Alaska Species Explorer

Killer Whale

Common Name: Killer whale
Scientific Name: Orcinus orca

The killer whale is one of the most wide ranged of all the mammals.  Found worldwide but more commonly in the higher latitude colder waters and in polar regions. In the North Pacific Ocean, killer whales are often sighted in all parts of Alaska, including the Bering Sea, Aleutian Islands, Prince William Sound, and Southeastern Alaska.

Conservation Status:

The AT1 stock of the North Pacific transient killer whale was designated as depleted under the MMPA after its drastic decline after the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska.

In November 2005, the Southern Resident population was listed as endangered under the ESA. NMFS designated critical habitat in November 2006 for the Southern Resident population.  This population is currently under review to be delisted.

Average Length: Males: 32ft, Females 28ft
Average Weight: Males up to 22,000lbs; Females up to 16,500lbs
Diet in the Wild:

In the eastern North Pacific, the "resident" killer whale populations mainly feed on salmonids, such as Chinook salmon and chum salmon.

"Transient" populations in the eastern North Pacific feed on marine mammals, such as (in order of frequency of observation) harbor seals, Dall's porpoises, harbor porpoise, gray whale calves, Steller sea lions, and various other species of pinnipeds and cetaceans.

Reproduction Period:

Sexual maturity of female killer whales is achieved when the whales reach lengths of approximately 15-18 feet (4.6 m-5.4 m), depending on geographic region. The gestation period for killer whales varies from 15-18 months, and birth may take place in any month--there is no distinct calving season. Calves are nursed for at least 1 year, and may be weaned between 1 and 2 years of age. The birth rate for killer whales is not well understood, but, in some populations, is estimated as every 5 years for an average period of 25 years.


Killer whales are most abundant in colder waters, including Antarctica, Norway, and Alaska. However, killer whales can also be fairly abundant in temperate waters. Killer whales also occur, though at lower densities, in tropical, subtropical, and offshore waters.

Threats in the Wild:

Pollution, reduced prey availability, ship collisions, oil spills, entanglement, and noise disturbance.

Did you know?:
  • Highly social animals that live in groups known as pods.
  • ASLC scientists have worked with these species in the Antarctic.
  • Represent the most widely distributed mammal species in the world.
Additional References: