Why do birds move when they sing?

My research asks the question: why do birds move when they sing? Much like an opera singer raises their chin during a song, or a toddler opens their mouth to scream, birds use motion to shape their sound. The two young Canadian geese in this image are mid-conversation (or perhaps mid-argument). One stretches its neck and opens its beak wide, which deepens the voice, making the bird sound bigger– and potentially more impressive– than it really is. My work explores how these physical gestures influence how sound is produced and how it’s perceived by others. Extended necks or opened beaks not only shape the sound, but they help draw attention to the gosling, even from a reluctant sibling. As an adult, similar movements during courtship may be key to convincing a potential mate that this loud, lanky bird is worth listening to.