Killer Whale
| Killer Whale | ||||||||||||||
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 Orcinus orca | ||||||||||||||
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| Binomial name | ||||||||||||||
| Orcinus orca |
The animals are characteristically colored, with a black back, white chest and sides and a white patch above and behind the eye. They have a heavy and stocky body and a large dorsal fin. Males can be up to 9.5 metres long and weigh as much as 10 tonnes; females are smaller, reaching 8.5 metres at most and a weight of 7 or 8 tons. Calves at birth weight about 180 kilos and are about 2.4 metres long. At about 1.8m the dorsal fin of the male is taller than the female's, and more upright. From a distance, females and juveniles can be confused with various dolphin and porpoise species.
Most live in the polar regions but they are found in all seas including the Mediterranean and Arabian Sea. At sea they are usually seen in pods of 5-25 whales, although groups of up to 150 have been seen together.
The Orca's diet depends entirely on availability, although pods can specialize and thus ignore potential prey. It is believed they require around 60kg of food daily. Their prey includes twenty species of cetaceans, five species of pinniped (seals), thirty species of fish, seven species of bird and two species of squid, in addition to a variety of other sea creatures, occasionally including larger whales such as Fin Whales, minke whales, Gray Whales, or even young Blue Whales. Orcas even hunt and kill great white sharks for their nutrient-rich livers and to eliminate competitors for food. It is from their attacks on other whales that they gained their name; they do not attack humans.
Man is their only predator. They are considered to be too small for commercial whaling, but they are sometimes killed because they compete with humans for fish. In the 1950's the US Air Force, at the request of the Icelandic government used bombers and riflemen to slaughter orcas in Icelandic waters. The operation was considered a great success at the time.
In recent years, the Orca's intelligence, trainability, and striking appearance have made it a popular public aquarium or zoo attraction. This, combined with the fact that the animal is not aggressive towards humans, has lead to the image of the species being rehabilitated from an object of fear like great white sharks to a respected predator, worthy of toleration, like the wolf in the United States. Orcas in captivity may develop pathologies such as dorsal fin collapse, seen in 60-90% of captive males.
The movie Free Willy (1993) focussed on the quest for freedom by a captive orca and his human well-wishers. The whale starring in the movie, Keiko, was originally caught in Icelandic waters. He was later returned to his native habitat and released, but continued to be dependent on humans for food.
See also:
- Pigmy Killer Whale
- False Killer Whale
