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, November 20 2010, Westport - Washington, USA. Picture: Steve Mlodinow.

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

This basic adult bears some resemblance to a Slaty-backed Gull x Glaucous-winged Gull hybrid. Most of those would show more streaking (vs. smudging) on head and neck than seen on this bird, but on the other hand, there is more streaking here than is typical for Western Gull x Glaucous-winged Gull. The black on outermost primaries is more extensive than would be seen on Slaty-backed Gull x Glaucous-winged Gull, the white "tongues" should be more extensive - it should extend to P8 - and P9 would most commonly have a white mirror on Slaty-backed Gull x Glaucous-winged Gull.