Scientists finally know the clever tricks orca use to hunt whale sharks

Views: 3618

For the first time, scientists have captured video evidence of orcas cooperatively hunting whale sharks, the largest species of fish on Earth. This graphic footage proves that whale sharks are a regular part of some orcas’ diets, and solves the mystery of how they are able to kill the massive fish.

On May 26, shark ecologist Kathryn Ayres was guiding tourists on an ocean safari near La Paz, Mexico when she saw a pod of orcas circling. “I knew some poor animal was being tormented,” Ayres said. “They like to play with their food.”

Along with photographer Kelsey Williamson , Ayres jumped in the water with her camera just in time to document five orcas taking down a juvenile 16-foot-long whale shark. Their video, published today in Frontiers in Marine Science shows the behavior in unprecedented detail.

Before now, only one other scientific report documented orcas eating a whale shark, videoed by sport fisherman further south in Mexico, but it didn’t detail the full predation sequence. Along with Ayres’s footage from this spring, the new research includes photos and videos of three other instances of orcas preying on these massive fish in Mexico’s Gulf of California. The first event in 2018 was caught on camera by a group of tourists planning to snorkel with sea lions on a rocky island north of La Paz. (They stayed in their boat once the attack began.) The second and third events were also captured by tourists in 2021 and 2023.

Now, with all these conclusive photos and videos, scientists can fully describe how the orcas take down the huge prey.

Sequence of killer whale attack on whale shark on 26 May 2024. Two of the killer whales brought the whale shark to the surface.

How orcas team up to hunt a whale shark

First, the orcas repeatedly ram a slow-swimming whale shark to stun it. When the fish loses its equilibrium, the orcas work together to flip it upside down to expose its unprotected belly. “You could hear the crunch of the final blow,” Ayres recalls, which incapacitated the shark. Next, the orcas bite off the whale shark’s pelvic fins, causing it to bleed to death. Then, they eat the fish’s organs, including its enormous fatty liver. It’s gruesome, and effective. Even birds capitalized … Read More