Colour-Ringed Hybrid Caspian Gull

Amongst the gulls at Shawell today I spotted a third-winter with the look of a Caspian Gull about it. However, it wasn't a classic and its short wings and slightly odd shaped bill left me underwhelmed.

It was having a wash and brush up and every now and then it would flap its wings hard enough to get it airborne for a few seconds. As its legs left the water I noticed it had a German green colour-ring. Eventually it flew to the shore and gave me a few seconds to read its colour-ring before it flew to the bank between the two lagoons.

Its colour ring read XZDX. I emailed Ronald Klien in Germany and he replied quickly (technology is quite amazing as I did that whilst watching the gulls). XZDX was considered to be most likely to be a hybrid and my observations agree with that. It looks like it has a bit of Herring Gull blood in it. 

Hybrid Caspian Gull XZDX

XZDX is quite a traveller as you can see from its life-history that is displayed below: