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

(last update: December 2015)

Kim Seog-min (South Korea)
Hideo Shimura (Japan)
Peter Adriaens (Belgium)
Mars Muusse (Netherlands)

Black-tailed Gull (crassirostris) sub-adult, October 11 2015, Chidiwa Unzen city, Nagasaki, Japan. Picture: Nobuo Fukushima.

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Probably 4CY bird, replacing outer old brown 3rd gen primaries for new 4th gen primaries. Relatively late moult with P9-P10 still old. Note also active moult in secondaries (central secondaries are still old, yet of adult type hence probably 3rd gen - not 2nd gen like).