Fishing is time-consuming business, so diving birds in Mexico’s Baja California are frequenting the local “sushi conveyor” instead. That conveyor comes in the hulking shape of the region’s reigning big fish: the whale shark. The crafty cormorants have figured out that the giant sharks provide an endless supply of remora sashimi.

In the clip, a diving cormorant yanks furiously at a remora fish attached to the skin of a passing whale shark, before finally pulling its meal free. It’s a truly remarkable sighting – in fact, this footage filmed back in 2012 may be the first (and only) example of its kind. According to marine biologist Dr Simon Pierce, who has done extensive work on whale sharks, experts have been excitedly discussing the video since it started making the rounds online earlier this week.

“It’s super cool!” he says. “I don’t think it’s been documented. I’ve never seen or heard of it previously, but that particular cormorant certainly knew what it was doing. Smart bird!”

An extended clip released by Manta Scuba Diving [JAC: this clip] confirms the event was no once-off: after its initial catch, the bird – likely a Neotropic cormorant or double-crested cormorant (Phalacrocorax brasilianus or Phalacrocorax auritus) – came back for both second breakfast and elevenses.