Killer Whale

The Killer Whale, Orcinus orca, is the largest member of the dolphin family.

Identification

The Killer Whale is a strikingly marked animal characterised by a body pattern of dramatically contrasting areas of intense black and white. The rounded head, indistinct beak, large pointed teeth and prominent upright dorsal fin complete what is considered one of the oceans most impressive mammals.

Alternative name/s

Orca.

Distribution

The Killer Whale is found in all oceans and seas of the world usually in family groups. They occur in most habitat types from coastal areas to the deep ocean waters, from the tropics to polar regions.

Feeding and diet

These animals are serious meat eaters and one of the most efficient large predators of the ocean. A cooperative hunter, they often work in packs, and will take a broad range of vertebrates including whales, seals, penguins, fish, sea otters, and turtles. Killer Whales have marked territorial behaviour and home ranges. Their prey is determined by what is available in their home ranges but they also seek out areas of seasonal abundance such as seal pupping sites.

Life history cycle

Killer Whales are a highly social species whose group size and composition is based on the dominance of a female line. The gestation period is thought to be about 15 months after which a single young is born. Group cooperation extends to care of the young, which will continue to suckle from the mother for an extended period of up to two years. The breeding season is variable, as is the interval between births. This latter period can be as little as three years or as long as eight.

Conservation status

The Killer Whale has never been the target of serious commercial hunting so the species worldwide is secure. There is some concern about depletion of individual populations and disruption to social structure from captures for the oceanarium trade and limited hunting in some parts of Asia, Northern Europe and the West Indies.

References

• Baker, A. N. 1999. Whales and Dolphins of Australia and New Zealand: an identification guide. Allen & Unwin, St Leonards, Australia.
• Bryden, M., Marsh, H. and Shaughnessy, P. 1998. Dugongs, Whales, Dolphins and Seals. A guide to the sea mammals of Australasia. Allen & Unwin, St Leonards, Australia.
• Menkhorst, P. 2001. A Field Guide to Mammals of Australia. Oxford University Press, Melbourne, Australia.
• Reeves, R. R., Stewart, B. S., Clapham, P. J. and Powell, J. A. 2002. National Audubon Society Guide to Marine Mammals of the World. Chanticleer Press, Inc New York, USA.