The adult is primarily white, with a black tail, black wings, and a dark mask at the base of a thick yellow bill. Brown head, neck, and upperparts; unkempt white patches may occasionally be seen. Mostly white underwings and a pale golden bill distinguish the immature booby from most other boobies. Up to the age of one year, when the Nazca Booby begins to develop an orange or pinkish bill color, they are nearly identical to the Nazca Booby.