Great Black-backed Gull (Larus marinus)

(last update: July 12, 2015)

Great Black-backed Gull 4cy May

Third-summer similar to third-winter, but brown on upperwing-coverts fades, combined with new blackish feathers, creating piebald pattern. White primary tips reduced or lacking. Bill as second-winter, but often with extensive dark yellow behind nail. (Malling Olsen, K. & Larsson, H. 2004  Gulls of Europe, Asia and North America. London: Christopher Helm).