The Viking Gull in Mallaig has now returned back to the harbour, now in fifth-winter plumage. The plumage is now virtually identical to an adult Glaucous Gull. The primary pattern is exactly as in an adult Glaucous Gull, the dark markings that were in the outer primaries in it's fourth-winter have now disappeared. The only distinguishing features to tell it's not a Glaucous Gull, is the injured leg, the leg colour and the overall small size. Stood next to a Herring Gull the bird appeared similar in size, rather than bigger as a Glaucous Gull should be.
For images of it in it's first-winter plumage follow the link here and check the sightings under the 23rd January.