HomeGlossary Bird topography Mantle The upper back, between the nape and the scapulars. In gulls, the shade of grey on the mantle and wings is one of the first things to judge. Bird topographyRelated termsFull glossary Nape The back of the neck. Supercilium A pale stripe above the eye, often called the eyebrow. 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. Casque A helmet-like growth on top of the bill or head. Primary projection How far the primary tips extend beyond the tertials on a perched bird.