A New Study Suggests Orcas Are Actually Three Different Species

We've long assumed Orcas were a single species but new research says otherwise.

Hiya!

I’m a millennial, which means at five years old, I was the prime audience for the blockbuster hit Free Willy when it came out in 1993. The movie is about the relationship between a boy and an orca in captivity named Willy, and as the title implies, the boy frees Willy. The film and theme parks like Seaworld brought much attention to the treatment of marine animals in captivity, especially orcas.

While the public’s attention has waned over the years, orcas are back in the news. This time for attacking and sinking boats. Not just a few times, but as of March 16, 2024, orcas have interacted with boats at least 700 times since 2020. Now, orcas are making headlines for a different reason. A new study adds the most compelling evidence yet that what we think of as orcas are actually multiple, distinct orca species.

Orcas, aka Killer Whales

Orcas (Orcinus orca) are among the most recognizable marine animals due to their striking black-and-white appearance and fearsome reputation as “killer whales.”

According to The United States National Oceanic and Atmospheric Administration (NOAA), the killer whale nickname came from 1869, after a young scientist named Edward Drinker Cope was invited to “review a manuscript the Smithsonian had received from a California whaling captain named Charles Melville Scammon.” NOAA reports that,

“Scammon’s manuscript described several large marine mammals of the West Coast, calling [orcas] ‘the wolves of the ocean,’ which he said lived ‘by violence and plunder.’”

While the Smithsonian may have meant for Cope to only browse the manuscript, Cope decided to edit it and then publish the revised manuscript in the Proceedings of the Academy of Natural Sciences of Philadelphia in 1869 — and he did it without telling Scammon. Cope gave Scammon credit for the orca’s descriptions, but Cope is the one who gave them the killer whale nickname.

Considering orcas are apex predators found throughout the global ocean, from pole to pole and everywhere in between, the nickname seems somewhat fitting. However, calling orcas “killer whales” is also misleading.

The biggest misconception is that despite their larger size and appearance, technically speaking, orcas are a type of dolphin. The confusion is understandable since whales and dolphins are closely related. Both belong to the cetacean family, which also includes porpoises, but orcas are more widely distributed worldwide than any other cetacean member.

Orcas are social, and most live in familial groups called pods that range from a few to over twenty related individuals, with the mother as the leader. The moms will even interfere and protect their sons (but not their daughters) from fights with other whales. Still, even with their mother’s protection, male orcas typically only live for between 30 and 60 years. Meanwhile, females can live between 50 and 90 years.

Most orcas remain in the pods they’re born into and only occasionally interact with other pods for short-term social interactions, like dining on seasonal prey concentrations or mating. Orcas learn hunting strategies, food preferences, and rituals through social learning and pass the knowledge down through generations, resulting in cultural behavioral differences between pods.

As a whole, orcas have the most diverse diet compared to all other cetaceans. At first glance, orcas appear to be generalist eaters, consuming whatever is available. They’re known to hunt smaller prey like fish but also larger animals, including sea lions and seals, sharks, rays, squid, whales, seabirds, and more.

However, a closer look reveals that orcas are actually picky eaters. Different orca populations and pods have unique diets, and once they learn what their family eats, they aren’t likely to stray from what they know.

But diet discrepticies aren’t the only differences researchers have observed in orca populations. Their varied yet specific diets, combined with the broad range of climates they live in and diverse behavior, including hunting habits and strategy, have led scientists to identify distinct ecotypes, or varieties, of orcas worldwide.

Previous Research

Phillip Morin, a marine-mammal geneticist with the National Oceanic and Atmospheric Administration (NOAA) Southwest Fisheries Science Center, has spent years collecting evidence about two particular Orca ecotypes — “residents” and “transients” — living across the Northern Pacific Ocean with plenty of differences between them.