Slaty-backed Gull
Larus schistisagus

Slaty-backed Gull(breeding), Unzen city, 17 Mar. 2012

Slaty-backed Gull(non-breeding), Unzen city, 9 Dec. 2009

Juv.(1cy), Unzen city 25 Nov. 2022

2cy, Unzen city 27 Feb. 2023