Some orcas have a taste for liver \u2014 specifically, the livers of great white sharks. <\/p>\n
Videos taken by scientists in Mexico reveal how the crafty whales<\/a> manage to snag bites of the apex predators\u2019 fatty organs. <\/p>\n Researchers filmed two orca hunts in the Gulf of California \u2014 one in 2020 and another in 2022. They show the pods attacking young great white sharks by flipping them on their backsides to stun them, then slicing their sides open to extract their livers. The team published the findings of their video studies in the journal Frontiers in Marine Science on Monday. <\/p>\n In one of the videos, all members of the pod share the pink liver fat while the rest of the shark\u2019s body sinks into the ocean\u2019s depths. During the hunt, a sea lion lurks, seemingly trying to sneak away with a free meal. But the orcas blow bubbles, apparently to deter the pest. <\/p>\n Erick Higuera-Rivas, a marine biologist and documentarian who filmed the hunts from a boat nearby, said he didn\u2019t immediately recognize the significance of the footage until he went to edit it.<\/p>\n \u201cI saw in the monitor that the shark had the liver hanging out on the side, already popped off. And a few minutes later, they came up with the liver in their mouth,\u201d said Higuera Rivas, who coauthored the study. \u201cI was surprised that it could be a great white. I was not believing it.\u201d<\/p>\n Heather Bowlby, a research scientist with Fisheries and Oceans Canada who was not involved in the research, said the footage offered a compelling reminder that even top predators must watch their backs. <\/p>\n \u201cWe\u2019re so conditioned to thinking of white sharks as the top of the food chain,\u201d she said. \u201cIt is always amazing to be reminded they are prey.\u201d <\/p>\n Higuera-Rivas and his fellow researchers said the hunts appear to be the work of the same group of orcas, which they\u2019ve named the \u201cMoctezuma pod.\u201d The pod frequents the waters off of Baja California and only hunt elasmobranchs \u2014 sharks and whales. Higuera-Rivas has been following the pod for more than a decade and filming their behavior, and he\u2019s observed how the whiles adapt their behavior to whatever species the group is targeting. <\/p>\n The only prior evidence that orcas hunt great white sharks comes from South Africa, where they have been preying on the sharks for years and extracting their livers, leaving shark carcasses to wash up on the beach. <\/p>\n Alison Towner, a marine biologist at Rhodes University who has studied the phenomenon in South Africa, said the behavior in Mexico is similar but not identical. The orcas in Mexico have been preying upon young sharks, whereas those in South Africa have primarily targeted adults. <\/p>\n The orca groups likely learned the behavior independently, Towner said. <\/p>\n \u201cSeeing this behaviour in Mexico suggests that specific orca groups have developed their own strategies for hunting sharks,\u201d she said via email. \u201cThe same organ is targeted, but the handling technique differs slightly from what we\u2019ve documented in South Africa, which points to group-specific learning.\u201d <\/p>\n The new study shows that the orcas in Mexico have identified a weakness that makes great white sharks vulnerable. <\/p>\n \u201cWhen it flips the shark upside down, it forces the shark to get into the state that is called tonic immobility,\u201d said Francesca Pancaldi, a coauthor of the study and a shark researcher at the Instituto Polit\u00e9cnico Nacional Centro Interdisciplinario de Ciencias Marinas. \u201cThey freeze. It\u2019s like a catatonic state. They just don\u2019t do anything.\u201d <\/p>\n The liver is a fatty and nutritious organ that takes up about one-fourth of a sharks\u2019 body, she added, which provides \u201ca lot of energy.\u201d<\/p>\n Researchers in both South Africa and Mexico agreed that the behavior is not likely new for orcas. Rather, it\u2019s new to scientists, who can now witness and document these hunts more easily because of improvements in drone technology. <\/p>\n \u201cI think it\u2019s been going on for centuries. It\u2019s just that it\u2019s not easy to observe something like this,\u201d Pancaldi said.<\/p>\n It\u2019s possible, though, that changes to the climate have increased the interaction between great white sharks and the Moctezuma pod, she added. <\/p>\n \u201cWe actually are seeing more presence of great white sharks in the Gulf of California in the last 10 years,\u201d Pancaldi said, adding that the species is responsive to changes in ocean temperatures during climate patterns like El Ni\u00f1o. <\/p>\n In South Africa, scientists took notice of orca attacks on great white sharks about a decade ago, Towner said. The attacks sent the sharks fleeing<\/a> from the normal spots where they feed, rest and reproduce, called aggregation grounds. <\/p>\n \u201cIRepeated predation has caused white sharks to abandon former core aggregation sites entirely,\u201d Towner said. \u201cMany sharks have likely moved offshore or into less monitored regions, which reshapes the coastal ecosystem.\u201d <\/p>\n