Orca (Killer) Whales
|Description & Characteristics:
Orca or Killer whales are the largest members of the dolphin family. Found in all waters, these splendid, toothed whales are sometimes called the 'wolves of the sea' because of their closely-related pack-like behaviors. Gracing the southern seas in abundance, Orcas tend to travel in small close-knit, family pods but can be found in groups of up to 50 individuals. Orcas have not been caught commercially since the early 1980's as a result of protective measures imposed by the International Whaling Commission (IWC). However, Orcas are still captured in small numbers for display at zoos and marine parks. This is an emotional and controversial issue to be sure, but not one of conservation significance as Orca populations are currently thought to be stable.
Probably the most striking feature of Orca whales is their unique coloration pattern. A dazzling contrast of jet black above and bright white markings beneath help make the Orcas both visually appealing and easily identifiable. Add to that their sleek, streamlined shape and imposing dorsal fins (especially in the adult male) and the result is a truly magnificent animal of the sea.
Orca whales are excellent swimmers and can perform impressive acrobatics in the water. They can often be observed breaching, a behavior in which the whale speeds to the surface and leaps completely out of the water, falling back with a spectacular splash. Or they may be seen 'spyhopping'--poking their heads straight out of the water to get a better look at their surroundings. 'Tail slapping' is another common activity possibly meant as a kind of warning to other members in pod.
Orcas are very efficient and sophisticated predators who often hunt in groups, attacking prey much as wolves attack larger caribou or moose, then sharing the spoils. They eat fish, squid, sharks, birds (including penguins), seals, sea turtles, octopi, and other whales. An Orca will tip up small ice floes to dislodge resting seals while other Orcas wait beneath the surface for the kill. They have even been observed attacking young, but still huge, Blue whales. Aside from human beings, Orcas have no natural enemies. They can dive to depths of up to 100 feet in pursuit of prey but prefer to hunt at or near the surface of the water.
Orcas are very social animals. The bonds between pod members are strong and last for life. Orcas share the responsibility of protecting young, and caring for the sick or injured.
Orca breeding occurs mostly in the winter to early spring. The gestation period is about 16-17 months. Newborn Orca calves instinctively swim to the surface within ten seconds for their first breath, helped along by mother's flippers. Calves are about seven feet long and weigh up to 400 pounds at birth. The mother and calf may stay together for a year or longer. Female orcas reach maturity at 6-10 years old, and males at 12-16 years old.
- Like other toothed whales, Orcas use 'echolocation' to navigate and find prey; they emit high-pitched clicks and sense them as they bounce back off objects.
- The largest population of Orca whales seems to be in Antarctica where it is estimated some 160,000 animals range.
- Orcas don't make long, seasonal migrations, though they may cover an area of hundreds of miles in order to find seasonal prey.
- Orcas can swim up to 30 miles per hour in short bursts.
- Orca pods have their own 'dialect' of discrete calls, which aid in navigation, detecting prey, or sensing danger.
- Typical of most whales, Orca calves are born tail first.