Orca

The orca or killer whale (Orcinus orca) is the largest dolphin and an apex predator of every ocean. The IUCN lists it as Data Deficient, because distinct ecotypes may represent separate species, and some regional populations are endangered.

🧬 Field Guide Specimen: Open Orca (Killer Whale) in the CRV Science Field Guide to log the specimen, see its place among the Mammals lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

Orcas in the northeastern Pacific split into fish-eating residents, mammal-hunting Bigg's (transient) whales and offshore groups that rarely mix, each with its own calls, diet and genetics. Similar divisions exist in Antarctica. Knowledge is passed from mother to offspring, which makes orcas a leading example of animal culture.

Pods are built around females, and offspring stay with their mothers for life. Female orcas live long after they stop reproducing, one of the few non-human mammals known to undergo menopause, and older females lead hunts and help their grandchildren survive.

The endangered Southern Resident population in the Pacific Northwest numbers only around 70 animals. They depend on Chinook salmon, whose decline, along with vessel noise and contaminants, has left them struggling to breed.

• Blue Whale — a baleen whale and prey of some orcas
• Food web — orcas at the top of marine food webs