Book 31, Question 95
What makes the hum in a hummingbird?
The hum comes from a hummingbird’s wings.
They beat so fast, roughly 50 times a second in many small species, that the beats blend into a buzzing tone. Larger hummingbirds have slower wing beats and make a lower hum. If you hear a soft hum near a flower, look carefully. It may be a hummingbird zipping by, making a sound without any voice.
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Quick answers
What makes the hum in a hummingbird?
The harmonics in the hummingbird’s hum are primarily caused by the pressure waves radiated from changing lift and drag forces as the wings flap back and forth.
Source: spectrum.ieee.org
More fun facts
- A more accurate thing to say, however, is that those lil’ wings are generating sound , and that presumably they’re doing so in a similar way to the wings of other birds, insects, bats, and even winged robots.
- By studying wild hummingbirds with and without their tail feathers, and also testing feathers in a wind tunnel , Clark figured out that when fast-moving air vibrates certain plumes, they flutter at an audible frequency.
- At the end of the dive, the wings beat out a loud chu chu chu as the tips of the outermost wing feathers vibrate rapidly.
- Anna’s and Costa’s Hummingbirds also sound off using this outer feather, but unlike those species, the Calliope’s outer feather then strikes other tail feathers.
- Broad-tailed males make this sound with their second innermost tail feather.
Sources: spectrum.ieee.org, Audubon