Killer whale - Largest predator of mammals
A Killer whale (Orcinus orca) is named 'killer whale', not because it kills humans, but because it kills other whales. They inhabit all oceans, but are most numerous in the Arctic ocean and the Antarctic. Sightings in warm waters are less frequent, but do occur. Killer whales migrate along with other species, on which they hunt, or even pack ice. Despite their beautiful appearance they are not considered an endangered species. Estimates in studies range from 70,000 to 180,000 in the Antarctic. The killer whale is the largest predator of mammals that exists on earth today. Male killer whales average 5.8 to 6.7 m and weigh between 3,500 and 5,500 kg. Orcas can swim as fast as 48.4 kilometers per hour, making them the second fastest mammal. Toothed whales are social animals, orcas (killer whales) travel in social units called pods, containing one adult male, several adult breeding females and a number of sub-adults of both sexes. Sizes may vary from as few as 4 to as many as 40. There is an occasional exchange of members between pods, especially during breeding season. They have an extremely varied diet, as far as animals living in the oceans are concerned, ranging from fish to birds, seals and even other whales.
Some researchers believe killer whales sleep using only one brain hemisphere at a time. The orca in the picture is spyhopping, researchers debate its purpose. Some say it is to spot seals or boats. Some say it is part of their tactics when two or more orcas help each other catching seals.
References
Seaworld Infobooks
Orca on Wikipedia
three comments:
My reading has focused on orcas in the Salish Sea, so I don’t know how much this will generalize.
Among the Salish Sea orcas, many are fish-eaters only (no mammals). Also, the whales travel in matrilinial groups, with the oldest female being in charge. Her offspring, both male and female stay with her for life. The whales breed outside their pod, rather than using the “one male with a harem” model. It would be interesting to see how orcas organize around the world.
spotted elephant (URL) - 01 04 06 - 03:41
The Killer Whale is not, in any way, the largest predator on the earth. The Blue Whale, which is vastly larger than a Killer Whale eats krill, which are living organisms, making it the largest predator.
violet - 14 12 08 - 06:10
That’s why it says ‘Largest predator of mammals’
dan - 14 12 08 - 15:31
or
