Bridled Tern Onychoprion anaethetus



They nest in colonies with other species of birds such as Sooty Tern (Onychoprion fuscatus), and Great Crested Tern (Sterna bergii), usually nests are separate by 5 m. These birds are aggressive during the breeding season; however, the birds that inhabit the Farallones not show this typical defense behavior. They have several strategies to reduce predation during playback, such as covering the eggs, place them scattered, and the eggs and chickens have a cryptic coloration. Both parents incubate the eggs with 24-hour shifts; parents are responsible for caring for the youth.

It breeds in rocky islands at the periphery of the coastal vegetation, from late April to late July in the southern Caribbean. The nest is placed on the ground, well hidden among broken rocks, cavities in rocks, cactus, small plants or other vegetation. The clutch size is 2 eggs, lays asynchronously, are oval, pinkish-whitish or creamy-white, covered with spots of brown, gray and lavender, measuring 46 x 33 mm. Incubation lasts 28 to 30 days. The chicks are semi-precocial, are born covered with pale gray down with dark brown mottling on back and gray down on belly. A few days old leave the nest and hide in the vicinity; they acquire the juvenile plumage at 30 days and fly for the first time at 55 - 60 days. Usually remain with parents 35 days after its first flight.

Recommended Citation

Bridled Tern (Onychoprion anaethetus), In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. retrieved from Neotropical Birds Online: