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

(last update: December 2015)

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

Active complete moult, moulting to 3rd cycle. Very 'untidy' looking bird. P10 old 2nd gen, P1-P7 replaced for adult-like 3rd gen primaries. Much black on bill, pale iris. Old tail-feathers with much black, bleached; the central rectrices dropped. In preening bird, note the old 2nd gen secondaries, lacking the bold white tips present in new 3rd gen feathers.