Killer whales are well known for inventive and sometimes brutal hunting strategies, from punting seals into the air to washing penguins off ice floes. But a newly documented phenomenon shifts the focus from live prey manipulation to the dramatic destruction of massive marine animals. According to findings published on July 23 in Frontiers in Ethology, scientists observed orcas targeting the dead carcasses of sharp-tail sunfish in a manner that leaves researchers both astonished and eager to understand the underlying motives.
Coordinated Ramming Mechanics Off the Baja Coast
The documented events took place in the Gulf of California—also referred to as the Sea of Cortez—off the coast of Mexico’s Baja California around San Jose del Cabo. In the observed instances, one adult orca grasped the backside of a sunfish by its tail to hold the massive creature completely steady in the water, while an adult male orca accelerated at high speed to slam directly into the fish. Study coauthor Kathryn Ayres took this video with a GoPro off the coast of San Jose del Cabo on July 29, 2024. The female lets go right before the male smashes into the fish, exploding its flesh into smithereens.
The physical impact was extreme against the sharptail sunfish, scientifically known as Masturus lanceolatus, which is one of the world’s largest fish. These animals can grow up to a few meters long and weigh 2,000kg. Because of their flattened bodies, these giant molas are particularly unusual in large fish and could make them more likely to fly apart after a high-speed impact, as Ayres suggested.
I was absolutely gobsmacked
by this behavior, says Marianne Nyegaard, a marine biologist at Auckland Museum in New Zealand who was not involved in the work. She had seen a couple videos of orcas battering sunfish on social media before the new paper did a deep dive on this phenomenon. I thought it was the coolest thing I had ever seen,
she says. Nyegaard is not necessarily surprised that orcas have come up with such a creative strategy, noting, Orcas will do all sorts of things. They are so clever at figuring out how to hunt and deal with a ton of different prey types.
That hunting is often a team sport, as when orcas band together to ambush blue whales or collectively make waves to knock penguins off ice.
Diver and marine scientist Kathryn Ayres captured underwater footage of the event, though her paper on the event has just appeared in the journal Frontiers in Ethology. The cooperative ramming behavior wasn’t entirely new to me, as I had previously observed similar coordinated ramming during a hunt involving a whale shark,
she told CNN.
Nutritional Benefits and Social Learning for Young Pod Members
Scientists examining the explosions point to several potential drivers behind the behavior, ranging from nutritional efficiency to sheer playfulness. Sharptail sunfish offer a massive amount of potential meat, even for a killer whale.
Orcas most likely annihilate sunfish this way to help feed their young, says Francesca Pancaldi, a marine biologist not involved in the work. After one of the sunfish explosions reported in the paper, she notes, a young orca began feeding on the small bits of carnage. But that may not be the only reason for this practice, adds Pancaldi, of the marine science center in La Paz associated with Mexico’s Instituto Politécnico Nacional.
“Killer whales are highly social animals, and a behavior can simultaneously provide nutritional benefits, reinforce social bonds and serve as an opportunity for younger individuals to learn hunting techniques.”
Francesca Pancaldi, marine biologist
Beyond feeding the young, the cooperation between the two orcas could strengthen social bonding within the pod, or serve as a vigorous form of play since orcas have been known to play with their food.
Play, Tradition, and the Versatility of Killer Whale Hunting
Marine biologists emphasize that killer whales possess exceptional cognitive flexibility when handling diverse prey. Whether the destruction of the sunfish carcass began as a bizarre form of play or a way to turn a large prey fish into instant chum for convenient nibbling, it highlights the capacity of orcas to invent strategies.
Researchers observing the Gulf of California events noted that orcas have been known to slap around stingrays, punt seals into the air and otherwise play with their food. Whether viewed as an elaborate game or a calculated method for generating a cloud of sunfish morsels for the young whales to feed on, the behavior underscores the adaptable and highly cooperative nature of killer whale societies.