Drones recently captured rare footage of harbour porpoise breeding behavior in the waters around Shetland, an archipelago in the North Atlantic approximately 106 miles from mainland Scotland.

Drones Capture Rare Porpoise Footage

Harbor porpoises (Phocoena phocoena) are speedy small creatures measuring approximately 4.9-6 feet and weighing around 121-176 pounds, with females slightly longer and heavier than the males. They are frequently spotted around Scotland’s coast and are extremely difficult to study because they spend a significant amount of time underwater.

“Harbour porpoises are seen from land around Shetland all year round, but one sighting involved intense splashing at the surface. We realized it might be mating behavior,” said Sophie Ariadne Francine Smith from UHI Shetland, who carried out the research, in a statement. “It is incredibly difficult to film porpoises from boats or from land. They don’t spend much time at the water’s surface, don’t follow a predictable line, like an orca, and they are incredibly fast.”

The team recorded 79 minutes from four coastal locations around the east and south of Shetland between 2019 and 2023. The largest gathering recorded included 26 animals in one location, compared to most reports, which rarely list more than two or three porpoises together.

While studying the footage, researchers noticed two types of mating behavior. The first showed males approaching females in what researchers believe to be mating attempts, and the second is a display behavior in which males will show their bellies to females.

“Drone technology means we can film them from above, which gives much more accurate accounts and a clearer interpretation of behavior,” said Smith. “Harbour porpoises are fast and elusive. For much of this mating behavior they only broke the surface for a few seconds – blink and you’d miss it, which is why using drones to capture footage has been such a boon.”

The study is published in the Journal of the Marine Biological Association of the United Kingdom.