Amateur videographer Chris Wilton has posted footage of northern resident orcas rubbing themselves off a beach in B.C.'s Discovery Islands, near Campbell River.
The YouTube video shows several orcas near the beach taking turns rubbing their bellies on the smooth stones in shallow waters as stunned observers look on.
Orca beach rubbing is believed to be a cultural tradition - maybe even a form of massage - passed down by generations of the whales. It has been documented for more than 40 years on the B.C. coast, but Wilton's video is still rare.
Jackie Hildering, who runs a blog called "The Marine Detective," told The Orca Network that she and two whale researchers recognized some of the whales and members of a northern resident pod.
"Absolutely remarkable footage of northern resident orcas with their culturally unique behaviour of rubbing themselves on beaches like this," Hildering said.