(noun) Short, blunt flight feathers along the inner edge of a bird's wing, close to the body. In flight, they form the trailing inner edge of the wing. These feathers are connected to the ulna and help provide lift during flight by creating the shape of the wing. Secondary feathers are generally shorter and broader than primary feathers, and they have relatively blunt tips. The number of secondary feathers a bird has varies by species from 6-40, and birds with longer wings – eagles and albatrosses, for example – have a greater number of secondaries.
Secondary feathers can be useful for bird identification in several ways. The distinct colors and markings, such as stripes or different colored tips, as well as the length of the feathers in relation to the rest of the wing can be used to identify a bird. For examples, the secondary feathers of a buteo form a distinctive bulge shape along the wing's outline which helps identify these hawks. When folded, the colors of secondary feathers may show as a wing patch to help identify birds.
Photo – Ferruginous Hawk Wing © Alan Vernon
SEH-cuhn-dair-eee FEH-therr or SEH-cuhn-dree FEH-therr
Secondary, Secondary Quill, Secondaries (plural)