Feathers are made of the protein called keratin, which also makes up human hair and fingernails.  The well-structured feathers that help birds fly are called contour feathers, which are a type of pennaceous feather. The softer, less-structured downy feathers that birds use for warmth are called plumulaceous feathers. The structure of the feathers generally makes them inedible for birds themselves, though the Slovenian Grebe birds regularly consume their own feathers! Can you name any of the parts of a feather?

The central part of a feather, known as the rachis or shaft, serves as its backbone, holding the entire structure together. This cylindrical structure is hollow, providing support for the feather's shape while remaining lightweight, enabling birds to fly effortlessly. 

Barbs and barbules on contour feathers “zip” together to maintain the feather's shape, and make it waterproof and insulating. 

The vanes are on either side of the rachis, and they make up most of the feather's surface area.

The afterfeathers are fluffier and less structured. Their main purpose is to provide warmth.

The calamus, also called the 'quill', is the hollow center of the feather that holds the everything together and connect the feather to the bird's body. Interestingly, this hollow tube also served a practical purpose in history—it was ideal for holding ink. This is why quill pens, those elegant writing instruments of the past (or Hogwarts!), were crafted from feathers.

Standards for The Structure of Feathers