Common and conspicuous seabird of coastlines and inshore waters along the Humboldt Current. Sometimes in flocks of hundreds, diving steeply into the sea among feeding frenzies of cormorants, gulls, and terns. Also seen perched on jetties and cliffs; often with cormorants and pelicans. Adult is distinctive with a snow-white head and neck, and dark upperparts with white scaling on back. Juvenile is dingier overall with a dusky head and body. Compare with Blue-footed Booby (often occurs with Peruvian), which always has white body contrasting with dusky neck.