Decoding the reasons why killer whales attack ships

The killer whales that crash into and sink ships in the Strait of Gibraltar may just be juveniles frolicking and following a behavioral trend.

Since May 2020, researchers have recorded nearly 700 incidents of killer whales colliding with boats near the Iberian Peninsula. This behavior confused sailors and scientists, many people suspected that killer whales taught their fellow whales to attack ships traveling in the area. Theories to explain their strange behavior range from food scarcity (killer whales view ships as enemies competing for their preferred prey) and a sudden resumption of sea activity after epidemic.

Killer whales approach yachts in the Strait of Gibraltar. (Photo: Telegraph).

However, leading marine biologist Alex Zerbini, chairman of the scientific council at the International Whaling Commission (IWC) and member of the research team appointed by the Spanish and Portuguese governments , said it was more likely that the killer whale's behavior was a new "cultural tradition" with no clear purpose . In other words, killer whales may just be chasing temporary excitement.

According to the team, some populations develop temporary behavioral tendencies that are unusual and the display does not appear to serve any obvious adaptive purpose. The researchers also listed several strange behaviors observed in killer whales at different periods over the years. For example, killer whales in the South Pacific developed the habit of carrying salmon carcasses on their heads in 1987, starting with young individuals and spreading throughout the population. The behavior quickly disappeared after that, then returned in the summer of 2008 and disappeared again. Another case of strange behavior that appeared and disappeared within 20 years was pairs of juvenile and adult male killer whales banging their heads together.

In recent accidents, the majority of killer whales that approached damaged or sunken ships were juveniles. They often swim slowly as if trying to lightly touch the rudder with their snouts. The animals' behavior is not aggressive, and not every interaction ends in destroyed boats, according to Zerbini.

The research team suspects that the new behavior may disappear at some point and reappear again. "When they play with the steering wheel, they do not understand that they can destroy that part and affect people. That is playful behavior instead of intentional destruction ," Zerbini emphasized.