Nazca Booby

The Nazca booby is a seabird that forms colonies on the islands where it lives. It has a yellow iris, a pinkish-orange bill, blackish facial skin like a mask and grey legs. Adults have white plumage with the greater wing coverts and the tail black. They show sexual dimorphism: the female is larger and heavier than the male, and there are also differences in the colour of the bill, although these are almost imperceptible. They are notable in that the female gives harsh calls and the male whistles. The chicks are altricial, with later stages of snowy colouring with down. In the juvenile stage, when they make their first attempts at flight, they have greyish plumage, as do the wings and the bill. It nests in areas near cliffs on ground with sparse vegetation, since they nest directly on the ground. They are pelagic in habit away from the islands where they nest. Its common name refers to the Nazca Plate and was given because its present distribution and its evolutionary history may be linked to this tectonic plate.