Focus on Feathers

Amazing Feathers

When you see a bird flying and notice a missing feather or two, you can say the bird is molting. Read on to find out what that means—and learn more about their amazing feathers.

Look at the Tips

Notice the tips of the feathers on the eagle's wings. They almost look like fingers! The eagle controls these feathers with its muscles. The eagle can make quick changes in flight by adjusting them in different ways. These feathers are called "primary" feathers.

Made of Keratin

This is a primary feather from an eagle wing. Peter Nye found it under an eagle nest. Feathers are made of a protein called keratin. Our hair and nails are made of the same material.

Strong Shaft

Feathers must be strong, light and flexible. The center of the feather is called the shaft. It gives the feather strength like a backbone. Barbs come off the shaft and form the main part of the feather. They zip together for strength.

Base of the Shaft

Near the base of the shaft the feather changes into softer down. This part of the feather is against the eagle's body. It holds a lot of air and acts as insulation against the cold and heat.

The Quill

This end of the shaft is called the quill. It is hollow. It grew out of the skin from feather follicles*. Human hair grows out of folicles, too! Tiny muscles allow the eagle to move their feathers.

Follicle: A cone-like sheath below the surface of the skin the feather grows out of.

Used as Tools

Do you know how people have used feathers as tools?

Peter Nye

Quill Pens

Before modern pens were invented a strong feather was used for writing. These pens were called "quill" pens. Remember, bald eagle feathers are now protected and wouldn't be used for this today.

Molting Time

Each year, during their molting time, eagles lose some old feathers and grow new ones. Not all feathers are lost at once. It takes several months. Young eagles go through four different plumages until they reach their mature adult plumage, which would be the fifth plumage type. These are: Juvenile, White-belly I, White-belly II, and Adult transition plumages. Once they reach maturity, it is likely that bald eagles molt their flight feathers just about every year.

What plumage would you call this bald eagle?