American Herring Gull (smithsonianus)

(last update: October 30, 2015)

Slaty-backed Gull (schistisagus) 4th cycle (4CY), September 15 2009, Nemuro, Hokkaido, Japan. Picture: Hannu Huhtinen.

Active complete moult, P1-P6 replaced, P9-P10 old. Old P10 with mirror and old secondaries adult-like indicate age 4CY. No black on bill. Small gonys spot on pale yellow bill (pink base) and iris with limited speckling. Broad tertial crescents (upper tertials new) but old 3rd gen secondary tips worn by September (secondaries exposed as central GC have been shed). Upperparts grey tone about equal to graellsii Lesser Black-backed Gull. Pink, short-looking legs.