What types of feathers do birds have? What are their functions?

Feathers are modified horny scales. They form a streamlined feather cover of the bird’s body and keep it warm.
Birds have three types of feathers. Contour (flywheels, tail feathers and integumentary) have a strong hollow trunk with a fan and a point. They form the feathers of the wings, tail and body. Down feather has a soft, loose fan without barbs. Down feathers are located under the outline. Waterfowl have well developed down – feathers with a short shaft and a tuft of barbs at the top in the form of a brush. Down feathers and down, having air spaces between feathers, protect the bird’s body from heat loss.