Remember hearing that myth growing up that pirates were lured to their death by mermaids or sirens singing hypnotically? Now we know they were probably hearing whale songs. But have you ever wondered how whales can produce these melodies without drowning? A collaboration between researchers at the University of Southern Denmark and the University of Vienna has identified unique structures in the throats of baleen whales that explain this phenomenon. Baleen whales, such as blue whales and humpback whales, have what look like bristles as teeth that filter plankton out of the water. Their throats, thousands of years ago, were forced to evolve and change shape when the baleen whales themselves evolved from land mammals and entered our seas. The shift from land to water meant new structures (only found in these whales) were developed in their voice box. Instead of having a pair of tiny cartilages at the top of their voice box, baleen whales have a U-shaped rigid structure that spans the length of the voice box. Also affecting their pitch, leading to low-frequency sounds underwater. 

Researchers were able to uncover this discovery by extracting voice boxes from stranded whales found on Scottish and Danish coasts and creating a 3D computational model. They also found the range of the low-frequency sounds created, which led to a sad realisation. The frequency range and how far whale songs can travel clashed with the range and how far human-made noise by shipping travels, meaning that communication between baleen whales is limited as human-made noise completely masks their voices. 

This adds to the call for stricter regulations on human activity in our oceans, as not only are baleen whales fighting to avoid propellers to stay alive, but also to be heard – a vital part of their survival. 

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