Photo 8751: Black-headed Gull 5RU L. ridibundus adult, January 04 2002, Le Portel / Boulogne-sur-Mer, France (50.42N,1.34E). 

This bird was ringed the day before, on January 03 2002 at Etaples and seen again on January 10 and February 21 2002.

From June into October the complete moult in Black-headed Gulls start with the inner primaries. The second generation inner primaries are dark from below with small greyish tips, in this individual from P1 to P8, best visible from above. From P3 outwards (sometimes from P5 outwards) the second generation primaries show much white, except on the outer-web of P10. The under-wing coverts are pale grey, the tail is moulted to all-white feathers and the bill and legs turn dark red. Only a few individuals can be recognised as 2cy (second calendar year) birds in October by the primary coverts, which may still show some dark markings. Otherwise, most 2cy Black-headed Gulls from October are indistinguishable from adults. This individual, 5RU, is in all respects in complete adult plumage.

Next moult starts in December and goes on into April. It’s a partial moult including the body and head: the head becomes typically brown with obvious eye-crescents. Some birds develop a pinkish wash on the breast, a phenomenon maybe related to diet. When this moult is completed, birds show the "adult summer" plumage.

Ringed Black-headed Gulls in the first week of January 2002 at Le Portel and Etaples (NW France):
Helsinki ST 167.479. This bird was ringed as pullus at the nest, June 28 1995, Korsnäs, Finland (62.55N,21.03E).
Black 5RU. This bird was ringed at the same spot as an adult on January 03 2002 (same day as the day of recovery).
Black 6RW. This bird was ringed as an adult on January 03 2002.
Black 5RV. This bird was ringed as an adult on January 03 2002 (day before the recovery).
Black R023. This bird was ringed as 2cy in 1995 and was reported since for more than 20 times at the same spot. 
Green CC66. It had also a metal ring number ST-172.055 and was ringed as full-grown adult, hatched before 1993. Ringing date: 30.4.1995 at Rautalampi, Finland (62.43N,26.45E).