BirdNote; The Alula

BirdNote®

Alula

Written by Bob Sundstrom

This is your captain speaking, BirdNote cleared for takeoff.

[Airplane cabin sounds]

When you look out the window of an airplane, you can see a number of flaps on the wing. The pilot controls these flaps to adjust lift and drag — they’re essential for maneuvering in the air. And the design of these flaps was inspired by the wings of birds.

(Red-tailed Hawk ML202280 J McGowan)

All flying birds have what’s called an alula on each wing. At the center of the front edge of the wing is a structure covered with three to five feathers that functions much like a flap on an airplane’s wing. The alula helps create lift and also prevents stall when a bird comes in for landing.

It’s fairly easy to see on some birds. As a hawk makes its descent, the alula sticks straight up like a feathered spike, helping the bird to precisely hit its target.

And some birds really put their alulae (AL-yuh-lee) to work. Falcons, Peregrines in particular, need a prominent alula to provide greater control when the wing is cupped or tucked as the bird dives at high speed, then turns deftly and snatches its prey. The bird equivalent of a fighter jet.

(Peregrine Falcon ML136378 M Andersen)

For BirdNote, I’m Michael Stein.

Support for BirdNote comes from the Cornell Lab’s Bird Academy, with online courses that share the wonder and joy of birds. More at All About Birds dot org.

###

Senior Producer: John Kessler

Production Manager: Allison Wilson

Producer: Mark Bramhill

Associate Producer: Ellen Blackstone

Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. ML202280 RTHA Recorded by J. McGowan ML136378 PEFA Recorded by M Andersen

BirdNote’s theme was composed and played by Nancy Rumbel and John Kessler.

© 2021 BirdNote April 2021 Narrator: Michael Stein

ID# alula-01-2021-04-14 alula-01

Resource: [https://www.birdsoutsidemywindow.org/2009/12/11/anatomy-alula/]

https://www.sciencedaily.com/releases/2015/06/150605103008.htm