Well that was unexpected. Just back into a bit more regular gulling, but driving to work in East Yorkshire, and came across an early morning post-roost flock of c100 Herring Gulls. Onto the verge, quick scan, and a sleeping juvenile that instantly shouted Caspian Gull! The dingy colouration, long narrow scaps, long legs and wings, and cracking greater coverts were all spot on. When it woke, the pale head, narrow bill and indented eye added to the look - what a bird!