Killer whales teach their mates to sink boats.

Scientists believe that a wounded female orca initiated the attacks on boats and led smaller individuals to follow suit.

Female orca teach her smaller calf to aim for the rudder. Photo: Chase Dekker

Killer whales attacked and sank a third yacht off the coast of Iberia, Europe. Experts believe this behavior is learned from the rest of the population. Three killer whales ( Orcinus orca ) rammed the yacht on the night of May 4th in the Strait of Gibraltar, Spain, breaking the rudder. "There were two small killer whales and one larger one," said Captain Werner Schaufelberger. "The two smaller killer whales targeted the rudder at the back while the larger one kept ramming the side of the boat with all its might." Schaufelberger said he saw the smaller killer whales mimicking the larger one. They carefully observed their companion's technique and also rammed the boat.

The Spanish coast guard rescued the crew and towed the boat to Barbate, but the vessel sank at the harbor entrance. Two days earlier, a pod of six orca had attacked another sailboat passing through the strait. Greg Blackburn, a sailor on board, saw the mother orca seemingly teaching her calf how to aim at the rudder.

Reports of encounters with orca in the Iberian coastal region began in May 2020 and have become increasingly frequent, according to research published in June 2022 in the journal Marine Mammal Science. The attacks primarily target sailboats and follow a clear pattern: the orca pods approach from the stern to attack the rudder and lose interest after successfully bringing the vessel to a halt. This interaction has been ongoing since 2020 in orca habitats, both in Galicia and Gibraltar, according to Alfredo López Fernandez, a biologist at the University of Aveiro in Portugal and representative of the Atlantic Orca Working Group.

Most encounters are harmless. In over 500 recorded interactions since 2020, only three involved sinking boats. The surge in aggressive behavior toward boats is a recent phenomenon. The research team suggests that a traumatic event may have triggered a behavioral change in orca whales, and that the rest of the population learned to emulate it. Experts suspect that the female orca named White Gladis experienced a painful moment, a collision with a boat, or being trapped due to illegal fishing, leading to a change in behavior. She was the individual who initiated the behavior of directly interacting with boats.

Killer whales are highly social animals, easily learning and mimicking the behavior of other individuals, according to a 2022 study. In most cases, killer whales swim in a line towards the rudder of a boat to bite, bend, or break it. They seem to perceive this behavior as beneficial, despite the risk of colliding with a moving structure. Since this unusual interaction began in 2020, four killer whales from a small population in the Iberian Sea have died, although their deaths were not directly related to collisions with boats.

The unusual behavior of orca whales may also be playful. They are incredibly curious and playful animals. Therefore, the interaction may resemble a game more than aggressive behavior, according to Deborah Giles, an orca researcher at the University of Washington and the nonprofit Wild Orca.

Due to the increasing number of accidents, experts are increasingly concerned about the safety of sailors and the Iberian orca population. In a 2011 survey, only 39 Iberian orca were recorded. "If the situation continues or worsens, it will pose a real threat to the safety of seafarers and the conservation of this endangered orca species," the research team stated.

An Khang (According to Smithsonian )

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