Small feathers covering quill bases of tall feathers and ear openings

These are small feathers which overlie the base of the flight feathers.

small feathers that cover the bases of the larger flight feathers of the wing and tail of a bird; includes upperwing coverts, underwing coverts, and tail coverts

smaller feathers covering large wing and tail feathers

The small feathers covering the bases of other, usually larger, feathers.