 The adult plumage is a uniform black, with the exception of a frill of white feathers nearly surrounding the base of the neck and, especially in the male, large patches or bands of white on the wings which do not appear until the completion of the bird's first moulting. The head and neck are red to blackish-red and have few feathers. The head and neck are meticulously kept clean by the bird, and their baldness is an adaptation for hygiene, allowing the skin to be exposed to the sterilizing effects of dehydration and ultraviolet light at high altitudes. The crown of the head is flattened. In the male, the head is crowned with a dark red caruncle or comb, while the skin of his neck lies in folds, forming a wattle. The skin of the head and neck is capable of flushing noticeably in response to emotional state, which serves to communicate between individuals. Juveniles have a grayish-brown general coloration, blackish head and neck skin, and a brown ruff.
