Slaty-backed Gull (schistisagus) / オオセグロカモメ / 큰재갈매기

(last update: December 2015)

Kim Seog-min (South Korea)
Hideo Shimura (Japan)
Peter Adriaens (Belgium)
Mars Muusse (Netherlands)

Slaty-backed Gull (schistisagus) 3rd cycle (3CY), September 16 2009, Hokkaido, Japan. Picture: Hannu Huhtinen.

Active complete moult, moulting to 3rd cycle. P1-P8 replaced for adult-like 3rd gen primaries (P8 > P7). Much black on bill, pale iris and extensive winter head streaking. New 3rd gen tail-feathers with much black again. Central secondaries still missing. Note adult-like patterned inner primaries and secondaries.