Three images of different individuals. Note the combination of old tertials and primaries in these individuals. The partial autumn moult (post-juvenile moult into so-called "first winter" plumage) takes place right from the moment the juveniles leave the colony (usually mid July) and is finished by late September. It's a partial moult of the head and body feathers. The head and under-parts become almost completely white, the head with a clear dark mask of variable size behind the eye extending over the nape. The eye-crescents are white. The second generation mantle and scapulars are plain grey. The edges of the rich brown wing-coverts bleach to pale brown and the white fringes are all but worn away. Only a limited number of lower lesser coverts and median coverts are included in the post-juvenile moult. All juvenile feathers show some wear by October, contrasting with the recently moulted second generation feathers. The base of the bill starts to turn paler and the legs remain dark, but on some birds turn slightly paler.

Next moult in Mediterranean Gull is again a partial moult, from February to April and includes body and head, bringing birds in so-called "first summer" plumage. Most noticeable is the replacement of head feathers: the head becomes much darker with some birds developing a full hood, but often still with white flecking. In this bird the head still shows the winter pattern. The remiges and rectrices remain juvenile and become very bleached and abraded: note the brown outer primaries. Some individuals include inner wing-coverts in this partial moult, but the juvenile outer wing-coverts are very abraded, but note the extend of wing-covert moult in the bottom image. The colour of bare parts become more adult-like, with the bill turning paler red-orange in some birds. In this bird, the bare parts are still dark.

photo below 9658: Mediterranean Gull 2cy, April 20 2002, Boulogne-sur-Mer, France (50.42N,1.34E).