Figure Drawing - Bird Horns

Bird characteristics: Body always covered with feathers; feet (toes and usually tarsometatarsus) covered with scales (thickened skin). Aquatic birds have webbed toes. No teeth; horny beak. Lightweight skeleton in flying birds (many hollow bones), with keel on sternum for attachment of flight muscles (pectoral muscles). No keel in large flightless birds (ostrich, emu, rhea). Completely bony ribs (no rib cartilage). Clavicles fused into single bone, the furculum (wishbone). Numerous neck vertebrae (number varies by species) provide great neck flexibility. Some of the middle thoracic vertebrae fused in some species (chicken); posterior thoracic, all lumbar, and all sacral vertebrae fused into...