Whales have many talents, but perhaps the most unique and mysterious is their hauntingly beautiful song. And scientists finally know how they do it.
The secret is a unique larynx that vibrates fat and muscles to produce sounds, rather than blowing air through it.
Singing underwater presents a difficult problem because, in theory, it would consume all the air.
But according to a new study by an international team of scientists, whales developed a larynx that is different from that of most other mammals.
It also provides information about the whales’ limited vocal range, something that can leave them vulnerable to having their sounds drowned out by boat engines and other human noises.
A humpback whale breaches near Bering Island, Kamchatka. Humpback whales and other baleen whales produce sound by recirculating air through a unique structure in their throat.
Whales have even been observed learning complex songs from each other.
The new study is small and was conducted with just three whales, but for the first time it provides an answer to how the songs of the world’s largest animals can travel miles across the ocean.
Until now, scientists didn’t know exactly how these ocean giants could achieve their signature feat.
The untimely disappearance of three whales gave scientists the opportunity to investigate the animals’ vocal anatomy.
The dead whales used in the study died from natural causes or accidents, the scientists behind the study wrote.
A male sei whale was found near Denmark and, although the cause of its death was uncertain, scientists described it as emaciated.
A female humpback whale likely drowned after becoming entangled in fishing gear, and the female minke whale likely died from a bacterial infection, the researchers wrote.
All of these whales are baleen whales, as opposed to toothed whales.
Baleen whales feed by filtering water through giant comb-shaped plates that capture marine invertebrates and small fish.
To find out how whales make sounds, the team, led by Coen Elemans of the University of Southern Denmark, dissected each animal’s larynx and blew air through it to see what happened.
What they discovered was that the whale larynx does not function in the same way as the vocal cords.
He study was published in the magazine Nature.
This painting of a humpback whale indicates the cartilages of the animal’s pharynx, part of the structures that produce sound.
Instead, a U-shaped piece of tissue vibrates against the fatty and muscular structures of the whale’s throat.
Blowing air through these structures in the laboratory produced the deep, resonant sounds that whales are famous for.
And their unique anatomy allows whales to recycle air while they sing, as well as avoid inhaling water.
It was “super exciting” to discover this, Elemans said BBC News.
Three young humpback whales swim with a diver. The special vocal structure of baleen whales allows them to sing for long periods of time without having to breathe and without choking.
Whale song travels long distances, but can be drowned out by ship engines and other human activities.
“This is the most comprehensive and significant study to date of how baleen whales vocalize, a long-standing mystery in the field,” Jeremy Goldbogen told the AP. Goldbogen, an associate professor of oceans at Stanford University, was not involved in the study.
These results open doors for future studies, he said, “given the extraordinarily diverse acoustic repertoires” of whales.
Unfortunately, research also shows how vulnerable animals are to human activities.
A computer analysis of vocal structures showed that there is a narrow frequency range of sounds that whales can make, leaving them vulnerable to disturbances.
Since ships and other human activities produce noises that are in the same range as whale songs, and since whales use their songs to find mates, human activity can make it difficult for whales to find each other and reproduce. .
“They can’t just choose, for example, to sing louder to avoid the noise we make in the ocean,” Elemans said.
And while this may not be as big of a problem for humpback whales and other species that live in groups, blue whales that cover long distances alone may be more vulnerable to human navigation and other activities that produce underwater noise.