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)

Black-tailed Gull (crassirostris) 4th basic moult / 4CY July - September

Birds in complete moult. When the old feathers with immature features will be shed, and new adult-like feathers grow in, it will become very difficult to exactly age all individuals. Therefore birds are grouped here as "sub-adults", without specific age.

Black-tailed Gull (crassirostris) sub-adult, September 01 2015, Tokyo, Japan. Picture: Yoshihiro Ogawa.
Black-tailed Gull (crassirostris) sub-adult, August 17 2008, Brantley Lake, Eddy Co., New Mexico. Picture: Jerry Oldenettel.
Black-tailed Gull (crassirostris) sub-adult, September 04 2011, Shikotan - Kuril Islands, Sakhalin Oblast, Russia. Picture: Dmitry Kulakov.
Black-tailed Gull (crassirostris) sub-adult, August 08 2013, Hachinohe-shi, Aomori Prefecture, Japan. Picture: Shigeo T.
Black-tailed Gull (crassirostris) sub-adult, August 19 2005, Tokyo, Japan. Picture: Trunck Wood.
Black-tailed Gull (crassirostris) 3CY, August 15 2014, Tokyo, Japan. Picture: Trunck Wood.
Black-tailed Gull (crassirostris) sub-adult, October 11 2015, Chidiwa Unzen city, Nagasaki, Japan. Picture: Nobuo Fukushima.
Black-tailed Gull (crassirostris) sub-adult, December 10 2014, Chidiwa Unzen city, Nagasaki, Japan. Picture: Nobuo Fukushima.