HomeGlossary Bird topography Tarsus The lower, usually bare, part of the leg above the toes. Tarsus colour and length help identify shorebirds; it is also a standard measurement in ringing. Bird topographyRelated termsFull glossary Cere The bare, often coloured skin at the base of the upper bill in raptors, parrots and pigeons. Mantle The upper back, between the nape and the scapulars. Tertials The innermost flight feathers, next to the body, which often cover the folded primaries on a perched bird. Speculum A bright, often iridescent patch on the secondaries of many ducks. Eye-ring A ring of contrasting feathers or bare skin around the eye. Scapulars Feathers on the "shoulder" that cover the join between wing and body on a perched bird.
Tertials The innermost flight feathers, next to the body, which often cover the folded primaries on a perched bird.