Baleen whales, including today’s blue, humpback, and fin whales rely on sounds to live in their watery world. Their songs must be able travel far in the murky, dark ocean so that they can find their kin and migrate hundreds of thousands of miles. In the more than 50 years that scientists have been studying whale song, it’s remained unclear what physical structures baleen whales use to make noise until now. A study published February 21 in the journal Nature finds that baleen whales evolved unique parts in their larynx that create their complex vocalizations.
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“Whales are absolutely amazing creatures, they are the biggest animals to have ever lived. They’re way bigger than the largest dinosaurs, they can dive deep, and are very social,” Coen Elemans, study co-author and a voice scientist at the University of Southern Denmark, tells PopSci. “Because it is so difficult to find another animal in a huge ocean, many of these behaviors are guided by sound. Thus understanding how they make sound is crucial to understand the biology of whales in general.”
Toothed whales vs. baleen whales
Whales fall into two main groups–toothed whales (Odontocetes) and baleen whales (Mysticetes). Toothed whales include, orcas, sperm whales, dolphins, and porpoises. Many of these species have visible teeth that they use to crush their prey.
Baleen–or whalebone–is a hard substance made up of keratin. It grows from the whale’s upper jaw in plates with bristle-like fringes. It works like a sieve to filter out the small fish or zooplankton that it eats.
“Baleen whales make sound with their larynx and toothed whales in their nose,” explains Elemans. “Both use the same mechanism of vibrating tissues just like human vocal folds, but with completely new structures.”
Evolving new vocal structures
In the study, the team examined three stranded…
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