Biology

How did whales evolve?

Whales evolved from warm-blooded, air breathing mammalian ancestors that lived on land. The transition from land to sea, probably in search of food, presented difficulties for which adaptations developed over many generations. Smooth skin and loss of protruding ear parts and hind limbs streamlined whales for swimming. The nostrils moved to the top of the head to facilitate breathing and an underlaying, insulating layer of blubber replaced hair for warmth. The body, supported by water, was able to reach its enormous size.

How do whales breathe?

Whales have lungs and must come to the surface to breathe. They have nostrils called blowholes. These are located on the top of the head to access air easily. When Southern Right Whales exhale, condensation from the 2 blowholes forms a 'v-shaped' 'blow'. The noise may be heard over a kilometre away.

The whalers cried out "there she blows" when they saw the blow of a whale exhaling.

How do Southern Right Whales feed?

Southern Right Whales are 'baleen whales' - instead of teeth they have comb-like baleen plates. When closed, their highly arched mouth covers the plates.

Southern Right Whales are giants of the ocean yet incredibly they eat some of the smallest animals such as copepods and krill.

The whales feed by taking mouthfuls of water containing many tiny crustaceans. As the water strains out through the spaces between the baleen, the crustaceans become trapped against the bristly plates and are swallowed.

How do whales swim?

Whales do not swim like fish. Whales have horizontal tail flukes that move up and down to propel them through the water. In comparison many fish have vertical tails which move from side to side for propulsion.

Southern Right Whales may use their tails to cool themselves, by lifting their wet tail into the breeze. They can also sail, using their tail flukes to catch the wind.

How do Southern Right Whales start life?

Southern Right Whale calves are born with very little insulating blubber and would perish if born in cold Antarctic waters. So each winter the whales leave their sub-Antarctic feeding areas and travel north to warmer waters. After birth the calves suckle on thick, rich milk, gaining about 90 kg per day. By spring they are ready for the long journey, and the mothers guide their calves to the sub-Antarctic feeding grounds.

Where do Southern Right Whales live?

Southern Right Whales inhabit the world's southern oceans. During the warmer months of the year they feed on small crustaceans in nutrient rich sub-Antarctic waters. When the days become cooler the whales migrate northward to warmer waters. They spend the winter months calving, mating or nursing their young before returning south in spring to feed again.