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Hummingbirds Whistle With Tails
Hummingbirds don't just hum, they chirp. But here's a surprise, they don't do either with their throats. It's all in their feathers, according new research that just came out. The species that was studied is called Anna's hummingbirds. The males make a loud whistling chirp when they dive toward the ground. The sound was to attract the attention of female birds.
For years, nobody was sure how the chirp was made. Two researchers say they've settled the question. Christopher Clark and Teresa Feo looked at a video of the birds diving, and noticed that their tail feathers spread out right when the birds chirped. So they caught 10 of the birds and pulled out some of their tail feathers. It didn't harm the birds; the feathers grow back in a month.
Then they took the feathers and put them together to make a fake tail, and spread them out the same way the would be during a dive. They used a machine that blows air, called a wind tunnel, to see if the wind rushing past the tails made the chirping sound. It did!
The whistling feathers are the result of changes in evolution that help the male hummingbird mate. Because the feather whistle is louder than one it could make with its throat, it increases the bird's chances of attracting females.
I'm Adelbert and that's what happened in Science this week!
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