Baleen whales evolved a unique larynx to communicate but cannot escape human noise
Baleen whales are the largest animals to have ever roamed our planet and as top predators play a vital role in marine ecosystems. To communicate across vast distances and find each other, baleen whales depend critically on ...
However, since whale songs were first discovered more than 50 years ago, it remained unknown how baleen whales produce their complex vocalizations—until now.
A new study in Naturereports that baleen whales evolved unique structures in their larynx that enable their low-frequency vocalizations, but also limit their communication range.
The study was led by voice scientists Professor Coen Elemans, at the Department of Biology, University of Southern Denmark and Professor Tecumseh Fitch at the Department of Behavioral and Cognitive Biology, University of Vienna in Austria.
"The toothed and baleen whales evolved from land mammals that had a larynx serving two functions: protecting the airways and sound production. However, their transition to aquatic life placed new and strict demands on the larynx to prevent choking underwater," says Tecumseh Fitch.
The study shows that baleen whales nevertheless can still produce sound with their larynx, but they have evolved novel structures to do so, that only exists in baleen whales. First, the tiny cartilages in the human larynx—called the arytenoids—that change the position of our vocal folds, have changed dramatically in whales.
Freediver descends between three juvenile humpback whales the size of buses. Credit: Karim Iliya
A humpback whale calf peering at the photographer as it plays in the warm protected waters of Moorea. Once the calves are strong enough, they will make the long journey with their mother back to the feeding grounds of Antarctica. Credit: Karim Iliya