14-8-2017 AMSTERDAM ZOO, NETHERLANDS - INCA TERN (MALE) (Larosterna inca)

The Inca tern is one of the world’s most beautiful and interesting birds. It occurs along the Pacific Coast from northern Peru to central Chile. This bird is easily recognizable with its dark gray body, and red-orange beak and claws, and its lovely white moustache. It is an adept flier that swoops and hovers before it dives after its prey. It sometimes plucks pieces of fish out from between sea lions’ teeth. Unfortunately, their populations are declining quickly because of the loss of nesting sites. They have been included in the “close to vanishing species” category. Inca terns in the wild live up to 14 years and in captivity up to 20 years.

The Inca tern is a large tern, approximately 40 cm (16 in) 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 is a diurnal, gregarious species, living and nesting in large colonies numbering several thousand birds, often close to gull colonies. Inca terns follow fishing boats and often associate with whales and sea lions when feeding, stealing food from these fellow marine mammals. Inca terns feed by plunge-diving from a height, after a brief flight above their prey, or by surface-dipping, whereby they swim or sit on the water and pick up prey from the surface. They are not strong swimmers, as their webbed feet are not big enough. Inca terns remain resident within their range, though non-breeding birds sometimes move, depending on food resources.