A male koala’s bellow may attract mates and intimidate rivals.
Female koalas may be attracted to larger mates as they could produce larger, more competitive offspring by mating with these individuals. Male koalas appear to modify their vocal tracts to make themselves sound much larger than their actual size.
According to Dr Benjamin Charlton from the Journal of Experimental Biology.
Together with Dr William Ellis and Dr Gary Cowin from the Moggill Koala Hospital, Dr Charlton investigated the position of the koalas’ larynx using MRI scans and post mortem examinations. The researchers discovered that the koala’s larynx has descended to the level of the third or fourth cervical vertebrae, instead of being located higher in the throat.
The investigations also revealed that the sternothyroid muscle, which attaches the larynx to the sternum, was anchored very deep in the thorax and could pull the larynx even further into the chest cavity. “The low larynx position may indicate strong selection pressures to broadcast, and possibly to exaggerate body size using formants in this species,” said Dr Charlton.
To examine the effects of the descended larynx on koala bellows, Dr Charlton recorded the bellows of the males at the
You may also like…