- A group of orcas off the coast of California has honed a brutal set of hunting skills.
- Trapping prey near an underwater canyon, they flip, drown, ram, and slap their targets to death.
- Killer whales are apex predators; their behavior can reshape ecosystems the fishing industry.
There's no shortage of awe when it comes to killer whales. The mysterious apex predators are continually shocking scientists with their ability to figure out creative new ways to kill their prey and shape their environment.
A new study tracking a pod of 183 killer whales off the coast of California is no exception.
These orcas found the perfect stage for an underwater ambush: a canyon in open water with steep walls, which they used to trap unsuspecting marine mammals.
"That was one of the most surprising parts of the study," Josh McInnes, a marine biologist at the University of British Columbia in Canada and an author of the study, told New Scientist.
Orcas patrolling the canyon were seen honing in on gray whale mother-and-child pairs, trapping them against the canyon walls and chasing them until the calves became exhausted.
The killer whales would then separate the calves from their mothers by body-blocking the parent and dragging the child toward open water.
There, the orcas could call reinforcements to ram the calves with their noses, flip them in the air, or slam them with their tails. Per the study, the killer whales would often finish the calves off by jumping on top of their blowholes, pinning them underwater long enough to drown.
The ordeal lasted between 1-and-a-half and 5 hours, after which the orcas would take turns feeding off the unfortunate calves' carcasses.
The behavior is "very unique, especially for this area at least," McInnes said, per New Scientist.
"We're constantly learning about killer whales. Every study that comes out is extremely valuable for our understanding of their ecology as well as their conservation needs," said McInnes.
It's not just the whales that fell prey to the orcas. Between 2006 and 2021, the scientists found that elephant seals, minke whales, and dolphins were often on the menu, per the study.
The findings were published in the peer-reviewed journal PLoS ONE on Wednesday.
Orca-hunting behaviors aren't just cool
Learning about these animals' fascinating behaviors doesn't only satisfy scientific curiosity. It's crucial to understanding the complex puzzle shaping marine ecosystems.
Previous studies have shown that even a few orcas picking up a new hunting behavior can entirely reshape the local food chain.
That was the case, for instance, of two orcas off the coast of South Africa that chased away all the great white sharks from the Gansbaai coast. The big fish were scared off when the killer whales learned how to suck out their prey's livers with almost surgical precision — while the fish were still alive.
In the great whites' absence, lower-level predators started rising toward the top of the food chain, reshaping the local ecosystem, scientists later found.
Experts are now keeping a close eye on this unique event as the great whites are relocating. This could have cascading effects on the local fishing and tourism industries, scientists have said.
"Over two decades of annual visits to South Africa, I've observed the profound impact these killer whales have on the local white shark population," Primo Micarelli, a marine biologist who studies the orcas in South Africa, told CNN, Business Insider previously reported.
"Despite my awe for these predators, I'm increasingly concerned about the coastal marine ecology balance," he added.
It's not just the orcas' predation on wildlife that can have knock-on effects.
Portugal last year had to ban whale-watching after local killer whales took to ramming leisure boats, leaving some ships irreparably damaged.
The orcas' extreme influence on local ecosystems could also be a powerful argument to push for their protection.
Better understanding their ways helps scientists forge tactics to protect orcas from human threats, such as disturbance from shipping traffic and noise, entanglement in fishing gear, and oil spills