Scientists have found out how whales “sing” – research – News

Scientists have found out that whales emit their characteristic “singing” thanks to the vocal apparatus, which has evolved over millions of years. They produce sounds in a unique way.

This is stated in a study published in the scientific journal Nature, writes The New York Times.

“The vocal apparatus evolved when fish crawled out of the sea and had to find a way to separate the air they breathe from the food they eat.”– explained Cohen Elemans, author of the study and professor of biology at the University of Southern Denmark.

The larynx is a kind of “corridor” to the respiratory tract or trachea, with a flap of tissue – the epiglottis, which prevents food from getting there. A little below the epiglottis, mammals have additional folds of tissue – vocal cords that produce sounds when exhaling. This causes them to vibrate.

“When the land-based ancestors of whales returned to life in the sea, they actually had to change their larynx because when these animals breathed at the surface, they had to exhale large amounts of air very quickly.” – noted Dr. Elemans. Vocal folds, like those of land mammals, could get in the way.

Whales and dolphins do not use their voices to sing like humans do. Their larynx closes to prevent water from entering their lungs. Instead, they make sounds with their noses. But scientists suspect that “musical” humpbacks and blue whales still use their vocal cords.

To find out, scientists studied the carcasses of three dead whales – humpback, minke and seiwal, which were washed ashore in Denmark and Scotland. These animals are too large to be kept in captivity and “sing” very deep underwater, so scientists would not be able to collect the necessary data by studying living whales.

In order to better understand how the vocal cords of these marine mammals work, they were connected to tubes and supplied with air. At first, nothing happened, but when the scientists changed the position of the larynx, connected to the vocal cords, the fat pad on it began to vibrate and the same sound of “whale singing” appeared.

According to William Tecumseh Fitch, an author of the study and a professor of cognitive biology at the University of Vienna, “on a scale of 10 it was an 11.” He said that this method of sound generation, when air is compressed between the fat pad and the vocal folds, has never been observed in any other animal.

Joy Reidenberg, a professor of anatomy at the Icahn School of Medicine at Mount Sinai, who was not involved in the study, said the study “changes our understanding of how these whales make sounds and may show a mechanism for how they can make sounds simultaneously several sounds”.

She also noted that it is necessary to study more species of whales and the structure of their vocal apparatus, especially adult male humpback whales, which are also able to “sing.”

The researchers also created digital models to study how lung volume limitations and water pressure might affect where and how the whales sing. The results showed that these mammals make sounds mainly in shallow water, where the lung volume and water pressure do not prevent them from making sounds. However, noise from human activities, such as shipping, can interfere with this process.

“Studying large whales is extremely challenging, but trying to figure out how they make sound when you can’t even see them underwater is an extra layer of complexity, so researchers have been very creative.” said Dr Ellen Garland of the University of St Andrews’ Marine Mammal Research Unit.

We previously reported that blue whales ingest more than 10 million pieces of microplastic every day.