In a groundbreaking discovery, marine biologists have documented orcas in Mexico’s Gulf of California hunting juvenile great white sharks, using drone footage that shows the killer whales flipping the sharks to immobilize them before extracting and consuming their livers. This behavior, recorded on multiple occasions, highlights the orcas’ sophisticated hunting strategies and could have significant implications for shark populations.
The research, published in the journal Frontiers in Marine Science, details three predation events observed in August 2020 and August 2022. A pod of five female orcas was filmed working together to attack young great white sharks, demonstrating coordinated efforts to subdue their prey. In each instance, the orcas pushed the sharks to the surface and turned them upside down, inducing a state of tonic immobility that left the sharks defenseless. This method allows the orcas to avoid bites and efficiently access the sharks’ organs.
Tonic immobility is a natural response in sharks when flipped over, causing temporary paralysis and altering their awareness. This technique enables the orcas to safely extract the nutrient-rich livers, which are high in energy and oils, before abandoning the rest of the carcass. The selective feeding on livers suggests a learned behavior that is passed down through generations within orca pods, reflecting their advanced intelligence and social learning.
This marks the first time such hunting behavior has been documented in Mexican waters, although similar incidents have been recorded in regions like South Africa and Australia. The consistency across locations indicates that certain orca groups have developed specialized skills for hunting sharks. Researchers identified that some of these orcas were previously known to hunt other shark species, such as whale sharks and bull sharks, underscoring their adaptability.
Erick Higuera, the lead researcher and a marine biologist, expressed surprise at the repeated attacks in the same area over different years, suggesting that juvenile great white sharks may be becoming a regular seasonal prey target. This could represent an additional pressure on white shark populations, which are already facing threats from overfishing and habitat loss. The study emphasizes the need for further monitoring to understand the full impact.
Alison Towner, a marine biologist from Rhodes University not involved in the study, highlighted the invaluable role of drone footage in advancing our understanding of these interactions. She noted that comparing behaviors across different orca groups and shark populations helps reveal cultural transmission within pods. The hunting technique is not widespread but specific to certain groups that have learned and refined it over time.
The findings raise concerns about potential long-term effects on great white shark numbers, particularly as juvenile sharks may be naive to orca threats compared to adults, which have been observed fleeing areas where orcas are present. This dynamic could shift predator-prey relationships in the Gulf of California, affecting marine ecosystem balance. Overall, the research underscores the importance of conservation efforts to protect critical habitats for both species and ensure ecological stability.