The chilly waters of north-east Scotland are home to the world’s most northerly group of bottlenose dolphins. They are protected by EU conservation laws and despite being a small population, appear to be thriving.

Euan McIlwraith heads out into the Moray Firth on a research boat to discover how photo-ID techniques are used to record the dolphins’ movements around the coast, and visits the University of St Andrews to find out more about their communications underwater.

As he discovers, every bottlenose dolphin creates a unique signature whistle for itself early in life. These are like a call-signs, used to communicate to the rest of the group, and recent research has shown they can mimic the calls of other dolphins, and that they respond when they hear their own whistle played back to them.

(Photo: Bottlenose dolphins. Credit: Charlie Phillips/WDC)