Why Are Orcas Called Killer Whales? Name Origin Explained

Where does the name killer whale come from?

People have known orcas as whale hunters for at least two thousand years. In the first century AD, the Roman naturalist Pliny the Elder described orcas attacking whales and their calves, comparing them to warships ramming an enemy. Whalers in later centuries saw the same thing: packs of black-and-white animals harrying and biting a whale until it was exhausted.

The usual explanation for the modern name is that Spanish-speaking sailors, often said to be Basque whalers, called the orca asesina ballenas, “killer of whales”. In English the words were turned around to “killer whale”. Since orcas also breathe air, blow at the surface and grow to 8 m (26 ft) or more, it was natural for sailors to call them whales themselves.

Over the centuries orcas had other English names too. Fishers and whalers sometimes called them “blackfish”, a name also used for pilot whales, or “grampus”, an old word that today is the scientific name of a different animal, Risso’s dolphin.

What does Orcinus orca mean?

The scientific name has a separate history. Carl Linnaeus described the species in 1758 as Delphinus orca, already placing it with the dolphins. In 1860 the Austrian zoologist Leopold Fitzinger created a separate genus for it, Orcinus, giving us Orcinus orca.

The word orca goes back to Latin, where Roman writers used it for a large, fierce sea animal; it may have been borrowed from an ancient Greek word for a kind of whale. Orcinus simply means something like “of the orca” or “orca-like”. A popular claim that it means “from the underworld”, after the Roman god of death Orcus, is a misunderstanding.

Why do many people now say orca?

For most of history, killer whales were feared and disliked. Fishers saw them as competitors for salmon and herring, and in the Pacific Northwest and elsewhere they were sometimes shot. That began to change in the 1960s. The first orcas kept in aquariums proved to be calm, intelligent and trainable, and scientists began studying wild families and discovered their stable, mother-led societies.

As the public image of the animal improved, the name “orca” spread. Marine parks used it, conservation groups preferred it, and many people felt that “killer” gave the wrong impression of an animal that has never been confirmed to kill a person in the wild. Today “orca” is the more common name in everyday English, while “killer whale” remains standard in much scientific writing and in the names of protected populations, such as the Southern Resident killer whales.

Do killer whales really kill whales?

Yes. Orcas are the only animals that regularly prey on large whales, and the name is well earned.

• Minke whales are the main prey of the large Type A orcas around Antarctica.
• Gray whale calves are ambushed by mammal-hunting orcas during the spring migration along the coasts of California and Alaska.
• Humpback whale calves are also attacked, and many adult humpbacks carry rake-like tooth scars. Humpbacks sometimes charge into orca hunts, as explained in Do humpback whales protect other animals from orcas?
• Blue whales, the largest animals on Earth, were seen being killed by orcas for the first time off Western Australia in 2019, including an adult or near-adult about 18–22 m (59–72 ft) long.
• Sperm whales defend their calves by forming a circle with their tails facing outward, a strategy that suggests orcas have long been a threat.

Killing a large whale takes teamwork. Orcas chase the target for a long time, take turns biting its flippers and tail, and try to keep it from surfacing to breathe. Scientists think large whales may have been a much bigger part of the orca diet before industrial whaling wiped out most of them.

Not every orca is a whale killer

Despite the name, most orcas never hunt whales. Each population specializes in particular prey. The resident orcas of Washington and British Columbia live almost entirely on salmon, orcas in Norway eat mainly herring, and New Zealand orcas often hunt rays and sharks. Only certain mammal-hunting groups take whales, and even they mostly eat seals, sea lions, dolphins and porpoises. The full range of prey is in What do orcas eat?

Other killer whales that are not orcas

Two other dolphins carry the “killer whale” name, although neither is a close relative or a whale hunter. The false killer whale (Pseudorca crassidens), which grows up to about 6 m (20 ft), is all dark gray and eats mainly fish and squid. The pygmy killer whale (Feresa attenuata), only about 2–2.6 m (7–8.5 ft) long, lives in warm, deep waters. Both got the name because they reminded early naturalists of the orca, but they are only distant cousins within the dolphin family.

The orca itself is the largest member of that family. Its place in the family tree is explained in Is an orca a whale or a dolphin?, and the species as a whole is described in our orca profile.