Mediterranean Gull (L. melanocephalus)
Mediterranean Gull 2cy W99 January 11 2010, Le Portel / Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
W99 green, ringed as pullus in NW France at Conchil le Temple, Pas-de-Calais in 2009.
The complete juvenile plumage lasts for only a short period in Mediterranean Gulls as they start to moult soon after fledging. This post-juvenile moult is a partial moult into so-called "first winter" plumage that starts from the moment the birds leave their colonies in July and will be finished by late September. This moult includes most of the head and body feathers. The head and under-parts become almost completely white, with a dark mask of variable size and intensity behind the eye extending as very narrow streaks over the nape. The eye-crescents are white and the dark smudge in front of the eye contrasts more than in full juvenile plumage. The second generation wing-coverts, mantle and scapular feathers are plain pale grey. The rich brown centres of the juvenile wing-covert centres bleach to a foxy brown and the white fringes quickly wear away. In most birds at least some wing-coverts are included in the post-juvenile moult. The extent of this covert moult is variable, in a few birds nearly all are moulted, in others all juvenile coverts are retained until the next complete moult that starts in May of the next year. All juvenile feathers show wear by September, contrasting with the recently moulted second generation feathers. The base of the bill starts to turn paler and the legs turn slightly paler as well.
Spring 2cy Mediterranean Gull have a partial moult, from February to April, which includes body and head resulting in a 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 many only have some black flecking. The remiges and rectrices remain juvenile and by April have become bleached and abraded. Some individuals include inner wing-coverts in this partial moult, but the juvenile outer wing-coverts are retained and therefore very abraded. The colour of bare parts become more adult-like, with the bill-base turning paler red-orange. Most birds have extensive black on the bill tip, most prominent on the lower mandible. This is the most variable plumage in Med Gull since the appearance of 2cy birds depends on the combination of the extent of the post-juvenile moult, and bleaching and wear in the winter quarters.