Scientists think they might have finally learned the secret to how whales sing their complicated songs.
We knew whales made a vast array of vocalizations, called songs, that can carry for thousands of miles underwater under the right conditions.
But only now are scientists learning more about the biological mechanisms that baleen whales use to make these unique noises.
Coen Elemans, from the University of Southern Denmark, led a team that studied the carcasses of three whales that had died after being stranded, representing three different baleen whale species: A humpback, minke and sei whale.
They found all of the whales have evolved a specialized voice box that isn't found in any other animals. It includes a u-shaped mass of tissue that enables whales to take in large amounts of air, and a unique "cushion" of fat and muscle that this tissue presses against to create sound.
The arrangement of the voice box is unique, but the researchers say it relies on the same underlying principles of vibrating air that allows other mammals and birds to vocalize.
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Mapping out these organs and modeling their behavior also gave researchers possible explanations for why shipping activity can be so disruptive to whales. They found there appear to be biological limits to the frequencies and volumes of whale songs, and to the water depths at which a whale can sing. In short, Elemans says, whales simply can't always sing louder than the shipping traffic around them.
“They’re really affected by (shipping noise) and it significantly reduces their ability to communicate,” he said. “There’s just no way for them to get louder.”
The study, published in the journal Nature, is the most comprehensive look yet at how baleen whales vocalize.
But the three whales studied were all juveniles, which means the findings still stand to be confirmed in research from adult specimens. And because measuring live whales in detail is a relatively difficult task, experts say the new modeling may provide the best insight for now into how whales sing and communicate.
