Doodled about with pic of Pom below to show definitive underwing pattern and barring on under tail coverts. Interestingly the tail now looks shorter. (No I didn't chop a bit off in Photoshop.) JB comments - " I would go for Pom - on broadness of wing base and steep hook on bill".
Common Tern showing classic dark wedge (caused by moult) in primaries, also note relatively long bill and short tail.
I'd anticipated a relatively birdless trip but immediately was struck by the large numbers of birds in the bay - principally terns but there were loads of auks as well and a few skuas. There appeared to be a pile of small fish in the relatively calm and sheltered bay.
There were about 80 Common Terns feeding close inshore, amongst these were a very few adult Arctic Terns and about 20 Sandwich Terns. 5 skuas hunted the terns remorselessly, 4 adult Arctic and 1 1stW (as I thought, but look at the photographs because the 1stW shows a classic "double patch", a bicoloured, thick bill with well demarkated dark tip, surely this is a classic juv/1stW Pom. That's the trouble with using the camera, fail to look properly at the birds. (Trouble with electric viewfinders as well, you photograph a poorly seen shape.)
The skuas were fascinating. You'd watch a tern catch a fish and 2-300m away a skua would leave the water and home in on it, picking the bird with the fish out of 20-30 terns swirling in the sky. The skuas formed a cordon around the feeding terns and were generally successful quite quickly. The only bird that held out for a marathon chase all along the bay shore was a Black-headed Gull.
As the afternoon wore on the tern numbers decreased and the skuas closed the cordon closer until terns were being chased by two or even three skuas all over the Kettle end of the beach. Whilst the most skuas I counted at any one time were 5, I suspect more were involved drifting in and out of the bay.
I'd have spent the whole day taking photographs but ...... this was a family trip so I failed to spend the time necessary to get the shots that were possible, and anyway had to spend time photographing the fashion parade (oh yes! lost that battle) and supervising offspring as Louise took the opportunity to walk to Kettleness (pay back for the hour I spent taking the photos I did get). Anyway small people played in sand, I got more time watching (slightly distant) skuas and terns (and failing to pick out the Pom, maybe it had siddled off). Also on offer were Red-throated Diver, Guillemot, Razorbill, Peregrine, Teal, numerous gulls, 2 Gannets 0 Kittiwakes, 0 Fulmars, 40 or so House Martins and a Chiffy.
It seems it was too windy for the clearwing.