Biology

Breeding is thought to extend from October through to January, peaking in November, with full-grown juveniles observed by mid-February. Peruvian terns are solitary to semi-colonial, usually nesting more than 50 m apart in sparse colonies of 2 to 15 pairs (2). Nests are scrapes in the sand without any additional nest material, into which one to two eggs are laid (2) (3). Eggs are incubated for 22 to 23 days (2), and the cryptic colouration of both the eggs and emerging chicks helps hide them from potential predators, such as the peregrine falcon (Falco peregrinus), grey fox (Dusicyon culpaeus) and skunk (Conepaetus rex) (2) (3). Even so, many eggs do not hatch and usually only one chick is raised (2). The diet mainly includes small fish, particularly anchovetta (Engraulis ringens) and krill (Euphausia). Like several other terns, this bird often feeds by hovering over water and then plunge-diving to snatch its prey (2).