Clockwise from top left: juvenile Iceland Gull 1, juvenile Iceland Gull 2, second-winter Caspian Gull, ringed first-winter Caspian Gull 'PNDZ', unringed first-winter Caspian Gull, adult Yellow-legged Gull.
I've had a couple of gull sessions in Peterborough over Christmas. Christmas Eve was pretty productive with two juvenile Iceland Gulls and three Caspian Gulls at Tanholt Pits. The 27th was slightly less produced but one Iceland remained at Tanholt alongside the ringed Caspian Gull above, and a different second-winter cachinnans was at Dogsthorpe Tip. The gull roost doesn't seem to be in full effect at CEGB reservoir, but the adult Yellow-legged Gull above was nice on 27th - michahellis are considerably scarcer than cachinnans in Peterborough in winter.
All the photos above are crap as I left my point-and-shoot in London, and had to make do with my iPhone.