Orca

The orca (Orcinus orca), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus Orcinus, it is recognizable by its distinct pigmentation; being mostly black on top, white on the bottom and having recognizable white eye patches. A cosmopolitan species, it inhabits a wide range of marine environments, from Arctic to Antarctic regions to tropical seas, but is more commonly documented in temperate or cooler coastal waters. Scientists have proposed dividing the global population into races, subspecies, or possibly even species.

Orcas are apex predators with a diverse diet. Individual populations often specialize in particular types of prey, including fish, sharks, rays, and marine mammals such as seals, dolphins, and whales. They are highly social, with some populations forming stable matrilineal family groups (pods). Their sophisticated hunting techniques and vocal behaviors, often unique to specific groups and passed down from generation to generation, are considered to be manifestations of animal culture. The most studied populations are off the west coast of North America, which include fish-eating "residents", mammal-eating "transients", and offshores.

The International Union for Conservation of Nature (IUCN) lists the orca's conservation status as data deficient as multiple orca types may represent distinct species. Some local populations are threatened or endangered due to prey depletion, habitat loss, pollution (by PCBs), captures for marine parks, and conflicts with fisheries. In late 2005, the southern resident orcas were added to the U.S. Endangered Species list.

Orcas have been revered by indigenous peoples while Western cultures have historically feared them. They have been taken by whalers when stocks of larger species have declined. The orca's image took a positive turn in the 1960s, due to greater public and scientific awareness and their display in captivity. Since then, orcas have been trained to perform in marine parks, a practice that has been criticized as unethical. Orcas rarely pose a threat to humans, and no fatal attack has been recorded in the wild. However, captive orcas have injured or killed their handlers in marine theme parks.