Orcas' Boat Attacks Linked to Socialization and Coordinated Learning.

A traumatized female orca named White Gladis may have triggered the recent incidents of killer whales ramming into and sinking sailboats near Portugal and Spain, but at least one other orca, Luna, has previously engaged in similar behavior for playful reasons. Luna, who lived alone and befriended humans, was killed by a tugboat in 2005. Orcas are known to be tactile and intelligent, and the fact that other orcas are mimicking the behavior suggests it is being positively reinforced. These interactions can be dangerous for both whales and humans.