A rogue pod of orcas responsible for a spate of boat attacks in the Strait of Gibraltar is communicating in a unique language that scientists have never documented before. The group, led by a female known as White Gladis, has been snapping rudders and disabling vessels since 2020.
A Silent but Deadly Strategy
Researchers had noted that the so-called 'Gladiator' pod, named in reference to the scientific term Orca gladiator, carried out its destructive attacks in eerie silence. This was unusual, as orca pods are typically highly vocal, especially during hunting or social play.
However, a new study suggests this silence is a tactical choice, honed by their specialisation in hunting alert and flighty tuna. To avoid startling their prey, these Iberian orcas learned to hunt quietly. Using cutting-edge underwater acoustic equipment, scientists have now eavesdropped on their previously unheard chatter.
Four Unique Calls Discovered
In just a few hours of recording, the team identified four distinct types of vocalisations that did not match any known orca calls from the North Atlantic or Pacific populations.
Dr Renaud de Stephanis, president of the Spanish conservation group CIRCE and a co-author of the research, told The Times: "We've been studying these orcas for 30 years. Until now they were thought to be very silent. But now we've learnt that their calls are totally, totally different to any others."
He described the find as akin to "suddenly finding a new [human] language in the middle of Europe," comparing the structural differences to those between Arabic and Latin.
Language, Learning, and a 'Playful' Menace
The unique language is believed to be culturally learned, not innate. Young calves pick up vocabulary and grammar from the pod's dominant female and other members, which is crucial for passing on specialised hunting strategies.
The vocalisations were found in a wider group of about 40 orcas, whose range stretches from the Strait to the Atlantic coast of Iberia. About 15 of these belong to the infamous Gladiator pod, linked to nearly 700 close interactions with boats and the sinking of several vessels.
Scientists, however, do not believe the orcas are actively seeking to harm humans. Dr de Stephanis suggests the boat attacks are a "playful, not aggressive" behaviour, possibly a passing fad similar to the Pacific orcas' trend of wearing dead fish as 'hats'.
"They focus on the rudder of sailboats because it reacts dynamically when pushed – it moves, vibrates, and provides resistance. In other words, it is stimulating for them," he explained. After damaging rudders, the pod has been seen batting the fragments around briefly before losing interest and swimming away.
The discovery of this unique communication system offers a fascinating new perspective on the intelligence and complex social culture of these remarkable marine mammals, even as their disruptive 'game' continues to baffle and concern sailors in one of the world's busiest waterways.
