Rare harbour porpoise mating behaviour has been captured by drones off Shetland’s coast.
The footage, taken between 2019 and 2023, provides one of the most detailed records of harbour porpoise mating behaviour ever documented in UK waters.
Harbour porpoises are frequently spotted around Scottish waters, but their mating behaviour has largely evaded scientific scrutiny.
Their small size, measuring between 2 metres for 1.5 metres, quick speed and the vast amounts of time they spend under water has meant that they have largely avoided observation.
But, local sightings prompted this research to take place. In 2024, Shetland was identified as an Important Marine Mammal Area (IMMA), based on vital local and community knowledge.
Scientists from Scotland and Shetland residents worked on the project and reported their findings in the Journal of the Marine Biological Association yesterday.
The team analysed more than 79 minutes of usable footage from four coastal bays – Gulberwick Bay, South Nesting Bay, Mousa Sound and Quendale Bay – in the east and south of Shetland.
They recorded gatherings of up to 26 animals in a single bay, far larger than the small groups of two or three typically reported for the species.