Gulls in NW Europe

(last update: September 25, 2011 )

Herring Gull adult, January 23 2013, Katwijk, the Netherlands.

Birds with plain grey greater primary coverts are considered full adult.

Bird below:
- sub-terminal black on P10 reduced to small black triangles;
- mirror on P9 merged to inner-web (thayeri pattern);
- black on P9 outer-web just reaches primary coverts;
- sub-terminal black on P5 absent.