It was ringed as a 3Cy.+ male Caspian Gull (which probably means it was an adult) ringed on the 19/4/2011 at a breeding colony in the far south of Poland to the west of Krakow and is in an area of Poland which has been colonised by Caspian Gulls and falls nicely now within their range. The precise ringing location was: ZWIROWNIA ZAKOLE, JANKOWICE, BABICE, POLAND.
Since being ringed it has also been reported on the 1/8/2011 at Wessem in the Netherlands.
It will now be interesting to see if it is recorded at any other sites in the UK or Western Europe or if it returns to its breeding colony in Poland, and hopefully we should now be able to track this if it is reported again.
I attach some more pictures taken by David of this Caspian Gull at Exceat Bridge, Cuckmere.
Map showing original ringing location in Poland on 19/4/11, where the ring was read in the Netherlands on 1/8/11 and Exceat Bridge on 16/12/12. The Polish Caspian Gull breeding colony where it was ringed falls to the south of the approximate hybrid zone mapped in BB104:12:705.
Adult ringed Caspian Gull at Exceat Bridge, Cuckmere seen on the 16/12/2012.