Scientific Name: Onychoprion anaethetus
Population Estimate: 610K to 1.5M
Range / Habitat: Bird of the tropical oceans, breeding off the Pacific and Atlantic coast of Central America including the Carribean, off small areas of western Africa, around Arabia and eastern Africa down to South Africa, off the coast of India, and in much of south-east Asia and Australasia excluding southern Australia and New Zealand. They overwinter at sea.
Field Notes: Medium-sized but delicate tern with thin black bill. Minimal black crest and eye stripe form a "bridle" on the otherwise white head and neck. Wings and tail dark grey, underparts white. Least Tern considerably smaller with yellow bill and legs.
Personal Notes: Seen offshore from Manuel Antonio, Costa Rica