But in the sea, there’s not much for the orcas to interact with, so they play with the rudders.”He compared the encounters to childlike behaviour: “They’re pushing, pushing, pushing – boom! Most of the interactions take place between spring and autumn, when orcas and boats cross paths during migratory patterns. That’s because the whales and boats are in the same area at the same time,” said Naomi Rose, a senior scientist at the Animal Welfare Institute. Photographs have identified 15 individuals out of a population of around 50 Iberian orcas, also called the Strait of Gibraltar orcas. As with other pods worldwide that share hunting techniques or vocalisations, the Iberian whales appear to have developed a cultural fad of targeting rudders, and teaching it to younger members.