I saw a white-winged gull on the beach at Druridge tonight. At frist I thought it was a glaucous gull, but it didn't 'look right' for a glauc. It was a fair way off, on the edge of the tideline.
My conclusion is, without better views, that it was a leucistic herring gull. The head shape and the depth/length/shape of the bill looked good for herring gull. It certainly was odd and looked like a full adult or maybe a third summer bird? It was generally all-over white, apart from some light grey on the wings, it looked a bit 'bright' for glaucous gull too.
Any local birders seen it about?