First-winter Herring Gull with yellow legs and bill base - Exmouth Quay. Not sure what to make of this bird. The tertials look remarkably plain and not at all Herring Gull-like, presumably due to wear, but in flight it looked like a perfectly ordinary Herring Gull. I wondered if the yellow is due to some sort of staining, but I think the colouration is too even for that. Just a pigmentation anomaly?