Photos taken this morning on Fife side of Firth of Forth. Very distant, so images poor, but thought it worth a go at ID. Briefly saw the bird flying away, and it seemed to have a white rump.
Photo with Sandwich Tern included as size comparison. Seems to have dark/black belly in this one, but I think this may be down to poor image quality.
Photo with Sandwich Tern included as size comparison. Seems to have dark/black belly in this one, but I think this may be down to poor image quality.