wing

Appendage of flight formed of hollow bones and feathers, and comprising the forelimb; in certain species, the wing is not adapted for flight.

secondaries

Rigid feather of flight inserted into the central portion of the wing; it protects the primaries when the wing is folded.

greater covert

Covert feather at the base of the wing protected by the middle coverts when the wing is folded.

scapular

Shoulder feather inserted into the edge of the back.

tertial

Rigid feather of flight inserted into the inner portion of the wing; it helps to decrease air turbulence.

middle primary covert

Short feather covering the base of the secondaries; it maintains the body’s internal temperature and allows air to glide over the wing.

primaries

Rigid feather of flight inserted into the outer portion of the wing; it provides propulsion.

lesser covert

Covert feather at the base of the wing arranged in rows and highly exposed to wind action.

middle covert

Covert feather at the base of the wing; it is protected by the lesser coverts when the wing is folded back.

alula

All the short wing feathers inserted into the thumb; they provide stability during slow flight.

primary covert

Short feather covering the base of the primaries; it maintains the body’s internal temperature and allows air to glide over the wing.