For four years, orcas have been ramming and sinking luxury yachts in European waters, perplexing scientists. These intelligent, gregarious creatures have demonstrated a new, destructive behavior that has confused scientists and boat owners alike. However, current research suggests an unexpected explanation: mere child’s play.

A playful misunderstanding

Following a lengthy examination, a team of biologists, government officials, and marine sector representatives concluded that the orcas’ acts were not motivated by aggressiveness or territorial disputes. Instead, these actions are driven by young orcas’ innate playfulness and curiosity.

The approximately forty severely endangered Iberian killer whales that eat only large fish have benefited from the region’s extraordinary recovery of bluefin tuna in recent years. 

“In addition, climate change could be playing a role,” the experts stated. The year-round abundance of tuna in the Gulf of Cádiz indicates that orcas no longer need to hunt as actively, leaving them more free time to indulge in playful behaviors or ‘hobbies’.

Juvenile orcas at play

The study concentrated on a core group of 15 orcas, mostly male juveniles and teens, who were identified as the major participants in these encounters. These young orcas, known as “the most curious and exploratory” of their species, have acquired a tendency to collide with boat rudders. This behavior, which was initially harmless, has increased as the orcas have grown larger and stronger. Notably, no orcas over the age of 25 have been spotted engaging in these behaviors, indicating that this is a young tendency.

“Killer whales are known to play with other objects or animals in their environment to the point of damaging them,” the investigators noted. This behavior is consistent with similar patterns reported in other orca populations, such as those in Washington, USA, where individuals have been known to ‘play’ with harbor porpoises, even hurting them.

Cultural transmission and fads

Orcas are well known for their ability to adopt and disseminate behaviors within their social groupings, similar to how viral fads spread among people. In 1987, for example, a female orca in the Pacific Ocean was sighted carrying a dead salmon on her head, a practice that swiftly spread to her pod and two others before disappearing. Similarly, the present trend of boat-bumping may be viewed as a passing fad.

“Different populations often have distinct dietary specializations that are maintained by cultural transmission, and these ‘ecotypes’ typically have a variety of persistent behavioral traditions,” the authors said. Examining ephemeral traditions in other well-studied cultures may help us understand the orcas’ recent interactions with boats.

The human perspective

While orcas’ actions may appear fun from their perspective, they have devastating implications for people. Since 2020, the Atlantic Orca Working Group (GTOA) has documented 673 incidents between orcas and watercraft, with at least four boats sinking. Just a few weeks ago, orcas repeatedly struck the 49-foot yacht Alboran Cognac in the Strait of Gibraltar, sinking it after the passengers and crew were rescued.

The rise in these kinds of encounters has forced authorities to issue warnings. The Spanish marine rescue service SASEMAR has cautioned boat owners not to venture too far from shore and to avoid lowering anchors in high-risk areas. “In an ideal world, there would be a simple strategy for mariners to follow when killer whales interact, which would avoid vessel damage and harm to the whales,” the scientists said. Unfortunately, such a strategy does not currently exist.

Moving forward

Experts agree: these encounters are not hostile in nature. It does not ring true to refer to them as ‘attacks’. Instead, they should be viewed as playful, sociable actions. The researchers found, “The singular agreement amongst the experts at this workshop is that the interactions between Iberian killer whales and vessels are not aggressive. The interactions have more elements consistent with fad behavior or play/socializing than aggression.”

While the tendency is likely to fade in time, boat owners and authorities remain cautious. The objective is that sustained research and surveillance will reveal new insights into these playful sea monsters, thereby reducing hazards and promoting cooperation between humans and orcas.