In the waters off Baja California, Mexico, a 50-year-old killer whale named Moctezuma has been leading his pod in repeated attacks on whale sharks, the largest fish in the sea.
While isolated reports of such interactions have surfaced in the past, a recent study published in Frontiers in Marine Science reveals that Moctezuma and his pod have executed these coordinated attacks at least four times between 2018 and 2024.
Moctezuma, a massive orca, was present for three of these documented incidents. The fourth attack involved other killer whales known to associate with him.
The attacks primarily target juvenile whale sharks, which measure between 20 to 26 feet long, a size that makes them particularly vulnerable to orca predators.
The orcas’ approach is brutal—ramming the shark from below to flip it over, inducing a catatonic state.
They then bite the shark near its genitals, causing severe bleeding before it spirals lifelessly to the ocean depths.
Moctezuma, a 50-year-old killer whale, demonstrates sophisticated hunting tactics on whale sharks.The motivation behind these attacks is clear: the orcas are after the whale sharks’ nutrient-rich livers. These organs are packed with calories that provide a significant energy source for the orcas.
Dr. Francesca Pancaldi, lead author of the study, suggests that while these attacks are alarming, they do not currently pose a major threat to whale shark populations, which are already endangered due to other environmental pressures like climate change and boat collisions.
Moctezuma’s actions raise intriguing questions about killer whale behavior.
Alisa Schulman-Janiger, a researcher with the California Killer Whale Project, notes that while the coordinated attacks are newly documented, similar events have likely occurred in the past.
Orcas are known for their complex social structures, and mothers and grandmothers play a crucial role in teaching younger generations vital hunting techniques.
It is possible that Moctezuma learned the methods of hunting whale shark livers from a female orca, perhaps even his mother.
As awareness of these attacks grows, it is clear that Moctezuma and his pod’s predatory behavior is a striking example of orca intelligence and adaptability in the wild.