Migration of whales is a seasonal response of marine mammals that is arousing increasing interest in terrestrial mammals. The Biodiversity Group of Environment Australia has an interesting overview site about whales in Australian waters. Southern Right Whales arrive in May to calve near Logans Beach at Warrnambool and stay until September/October. During the migration season on the NSW South Coast (September–November), whale-watching boat trips can be undertaken from such places as Eden, Narooma and Jervis Bay. Whales may be sighted off Coffs Harbour in May–June and again in October–November. Off Central Queensland’s Fraser Coast, whales may be sighted from August–October. Other spots are Albany and Esperance (July–October) in Western Australia, along the Great Australian Bight and Victor Harbor in South Australia.
Cetaceans (whales, porpoises and dolphins) are warm blooded, air breathing marine mammals which give birth to live young. About 80 species of Cetacea exist today, from relatively small porpoises to the giant Blue Whale, which may be 30 metres long. Cetaceans are found in all the world's oceans.
Whales feed in two different ways. Some filter
plankton (tiny animals and plants that float in the water) through fringed
plates which hang from the roof of their mouths.
These plates are made up of a horny substance called baleen. These types of whales may gulp at their food and squeeze the water out, or swim with their mouths open until enough food builds up on the baleen plates.
Most have grooves in their throats, which expand when they are feeding. Other whales have teeth, generally feeding on fish and squid. Although all whales eat animals of some sort, the Killer Whale is the only true flesh eater. It eats penguins, seals, sea lions and other cetaceans, as well as fish and squid.
About 43 species of cetaceans live in or migrate through Australian waters.
The following table details some of the species which may be seen in Australian waters.
Table 1 Species seen in Australian waters
|Name||Distinguishing Features||Max Length/Weight||Main Diet||Additional Information|
|Southern Right Whale Eubalaena australis||Wart-like hardened lumps on the head where whale lice have grouped under the skin.||18 metres/96 tonnes||Krill (shrimp)||Called the "right whale" because it swam slowly|
|Humpback Whale Megaptera novaeangliae||Long flippers and a lumpy dorsal fin||16 metres/48 tonnes||Krill||Famous for its singing and acrobatics Protected since 1965|
|Sperm Whale Physeter macrocephalus||Long blunt head and single blow hole||20 metres/38 tonnes||Squid||Largest brain of any creature (10 kilograms) Dives to over one kilometre and stay down for 90 minutes|
|Blue Whale Balaenoptera musculus||Short flippers and a long streamlined body||30 metres/130 tonnes||Krill||Largest creature ever to live. Populations were drastically reduced by whaling. There may now be less than 10,000 in the southern hemisphere|
|Mink Whale Balanoptera acutorostrata||Flat head. Fin appears at the same time as the whale blows||10 metres/ 9 tonnes||Krill||The smallest rorqual (whale with throat grooves). Migrates to antartic waters in summer to feed|
|Long-finned Pilot Whale Globicephala melaena||Stronly curved, long based fin . Broad round forehead. Grey saddle patch||8 metres/ 4 tonnes||Squid||Distinct populations exist in both hemispheres. Can produce an amazing variety of sounds|
|Bottle-nosed Dolphin Tursiops truncatus||Tall curved dorsal fin. Short distinctive beak||4 metres/0.4tonnes||Fish||Found in all warm and temperate oceans, usually within 800 kilometres of land|
|Killer Whale Orcinus orca||Tall, erect fin in the male. Striking black and white markings||10 metres/7 tonnes||Fish,Squid,Penquins, Seals, Dolphins||Widely distributed. Enormous appetite (eats about 50 kilograms a day). Travels in social units (pods) of usually less than 30.|
Whales have been hunted for over one thousand years. Early hunting methods were primitive. With the development of harpoon guns, explosive harpoons and steam-driven whaling boats, large-scale commercial whaling caused the numbers of several species to decline.