Grey underwings We are playing mean tricks with you here, throwing you a bird which is largely submerged in water, and so only giving a limited number of ID clues. Possibly it has just plunged to catch a fish, or perhaps it has been photographed mid-bath. Whatever it is up to, there should still be enough on show to give you a decent chance of identification. Firstly, and crucially, those underwings are pretty uniformly grey, which should immediately set alarm bells ringing: this is not a ‘conventional’ sea tern, but looks like one of the three marsh terns in the genus Chlidonias. White-winged Black Tern has very obvious contrasting underwing with black wing coverts. Whiskered Tern has striking white cheeks and a red bill. This bird has a blackish head and bill (just visible) with no white or red on show. It is a spring Black Tern.
KEY FEATURES Fairly uniformly grey underwings Dark head; bill black Breast looks dark grey (not easy to see)