A keratinous outgrowth of the skin of birds that is highly modified for the purposes of flight, insulation, and display. Feathers can be divided into distinct types: contour feathers, down feathers, intermediate feathers, filoplumes, powder down, and bristles. They are pigmented, iridescent colours being due to scattered light from specially structured feathers. Worn feathers are annually renewed by moulting.
Subjects: Zoology and Animal Sciences.