Black-headed Gull Chroicocephalus ridibundus

(last update: 3-04-2011)

Tim Audenaert
Maarten van Kleinwee


BHG 1cy May
BHG 1cy June
BHG 1cy July
BHG 1cy August
BHG 1cy September
BHG 1cy October
BHG 1cy November
BHG 1cy December

BHG 2cy January
BHG 2cy Febuary
BHG 2cy March
BHG 2cy April
BHG 2cy May
BHG 2cy June
BHG 2cy July
BHG 2cy August
BHG 2cy September
BHG 2cy October
BHG 2cy November
BHG 2cy December

BHG adult January
BHG adult Febuary
BHG adult March
BHG adult April
BHG adult May
BHG adult June
BHG adult July
BHG adult August
BHG adult September
BHG adult October
BHG adult November
BHG adult December

Below: First-calendar year Black-headed Gull, August 18, 2009, Grote Dobbe, Zoetermeer, The Netherlands (52.059N, 4.494E). Photos: Maarten van Kleinwee.

First-calendar year Black-headed Gull, moulting to first-winter (formative) plumage. In this post-juvenile moult, all feathers are replaced except those on the wings and in the tail.

In this individual, the body is now almost completely white and the brown markings on the head and hind neck have started to fade. The scapulars still show predominantly first-generation, juvenile brown feathers, while the scapulars have been mostly replaced by gray, second-generation feathers The outer tail feathers show dark markings on the inner web (the norm is a fully dark tip on T6, while on a minority T6 is completely white). In the lower image, not the dark markings in the outer web of P6-P10, parts of which can be retained in later years.