Adult Caspian (?) - Llys-y-fran

What looks like an adult Caspian at Llys-y-fran this evening, unfortunately it was getting on for 500m away and thrashing around bathing for most of the time, the joys and frustrations of gulling but I managed a grainy video and extracted a few stills. A big gull with a peppercorn eye, long parallel bill with dark mark on gonys, lot of white on outer primaries, large tip P10, smaller mirror P9 (I think we've seen this bird before but like tonight it was at distance).

Otherwise 3 adult Yellow-legs, 1,600 BH gulls tonight the most so far, 3 Meds (2 adult and a 1w). Lots of gulls on the water at 3pm with waves arriving from over the dam wall and passing me as I drove through Crundale on the way. 2,000 at 3pm, 4,000 4pm, 6,000 4:30pm and est 7,000 at 5pm