- Common Name
- killer whale, orca
- Genus Species
- Orcinus orca
- Killer whales are easily recognized by their large size and striking black and white coloration. The dorsal surface and pectoral flippers are black except for a grayish patch (saddle) that lies behind the dorsal fin and a white eyespot located just above and slightly behind each eye. The ventral surface, lower jaw and undersides of the flukes are predominately bright white.
Male: In mature males, the dorsal fin is tall and triangular and may reach a height of 1.8 m (6 ft). Also, adult males tend to be larger than adult females.
Female: In most females, the dorsal fin is typically smaller and slightly falcate (curved back), reaching an average height of 0.9 to 1.2 m (3 to 4 ft).
- Calves average 2.6 m (8.5 ft) in length
Male: Averages 5.8 to 6.7 m (19 to 22 ft.); largest males on record were 9.8 m (32 ft)
Female: Averages 4.9 to 5.8 m (16 to 19 ft)
- Newborn calves weigh 136 to 181 kg (300 to 400 lbs.)
Male: Averages 3,628 to 5,442 kg (8,000 to 12,000 lbs.); largest males recorded weighed 10,000 kg (22,000 lbs.)
Female: Averages 1,361 to 3,628 kg (3,000 to 8,000 lbs.)
- Fishes, marine mammals, birds and sea turtles
- 15 to 18 months; 17 months on average
- Estral Period
- Varies; tends to come into estrus several times a year or more
- Nursing Duration
- 12 or more months (wean)
- Sexual Maturity
- Male: At about 5.5 to 6.1 m (18 to 20 ft.); 10 to 13 years
Female: At about 4.6 to 4.9 m (15 to 16 years); 6 to 10 years
- Life Span
- Male: Approximately 30 years (more info)
Female: Approximately 50 years (more info)
- Oceans worldwide; most abundant in the Arctic and Antarctic and in areas of cold-water upwelling
- Coastal and offshore waters; resident pods may frequent localized waterways (bays, sounds, etc.) whereas transient pods tend to cover more extensive, varied areas
- Global: Estimated 80,000 to 90,000; possibly more
- IUCN: Data Deficient
CITES: Appendix II
USFWS: Endangered (specific to a subpopulation found along the U.S. western seaboard known as the Southern Resident Distinct Population Segment (DPS))
- Killer whales are toothed whales and are the largest member of the dolphin family, Delphinidae.
- The distinctive coloration of killer whales is a type of camouflage known as disruptive coloration, in which the color pattern of an animal contradicts the animal's body shape. In the flickering, filtered sunlight of the sea, other animals may not recognize a killer whale as a potential predator.
- Killer whales live in groups called pods. A pod may have less than 5 to about 30 individuals: a mix of males, females, and calves of varying ages. Sometimes, several smaller pods join together to form larger herds of 50 or more whales.
- A female-dominant social hierarchy exists within a group of killer whales. The animals may rank and establish themselves within the hierarchy by behaviors such as tail-slapping, head-butting, jaw-snapping, biting, tooth-raking and various other postures and gestures.
- Killer whales are apex or top predators in the ocean. Known as "wolves of the sea," killer whales often hunt cooperatively in pods for food; working together to encircle and herd prey into a small area before attacking. When hunting a large whale, a pod of killer whales may attack the whale from several angles. They may also slide out onto sandbars or ice floes in pursuit of prey and are capable of hitting ice floes from below to knock prey into the water.
- A recent survey of killer whales off the coast of New Zealand documented that 23% of males had bent dorsal fins.
- Killer whales are among the fastest swimming marine mammals. They can swim as fast as 48 kph (30 mph), but they usually cruise at much slower speeds, about 3 to 10 kph (2 to 6 mph).
- For more information about killer whales, explore the Killer Whale Info Book
Ecology and Conservation
Although the worldwide population of killer whales is unknown, we do know that killer whales are not endangered (with the notable exception of the Southern Resident DPS – see Status). In some areas of the Antarctic alone their numbers have been estimated at about 180,000. Researchers can identify individual killer whales by taking pictures of dorsal fins, noting differences in shape, relative size, and scars. As with other marine mammals, the U.S. Marine Mammal Protection Act of 1972 protects killer whales.
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Leatherwood, Stephen, and Reeves, Randall R. The Sierra Club Handbook of Whales and Dolphins. San Francisco: Sierra Club Books, 1983.
Nowak, Ronald M. (ed.). Walker's Mammals of the World. Vol. II. Baltimore: Johns Hopkins University Press, 1991.
Parker, S. (ed.). Grizmek's Encyclopedia of Mammals. Vol. IV. New York: McGraw-Hill Publishing Co., 1990.
Reeves, R. R., Stewart, B.S., Clapman, P.J., and J.A. Powell (Peter Folkens illustrator). National Audubon Society: Guide to Marine Mammals of the World. New York: Random House, 2002.
Wlodarski, L. Killer Whales: Creatures of Legend and Wonder. Orlando. SeaWorld, Inc. 2000.