Brilleterne Onychoprion anaethetus

Tropical tern with gray back, black cap, and white forehead. Nonbreeding and immatures have a messy dark nape. Most similar to Sooty Tern but paler gray above with more extensive white tail edges, paler undersides of flight feathers, as well as longer and more slender eyebrow. Also compare with the paler Gray-backed Tern. Bridled Tern is found in warm tropical waters worldwide. It breeds on islands, usually concealed by a large rock or bush. Otherwise, usually stays far offshore, often seen perching on floating wood or debris. Rarely seen near land except when blown off course by a hurricane.