Scientists solve whale song mystery

Whales sing loud enough that their songs travel through the ocean, but knowing the mechanics behind that has been a mystery.

Scientists now think they have an idea, and it's something not seen in other animals: A specialized voice box.

Experts say the discovery, while based on a study that is too tiny to be definitive, will direct future research into how whales communicate.

In a paper published on Feb. 21 in the journal Nature, Coen Elemans of the University of Southern Denmark and colleagues studied the voice boxes, or larynxes, from three dead, stranded whales — a humpback, minke and sei, which are all types of baleen whales.

In the laboratory, the scientists blew air through the voice boxes under controlled conditions to see what tissues might vibrate. Researchers also created computer models of the sei whale's vocalizations and matched them to recordings of similar whales taken in the wild.

Whales' ancestors were land-dwellers about 50 million years ago before moving into water. Elemans said the animals adapted their voice boxes over tens of millions of years to make sounds underwater.

Unlike humans and other mammals, baleen whales don't have teeth or vocal chords. Instead, in their voice boxes, they have a U-shaped tissue that allows them to breathe in massive amounts of air and a large "cushion" of fat and muscle not seen in other animal species. Whales sing by pushing the tissue against the fat and muscle cushion, Elemans said.

"This is the most comprehensive and significant study to date on how baleen whales vocalize, a long-standing mystery in the field," said Jeremy Goldbogen, an associate professor of oceans at Stanford University, who was not involved in the new research.

He noted there is more...

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