Orcas Target Young Great White Sharks in Gulf of California

In a notable shift in marine predator behavior, orcas from a specialized hunting pod have been observed targeting young great white sharks in the Gulf of California. These orcas, referred to as Moctezuma’s pod, use a sophisticated technique to immobilize their prey by flipping the sharks upside-down, allowing them to consume the nutrient-rich liver. The observations, documented in a study published in Frontiers in Marine Science, suggest that orcas may be hunting great white sharks more frequently than previously understood.

Marine biologist Erick Higuera Rivas, who leads the research at Conexiones Terramar and Pelagic Life, emphasized the intelligence and social learning of orcas. “Orcas that eat elasmobranchs—sharks and rays—could eat a great white shark if they wanted to, anywhere they went looking for one,” he stated. This behavior highlights the advanced hunting strategies that orcas employ, which are transmitted through generations within their pods.

Observations of Successful Hunts

During routine monitoring, scientists were able to document two separate hunts that resulted in the deaths of three juvenile white sharks. The first hunt occurred in August 2020, where five orcas were seen pursuing a juvenile shark. They worked collaboratively to turn it upside down, taking it underwater and emerging with its liver. In a similar hunt in August 2022, another juvenile shark was targeted, demonstrating the orcas’ effective hunting method.

The practice of flipping sharks upside-down induces a state known as tonic immobility, rendering the shark defenseless. As Higuera explained, this technique allows the orcas to access the liver and potentially other organs while discarding the rest of the carcass. “This is the first time we are seeing orcas repeatedly target juvenile white sharks,” noted Dr. Salvador Jorgensen, a co-author of the study. He remarked that while adult white sharks swiftly evade hunting orcas, juveniles may lack the same survival instincts.

Environmental Changes and Future Research

The changing distribution of white sharks in the Pacific Ocean may be contributing to this predation. Climate phenomena, including El Niño, have altered the nursery areas for white sharks, increasing their presence in the Gulf of California. This shift could expose juvenile sharks to predation by Moctezuma’s pod more frequently, as new cohorts may be easier targets.

The scientists plan to conduct a comprehensive survey of the orca population’s diet to ascertain whether they regularly hunt white sharks or primarily focus on juveniles when available. Such research is vital for understanding the ecological dynamics at play, though it is not without challenges. “Dr. Francesca Pancaldi, a co-author from the Instituto Politécnico Nacional Centro Interdisciplinario de Ciencias Marinas, highlighted that gathering data on orca feeding behavior is complex and costly. The unpredictable nature of orca hunts adds an additional layer of difficulty.

The findings underscore the importance of further research into orca feeding behaviors, which could inform conservation strategies and habitat protection measures. Understanding these interactions is crucial for managing human impact on marine ecosystems and preserving the delicate balance within oceanic food chains.