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)

hybrid Glaucous-winged x Western Gull (glaucescens x occidentalis) adult, January 14 2011, Mukilteo, Washington, USA. Picture: Steve Mlodinow.

Please visit Steve's Flickr photostream, for many more images. And also Dave Appleton's blog on hybrids!

Obvious smudge on head and primaries almost blackish in resting bird, but compare to next image where pigment on outer primaries appear rather greyish, not solid black and only treaching to primary coverts on outer web of P10, not on P9-P8.