Killer whales near the Iberian peninsula are colliding with, and sinking, boats.
Researchers think they may be imitating the behavior of a single female named White Gladis.
It's possible White Gladis was triggered after being hit by a boat, or that the behavior is playful.
Killer whales are targeting boats near Spain and Portugal, and researchers say it may be because they are imitating the behavior of one specific orca.
The concerning encounters between boats and the orca population off the Iberian Peninsula began in 2020.
Three years later, researchers have documented hundreds of incidents in which an orca directly approached or collided with a boat. In these encounters, the orcas' behavior generally follows the same pattern: approaching the back of the ship and hitting the rudder until successfully causing the boat to stop.
Most of the interactions have caused minimal damage, but in three separate cases, the whales have caused sailboats to sink.
The behavior may trace back to a single female killer whale named White Gladis.
Alfredo López Fernandez, a biologist at the University of Aveiro in Portugal who is studying the orcas, told LiveScience that one leading theory for why this is happening is that White Gladis experienced a "critical moment of agony," perhaps by colliding with a boat, and then took to assaulting them.
"That traumatized orca is the one that started this behavior of physical contact with the boat," López Fernandez said.
The orcas might be trying to play
Killer whales are highly intelligent, social creatures, and are known to learn and pick up behaviors from each other, intentionally or not. It's clear to researchers that the behavior is spreading, and that an increasing number of orcas in this specific population are participating.
"We do not interpret that the orcas are teaching the young, although the behavior has spread to the young vertically, simply by imitation, and later horizontally among them, because they consider it something important in their lives," López Fernandez told LiveScience.
Another expert told Insider that the behavior may indeed be the result of imitation, but perhaps with a different intent: play.
Andrew Trites, director of the Marine Mammal Research Unit at the University of British Columbia in Canada, said he thought it may not be accurate to say the orcas are "attacking" the boats, even if it feels that way to the people sailing in them.
"They're very tactile. They have a sense of touch," Trites said of orcas, explaining that they are known to rake their teeth over the body of another killer whale, as well as rub and bump into each other. He thinks the interactions with boats are likely a "playful activity that's gotten way out of hand."
If White Gladis was indeed struck by a boat and traumatized, he thinks if anything she would go out of her way to avoid colliding with one again, rather than ram into them. He also said the fact that other orcas are mimicking and adopting the behavior suggests they are benefitting from it or gaining pleasure from it, which also indicates play.
The behavior is unlikely to spread to other orca populations
Even if all the orcas in the Iberian population, around 39 at last count, end up imitating and adopting this behavior, it's unlikely it will spread to killer whales elsewhere, such as populations around North America.
"There's very little chance of them learning from the group in Spain and Portugal, in part because the different ecotypes of killer whales around the world don't interact with each other. They keep apart," Trites said, noting that orca populations represent different ecotypes that eat different foods and display different behaviors.
The three ecotypes found in British Columbia, for instance, don't socialize. "They're not hanging out, swapping stories," he said.
But if more and more orcas of the Iberian population continue to clash with boats, it could eventually result in serious injury or death to a person or a whale.
Or, Trites said, the killer whales might just get bored with the boats and stop taking part.
Read the original article on Business Insider