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Types of Feather Anatomy

Essential for a birds' survival as a species, feathers are complex structures that serve several functions --- flight, insulation and protection. Although all types of feathers share the same basic structure, some feathers look different from one another and have different roles. The three basic types of feathers are contour, flight and down, along with a few specialized types of plumes.

Basic Structure
- All types of bird feathers share some basic parts. Feathers have one central, hollow support shaft called the "rachis." The lower bare part of the shaft is called the "calamus," or "quill." Farther up is the central vane, which has finer side branches called "barbs." The barbs have tiny filaments called "barbules" that have hooklets that attach to the barbules on each side. This links the feather barbs together to allow for flight and water resistance.
Contour
- Contour feathers are found along a bird's body and give it a smooth, rounded shape. They protect and insulate birds from the elements including rain, snow and wind. Contour feathers also streamline a bird for flight and protect against injury. These types of feathers tend to be the most vividly colored of any on a bird's body.
Flight
- Remiges on a bird's wing allow it to fly.
  
  Flight feathers are a type of contour feather. They are essential to a bird's ability to take to the air. They are the largest feathers found on a bird's tail and wings. On the wing, flight feathers are known as "remiges" and are divided into three types. Typically there are 10 primaries, 10 to 14 secondaries and a handful of tertiary feathers. The tail feathers are called "retrices." They serve as a rudder for a bird in flight, as well as a brake.
Down
- Finally, down feathers are the small soft feathers found under contour feathers. They lack barbules so they do not smoothly zip together as do contour and flight feathers. This allows down feathers to capture a layer of air near the skin. The air acts as an insulating layer that protects a bird from cold and heat. For centuries humans have known about this quality of down feathers and collected them to use in blankets and coats.
Other Types
- There are a few other types of feathers found on some birds. Filoplumes have fine, long bare shafts with a few barbs at their tip. Scientists are not sure what their use is but suspect filoplumes may be a sensory function. Semiplumes are a hybrid of down and contour feathers that are used in courtship displays and for insulation. Bristles are hard, nearly bare shafts found around the eyes and mouths of some birds. They serve a protective function.

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