Whales sing so loudly that their songs travel across the ocean, but understanding the mechanisms behind this has remained a mystery. Now, scientists believe they have an idea, which is something not observed in any other animals: a special vocal box. Experts say this discovery, although based on a very small study and therefore not definitive, will guide future research on how whales communicate.
In research published Wednesday in the journal "Nature," Quinn Elimane from the University of Southern Denmark and colleagues studied the vocal boxes, or larynxes, of three deceased whales: the humpback, the minke, and the fin, all of which are baleen whale species. In the lab, scientists blew air through the vocal boxes under special conditions to identify which tissues might vibrate, and they also created computer models of fin whale sounds and matched them with recordings of similar whales captured in the wild.
The ancestors of whales lived on land about 50 million years ago before moving to water. Elimane stated that these animals have adapted their vocal boxes over tens of millions of years to produce sounds underwater. Unlike humans and other mammals, baleen whales do not have teeth or vocal cords; instead, their special vocal boxes contain U-shaped tissue that allows them to inhale vast amounts of air, along with a large "pad" of fat and muscle not found in other animal species.
Elimane explained that whales sing by pushing the tissues against the fat and muscle pad. In this context, Jeremy Goldbogen, an associate professor of oceanography at Stanford University who was not involved in the new research, said: "This is the most comprehensive and important study to date on how baleen whales vocalize, which has been a long-standing mystery in the field." He also pointed out that there is more to study "given the unusually diverse vocal repertoire" of whales. It is known, for instance, that humpback whales sing elaborate songs that travel across oceans.
