There have been numerous accounts in recent years of orcas ramming boats—and sometimes sinking them. Scientists believe this may be a form of culturally learned behavior passed down through generations. Now we have fresh examples: orcas in the Gulf of California were filmed teaming up to ram sunfish with so much force that the carcasses exploded into small fragments. While orcas have been known to use force to remove flesh from prey, this is something different, according to a new paper published in the journal Frontiers in Ethology.
“We think this may help younger orcas feed more easily, or it could also just be for fun,” said co-author Kathryn Ayres of Beneath The Waves, a nonprofit organization promoting ocean health. “Orcas are known for playing with their food.”
Orcas engage in cooperative hunting strategies that can involve striking or killing animals—sometimes eating their prey, sometimes not—so the behavior could be described as social interaction, play, or practice as a mode of social learning. Orcas have been observed ramming whale sharks as another orca held the prey steady. Other cooperative strategies include herding mobile rays, blocking an escape path while hunting white sharks, and deliberately producing waves to bump penguins off ice floes.
When hunting species like sunfish, orcas typically rely on a three-pronged strategy. First, an orca will target the pectoral fins, then slash the sunfish across its body to remove the viscera. After that, the orca will use its beak to get at the remaining tissue. The newly observed “ram-to-fragment” behavior might represent a more sophisticated version of that basic strategy.
Play with your food
The first instance occurred in July 2024 off the coast of San Jose del Cabo in Mexico. A tourism operator filmed three adult female orcas, one male, and one juvenile catching and eating a spine-tail devil ray. Just after, the same operator filmed one of the adult females holding the carcass of a sunfish in her mouth. The sunfish had a large lateral wound, so the viscera had likely already been removed. The male orca then charged at the carcass, with the female releasing it just before impact. There was an audible sound upon impact as the carcass fragmented and bits of flesh dispersed in the water. The juvenile orca proceeded to eat the smaller fragments while the adults fed on what remained of the split-open body.
