In the Strait of Gibraltar – a famous marine road connecting the Mediterranean and the Atlantic – lives a critically endangered sub-population of a few hundred long-finned pilot whales (Globicephala melas).

Despite their name, these dark and blubbery marine mammals aren’t technically whales – they’re large oceanic dolphins which are believed to have a navigator or lead for each pod. Hence the “pilot” part of their name.

There are two types of pilot whales – short and long-finned. They’re generally found in deep offshore waters but can appear in coastal areas. And like other dolphins, they use high frequency sounds to talk to each other in their pods. These clicks and squeaks travel shorter distances compared with the melodic songs of humpback whales.

And as a new paper led by Milou Hegeman from Aarhus University in Denmark and published in the Journal of Experimental Biology shows, the pilot whales that live in the Strait of Gibraltar are having to shout at the upper limit of their range in order to hear each other over........

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