Slaty-backed Gull (schistisagus) / オオセグロカモメ / 큰재갈매기

(last update: December 2015)

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

Western Gull (occidentalis) 2nd cycle (2CY), December 17 2015, Eureka waterfront, CA. Picture: E Fox.

Please visit Fox's Flickr photostream, for many more images.

How to tell the hybrid combo "Olympic Gull" (occidentalis x glaucescens) in 2nd cycle and 3rd cycle from immature pure Westerns? It can be struggling with distinguishing sub-adult Westerns from GWGU crosses. 2nd winter WEGU should have head streaking, but how much (if any) is too much for a pure Western? This here pictures gull seems otherwise good for WEGU.