This second-calendar gull of presumably Nearctic origin has all the characteristics of a dark male Thayer's Gull. However, the overall darkness of the bird, the extent of dark in the uppertail and the patterning of the scapulars do raise some questions and do suggest much in the way of North American Herring Gull influence.
Dermot Breen found and photographed this bird on Ross Beach, near Claggan, on Tuesday and saw it again much better today.
It is interesting to compare with these Japanese 'Thayer's Gull' images
