Tern tern tern

The clear skies and calm conditions continue unabated. Over 230 each of L T Duck and W W Scoter flew by, 140 R B Merganser, and 20 R T Loon. Towards the end of the count a steady passage of approx 50 Herring and Ring Billed Gulls was evident. One Piping plover was present. Highlight was about 3 groups of terns going through mid-distance first thing totalling 38. I am familiar with Common and Arctic which breed in N Wales where i live. They were silhouetted against the light so plumage features could not be discerned but they had tail streamers the length of Arctics. This is a pelagic species which tends to migrate up the east and west coasts; the other species with long tail streamers is Forsters which is a scarce but regular migrant, usually in small numbers. Interestingly i had a lone tern three days ago with long tail streamers; i noted at the time that its' call was "unlike Common".
One Red Necked Grebe was the first for many days.