Five Astounding Orca Behaviors Explained, From Ramming Boats to Hunting Great White Sharks - Smithsonian Magazine

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Mass Media Fellow, AAAS

Few animals captivate the human imagination like orcas. Their recent attacks on sailing yachts have made news, but our encounters with the predators go way back.

Humans have long feared and revered the animals, also known as “killer whales,” which are not actually whales but instead the largest member of the family that includes dolphins. When Pliny the Elder recorded the orca in his first-century encyclopedia, he described it as “an enormous mass of flesh armed with teeth” that offered no mercy. But people have also worked alongside the powerful creatures: Australian whalers in the 1800s cooperated with orcas to capture and kill baleen whales, a tradition that may have originated thousands of years before with Indigenous Australian hunters.

In the 1960s and 1970s, aquariums and marine parks like SeaWorld collected wild-caught orcas, but public opinion took a turn when it was revealed that professional orca catchers like Ted Griffin used explosives to corral the creatures into nets, where they sometimes tangled and drowned. The last animals were taken for public display in U.S. waters in the mid-1970s, thanks to restrictions from the Marine Mammal Protection Act. Captive breeding programs began, but those came under fire, too, after activist efforts and the documentary Blackfish illustrated orcas’ poor health in captivity. In 2016, SeaWorld announced it would end its breeding program.

Captive orca tricks that involve swimming with humans, like an animal balancing a trainer on its nose, are now banned in the United States. But those acts never came close to the amazing feats of orcas in the wild. We called up four experts to learn about five of their most remarkable behaviors.

They get caught up in fads, including ramming boats

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Orcas are intelligent and intensely social animals that pick up behaviors from fellow orcas. Take a trend described in Puget Sound in 1987, where one orca reportedly started carrying around a dead salmon on its head. This “salmon-hat” practice spread to two other pods before subsiding. Josh McInnes, a behavioral ecologist from University of British Columbia’s Institute for the Oceans and Fisheries Marine Mammal Research Unit, says that while he can’t explain that behavior, he’s witnessed orcas playing around in a similar way with jellyfish.

The latest fad among the marine mammals has been damaging sailing vessels in the Strait of Gibraltar and further north off the coasts of Spain and Portugal. Since 2020, reports have the animals charging at boats and tearing chunks off rudders. Orcas have anecdotally taken down ships in the past before—once in 1972 east of the Galapagos and another time in 1976 off the coast of Brazil. But the recent activity marks the first time the behavior appears to be spreading, perhaps as far as Scotland.

“Normally, it doesn’t catch on like this,” says Robert Pitman, a marine ecologist and affiliate at Oregon State University’s Marine Mammal Institute, but in particular, “if [the matriarch] finds something that catches her interest, then it can easily pass along to other members of the group.”

Researchers haven’t been able to determine how this particular trend started or why more orcas seem to be joining in. Some scientists suggested in a 2022 study in Marine Mammal Science that the behavior might stem from the increased presence of ships among this endangered population, from the competition for food with fishing boats or from one orca’s response to being hit by a boat. Deborah Giles, science and research director of Wild Orca, a nonprofit conservation organization based in Washington, speculates that orcas could be playing by catching a ride on the ship like a skateboarder holding on to the back of a truck. “We’ve seen the young animals grab onto the trailing edge of an older, larger animal and be drug along for the ride,” she says.

They eat great white sharks

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Some orcas specialize in prey like bluefin tuna, elephant seals or even blue whales—but others focus on hunting sharks. In 2011, researchers first documented the behavior in the Pacific Ocean. Later, aerial footage showed orcas in Monterey Bay snacking on a great white shark. In the video, a shark is passed from mouth to mouth among the pod members as they share the catch. Farther south, orcas of South Africa have been spotted descending on great whites and plucking out their extra-nutritious livers.

Killer whales are hunting great white sharks and eating their livers https://t.co/1kChF4xtS2 pic.twitter.com/0pPBGHtN0a
— Newsweek (@Newsweek) May 12, 2017

How are orcas taking down such a fearsome creature? Hunting in a pack helps. Sharks are typically loners, while orcas will travel in a pod, making it easier to corner prey. Orcas sometimes “karate chop” the shark; they propel it to the water’s surface, then twist their tails sideways to strike the shark. Other times, the orcas force the sharks upside down, and a reflex triggers the fish into a paralysis-like state.

Orcas can clear an area of sharks just by showing up. In the Farallon Islands off the coast of California, where white sharks appear seasonally to eat young elephant seals, the sharks will abandon their territory and not return for the whole year if orcas show. For the black-and-white predators, sharks are “just another form of protein,” says McInnes. “And it’s unfortunate that the shark is not as high on the food chain as the killer whales.”

They surge onto the shore to hunt

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Orcas develop specialized tactics for hunting their local prey. Some orcas eat fish and echolocate to find their targets, while others glide silently through the water to sneak up on elephant seal pups. “It’s like the entire neighborhood goes quiet,” says Salma Abdel-Raheem, an elephant seal researcher at University of California, Santa Cruz. “It’s spooky.”

In the Antarctic Ocean, orcas famously create waves to wash seals off ice floes. But one of the most spectacular ways orcas hunt straddles the land and the sea. Orcas in several places, including off the coasts of British Columbia and Patagonia, launch themselves up onto the beach to hunt. They approach seals or sea lions on the shore and swim straight up onto the sand or rocks, snatching their prey before wriggling back into the sea.

Juvenile orchids learn this method, called “intentional stranding,” from their mothers, says McInnes. A female will actively push a young orca up away from the water until it learns how to get up onto shore and back.

They have reunions

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When they’re not hunting, orcas can engage in other behaviors that reflect their complex social structures. One of the most mysterious is the “greeting ceremony” seen in the salmon-eating population off the West Coast of the U.S. and Canada. Giles compares it to a reunion of a big extended family.

When two groups, or pods, come into contact after not seeing each other for some time, says Giles, the members of each pod line up to face the other group across a 300-foot stretch of water. They float in this formation “pec to pec, basically elbow to elbow” in two rows, she says. “And they just hover there at the surface with no vocalizations.”

After a few minutes, the ceremony then morphs from silence into a party atmosphere. Orcas break rank and rush together, swim around each other, vocalize, slap tails and jump out of the water. These gatherings can lead to larger groups with members from three pods that frequent the area. “It’s an amazing behavior,” says Giles. “It gives me chills just thinking about it.”

They speak with an “accent”

Humpback whales are known for their haunting song, but orcas are studied for their accents. Orcas do not actually possess vocal cords, but instead talk through their noses. Using fleshy structures mounted inside the nasal cavity, the creatures can produce an array of squeals, clicks and groans through their blowholes.

In the North Pacific, researchers have found that each pod is marked by a sonic signature or dialect in their calls, which will be similar but not identical to the accents of nearby pods. Giles describes the difference as “like a Valley Girl with the words a valley girl would use, versus an upstate New Yorker.”

The differences between calls become larger, akin to the gaps between human languages, when the pods are more distantly related to each other. Scientists studying orcas suspect that individuals acquire these sounds over the course of their lives from family members and, on occasion, unfamiliar orcas. The animals also show the ability to imitate sounds from other species—including humans. Such complex sounds may be key to how the animals enrich their social lives and coordinate their hunting.