Albert de Jong
Larus cachinnans 1CY PUNP August & December 2010, Poland & Switzerland. Picture: Michal Rycak & Ernst Weiss.
Yellow PUNP and metal UKK L-009607, ringed as pullus on June 05 2010, at Cherkasy Kreminchuk reservoir, Ukraine (49,4 32,15).
below: cachinnans 1CY PUNP August 09 2010, Lubna, Poland. Picture: Michal Rycak.
Juvenile plumage, just starting to moult scapulars. Tertial pattern like in michahellis. This bird has textbook jizz and plumage patterns, but overall it looks rather dark. This darkness on the head and body is actually rather regular in fresh juveniles (note that just the first feathers in the mantle and scapulars have been replaced), but British birders used to seeing Caspian Gulls in midwinter might be thrown by how they appear in summer.
below: cachinnans 1CY PUNP December 2010, Switzerland. Picture: Ernst Weiss.
Coverts and tertials juvenile.