Orcas gang up against great white sharks to eat their livers

Orcas in the Gulf of California hunt young great white sharks using a clever tactic: turning them upside down to immobilize them. The discovery suggests there may be a previously unrecognized group orcas in a region that specializes in shark hunting.

Only a few populations of orcas are known feed on sharksand even fewer have been found to eat the great white (Carcharodon carcharias). For example, orcas (Orcinus orca) off the coast of San Francisco they were the killing of a great white in 1997 was documentedand a great white carcass near Australia showed signs of an orca attack in 2023. But until recently, there was only one known case, recorded in South Africa, of animals hunting young great white sharks.

Jesus Erick Higuera-Rivasan independent marine biologist from Mexico, and his colleagues recorded videos of orcas in the Gulf of California hunting young great white sharks on two separate occasions. The first, taken in August 2020, showed five females orcas working together to push the young great white to the surface. “The orcas rammed the great white to turn it upside down,” says Higuera-Rivas.

This maneuver forced the shark into a state of temporary paralysis, called tonic immobility. It also enabled orcas in order to get hold of the energy-rich shark liver that they shared among themselves. A few minutes later, the pod repeated its attack on another adolescent great white. In August 2022, the research team filmed another group of five orcas using the same technique to hunt a young great white around the same location at the same time of year.

Researchers identified some of the orcas in the first incident as those previously observed hunting cetaceans and bull sharks. The footage of the second incident was not clear enough to determine whether these orcas belonged to the same pod. “But it’s very possible,” says Higuera-Rivas.

Orca populations vary drastically depending on where they are found. “Orcas are hunting machines. They are like snipers – they use specific hunting strategies, very specific depending on their prey,” says Higuera-Rivas. These findings suggest that orcas belong to a previously unrecognized group that eats sharks, he says.

“So now we have an example of another unique feeding strategy that probably isn’t shared by any other group [orcas] in the world,” he says Andrew Trites at the University of British Columbia in Canada. However, more research is needed to know for sure, since orcas could be an offshoot of those from the Pacific Northwest that prey on other shark species, he says.