Mediterranean Gull 8AT adult, February 06 2003, Le Portel /Boulogne-sur-Mer, France (50.42N,1.34E).

This individual is ringed: right white 8AT. From late summer to September, a complete moult takes place, bringing birds into so-called "adult winter" plumage. The head pattern in wintering bird resembles "first winter plumage" after finishing the complete moult: a blackish mask behind the eye. 

The next moult in Mediterranean Gull is again a partial moult, from January to April, and includes body and head, leaving birds in so-called "adult summer" plumage from early April onwards. The head develops a jet-black hood, extending down the nape. Adult birds have broad white crescents above and below the eye.
The secondaries are completely white. The adult primaries are shiny pearly-grey, flashing white at a distance. There is a black line along the outer-web of P10, but on P9 as well in some birds. The secondaries, the under-wing and the tail are completely white. The bare part coloration by February: Iris brown, orbital ring red or orangey-red, the bill red or orangey-red with a black bill-band (and a yellowish tip) and the legs dull reddish or dark.

White 8AT was ringed as >3cy bird (adult) on May 25 2001 in the breeding colony of Kreekrak Oost, the Netherlands (51.27N,04.14N). It then appeared at Le Portel (50.42N,01,37E) to complete the moult from June 28 2001 to December 13 2001. During this period of six months, it was seen 17 times.
In spring 2002, it was rediscovered at Zandvlietsluis (51,20N,04,17E), and was seen from April 25 to May 15 2002. From August 01 2002, it has been seen already 12 times so far, it was seen last February 20 2003 spending the winter months again at Le Portel.