Southern right whales belong in separate breeding groups which travel to their own areas to reproduce (5). Up to eight males may mate with one female (5) between July and August, but unusually for mammals, aggression between males is minimal (2). Females calve once every three years between June and August, with a gestation period of 11 to 12 months. Calving females go for four months during the winter months without eating, and give birth to a single, large calf weighing up to 1,500 kilograms (2). Females will nurture and feed their calves in the shallows where they are well protected from attacks by orcas and great white sharks (5). Calves are weaned after a year, and will reach sexual maturity at nine to ten years (2). These enormous animals eat some of the smallest creatures in the ocean, filtering water through long and numerous baleen plates to feed on the small plankton including larval crustaceans and copepods (2). Southern right whales produce short, low-frequency moans, groans, belches and pulses (7). Typical feeding dives last between 10 and 20 metres and southern right whales are also frequently seen at or above the surface of the water, slapping the water with its tail and flippers, rolling, and breaching (launching out of the water and landing on the side or back). The function of these behaviours is not known (7).