How people use feathers. Feathers consist chiefly of keratin, a substance also found in the hair of mammals and the scales of fish and reptiles. Unlike hair and scales, feathers have a complicated branching pattern. Kinds and parts of feathers. The parts of a feather vary, depending on the feather.
Contour feathers grow on a bird's body only in special areas called pterylae.
From the pterylae, the relatively large contour feathers fan out to cover the bird almost completely. A typical contour feather has a broad, flat vane attached to a long central shaft. The shaft consists of two parts. A hollow, rounded base, called the calamus or quill, extends from the bird's skin to the vane. The solid, tapering upper part of the shaft, called the rachis, runs through the vane.