Black-tailed Gull (crassirostris) / ウミネコ / 괭이갈매기

(last update: December 2015)
Coordinators:
Kim Seog-min (South Korea)
Hideo Shimura (Japan)
Peter Adriaens (Belgium)
Mars Muusse (Netherlands)

crassirostris rings
crassirostris PDFs

1CY July-Sept
1CY Oct-Dec

2CY Jan-March
2CY April-June
2CY July-Sept
2CY Oct-Dec

3CY Jan-March
3CY April-June
3CY July-Sept
3CY Oct-Dec

sub-ad Jan-March
sub-ad April-June
sub-ad July-Sept

adult Jan-March
adult April-June
adult July-Sept
adult Oct-Dec

Black-tailed Gull (crassirostris) adult, May 03 2015, Hachinohe-shi, Aomori Prefecture, Japan. Picture: GenJapan.

Please visit GenJapan's photostream on Flickr.

Note dark centres on primary coverts, which is probably present in true adults as well (hence in general probably no safe indication for immaturity, but shape and bordering of black centres may still be of value).