What type of feathers are primarily involved in the flight of birds?

Primaries are the type of feathers primarily involved in the flight of birds. These are long, stiff feathers attached to the outer part of the wings and are critical for generating lift and thrust during flight. The primary feathers are designed for aerodynamics, allowing birds to maneuver efficiently and control their flight patterns. They work in collaboration with secondary feathers and other wing structures to facilitate various flight techniques.

In the context of the other types of feathers, down feathers serve mainly for insulation rather than flight, helping to keep birds warm. Contour feathers, while they cover the body and give shape to the bird, also do not play the primary role in flight mechanics. Filoplumes are small, hair-like feathers that mostly serve a sensory function, helping birds detect changes in their feather positions but do not contribute directly to the flight capabilities. Thus, primaries are specifically adapted and essential for the active process of flying in birds.