This is scientific American 60 Second Science. I'm Annie Sneed.

Feathers are not just for flight.

The key birds warm, become part of their their nests and help them attract mates.

And for one Australian bird, feathers even help produce an important sound, an alarm.

People had long noticed that these birds produced these loud whistles.

Trevor Murray, a postdoctoral researcher at the Australian National University.

My supervisor, Rob McGra, in collaboration with Mahingi thought that they were used as an alarm.

So they did some playbacks and they could show quite strongly that if you play back these sounds

to other birds, they flee straight away. So what I was really interested

in was following up on that research and finding out how they produce the sound, whether

it is actually a signal, and whether it's a reliable signal.

The team focused their experiment on specific feathers in the crusted pigeon's wing.

We were able to target the eighth primary feather, which is unusually narrow.

It's about half the width of the surrounding feathers.

And then we also removed on different sets of birds.

We also removed those neighboring feathers, the ninth primary

feather and the seventh primary feather.

We're able to see that the eighth primary feather, when it was missing, the high note had completely disappeared.

So the eighth primary feather produced that high note, and the ninth primary feather, it turns out,

actually produced the low note.

And if the birds are fleeing from danger, they produce a louder and higher

tempo whistle than they do during a normal takeoff. The study is in the journal

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