The Bird Way: A New Look at How Birds Talk, Work, Play, Parent, and Think

by Jennifer Ackerman

The voice box of birds is a structure called a syrinx, buried deep in a bird’s chest cavity. Sound emerges when the membranes of the syrinx vibrate, shifting the flow of air through the organ. The syrinx in birds varies from the bulbous resonance chambers and long looping trachea of ducks, geese, and swans—up to twenty times the expected length—which produce sound that exaggerates their body size, to the tiny pair of chambers in songbirds, controlled by delicate syringeal muscles. Some songbirds have such fine control over the multiple muscles in both sides of their syrinx that they can produce different sounds at the same time, in essence, singing a duet with themselves.