the largest quills of a bird’s wing. They overlie each other, forming the springy and movable supporting surface of the wing. There are primary and secondary flight feathers. The primary flight feathers, or primaries, are attached to the bones of the carpus; flying birds have nine to 11 primaries. Secondary flight feathers, or secondaries, are attached to the ulna and number anywhere from six (hummingbird) to 40 (albatross). Sometimes tertiary flight feathers are distinguished; attached to the humerus, they are characteristic of such long-winged birds as the albatross.