A bird's feathers are made of keratin, the same material as human hair.

The longer version

Keratin is a tough fibrous protein built from long chains that coil around each other and bond with sulfur bridges. The same family of proteins makes human hair, fingernails, reptile scales and horn. In a feather the keratin is laid down as a dead, dry layer, so a grown feather has no blood supply and cannot heal itself once damaged.

Because the material is dead, a frayed feather stays frayed until it is dropped and replaced. Keratin is also why feathers resist water and rot so well, and why old pillows and study skins last for decades. Heat and pH change those sulfur bonds, which is how a bent feather can be straightened with steam.

Where this entry sits

Here you will find feathered trivia about flight, migration, nests, eggs, and the songs birds sing. Expect short surprising facts on penguins, owls, hummingbirds, and other familiar birds from gardens, forests, wetlands, and distant coastlines. The full list sits on the Birds page, where every entry is listed in order.