The Inca Tern is a seabird in the family Sternidae. It is the only member of the genus Larosterna.This uniquely plumaged bird breeds on the coasts of Peru and Chile, and is restricted to the Humboldt current. It can be identified by its dark grey body, white moustache on both sides of its head, and red-orange beak and feet.The Inca Tern is a large tern, approximately 40 cm long. Sexes are similar; the adult is mostly slate-grey with white restricted to the facial plumes and the trailing edges of the wings. The large bill and legs are dark red. Immature birds are purple-brown, and gradually develop the facial plumes.The Inca Tern breeds on rocky cliffs. It nests in a hollow or burrow or sometimes the old nest of a Humboldt Penguin, and lays one or two eggs. The eggs are incubated for about 4 weeks, and the chicks leave the nest after 7 weeks.