Researchers for the first time have documented orcas cooperating to smash their prey. Both instances were captured on video.
It’s like Lucy holding a football for Charlie Brown in the classic comic strip Peanuts – except they’re killer whales, and they obliterate the ball.
Scientists have now documented two instances of orcas ramming into prey so hard that it explodes into little fishy pieces, a new behaviour for a species known for smashing into human boats and playing with its food. In both cases, which were captured on video, one orca holds the prey in place as another orca hurls its full body at it, nose-first. There’s a wet crash, and then it begins to rain fish parts as the orcas happily swim around.
“Orcas are known to selectively dismantle prey,” Erick Higuera, one of the authors of the paper published Thursday in the peer-reviewed journal Frontiers in Ethology, said in an interview. “Exploding large vertebrae into thousands of fragments through kinetic impact alone is entirely unique.”
The targets of this aggressive predation are sharp-tail sunfish, a fat but bony species that orcas have been known to prey on in the past. They can be 90cm to 1.8m in length and weigh around 90kg, with peculiarly shaped bodies that give them the appearance of an oversize swimming bullet. Sunfish are slow-moving plankton eaters that come to the surface waters to rest and remove parasites. There, they can be vulnerable to orca attacks.
One of the species’ defences is a gelatinous, dense surface layer that is difficult to pierce. By ramming the sunfish, the orcas can break up the carcass into more manageable pieces.
In the new paper, researchers argue that the orca behaviour could be a hunting strategy, or just a way of being playful with their young – much like the orcas that have been spotted ramming boats in Spain and Portugal for fun. In one of the incidents involving sunfish, in July 2024, nearby young orcas were seen snacking on the floating fragments of sunfish as the adults consumed the rest of the carcass.
“Adult females use these events as crucial teaching tools,” Higuera said. “It is a primary mechanism for practising complex motor skills, strengthening team coordination.”
Killer whales are highly social animals that have been spotted playing with stinging jellyfish and grooming each other with pieces of kelp. And they have exhibited their sometimes-grisly hunting habits with sharp-tail sunfish and their relatives before.
In 2023, researchers documented several instances of orcas that hunted sunfish by boring a wound in the sides of their prey and then eating their fatty organs while the fish were still alive. In some cases, they would insert their noses inside the fish to keep feeding. Orcas have also been observed carrying around chunks of sunfish flesh after feeding.
The orcas described in the new paper were observed holding the sunfish, likely already dead, by their rudder-like “tails” at the backs of their bodies. One of the sunfish was spotted with a large wound, indicating that the orcas had already had a few bites.
The two sightings occurred in the Gulf of California near Mexico, one by a researcher and one captured on social media. Orcas in that area have also been spotted hunting young great white sharks, eating their livers and fatty organs.
Like humans passing down recipes over the years, it’s been shown that orcas can sustain hunting traditions over generations. Higuera said that, as a result, it is possible that this ramming behaviour is unique to the regions where they have been observed. He cautioned, however, that more study of orca hunting in other areas was needed.
“Because this extreme fragmentation has not been documented in sunfish predations elsewhere, it is likely a culturally learned tradition unique to these specific parts,” he said.
Sign up to Herald Premium Editor’s Picks, delivered straight to your inbox every Friday. Editor-in-Chief Murray Kirkness picks the week’s best features, interviews and investigations. Sign up for Herald Premium here.