A pod of orcas has reportedly developed specialized skills to hunt the whale shark, the largest fish in the world, based on predation events observed in the southern Gulf of California from 2018 to 2024.
Coordinated attacks and behaviors of the orca pod are detailed in a study co-authored by Mexican and American researchers published in Frontiers in Marine Science.
The team documented four such hunting events, showcasing a collaborative hunting technique that focuses on attacking the whale shark's pelvic area.
Marine biologist Erick Higueras, lead author of the study, expressed amazement at how orcas strategically work together to target a specific area of their prey, highlighting their prowess as apex predators.
Researchers believe this pod may have acquired specialized knowledge that enables them to hunt the world’s largest fish, which can reach lengths of up to 18 meters.
Whale sharks feed in concentrated areas of the Gulf of California, sometimes when they are still young, and anecdotal evidence suggests orcas may be hunting them.
However, the four cases described are distinct, as all members worked cooperatively and may belong to a specialized pod for hunting whale sharks.
In three of the four hunting events, a male orca named Moctezuma was present. Additionally, a female previously observed with him also participated in one case, suggesting they may be related or part of the same pod.
When hunting, all pod members collaborate to flip the whale shark upside down, inducing tonic immobility, where the shark cannot move voluntarily, making it easier for the orcas to approach the pelvic area and extract nutritionally important organs.
The orcas likely target the ventral area as it is believed to be the least protected part of the shark's body, allowing easier access to vital organs.
While whale shark livers are a significant part of orca diets, there have been no documented instances of them consuming this organ.
This hunting behavior suggests that some orcas in the Gulf of California have developed unique skills for hunting whale sharks. Evidence from other regions is limited, but the possibility exists that similar behaviors could have been learned elsewhere.
The predation events were captured through images and videos, with individual orcas identified using dorsal fin photographs and distinctive features like scars.
Collecting the necessary data was challenging for scientists, as attacks are unpredictable, access to images and videos can be limited, and the quality of images is often too low for reliable identification.
The existence of a whale shark hunting pod in the Gulf of California underscores the need for monitoring marine adventurers and tourists. Higueras emphasized the importance of regulatory norms to ensure that any non-extractive activities are conducted respectfully and sustainably.
Furthermore, if the hypothesis holds that Moctezuma and his pod have gained ecological and behavioral knowledge for hunting whale sharks in the Gulf, they may be vulnerable to potential declines in this specific prey due to climate change in the region.
Ultimately, the new findings regarding these orcas help researchers better understand their unique adaptations to their ecological needs and geographical location.