What Makes Feathers Both Strong and Light

Bird feathers are famously light, but they’re also strong, holding up under tricky flying and high winds. They’re made of beta keratin, a tougher version of the keratin that makes up human fingernails and hair. They also have an intricate branching structure that makes them highly flexible and free of unnecessary weight.

BirdNote^®

What Makes Feathers Both Strong and Light

Written by Conor Gearin

This is BirdNote.

You’ve probably heard the expression “light as a feather.” And bird feathers are amazingly light. But they’re also strong, holding up to gale-force winds and letting birds perform steep-banked turns and dives.

[Red-tailed Hawk call]

So how can bird feathers be both strong and light? The answer begins with the feather’s basic building block, a molecule called beta keratin. It’s a tougher version of the keratin that makes up human fingernails and hair. With this sturdy material, bird feathers can do more with less.

[Common Terns diving in the water]

But it’s also about how those building blocks are arranged. A bird feather has a central shaft with many thin barbs that branch off. But zoom into those barbs, and you’ll see that there are lots of tiny barbules that branch off of the barbs. These barbules have hooks that help lock the barbs together like Velcro.

This branching structure provides support throughout the feather, but it also has thousands of tiny gaps, making feathers flexible and free of unnecessary weight.

[Hummingbird buzz]

From tiny hummingbirds to big, strong Ospreys, the intricate features of feathers allow for amazing displays of speed and agility.

[Osprey calls]

For BirdNote, I’m Ariana Remmel.

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Senior Producer: John Kessler
Producer: Mark Bramhill
Managing Editor: Jazzi Johnson
Managing Producer: Conor Gearin
Content Director: Jonese Franklin
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Red-tailed Hawk ML166694 recorded by Jay McGowan, Common Tern ML341702971 recorded by Jay McGowan, Osprey ML217862641 recorded by Paul Marvin, and Rufous Hummingbird ML109124 recorded by G. Keller
BirdNote’s theme was composed and played by Nancy Rumbel and John Kessler.
© 2023 BirdNote July 2023
Narrator: Ariana Remmel

ID# feather-10-2023-07-17 feather-10

Reference:
https://academy.allaboutbirds.org/feathers-article/
https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-014-0249-1
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2736122/