Killer whales have been behaving pretty strangely over the last few years – from devouring dolphins to sinking ships. Now, new research reveals they’ve also developed a gruesome killing tactic so that they can feast on the livers of young great white sharks.
It’s not easy to take down the world’s scariest fish, but a pod of killer whales, also known as orcas, in the Gulf of California have learned how to do it. Working together, they flip the shark upside down – a move that paralyses it – before tearing out its energy-rich liver to share.
What’s more, they’ve been caught on camera doing it.
Is this sort of grisly murder normal for killer whales? Yes, Prof Callum Roberts, marine biologist at the University of Exeter, who was not involved in the study, told BBC Science Focus.
“Orcas may be the most intelligent of all marine creatures, judging by their endless creativity in catching prey. In the distant past, they targeted whales caught by industrial whaling vessels and ate their tongues.”
While incidences of killer whales eating adult great whites have been recorded in recent years, these new observations are the first evidence of repeated targeting with precise hunting techniques.
The team of researchers behind the study were observing a pod of orcas when they saw them kill not one but two great whites in August 2020, then witnessed another pod devour a third in 2022.
By pushing the sharks to the surface and turning them upside down, the killer whales induce a state of ‘tonic immobility’ in the sharks, which is caused by the rapid change in their surroundings. In this defenceless state, the killer whales can take whatever they want from its body and leave the rest behind.
The young sharks don’t have the experience to know to flee a pod when they see it coming. But the researchers behind the new study, published in Frontiers in Marine Science, say this suggests killer whales may hunt great white sharks more often than we realised.
“I believe that orcas that eat elasmobranchs – sharks and rays – could eat a great white shark, if they wanted to, anywhere they went looking for one,” said lead author Erick Higuera Rivas.
“This behaviour is a testament to orcas’ advanced intelligence, strategic thinking, and sophisticated social learning, as the hunting techniques are passed down through generations within their pods.”
Climate change may also be playing a key role. El Niño, a natural phenomenon of warming in the Pacific Ocean, is getting more intense – and one of the impacts is that great white shark nursery areas are widening into orca territory. These areas are filled with inexperienced, young sharks – easy pickings for killer whales.
But experts are concerned that this new behaviour could be bad news for shark species.
“What is good for Orcas is not good for sharks, both of which are threatened species,” said Roberts. “Let’s hope they don’t pass on their hunting tips too widely.”
About our expert
Callum Roberts is a professor of marine conservation at the University of Exeter. He was the chief scientific advisor for the BBC One series Blue Planet II, and has written several books, including Ocean of Life: How our Seas are Changing (Penguin Books, £22) and Reef Life (Profile Books, £12.99).
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