Black-headed gull.

Chroicocephalus ridibundus
... sorry, or is it a Lesser black-headed gull?

Better in large (please press "L").

I had a fun photo session in the drizzle this afternoon: I went to Mount Pond on Clapham Common after lunch with a friend, and saw that all the birds were over at one side being fed by a chap with a loaf of bread. The best thing was that the gulls were catching the bread in the air! They could turn very sharply, and could even hover briefly: they're much more aerobatic than I thought they'd be.
What a display! I whizzed around to that side of the pond, and started happy snapping, and got quite a few with which I was pleased despite the bad light and drizzle.

When he finished his loaf of bread and was making a move, I said, "They're amazing: I never knew that these little gulls were so aerobatic! They're black-headed gulls aren't they?". He replied "Lesser!".
Fair enough: I did ask! I can't find any satisfying information on the difference between "black-headed gulls" and "lesser black-headed gulls" (although plenty on lesser black-backed gulls...) so will just have to continue calling them simply "black-headed gulls". Can anyone enlighted me?
He was very friendly after that.

I went to visit the fledglings this morning (Shock! Horror!), but they were just grazing peacefully across the path from the pond. There were 4 cormorants on the pond/island (the most I've seen at once) but the light was too poor to get a decent shot (they were at a distance, so I wanted to use the long end of my 200mm lens, yet 1/40" was the quickest speed I could use with my aperture wide open on ISO400).

Did anyone find my four 200s yesterday?
Thank you for all the positive feedback: it was very uplifting. :o)