covert feather

US /ˈkʌvərt ˈfɛðər/
UK /ˈkʌvərt ˈfɛðər/
"covert feather" picture
1.

Any of the small feathers covering the bases of the larger flight feathers of a bird's wing or tail.

:
The bird's beautiful plumage was highlighted by the iridescent covert feathers.
Ornithologists often examine the pattern of covert feathers for species identification.