Mainly Gulls (19th March 2012).

Yet another Iceland Gull had been seen at Rainham on Friday and Saturday (16th & 17th), but this one was a bit different, and was something that I was keen to try and see - a Kumlien's Gull. Kumlien's Gulls are usually treated as a race of Iceland Gull, breeding slightly further west in north-eastern parts of North America than the nominate race (or 'typical' Iceland Gulls) which breed in Greenland, but are now often considered to be hybrids between Iceland Gulls and Thayer's Gulls.

Whatever they are, it didn't really matter because the bird didn't show at all today! There had also been no sign on Sunday, but I hadn't really expected there to have been, and didn't visit then, because the refuse tip isn't operational on Sundays so there are fewer gulls visiting.

There were still interesting birds to see, with at least two 2nd winter Iceland Gulls present, and seen frequently over the tip, bathing in the River Thames, or just loafing about with the hundreds of Herring Gulls, Lesser Black-backed Gulls, Great Black-backed Gulls, Common Gulls, and Black-headed Gulls.

Careful checking through the gulls here usually produces Yellow-legged Gulls, of which possibly about a dozen were present (all immatures)...

...and with a little bit of time and/or luck it is also usually possible to find Caspian Gulls - I saw at least two 1st winters, and one 2nd winter. Caspian Gulls (and Yellow-legged Gulls) can be easy to overlook, but once you know what you are looking for some Caspian Gulls at least can be picked out quite easily by their shape and stance. One of the 1st winter Caspian Gulls is on the right in the photos below.

Large gatherings of gulls are also worth checking for individuals that have been colour ringed. These rings are designed to be possible to read in the field with a telescope (or binoculars if you are close enough) and by reporting the code and ring colour via the BTO you can help to further the study of gull movements (the same is true for other types of bird). A Lesser Black-backed Gull that I saw while on holiday in the Gambia a month ago turned out to have been ringed on the Suffolk coast!

I managed to read the rings on four gulls, including the one below. There is a good chance that they were all ringed by the London Gull Group on Rainham tip and haven't moved anywhere though:

When I pulled my attention away from the gulls, other birds along the Thames foreshore included a pair of Oystercatchers, a Scandinavian Rock Pipit, and two Water Pipits. One of the Water Pipits was a very smart individual in full breeding plumage, with a pink breast and pale grey head. That one didn't allow itself to be photographed though, and I had to make do with a poor shot of this moulting individual: