Mediterranean Gull adult 17M, February 07 2003, Boulogne-sur-Mer, France (50.42N,1.34E). 

This individual is ringed: left green 17M, in a group of five adult Mediterranean Gulls and two Black-headed Gulls. From late summer to September, a complete moult took place, bringing adult Mediterranean Gulls 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 a partial moult, from January to April, and includes body and head, leaving birds in so-called "adult summer" plumage from early April onwards. However, some birds may develop a black hood from late February onwards. The head shows a jet-black hood, slightly 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. 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.

Ring readings:

• 17M Right as >3CY (metal: Bruxelles E903199) on June 13 2001 at Berendrecht, Antwerpen,
  BELGIUM (51,2N 4,19E), male according size in colony, March 07 2002.
  
  
• 24/07/01  Boulogne-sur-Mer, Plage, Pas-de-Calais, FRANCE  50,44N 1,36E
• 25/07/01  Boulogne-sur-Mer, Plage, Pas-de-Calais, FRANCE  50,44N 1,36E
• 01/08/01  Boulogne-sur-Mer, Pas-de-Calais, FRANCE  50,43N 1,37E
• 15/08/01  Boulogne-sur-Mer, Pas-de-Calais, FRANCE  50,43N 1,37E
• 28/09/01  Wimereux, Plage Nord, Pas-de-Calais, FRANCE  50,46N 1,37E
• 28/11/01  Boulogne-sur-Mer, Pas-de-Calais, FRANCE  50,43N 1,37E
• 07/03/02  Zandvlietsluis (new colony), Antwerpen, BELGIUM  51,2N 4,17E
• 09/03/02  Zandvlietsluis (new colony), Antwerpen, BELGIUM  51,2N 4,17E
• 23/03/02  Zandvlietsluis (new colony), Antwerpen, BELGIUM  51,2N 4,17E
• 30/03/02  Zandvlietsluis (new colony), Antwerpen, BELGIUM  51,2N 4,17E
• 13/04/02  Zandvlietsluis (new colony), Antwerpen, BELGIUM  51,2N 4,17E
• 24/09/02  Le Portel, Pas-de-Calais, FRANCE  50,42N 1,34E
• 18/12/02  Le Portel, Pas-de-Calais, FRANCE  50,42N 1,34E
• 26/12/02  Le Portel, Pas-de-Calais, FRANCE  50,42N 1,34E
• 07/01/03  Folkestone, Copt Point, Kent, GB  51,05N 1,12E
• 04/02/03  Le Portel, Parking Roro, Pas-de-Calais, FRANCE  50,44N 1,35E
• 07/02/03  Le Portel, Pas-de-Calais, FRANCE  50,42N 1,34E
• 20/02/03  Le Portel, Pas-de-Calais, FRANCE  50,42N 1,34E