A familiar Caspian Gull and a Scandinavian invasion

Another Saturday on the Thames near home, and it was predictably gull packed. The tides this weekend are pretty good, with late morning/midday low tides allowing 6 hours of exposed mud in the Rotherhithe/Greenwich/Thames Barrier area. I started off in Rotherhithe, where on Greenland Dock there was a Rainham ringed Black-headed Gull with a decent history (seen in Latvia three times as well as Glamorgan and Norfolk) while the mud by the Hilton Hotel offered two new Norwegian ringed Black-headed Gulls: -

adult Black-headed Gull Rotherhithe, London 4th March 2017 - ringed as an adult male at Engervannet, Bærum, Norway on 22nd April 2016 and seen at Hovindammen, Oslo, Norway on 25th April 2016

1st-winter Black-headed Gull Rotherhithe, London 4th March 2017 - ringed as a chick at Sognsvann, Oslo, Norway on 12th June 2016

It was then onto Thames Barrier Park, where I joined the usual suspects Dante and Jamie P along with Niall K and Dave J (both here to get some Casp loving). And on cue, a first-winter Caspian Gull turned up and came to the offering of bread. Quite remarkably this was one of the two Caspian Gulls I had last Sunday in Rotherhithe, which was also seen at Beddington yesterday by Josh and David C: -

1st-winter Caspian Gull Thames Barrier Park, London 4th March 2017

There were also three Yellow-legged Gulls there (all regulars, a second-winter and two first-winters). I then headed to the O2 at Greenwich with the crew, and although there were no Caspian Gulls here (which always disappoints young Dante), it had a load of interesting birds including a Norwegian Common Gull, two Danish Great Black-backed Gulls and ten Thames ringed Herring Gulls: -

1st-winter Great Black-backed Gull Greenwich O2, London 4th March 2017 - ringed as a chick at Græsholm, Nordjylland, Denmark on 30th June 2016

1st-winter Great Black-backed Gull Greenwich O2, London 4th March 2017 - ringed as a chick at Græsholm, Nordjylland, Denmark on 26th June 2016, seen at Hirtshals Havn, Nordjylland, Denmark 21st September 2016 and Thames Barrier Park on 5th February 2017

2nd-winter Common Gull Greenwich O2, London 4th March 2017 - ringed as a 1st-winter female in Oslo, Norway on 2nd October 2015

At least three first-winter Yellow-legged Gulls showed well, including this confiding bird which has been seen regularly the last month or so between the O2 and Thames Barrier Park.

1st-winter Yellow-legged Gull Greenwich O2, London 4th March 2017

With increased numbers of Lesser Black-backed Gulls and a good push of new Black-headed Gulls (indicated by the new rings), hopefully tomorrow will be just as productive. It'd be nice to get a handful more Caspian Gulls by the time the season is out...