One month ago, an iceland gull was seen at Chipiona Harbour (Jorma Vickholm). A few days later, on December 12th, this same bird was seen by myself and Rafa García.
Our first impression was of a totally white medium-sized gull, bigger and paler than the mediterranean gull. At first sight, it seemed to be a second-winter, but it really was a first-winter. Note short bill (50-50 black-pink), totally dark eyes and very rounded head. This bird appears almost white with only light brown upperpart-markings.
Most probably Larus glaucoides ssp. glaucoides, but pale birds are inseparable from kumlieni. Greenland represents the main breeding area.
More photos here.