Videos show killer whales hunting great white sharks and eating their livers
Some killer whales have a taste for liver, specifically the liver of great white sharks.
Videos captured by scientists in Mexico reveal how skilled whales manage to bite off the fatty organs of predators.
Researchers filmed two killer whale hunts in the Gulf of California — one in 2020 and one in 2022. They show pods attacking young great white sharks by flipping them onto their backs to stun them, then opening their sides to extract their livers. The team published the results of their video studies in the journal Frontiers in Marine Science on Monday.
In one video, all members of the pod share pink liver fat while the rest of the shark’s body dives into the depths of the ocean. While hunting, a sea lion lurks, seemingly trying to sneak away with a free meal. But killer whales blow bubbles, apparently to deter the pest.
Eric Higuera Rivas, a marine biologist and documentarian who filmed the fishing from a nearby boat, said he did not immediately realize the significance of the footage until he went to edit it.
“I saw on the screen that the shark’s liver was hanging off the side, and it had already exploded,” said Higuera Rivas, who co-authored the study. “After a few minutes, they found the liver in their mouth.” “I was surprised that he could be a great white. I couldn’t believe it.”
Heather Bowlby, a research scientist with Fisheries and Oceans Canada who was not involved in the research, said the footage serves as a compelling reminder that even top predators should watch their backs.
“We’re used to thinking of white sharks as the top of the food chain,” she said. “It’s always amazing to be reminded that they are prey.”
Higuera Rivas and his fellow researchers said the hunts appeared to be the work of the same group of killer whales, which they named the “pod of Moctezuma.” The pod frequents the waters off Baja California and hunts only sharks and whales. Higuera Rivas has been following the group for more than a decade and photographing its behavior, and he has noticed how this group adapts its behavior to whatever species the group is targeting.
The only previous evidence of killer whales hunting great white sharks comes from South Africa, where they have been preying on sharks for years, extracting their livers, and leaving the shark carcasses to wash up on shore.
The behavior in Mexico is similar but not identical, said Alison Towner, a marine biologist at Rhodes University who has studied the phenomenon in South Africa. Killer whales in Mexico preyed on young sharks, while those in South Africa primarily targeted adults.
Towner said it’s likely that the orca groups learned the behavior independently.
“Seeing this behavior in Mexico suggests that certain groups of killer whales have developed their own strategies for hunting sharks,” she said via email. “The same organ is targeted, but the handling technique is slightly different from what we documented in South Africa, which suggests group-specific learning.”
The new study shows that killer whales in Mexico have identified a vulnerability that makes great white sharks vulnerable.
“When you turn the shark upside down, it forces the shark into a state called tonic immobility,” said Francesca Pancaldi, a co-author of the study and a shark researcher at the Instituto Nacional Politécnico Nacional Central de Ciencia Marinas. “They freeze. It’s like a stalemate. They’re not doing anything.”
She added that the liver is a fatty and nutritious organ that occupies about a quarter of the shark’s body, and provides “a lot of energy.”
Researchers in both South Africa and Mexico agreed that this behavior is likely not new for killer whales. It’s even new to scientists, who can now view and document these hunts more easily due to improvements in drone technology.
“I think this has been going on for centuries,” Pancaldi said. “But it is not easy to notice something like this.”
She added that it is possible that changes in climate have increased the interaction between great white sharks and Moctezoma pods.
“We’re actually seeing more great white sharks in the Gulf of California in the last 10 years,” Pancaldi said, adding that the species responds to changes in ocean temperatures during weather patterns like El Niño.
Scientists in South Africa have observed orca attacks on great white sharks about a decade ago, Towner said. Attacks The sharks were sent fleeing One of the natural places where they feed, rest and reproduce, which are called gathering areas.
“Repeated predation by white sharks has caused former primary aggregation sites to be completely abandoned,” Towner said. “It is likely that many sharks have moved offshore or to less monitored areas, reshaping the coastal ecosystem.”
After the sharks left their resting places, the numbers of fur seals and sevengill sharks increased. This subsequently caused the species’ main prey – such as small fish and small sharks – to collapse, according to the British Daily Mail. Research published in Frontiers in Marine Science Earlier this year.
Towner said just two adult male orcas, named Port and Starboard, were behind repeated attacks on white sharks in South Africa. She said that the attacks put pressure on great white sharks, which are characterized by slow growth and reproduction, and this could happen in Mexico as well, if this behavior becomes more frequent.