Orcas are called “killer whales” for a reason. These apex predators are adept pack hunters, using coordinated attacks and specialized techniques to take down their prey.
Scientists recently captured stunning drone footage of a pod of orcas in the Gulf of California killing juvenile great white sharks by flipping them upside down and feasting on their livers. Researchers described the attacks in a new study published Monday in the journal Frontiers in Marine Science.
The video is the work of the study’s lead author, marine biologist and wildlife underwater cinematographer Erick Higuera, and Marco Villegas. Higuera has been filming and studying orcas for more than a decade, but the first time he observed this particular shark-hunting behavior was in August 2020. At first, he couldn’t tell based on the drone footage what species of shark the pod was hunting.
“I thought, ‘Well, it might be a sand tiger shark,’ you know—one of those similar looking sharks. But I never thought that it was going to be a great white,” Higuera told Gizmodo.
Bewildering behavior
While interactions between these two lethal predators are considered rare, scientists have documented orca attacks on great white sharks in South Africa, Australia, and other areas of the California coast. Killer whales target these sharks for their nutrient-rich livers, which can weigh up to 1,300 pounds (600 kilograms), according to Higuera—that’s about a quarter of the shark’s total mass.
Flipping sharks upside down is a common hunting strategy orcas use to induce a state of tonic immobility. The move temporarily paralyzes the shark, preventing it from fighting back. It also gives orcas direct access to their liver.
What’s unique about this pod of orcas in the Gulf of California is that they are targeting juvenile great whites as opposed to adults, study co-author Salvador Jorgensen, a marine ecologist and assistant professor at California State University Monterey Bay, told Gizmodo.
Orcas tend to hunt adult great whites because they offer a bigger reward. “The liver is much larger,” Jorgensen explained. “But what we’re seeing in the Gulf of California is that they’re repeatedly going after small individuals that maybe were born a year or two ago.”
Figuring out what’s driving these orcas to target young great whites instead of adults will require further research, but the authors have some ideas about the advantages this strategy may offer.
Shifting hunting tactics
What juvenile great white sharks lack in liver size they may make up for in ease, according to the researchers. It might just be simpler for a pod of orcas to flip a younger, smaller great white onto its back, enabling an easier kill.
Juvenile great whites may also be more naive than adults. Fully grown great whites have an uncanny ability to sense when orcas are near. “If they even get the tiniest scent or hint of an orca, all of those white sharks will flee from that area,” Jorgensen explained. If that’s a learned behavior, this would suggest that younger sharks are more vulnerable to orca attacks, he said.
“Maybe they don’t have that flight strategy developed yet,” Higuera suggested.
Climatic shifts could be playing a role as well. The increased frequency of El Niño events and marine heat waves in the Pacific Ocean appear to have altered great white shark nursery areas, increasing their presence in the Gulf of California. That shift may have presented this particular pod of orcas with an opportunity, offering up seasonal cohorts of juveniles.
Whatever the case, documenting repeated orca attacks on juvenile great whites for the first time raises many new questions about both species and their interactions. “It’s exciting that in this day in age when we have sensors and cameras everywhere, we’re still finding new stuff,” Jorgensen said. “There’s still mysteries like this in the ocean.”
