Killer whales have declared war on the world's largest sharks as they train themselves in deadly new skills to kill sea monsters.
Killer whales in the Gulf of California have been spotted hunting whale sharks to kill them in “coordinated” attacks.
Experts believe the giant predators may have acquired “special” knowledge to allow them to hunt in a way never seen before in their species.
Whale sharks feed in locations in the Gulf of California, off Mexico, sometimes when they are young and smaller.
Scientists say that, at this stage of life, they are more vulnerable to attack by predators.
Now, researchers in Mexico have reported four separate incidents of killer whales — which grow up to 59 feet long — hunting young whale sharks for the first time.
Marine biologist Eric Higuera Rivas was lead author of the report published in the journal Frontiers in Marine Science.
He said: “We show how killer whales displayed a cooperative hunting technique on whale sharks, characterized by a focus on attacking the pelvic region, causing the whale shark to bleed and allowing the orcas to access the fatty liver.
“One individual was involved in three of the four events, along with other members who may belong to a group specializing in shark hunting.”
The attacks occurred between 2018 and this year in the southern Gulf of California and were captured in photos and videos taken by members of the public and scientists.
Individual killer whales were identified by analyzing images of their dorsal and distinctive fins Features Like scars.
A male orca named Moctezuma was present at three of the four hunts.
The female orcas previously observed with Moctezoma also participated in one hunt, suggesting that they may be related or members of the same group.
“When fishing, everyone in the group works together and hits the whale shark and turns it upside down,” Higuera Rivas said.
“In this situation the sharks enter a state of immobility and are no longer able to move voluntarily or escape by going deeper.
“By keeping them under control, killer whales have greater ease and speed of approaching the shark's pelvic area and are able to extract organs that are nutritionally important to them.”
The research team says killer whales may target the ventral side of whale sharks because their bodies are thought to be the least protected. For example, there is less muscle and cartilage in that area, allowing easier access to the aorta.
They believe that hunting in this way may mean that some killer whales in the Gulf of California have acquired “special skills” that help them prey on whale sharks.
Other killer whales may have learned to do the same thing in other areas, but the evidence is limited, the researchers said.
The fact that there is a place for whale shark fishing in the Gulf of California increases the need for management for marine adventurers and tourists, says Higuera Rivas.
“There must be a specific regulatory base that ensures that any type of non-extractive use activity is carried out in a respectful and sustainable way,” he said.
Higuera Rivas believes that if the theory that Moctezuma and his group obtained ecological and behavioral information to hunt whale sharks in the Gulf of California holds true, the pod may be “vulnerable” to the potential disappearance of the identified prey due to climate change.
He added: “It is very impressive how killer whales work together strategically and intelligently to reach only a very specific area of prey.
“It highlights the great predators that they are.”