Herring Gull (argentatus & argenteus)

(last update: February 11, 2013)

Herring Gull sub-adult, July 09 2013, Katwijk, the Netherlands.

This individual probably best left un-aged, as key-features are missing here due to moult. 4CY birds normally aged by sub-terminal pattern on central primaries: P5-P6 with clear cut blackish band and inner primaries adult-like grey.
Active moult in primaries (complete moult in summer months): P3/P6. No obvious mirror on P10.