Orca (Orcinus orca)

Status: needs expert review. The IUCN assesses the species globally as Data Deficient and recognises that its taxonomy is unresolved (multiple ecotypes, with some populations proposed as distinct species); a science reviewer should confirm the current assessment and the status of regional populations before approval. The orca, or killer whale (Orcinus orca), is the largest member of the dolphin family and the most widely distributed cetacean.

At a glance

Field	Value	Source
Scientific name	Orcinus orca	WoRMS / authority
Guild	cetacean (oceanic dolphin)	—
IUCN status	Data Deficient (assessed 2017); global trend unknown	IUCN Red List
US ESA status	Only the Southern Resident Distinct Population Segment is listed Endangered; all populations MMPA-protected	NOAA Fisheries
International trade	CITES Appendix II	CITES
Range	All oceans; most widely distributed of all cetaceans	NOAA Fisheries

Identification

A large black-and-white toothed cetacean. NOAA Fisheries reports lengths up to about 32 feet (roughly 10 m) and weights up to about 11 tons. Distinctive features include the tall dorsal fin (taller and straighter in adult males), a white eye patch, and a grey "saddle" behind the dorsal fin. Coloration and fin shape vary by ecotype.

Ecology and behavior

NOAA Fisheries describes orcas as apex predators with the most varied diet of all cetaceans: diet varies sharply by population and ecotype, with some populations specializing on fish (notably salmon) and others on marine mammals and squid. Different ecotypes show distinct foraging, vocal, and social patterns; NOAA Fisheries gives typical lifespans of around 30 years for males (up to 60+) and around 50 years for females (up to 90+). Behavioral and ecotype distinctions should be cited to published research and confirmed in review.

Conservation status and threats

The IUCN Red List lists Orcinus orca globally as Data Deficient (assessed 2017): there is not enough information to assess global extinction risk, partly because the species comprises multiple ecotypes that may warrant separate assessment. This global "Data Deficient" label does not mean individual populations are secure. NOAA Fisheries lists the Southern Resident Distinct Population Segment as Endangered under the US Endangered Species Act, with reduced prey availability (especially Chinook salmon), vessel disturbance and underwater noise, and bioaccumulated chemical contaminants among the principal threats; oil spills and fishing-gear entanglement are also listed. The species is on CITES Appendix II. Report figures as the cited authorities state them; a reviewer should confirm population-level detail.

How to observe responsibly

Orca watching is regulated and rules vary by region. NOAA Fisheries advises observing whales from a safe distance of at least 100 yards (about 91 m); in Washington State waters, federal rules prohibit approaching within 200 yards of a Southern Resident killer whale. Follow the reviewed observation guide and the strictest applicable local rule. If an animal changes its behavior because of your presence, you are too close — withdraw. This page keeps to regional granularity (ETHICS.md) and does not publish precise locations.

How you can help

• Log sightings to a recognized citizen-science platform (see the iNaturalist dataset card).
• Support salmon-recovery, quieter-vessel, and contaminant-reduction programs through credible organizations such as Whale and Dolphin Conservation.
• Report dead, injured, or entangled animals to your regional marine-mammal stranding network.