from the archives: Feathered Friday - The male broad-tailed hummingbird

by Rachel and Andy Ames

Nothing says summer in the Rocky Mountains like the buzz of the male broad-tailed hummingbird. How does he make that sound and why? This ubiquitous sound is caused by air moving through a tapered outer wing feather (called the 10th primary). As the air moves through the feather, it can produce a high-pitched trill. When the bird is hovering, it sounds more like a hum or buzz. Males use the sound as part of their courtship display and as way to defend their territories. Perhaps their most spectacular display is the “J” pattern when they fly high in the air, hover for a few seconds and then dive down at break-neck speeds before pulling up again. If you happen to enter into a male’s territory, you might feel like you are being attacked! As their feathers wear down, the sound will become muted and then we will know that summer is nearing the end. Here are some pictures that show this tapered 10th primary feather so that you can see how the sound is made.