Great Black-backed Gull (Larus marinus) BTO HT31765 9CY, February 06 2016, Boulogne sur Mer, France. Picture Jean-Michel Sauvage.
Bird ringed by North Thames Gull Group near London, in winter on a landfill. Data:
London Ring Number: HT31765, ringed as 1st year, sex unknown, on December 20 2008 10:40:00 at Pitsea Landfill Site, Essex, UK (51.32N 0.30E).