Scientists have observed orcas using a high-speed ramming technique to break apart sunfish, a behavior never before formally described.

Researchers in the Gulf of California have documented a previously unreported hunting behavior where orcas use high-speed collisions to fragment sunfish carcasses. The behavior, which involves one orca holding the prey while another strikes it, was recorded during two separate incidents occurring over a year apart. Scientists suggest the technique may aid in feeding younger orcas or serve a social function.

Documenting the Ramming Technique

The behavior was first observed in July 2024 when a group of orcas, including a juvenile, interacted with a dead sharp-tail sunfish. A female orca gripped the fish by its tail fin to hold it steady, while a male charged at high speed, striking the carcass just as the female released it. The impact caused the sunfish tissue to disintegrate into fragments, which the juvenile then consumed. A second, similar incident was filmed by Héctor Franz in September 2025, following the same sequence of holding, releasing, and ramming.

Potential Benefits and Biological Impact

Researchers believe this ramming strategy may help process prey, making it easier for calves and juveniles to feed. Beyond nutritional access, the fragmentation of the sunfish releases its unique skin and capsule microbiome into the water. Scientists hypothesize that this exposure could offer nutritional or immune-related benefits to the orcas. While the behavior facilitates feeding, researchers also note that the interactions could serve a social function or represent a form of play, as orcas are known to play with their food.

Species-Specific Observations

The fragmentation behavior has so far only been recorded with sharp-tail sunfish. Researchers suggest that the tissue of this specific species may respond to high-impact collisions in a unique way, whereas larger sunfish species might not break apart as easily. Because the sunfish in both observed cases were already dead, the researchers concluded that the ramming was used to process the prey rather than to kill it. Further research is required to determine if the same orcas were involved in both events, as identifying individuals requires clearer footage of dorsal fins and eye patches.