Inca tern (en); andorinha-do-mar-Inca (pt); sterne Inca (fr); charrán Inca (es);
Confined to the Pacific coast of South America, these birds breed in the coasts of Peru and Chile.
The Inca tern is a large tern, 40-42 cm long. Males and females are similar in size, with a wingspan of 60 cm and a weight of 220 g.
This species feeds in the cold waters of the Humboldt current. It breeds on inshore (and occasionally offshore) islands and rocky coastal cliffs.
The Inca tern feeds by plunge diving for fish. Often in large flocks, they prey on schooling anchoveta Engraulis ringens, mote sculpins Normanychtic crokeri and silversides Odothestes regia. They also eat crustaceans and scavenge offal and scraps from sea-lions and fishing boats.
The Inca tern nests in a hollow or burrow, or sometimes the old nest of a Humboldt penguin Spheniscus humboldti, and lays one or two eggs. The two main peaks of egg-laying occur in April-May and October. The eggs are incubated for about 4 weeks, and the chicks leave the nest after 7 weeks.
IUCN status – NT (Near-threatened)
Although still common in many locations, the current population of 150.000 is much lower than in the past. Recent phenomena of El Niño Southern Oscillation (ENSO) have caused mass breeding failure. The guano industry and overfishing of their prey are the two main threats on this species.