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The orca, or killer whale, is one of the ocean’s most feared creatures. They are highly intelligent and capable of unusual hunting techniques. Their normal diet consists of smaller fish, marine mammals, turtles and even sea birds. However, a pod of Mexican orcas has added young whale sharks to their menu.

Researchers have observed orcas launching themselves at juvenile whale sharks in the waters around the southern part of the Gulf of California. These orcas hunt in packs, and scientists suspect that there is one pod of orcas that is responsible for all four known whale shark attacks that have taken place in the last six years (from 2018 to 2024). A large male orca, named “Moctezuma” by Mexican scientists, has been sighted during three of the four attacks. Also, the female orcas responsible for the fourth attack have previously been spotted swimming with Moctezuma.

Whale sharks have the potential to grow up to 20 metres in length, so how are these much smaller orcas (approximately only 10 metres long) attacking them? The answer is simpler than you think – group work and critical thinking! The orcas work diligently as a team to ram the younger whale sharks and flip them over. Driven by fear, the whale shark then enters a stage of paralysis or “tonic immobility” where they cannot move or dive into deeper waters to escape.

Francesa Pancaldi, a marine biologist, described the whale shark as a huge animal with tiny teeth. He says, “It’s relatively slow compared to other sharks and it cannot defend itself, other than dive down. The whale shark is a great diver.”

The orcas focus on attacking the vulnerable pelvic area, which causes the whale shark to bleed out, and gives the orcas access to the fatty liver. Erick Higuera Rivas, another marine biologist, says, “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.”

Scientists cannot say for sure if this ability to successfully hunt down the whale sharks is limited to this specific Mexican pod or if it is spreading to the wider orca population.

What is causing these orcas to hunt these newer, larger prey – Is it evolution? Is it adaptation? Is it simply the orca’s answer to the disruption in their food supply bought upon by climate change?

Oas Kulkarni was an outstanding participant in Double Helix’s Young STEM Journalism Bootcamp. This year, Double Helix partnered with Letterly to launch the inaugural 4-week program, inviting students aged 8 to 18 to write science news articles on the topics that matter to them! This article went through multiple rounds of editing with 1-to-1 feedback from Letterly’s highly qualified and passionate writing coaches. Double Helix editors provided a final edit for accuracy and style.