The main tail feathers are the so-called 'rectrices'; upper and lower (or under) tail covert feathers (greater and lesser of both) conceal the bases of these. The rectrices are usually referred to by numbers, counting outwards from the right and left members of the central pair. Most commonly there are 12 rectrices, but larger numbers are quite frequent. See picture under 'bird topography'.

Alternative forms for tailfeathers : rectrices, tailfeather.