<Dd> Singular: rectrix . From the Latin for "helmsman", they are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the tail of a bird, which help it to brake and steer in flight . They lie in a single horizontal row on the rear margin of the anatomic tail . The vast majority of species having six pairs . They are absent in grebes and some ratites, and greatly reduced in size in penguins . Many grouse species have more than 12 rectrices . Some species (including ruffed grouse, hazel grouse and common snipe) have a number that varies among individuals . Domestic pigeons have a highly variable number, due to centuries of selective breeding . </Dd> <Dd> Main article: Flight feather § Remiges </Dd> <Dd> Singular: remex . Also defined herewith: postpatagium . From the Latin for "oarsman", they are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings of a bird . They are located on the posterior side of the wing . Ligaments attach the long calami firmly to the wing bones, and a thick, strong band of tendinous tissue known as the postpatagium helps to hold and support the remiges in place . Corresponding remiges on individual birds are symmetrical between the two wings, matching to a large extent in size and shape (except in the case of mutation or damage), though not necessarily in pattern . They are given different names depending on their position along the wing . </Dd> <Dd> Breeding summer visitor Resident year - round Winter visitor Range map for Eurasian blackcaps--corresponding to the example use of "resident" in its definition at the left </Dd>

Feather is a term used to describe the appearance of