FACTS AND FIGURES
© the Mammal Research Institute
WWF Whale watching in South Africa The Southern Right Whale
by Peter Best
Eubalaena australis from eu (Greek for right), balaena (Latin for whale) and australis (Latin for southern).
Calves vary in length at birth from 4.5 to over 7 m (average 6.1 m). Bigger females have bigger calves.
Adult females range from 12.4 to 15.5 m with an average of 13.9 m; weights unknown, but using information for northern right whales suggests 29-58 tonnes (average 41 tonnes). Adult males probably follow the pattern of most baleen whales in being a little smaller.
Probably long-lived, with an average life expectancy of about 50 years; some individuals may live much longer.
Length of pregnancy
A year or slightly longer.
Length of nursing
Six months to a year. The calf suckles from a pair of teats situated either side of the genital aperture.
Characteristically black except for pale brownish "callosities" on the head. Most individuals have some white on the belly, and some have white spots or brownish-grey streaks on the back. A rare colour form (present in 4% of the population) is born mostly white apart from black spots especially in the neck region; these animals darken with age and become a brindle colour when adult.
Patches of raised, roughened skin scattered over head and pale brown in colour. Locations correspond to positions of rudimentary hairs. Much variation in size and shape (and sometimes position); the most prominent (at the tip of the snout) is called the "bonnet". Characteristic of right whales.
Flukes and flippers
Tail flukes are made of connective tissue, 4.3-5.7 m wide in adults. Flippers are supported by a skeleton derived from the forelimb of land mammals, and are squareish in outline. There is no dorsal fin.
Swimming and diving
Cruising speed 0.5-4km/hr (0.25-2.2 knots). Top speed possibly 14km/hr (9 knots). In coastal waters most dives less than 4 minutes and up to 8 minutes in duration; in open ocean dives may last longer, as northern right whales recorded diving to about 300 m depth.
Right whales in coastal waters produce a variety of low frequency (less than 1.000 Hz) sounds, that can be described as moans, growls, pulses and belch-like noises. These are used for communication, some being produced mainly by resting or swimming whales and others by whales actively interacting.
Periodically a whale may thrust three-quarters or more of its body out of the water, pivot onto its side and back, and fall back with an enormous splash into the sea. This jumping, technically known as "breaching", frequently occurs several times in succession (thus giving photographers a chance to get set up). there may not be a single reason why whales breach. When performed by young calves, for instance, it seems that the activity is one of sheer exuberance. At other times breaching may serve a communication function, or as a form of display to other individuals. As small pieces of loose skin are frequently found floating just after a whale has breached, perhaps the activity also assists in the moulting process (and the loss of whale lice). Whatever the reason, it is undoubtedly the most spectacular of all whale behaviours.
Sailing and Lobtailing
Occasionally the right whale may lift its tail clear of the water and hold it there vertically for long periods, like a giant black butterfly. It has been suggested that the whale is indulging in a little "sailing", using the wind on the surface area of the tail to push its body through the water. another view is that this represents a form of temperature control for the body, either through solar radiation or evaporative cooling, as the blood vessels in the tail form a counter-current system much like a radiator. A third option is that the whale is feeding on organisms close to the sea-floor. At other times the tail is lifted clear of the water but then brought down sharply on the surface of the water to produce a loud slap and a shower of spray. This activity is called "lobtailing", and may occur repeatedly over long periods. The reason for this behaviour is also unknown, but it could represent a form of social communication, perhaps alarm (when done singly), annoyance or mild threat.
Like some other cetaceans, right whales may well have reasonable vision in air as well as water, and this may be why they sometimes lift their heads vertically from the sea, an activity known as "spyhopping" by the whalers. Certainly this behaviour has been shown by calves in response to an orbiting helicopter, when the calf´s head follows the movement of the aircraft.
Playing with kelp
In areas where kelp is found, right whales may be seen within the outer edge of the beds, or actively manipulating a piece of floating kelp, so that the fronds rub over the back and particularly the head. The whales appear to be deriving some kind of pleasure from this contact, possibly from the release of loose skin and associated whale lice.