FEATHER

FEATHER

A feather is one of the soft, fringed plumes that cover the bodies of birds. Some feathers are tiny and downy, while others are large and brilliantly colored. Feathers are made out of keratin, the same protein found in hair and nails. 

The types of feathers include:

1. Feathers with Vanes: Contour and Flight Feathers.

Features and functions in birds. Contour feathers form most of the surface of the bird, streamlining it for flight and often waterproofing it. The basal portion may be downy and thus act as insulation. The major contour feathers of the wing (remiges) and tail (rectrices) and their coverts function in flight.

2. Down.

The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds.

3. Filoplume.

Filoplumes are hairlike feathers with a few soft barbs near the tip. They are associated with contour feathers and may be sensory or decorative in function. Bristlelike, vaneless feathers  occur around the mouth, eyes, and nostrils of birds.

4. Semiplume.

Semiplumes fall between contour feathers and down feathers, combining a large rachis with downy vanes. Semiplumes are distinguished from down feathers in that the rachis is longer than the longest barbs. They fill in or smooth out the various contours of a bird's body while insulating it, and they also provide flexibility at constricted areas, such as the base of the wings. Semiplumes are usually hidden beneath the contour feathers and are small and often white.

5. Bristle.

Not all species of birds have bristle feathers. Bristles are specialized feathers that are believed to perform a tactile function. They have a stiff, tapered rachis and few, if any barbs that appear only at the base of the feather. Bristles are usually found on the head or neck, often around the mouth or eyelids.

Colors of feather

The colors of feathers are produced by pigments, by microscopic structures that can refract, reflect, or scatter selected wavelengths of light, or by a combination of both.

Most feather pigments are melanins (brown and beige pheomelanins, black and grey eumelanins) and carotenoids (red, yellow, orange); other pigments occur only in certain taxa – the yellow to red psittacofulvins (found in some parrots) and the red turacin  and green turacoverdin (porphyrin pigments found only in turacos).