Orca (Orcinus orca): Killer Whale Facts, Diet and Pods

What does an orca look like?

The orca is one of the easiest whales to recognize. Its body is mostly glossy black, with a white lower jaw and throat, a white belly that extends into patches on the flanks, and an oval white patch above and behind each eye. Behind the dorsal fin lies a gray “saddle patch”, and the underside of the tail flukes is white. In newborn calves the white areas are tinged yellow or orange.

The head is rounded and blunt, without the obvious beak of many smaller dolphins. The flippers are large and paddle-shaped, and the mouth holds about 40–56 strong, cone-shaped teeth that interlock when the jaws close. Orcas do not chew: they grip, tear and swallow.

Adult males are easy to tell from females. A male’s dorsal fin is a tall, straight triangle up to about 1.8 m (6 ft) high, while females and young males have a curved fin about half that height. Every orca’s fin and saddle patch carry unique nicks, scars and markings, so researchers can identify individuals from photographs. Photo-identification, pioneered by the Canadian biologist Michael Bigg in the 1970s, is the reason so much is known about orca families.

How big do orcas get?

Orcas are by far the largest dolphins, and males grow much bigger than females.

Size varies between populations. The fish-eating Type C orcas of the Ross Sea in Antarctica and the offshore orcas of the North Pacific are smaller than the mammal hunters of the same oceans. Even the biggest orca is dwarfed by the blue whale, which can be three times as long.

Where do orcas live?

Orcas live in every ocean, from the edge of the polar pack ice to the tropics, making them one of the most widely distributed mammals on Earth. They are most common in cool, productive coastal waters at high latitudes. Surveys have found the highest densities off Norway, around the Aleutian Islands and in the Gulf of Alaska, and along much of the Antarctic coast. They are also regularly seen off British Columbia and Washington, Iceland, the Faroe Islands, New Zealand and Patagonia.

Orcas are rarer in warm seas but do occur there, including the Caribbean, the Gulf of Mexico and around Hawaii. A small population lives year-round in and near the Strait of Gibraltar, and a tiny group known as the West Coast Community lives off western Scotland and Ireland. Occasionally orcas swim up rivers: they have been recorded about 160 km (100 mi) up the Columbia River in the United States.

The total population is unknown, but NOAA puts it at about 50,000, of which roughly 25,000 are thought to live in Antarctic waters.

Orca types and ecotypes

Orcas look much alike around the world, but they are divided into distinct populations called ecotypes, which differ in diet, behavior, calls and genetics. They rarely or never interbreed, even when they share the same waters.

• Residents of the northeastern Pacific eat fish, above all salmon, and live in large, stable family groups.
• Bigg’s orcas, also called transients and named after Michael Bigg, hunt marine mammals such as seals, sea lions, porpoises and whales, and travel in small, quiet groups.
• Offshore orcas roam the open Pacific in groups of 20–75 and appear to eat fish, including sharks.
• Antarctic types A–D range from large minke whale hunters (Type A) to seal and penguin hunters (Type B) and small fish eaters (Type C).

Many scientists think some ecotypes are separate species. A 2024 study proposed naming residents and Bigg’s orcas as two new species, but the Society for Marine Mammalogy currently treats them as subspecies of Orcinus orca while research continues.

What do orcas eat?

Orcas are apex predators with the widest diet of any whale, yet each population is a specialist. Northeastern Pacific residents feed almost entirely on salmon, especially large Chinook salmon. Orcas in Norway herd herring into tight balls and stun them with tail slaps, a technique called carousel feeding. Bigg’s orcas ambush harbor seals, sea lions and porpoises, and gangs of them chase gray whale calves on migration.

Some hunts are famous. In Antarctica, Type B orcas swim side by side to make waves that wash seals off ice floes. In Patagonia and at the Crozet Islands, orcas deliberately strand themselves on beaches to grab sea lion and elephant seal pups. In 2019, orcas off Western Australia were observed killing blue whales, and in South Africa and California they have killed great white sharks to eat their oily livers. The full menu, region by region, is in What do orcas eat?

Pods, family life and communication

Orca society is built around mothers. The basic unit is the matriline: an older female, her sons and daughters, and her daughters’ offspring. Among resident orcas, both sons and daughters stay with their mother for life, a pattern almost unknown in other mammals. Related matrilines travel together as pods, and pods with similar calls form clans.

Each pod has its own dialect, a set of 7–17 distinctive calls passed down through generations. Orcas also produce clicks for echolocation, finding prey by listening for echoes, and whistles used at close range. Bigg’s orcas stay mostly silent while hunting, because seals and porpoises can hear them coming.

Hunting techniques, calls and even passing fads are learned from relatives, so many scientists describe orcas as having culture. In 1987, Southern Resident orcas briefly took up the habit of carrying dead salmon on their heads, and the “salmon hat” trend reappeared in 2024. How these families work, from matriarchs to babysitting, is explained in How do orca pods work?

Reproduction and lifespan

Females start to mature at about 10–13 years old. After a pregnancy of 15–18 months, one of the longest of any whale, they give birth to a single calf, usually about once every five years. Calves nurse for at least a year and are fully weaned by about two years old. Early life is risky: an estimated 37–50% of calves die in their first seven months. Males reach sexual maturity at about 15 but usually do not father calves until their twenties, and they mate with females from other pods, which avoids inbreeding.

Orcas are one of only a few mammals, along with humans and some other toothed whales, known to go through menopause. Females stop breeding at around 40 but may live for decades longer, and these older females lead their families to food. According to NOAA, wild females live about 50 years on average and some reach 80–90, while males average about 30 years and only a few reach 60. A famous Southern Resident matriarch called Granny (J2) was once claimed to be over 100, but later studies suggest she was more likely 65–80 when she died in 2016.

Threats and conservation status

The IUCN Red List classes the orca as Data Deficient. This does not mean orcas are safe: because the species probably contains several separate species or subspecies, its overall status cannot be judged. Some populations are clearly in trouble.

• Southern Residents. Listed as endangered in Canada and, since 2005, in the United States, this salmon-eating community of three pods counted just 76 whales on July 1, 2026. Shortages of Chinook salmon, pollution and noise and disturbance from vessels are the main threats.
• Strait of Gibraltar orcas. This group of about 35–40 animals, which follows Atlantic bluefin tuna, has been assessed as Critically Endangered on the IUCN Red List since 2019.
• AT1 transients. This small Alaskan group of Bigg’s orcas fell from 22 whales to fewer than ten after the 1989 Exxon Valdez oil spill and is expected to die out.

As top predators, orcas build up long-lasting pollutants such as PCBs in their blubber. Lulu, a member of Scotland’s West Coast Community found dead in 2016, had some of the highest PCB levels ever recorded in a whale. Past threats included whaling, which killed thousands of orcas in the 20th century, and live captures for marine parks. International trade is controlled under CITES Appendix II.

Orcas and people

For many Indigenous peoples of the Pacific Northwest, including the Haida, Kwakwaka’wakw and Tlingit, the orca is a powerful and respected figure in art and stories. Western sailors and fishers long feared orcas as rivals, and some were shot. Attitudes changed in the 1960s, when the first orcas displayed in aquariums turned out to be gentle and intelligent, and photo-identification research showed how small and fragile local populations were.

Today orca watching draws visitors to British Columbia, Washington, Norway and Iceland. Wild orcas have never been confirmed to kill a person, although captive orcas have injured trainers, as explained in Are orcas dangerous to humans? Since 2020, a few orcas off Spain and Portugal have repeatedly struck the rudders of sailing yachts, a puzzling behavior that has sunk a handful of boats but hurt no one.

Myths and facts

Myth: an orca is a whale, not a dolphin. It is both: a toothed whale that belongs to the dolphin family. The details are in Is an orca a whale or a dolphin?

Myth: killer whales got their name from killing people. The name refers to their habit of killing other whales, which sailors noticed centuries ago.

Fact: the Latin name has nothing to do with hell. Orcinus is often said to mean “from the underworld”, but it comes from orca, a Latin name that Roman writers such as Pliny the Elder used for a large sea animal.

Fact: orcas once worked with whalers. In the 19th and early 20th centuries, orcas at Eden in New South Wales, Australia, regularly helped shore whalers catch baleen whales, and were rewarded with the tongue and lips of the dead whales.