Orca (Orcinus orca), also known as the killer whale, is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is recognizable by its black-and-white patterned body.
A cosmopolitan species, killer whales can be found in all of the world's oceans in a variety of marine environments, from Arctic and Antarctic regions to tropical seas; they are absent only from the Baltic and Black seas, and some areas of the Arctic Ocean.
Orcas have a diverse diet, although individual populations often specialize in particular types of prey. Some feed exclusively on fish, while others hunt marine mammals such as seals and other species of dolphin. They have been known to attack baleen whale calves, and even adult whales. Killer whales are apex predators, as they have no natural predators.
They are highly social; some populations are composed of very stable family groups (pods) which are the most stable of any animal species. Their sophisticated hunting techniques and vocal behaviours, which are often specific to a particular group and passed across generations, have been described as manifestations of animal culture.
Why They Matter
Orcas are top predators in most marine ecosystems and impact the populations of common prey, such as seals and sea lions in breeding areas.
The International Union for Conservation of Nature assesses the orca's conservation status as data deficient because of the likelihood that two or more orca types are separate species. Some local populations are considered threatened or endangered due to prey depletion, habitat loss, pollution (by PCBs), capture for marine mammal parks, and conflicts with human fisheries. In late 2005, the southern resident orcas, which swim in British Columbia and Washington state waters, were placed on the U.S. Endangered Species list.