HomeGlossary Bird topography Casque A helmet-like growth on top of the bill or head. Found in hornbills and cassowaries; its size and colour are key identification features. Bird topographyRelated termsFull glossary Culmen The upper ridge of the bill from its tip to where the feathers begin. Cere The bare, often coloured skin at the base of the upper bill in raptors, parrots and pigeons. Tertials The innermost flight feathers, next to the body, which often cover the folded primaries on a perched bird. Scapulars Feathers on the "shoulder" that cover the join between wing and body on a perched bird. Tarsus The lower, usually bare, part of the leg above the toes. Primary projection How far the primary tips extend beyond the tertials on a perched bird.
Tertials The innermost flight feathers, next to the body, which often cover the folded primaries on a perched bird.