Humpback whales use songs to communicate with each other across oceans
Karim Ilya
Biologists have discovered how baleen whales produce their unique songs. It involves the uniquely shaped larynx.
Baleen whales, including humpback whales, communicate through complex songs that can be heard over great distances. “People recorded the first whale sounds in his 1970s, but only recently have we started to recognize the different sounds these animals actually make,” he says. Cohen Elemans At the University of Southern Denmark. “Now the question is, how do they do this?”
To learn more, Elemans and his team extracted the larynxes of three recently deceased baleen whales.Balaenoptera borealis), humpback whale (Megaptera novaeangliae) and the northern minke whale (Balaenoptera acutorostrata).
The larynx, commonly known as the voice box, is an organ located in the upper neck of mammals. As air flows through the organ, the tissue folds vibrate, creating sound.
But that's not the case with baleen whales, Ellemans says. When the researchers examined the whale's larynx, they discovered that the organ had an unexpected shape, with a cushion of fat on one side.
When these whales breathe, air is forced against the fatty material, which vibrates and makes sound. “I've never seen this in any other animal,” Ellemans says. “This is unique to baleen whales.”
Whales can also recycle air from their lungs, which is useful when they are underwater for long periods of time. When you exhale through the trachea and larynx, air enters a sac with walls that contract, returning air to the lungs.
Using a computer model of its larynx, the researchers found that baleen whales can generate frequencies of up to 300 hertz at depths up to 100 meters below the ocean's surface. This is within the frequency range of noise emitted by ships, raising concerns that ship noise could drown out their songs.
“These whales can't escape this situation,” Elemans said. “Therefore, we need to take steps to reduce noise.”
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Source: www.newscientist.com
