# Orca — Facts, Threats & Conservation

*Orcinus orca (Linnaeus, 1758)*

> The orca (Orcinus orca) is the world's largest oceanic dolphin — a black-and-white apex predator found in all oceans, with pod-specific diets and cultures; globally assessed as Data Deficient on the IUCN Red List.

**IUCN status:** Data Deficient (IUCN global assessment)  ·  **WARN range:** Arctic, Antarctic, North Pacific, North Atlantic, temperate and tropical seas worldwide

## Quick facts
| Fact | Value |
| --- | --- |
| Also called | Killer whale |
| Family | Delphinidae (oceanic dolphins) |
| Length | Up to ~9 m (males) |
| IUCN global | Data Deficient |
| Diet | Fish, seals, squid — varies by ecotype |
| Social structure | Matrilineal pods |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla
- **Family:** Delphinidae
- **Species:** Orcinus orca

## Conservation status
- **Status:** Data Deficient globally on the IUCN Red List; several regional populations Endangered or Critically Endangered.
- **Population:** Roughly 50,000 worldwide; Southern Residents about 75
- **Trend:** Stable globally; decreasing for depleted regional stocks
- **Assessed:** 2017
- **CITES:** Appendix II
- Debate continues over whether orcas comprise one species or several distinct taxa.

## Key facts: Orca
- Orcas are dolphins, not true whales — the largest species in family Delphinidae.
- Resident, transient and offshore ecotypes in the North Pacific differ in diet, vocal dialects and genetics.
- Southern Resident orcas of the US Pacific North-west are Endangered with only about 75 individuals.
- Captive display and live capture historically depleted some populations; many countries now restrict capture.
- Persistent organic pollutants accumulate in blubber and affect reproduction in long-lived pods.
- Ship noise and salmon declines threaten fish-eating resident populations.

## What is an orca?
Orcinus orca is a toothed cetacean — a marine mammal with conical teeth rather than baleen. Males may exceed nine metres and weigh ten tonnes; females are smaller with a curved dorsal fin. The striking counter-shaded colouration may confuse prey when viewed from above or below.

Orcas live in matrilineal pods led by older females. Grandmothers share knowledge of salmon runs and hunting routes. Calves stay with their mothers for life in resident fish-eating communities. Transient orcas roam wider territories hunting marine mammals in silence to avoid alerting prey.

Because populations behave like distinct cultures, some scientists argue for splitting orca into multiple species or subspecies. That uncertainty underpins the global Data Deficient IUCN listing.

## Hunting, communication and intelligence
Orcas employ coordinated hunting: wave-washing seals off ice floes, beaching to catch sea lions, or herding fish into bait balls. Each ecotype passes techniques through social learning — evidence of culture among non-human animals.

Vocal repertoires differ between pods; resident orcas use discrete call types inherited maternally. Echolocation clicks locate prey in murky water. Brain size and social complexity rival those of other cetaceans.

Prey specialisation shapes tooth wear and toxin loads. Mammal-eating transients carry higher PCB concentrations because seals concentrate pollutants.

## Threats and conservation
Globally orcas are not scarce, but local populations face extinction. Southern Resident killer whales depend on Chinook salmon; dammed rivers and overfishing reduce food. Vessel traffic increases stress hormones and masks echolocation.

Historical live capture for aquaria removed entire generations from the Pacific North-west. Oil spills, military sonar and entanglement in fishing gear kill individuals. In the Arctic, climate change opens new shipping routes through critical habitat.

Recovery plans focus on salmon restoration, vessel distance rules, pollutant cleanup and ending wild capture. CITES Appendix II regulates international trade in parts and live animals.

## Orcas and people
Indigenous coastal peoples feature orcas in art and oral tradition as kin or guardians. Modern whale-watching generates income when boats follow approach guidelines that prevent harassment.

Debate continues over captive orcas: welfare concerns led several countries to ban breeding and import. Remaining display animals highlight longevity and social needs poorly met in tanks.

Readers can support orca conservation through sustainable fisheries advocacy, reduced ocean noise and respect for wild animals at distance — never feeding or approaching closely.

## Related WARN guides
Orcas are the largest oceanic dolphins — read WARN's dolphin guide for Delphinidae context, the sperm whale and blue whale pages for other deep-diving cetaceans, and the whale hub for the wider group.

Seal and sea lion guides cover mammal-hunting ecotypes' prey; sea turtle pages address shared ocean threats.

Salmon restoration, vessel distance rules and an end to wild capture underpin orca recovery.

## What WARN does
WARN publishes free marine wildlife education for readers in Pakistan, Indonesia, Malaysia, Brazil and Colombia — coastal and ocean-facing nations where understanding apex predators supports broader habitat protection. We do not run orca programmes, but healthy seas underpin every WARN appeal.

If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.

## Frequently asked questions: Orca
### Is an orca a whale or a dolphin?
An orca is a dolphin — the largest member of the oceanic dolphin family Delphinidae. 'Killer whale' is a traditional name reflecting its size and predatory power.

### Are orcas endangered?
Globally the IUCN lists orcas as Data Deficient. Some populations, such as Southern Resident killer whales, are Endangered with fewer than 80 individuals.

### What do orcas eat?
Diet varies by population: fish — especially salmon for residents — seals, sea lions, squid, sharks and even other whales for mammal-hunting ecotypes.

### How long do orcas live?
Females can exceed 80 years in the wild; males typically live 30 to 60 years. Long generation times slow population recovery.

### Do orcas attack humans?
Wild orcas rarely harm people. Most incidents involve captive animals. Wild pods may approach boats out of curiosity but serious attacks are exceptionally uncommon.

### Where do orcas live?
In all oceans from polar ice to equatorial waters. Different ecotypes occupy specific regions — for example, fish-eating residents in the north-east Pacific.

## Sources
- [IUCN Red List — orca](https://www.iucnredlist.org/species/15421/50368151)
- [Smithsonian Ocean — killer whale](https://ocean.si.edu/ocean-life/marine-mammals/killer-whale)
- [Encyclopaedia Britannica — killer whale](https://www.britannica.com/animal/killer-whale)
- [Wikipedia — Orca](https://en.wikipedia.org/wiki/Orca)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/orca