Piping Plovers (Charadrius melodus), male approaching female while performing goose-stepping display before copulation, near nest site on beach, northern Massachusetts coast, USA. (Per Birds of North America Online: Approaching the female, the male rises into an erect posture, beating a high-stepping and increasingly rapid tattoo with both feet. Upon reaching the female, he may continue the tattoo for several minutes before flapping his wings and mounting.)