The first juvenile Yellow-legged Gulls have started to appear. Each session on 'my' stretch of the Thames between Craven Cottage, Fulham, and Chiswick Pier produces up to five michahellis, usually always involving a different selection of birds. I've had at least three different juveniles over the past couple of weeks, although most of the birds seen have been 2cy and 3cy, with the one or two older birds thrown in for good measure.
Juvenile Yellow-legged Gull, Fulham, 23 July 2017
2cy Herring (left) and 2cy Yellow-legged Gulls, Fulham, 23 July 2017
2cy Caspian Gull 'X307', Fulham, 21 July 2017
The second bird, first seen just two days after X307's appearance, was a more familiar face - 'G0UT', a Thames-ringed Casp that first visited this stretch of the Thames back in late March, a few days after it was ringed at Pitsea. Here are a few pics of it from back then. I'd say this one is a bit less impressive than X307, showing a few more hints that Herring Gull might be mixed in somewhere down the line. A few images from recent visits below, it seems pretty regular at the moment so here's hoping it hangs around here for a while.
4cy Herring x Lesser Black-backed Gull, 29 July
Juvenile Great Black-backed Gull, 29 July. This species must breed somewhere along this stretch of the Thames - I see at least one pair of adults throughout the year and two youngsters present last week were very fresh. There are usually a few immatures hanging around as well.