groups in the Antarctic waters, facilitating mass feeding opportunities for the whales. Southern right whales do not have teeth, but instead have long baleen plates hanging down from their upper jaw (similar in theory to vertical blinds). They can have more than 200 of these baleen plates, which range in length up to over 2m. These baleen plates have a fringe of hairs running down their sides. The whales swim into the swarms of plankton with the mouth open. To filter out the water they close their mouth, and use their tongue to push the water between the hairy baleen plates (like a sieve), while still keeping the food in their mouth. Feeding behavior is rarely observed while in their mating grounds (with the exception of the nursing calves).
Southern Right Whales are thought to be fairly long lived, at least 50 maybe up to 100 years!
Most females have been observed to work on a 3 year cycle (one year of pregnancy, up to one year with the calf, and one year to recover and rebuild food reserves in preparation of a new cycle). The calves nurse from the mother but it is uncertain for how long this nursing lasts.
Because they were the right whales to catch, the Southern right whale population plunged significantly starting in the late 18th century, right into the 20th century. The whales were initially killed via traditional harpooning but whaling modernized in the early 20th century and boasted steam powered boats with harpoon cannons, further facilitating the decline of the whales. The Southern right whales becoming internationally protected in 1935, but numbers were at a drastic low prior to this. In 1997 the South African population was estimated at 3100 whales, from a total of 7500 in the southern hemisphere, still only thought to be about 10% of original numbers.
Best, P. 1997. Whale watching in South Africa. The Southern Right Whale. Marine Mammal Research Institute, University of Pretoria, Pretoria. 2nd edition. 28pp.
Best, P. 2007. Whales and Dolphins of the Southern African Subregion. Cambridge University Press, Cambridge. 338pp.
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