Hello All
This afternoon I found a different Slaty-backed Gull among about 1500 or
2000 gulls that congregated on the Boeing buildings visible from Cedar River
Park near the bathrooms. Gulls have not been coming into the sandbar the
last several times I have visited, so this spot is your best chance.

This bird is in almost complete alternate plumage, with just a few faint
brownish streaks behind the eye. The mantle is deep blackish-gray, with
broad white tips to the secondaries and a very broad tertial crescent. The
outer primaries, from below, were just over 2/3rds white when folded. The
bird flew up and landed again twice while I watched, and the second time I
was able to get good views of the spread wing. The pattern was complex, with
a large mirror on P10, separated from the apical spot by a small strip of
black, and a smaller, but still moderately-sized mirror on P9. There were
obvious white subterminal "moons" on each feather from the outer secondary
to P8, the one on P8 being the smallest. These were evidenced on the folded
wing by "comma"-shaped inner primary spots.

The bird is large and rotund, slightly larger than the surrounded
Glaucous-winged, Western, and hybrids, with a shortish bill and deep,
vibrant pink legs. I took a few digiscoped photos, but light was fading and
because of my camera's shoddy performance in low light I do not anticipate
conclusive results. But I do hope someone else gets a chance to see this
neat bird.

Cheers,
Charlie Wright
Bonney Lake, Washington