Gulls in NW Europe
(last update: September 25, 2011
Herring gull 4cy/5cy (argenteus), August 25 2011, IJmuiden, the Netherlands.
Black in old tail feathers, no mirror on P10 and pinkish bill-base in stead of yellow all indicate sub-adultness. Lack of mirror strongly points to 4cy. P8-P10 old, P5 fully grown.
