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, September 26 2016, Chidiwa Unzen city, Nagasaki, Japan. Picture: Nobuo Fukushima.

Please visit Nobuo's website.

No signs of immaturity in this moulting bird, therefore probably adult but could be 4CY. Still moulting outer primaries: P7 fully grown, P8 growing, P9-P10 missing, new primaries all with small white tips. At the same time active moult in secondaries.