I had had good luck finding this bird on many
occasions since 2013 when I believe it was first
found at Gog-Le-Hi-Te Mitigated Wetlands. Earliest
finds were quite distant on industrial roofs seen
from the Wetlands and then closer in the river
gull bathing spot nearby. I believe it was last
year that it generally moved to the area near the
11th Street Bridge - often roosting on the
building roofs immediately west. Then the
buildings were torn down and the gull was most
often found on the concrete slabs where the
buildings had once stood. I saw it briefly there
in January but forgot to take a picture (a goal
for all sightings this year). Then the frustration
began: in addition to a couple of specific trips
to find it, I stopped there on the way to or from
the Coast, to Nisqually and other places south.
Despite it being frequently reported (or I wonder
if sometimes possibly misreported) I simply could
not find the bird. Often in particular light, a
somewhat darker mantled "Olympic Gull" (Glaucous
Winged/Western Hybrid) caught my attention and I
momentarily thought there was success - but the
mantle on this bird is strikingly dark and those
seeming successes were instead added to the list
of failures. I know of several other birders who
have had the same results. I probably tried for
it at least 7 times and I know of others who have
failed more than twice that many times.

Finally today I was able to find the Slaty Backed
on the westernmost of the two slabs. It is now at
least for awhile possible to actually drive on to
the slab. This was the case last week when I was
there and it was being used for longshoremen
parking and had 40+ cars there. Even so the gulls
remained - often on the cars themselves. The Gull
was NOT there when I first scanned the area and
then drove onto the slab and carefully looked at
EVERY gull on the slab and in the river. I left
disappointed but decided to park next to the
closed off 11th Street Bridge and walk up it to
scan again and also to look East in the river. It
took at most 5 minutes to get to a scanning
position on the bridge and BANG there it was -
right in the middle of the lower/second/western
slab where I had driven just moments before. It
was unmistakeable and would not have been missed
on my first look so it must have flown in just as
I left - perhaps explaining some of my earlier
misses - timing just had to be right. So a success
story - made better by being able to approach it
closely (when I returned) and to see close up the
broad white trailing edges to the wings in
distinct contrast to the dark mantle and also the
so-called "string of pearls" on the wing tips and
the awesome eye with its bright red orbital ring,
yellow iris and dark center. Beautiful bird -
finally well photographed.

Anyone interested in a picture can find it at
https://picasaweb.google.com/103072475474183849815/EBirdPhotos?authkey=Gv1sRgCN6ZmOrK_K3a4wE#6130306304711804530

--
Blair Bernson
Edmonds