The hummingbird’s tail secret—revealed!

by Philip Bell                                                                                                                                                                                                                                              Vol. XXIV, No. 8, September 2011

Researchers at the University of California, Berkeley, studied the high-frequency chirping noises made by males of a species called Anna’s hummingbird. They found that these chirps did not come from the head end, as assumed previously, but from the tail.

In fact, this bird makes these loud sounds by super-quick movements of its tail feathers (too fast for humans to see with the naked eye), something never previously observed in any bird.

The researchers also discovered remarkable evidence indicating the anatomical and behavioural features are just right for making these sounds. For example, the trailing vane (a sheet of interconnecting hooks and barbules) of each tail feather flutters up and down and the 4kHz sound is only produced if a travelling wave moves the entire length of the feather (base to tip or tip to base). In ingenious experiments, the researchers investigated the response of feathers in jets of air using high speed video (up to 20,000 frames per second). When the scientists manually separated some of the barbs, so upsetting the continuous sheet, it disrupted the feathers’ ability to make the sound. But reconnecting the barbs restored the wave synchrony, and the ‘chirps’ could once again be heard.

Who would have ever expected that hummingbirds can make ‘chirping’ noises in such a manner, i.e. with a tail that is just right for doing so? Such features speak of having been designed, by a Master Designer—the One Who made all creatures, including you, me, and the birds which ‘sing among the branches’ (Psalm 104:12).