Mediterranean Gull; Gaviota Cabicinegra

Adult can be told from the very similar Black-headed Gull by the black hood, as opposed to a dark brown hood, and the lack of black primary flight feathers. See pic 2 to see the two differing hood colours. See here http://www.projectnoah.org/spottings/12083745 for a picture showing top and bottom of wings with no black feathers.