Forwarding a message from Cameron Cox:

Tweeters,

Yesterday evening, 02/08, around 5pm, I found a full adult Slaty-backed Gull
in Renton at Gene Coulon Park from the floating boardwalk. The bird was
floating in the water in a huge raft of gulls that were roosting on the
water. It was ridiculously obvious as every other close bird was an adult
Glaucous-winged Gull. Just a stunning bird, mantle color was at the dark
end for Slaty-backed, clearly darker than graellsii Lesser Black-backed Gull
but paler than intermedius. It was about the same size as the
Glaucous-winged, but appeared to be slightly heavier than most, with a
larger head and proportionally smallish bill, with only two primary tips
extending beyond the tip of the tail. The bill was bright yellow with a
large red gony spot. The eye was small and the iris was very pale. In a
narrow ring around the eye there was a distinctly darkened area, giving the
appearance of a black-eye, and it had pale gray, linear head streaking
mainly on the nape. On the water it showed a huge white tertial crescent
and strong tertial step, the scapular crescent was quite large as well. I
waited for twenty minutes until a kayaker paddled through the gulls to see
it fly. As it was fairly dark at this point, as the bird took off I wasn't
able to see the "string of pearls". However it briefly lifted its wings on
landing and I could see a white tongue on the 7th or 8th primary.

If you go to look for it, go fairly late, I have been to this spot 5-6 times
in the past two weeks and never seen more than a few hundred gulls.
Yesterday, however, when I arrived at 4:45 gulls were just piling in and the
numbers of gulls doubled quite quickly. I estimate that there were 4-5000
gulls present with some bird still arriving when I left at 5:25 to fight
traffic. It also helps to go on a calm day because the birds won't roost on
the water when it is choppy. Good luck to everyone. I hope someone gets a
photo because it was a little too dark and too far away last night and my
attempts to digiscoped the bird failed.

Cameron Cox
Seattle
Cameron_cox at hotmail.com