Other than humans, killer whales are the most widely distributed mammals in the world. They are found in every ocean, from the Arctic to the Antarctic, but are most numerous in the waters covering high-latitude continental shelves. They also are unchallenged as the top predator of the waters they inhabit. Lacking natural enemies, they are capable of growing very large and very old. Adult males average 27 feet in length and weigh more than four tons.
Females are slightly smaller.
In the wild, males can live more than 50 years and females can survive into their eighties. Calves, typically 8 feet long and weighing between 300 and 400 pounds at birth, nurse underwater for a year or more. When not nursing, a calf swims just behind the mother's dorsal fin, slipstreaming in her wake. From this vantage point, it evidently picks up pointers, from how to make sounds to how to catch fish. Mothers are not the only members of the pod capable of giving lessons, Balcomb recently noticed.