What term describes the type of feather primarily responsible for flight in birds?

The term that describes the type of feather primarily responsible for flight in birds is flight feather. Flight feathers are specifically adapted for the aerodynamic needs of birds, allowing them to generate lift and maintain stability during flight. These feathers are typically long and stiff, located on the wings and tail, and they play a crucial role in the mechanics of flying. The structure and arrangement of flight feathers enable birds to manipulate their flight patterns, control ascent and descent, and navigate through varying air currents effectively.

Contour feathers, while they do provide some aerodynamic advantages, primarily serve to cover the body, provide insulation, and protect the softer down layer beneath. Down feathers are soft and fluffy, designed for insulation rather than aerodynamic function. Tail feathers help in steering and braking during flight, but they do not solely account for the primary flight action. Thus, flight feathers are the most specialized for enabling and enhancing the flight capabilities of birds.