The voice box sits on top of the windpipe and contains the vocal cords, which open during breathing and close when the goose wants to honk. When the goose produces the airstream that will become the honk, the airstream passes between the vocal cords, which then vibrate between 100 and 1000 times per second, depending on the pitch of the honk. By themselves, the vocal cords produce a noise that sounds like simple buzzing.

What’s needed to make a meaningful honk is a resonator and the structure above the vocal cords, including the throat, nose, and mouth, are part of the resonator system in geese as well as in humans. The buzzing sound created by the vocal cord vibration is changed by the shape of the resonator tract to produce the unique goose sound.

What this means is that over the centuries the throat, nose, and mouth structure of the Trois Rivieres goose has changed compared to the same resonator structure in other Canadian geese.

This is an extract from the book Animals Evolution Avoided