Sterna paradisaea
Differs from Common Tern in shorter head, and blood-red bill. Legs shorter, but tail streamers longer (extends well past wings in sitting birds). Underparts of primaries with sharply bordered dark trailing edge (diffusely bordered in Common Tern). Both primaries and secondaries transparent to sunlight. Crest less apparent than in Common Tern and underside greyer. Cheeks white just below the black cap, often in contrast to grey lower cheeks. Juveniles lacks buff coloured back.
Similar to Common Tern but higher pitched. Typical call a series of high pitched "tip-tip-tip", and longer, ringing, high-pitched "kriiiiii" calls. The drawn out "kree-aaahh" call falls less distinctly in pitch than Common Tern.
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology
