Killer whales are a species.
The killer whale or orca ( Orcinus orca ) is a toothed whale belonging to the oceanic dolphin family , of which it is the largest member . Killer whales are highly social ; some populations are composed of matrilineal family groups ( pods ) which are the most stable of any animal species . The International Union for Conservation of Nature currently assesses the orca 's conservation status as data deficient because of the likelihood that two or more killer whale types are separate species .