It has been known for some time that Asian elephants - in addition to the famous Toröö - also produce high-pitched squeaking sounds. Especially when they are excited. In order to capture these special sounds, our team of behavioral biologists - Veronika Beeck and Evelyn Fuchs - from the University of Vienna traveled to Nepal in the winter of 2018, among other places - carrying a special acoustic camera with 48 microphones, the "Star Array". It makes sounds visible in bright colors, similar to the image of a thermal camera. In this way, the source of the sound production can be calculated very precisely.
The general rule for mammals is: The larger the animal, the longer the vocal cords and the lower the pitch of their sounds. Conversely, this means that there is an upper limit to the pitch that can be achieved with the help of the vocal cords in the larynx. And the extremely high squeaks of the Asian elephants do not fit into this spectrum.
Our pictures from Nepal now also clearly show that the excited squeak does not come from the trunk at all, but from their mouth. Funnily enough, the animals produce this sound, which differs from the characteristic trumpeting, just by pressing air through their tense lips like a trumpet player. This technique of sound production with buzzing lips ("lip buzzing") is so far unique in the animal kingdom. However, the trumpet sound of elephants has not yet been adequately researched. Until now, research has focused on the low-frequency infrasonic sounds, but elephant communication also consists of more than just these "rumbles". We need to consider all the sounds in the repertoire if we are to better understand the elephant communication system.
Vote now! Elephant sound researcher Angela Stöger has been nominated as Austrian of the Year in the category Research as part of the "Aktion Austria 21" of the newspaper die Presse.
