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

(last update: December 2015)

Slaty-backed Gull (schistisagus) 2nd cycle (2CY), September 16 2009, Hokkaido, Japan. Picture: Hannu Huhtinen.

Active complete moult, moulting to 2nd cycle. Inner greater coverts replaced, but central greater coverts missing, exposing the bleached white old juvenile secondaries underneath. Last old juvenile wing-coverts to be found in the upper row of lesser coverts (carpal edge will be replaced last). P10 still old juvenile, very worn. P1-P7 new. Dark iris, pale base on bill.