A pod of killer whales in the Gulf of California is believed to have learned a unique set of skills to hunt the world’s largest fish: the whale shark.
Killer whales (Orcinus orca) are known to prey on other marine mammals, turtles and fish. They can grow to about 8m.
But whale sharks can grow up to 18m, and it was thought they might be a bridge too far for one of the ocean’s most accomplished hunters.
However, when whale sharks are younger and smaller they are more vulnerable to predation.
Stories from locals suggest that orcas have been hunting whale sharks. Now scientists believe they have proof which they have published in the journal Frontiers in Marine Science.
“We show how orcas displayed a collaborative hunting technique on whale sharks, characterised by focusing on attacking the pelvic area causing the whale shark to bleed out and allow orcas access to the lipid-rich liver,” says senior author Erick Higuera Rivas, a marine biologist at the non-profit Conexiones TerraMar.
The scientists and members of the public captured images and video between 2018 and 2024 which show orca hunting whale sharks. Getting the footage was not easy as it isn’t possible to predict when attacks will take place.
“One individual was engaged in 3 of the 4 events, alongside with other members who might belong to a pod specialised on hunting on sharks.”
The orca spotted in 3 of the hunts is a male named Moctezuma.
“When hunting, all pod members work together, hitting the whale shark to turn it upside down. In that position the sharks enter a state of tonic immobility and can no longer move voluntarily or escape by going deeper,” Higuera Rivas explains.
“By keeping it under control, the orcas then have greater ease and speed in approaching the pelvic area of the shark and are able to extract organs of nutritional importance for them.”
“It is very impressive how orcas work together strategically and intelligently to access only a very specific area of the prey. It highlights what great predators they are,” adds Higuera Rivas.
This highly specialised hunting style has not been reported in other orca pods, but the scientists say that they cannot rule out that other populations hunt in a similar way.
The scientists say the discovery of this whale shark-hunting pod increases the need to manage marine tourism in the region.
“There must be a specific regulatory norm that guarantees that any type of non-extractive use activity is carried out in a respectful and sustainable manner,” Higuera Rivas says.
The scientists also warn that the orca pod could be vulnerable due to the pressures on whale shark numbers related to climate change.
The Ultramarine project – focussing on research and innovation in our marine environments – is supported by Minderoo Foundation.