I'm back in Calif now, but, thanks to the persistence of
Ruth Sullivan, I confirmed the dream bird I've been looking
for for years, a SLATY-BACKED GULL.

Late on Jan 2 I was heading back to my car from the Gog-le-hi-te
Wetlands (near Portland and Lincoln in the Port of Tacoma area)
when I decided to scope the gulls on the roof of the meat plant
one more time. There was a darker one up there, so I looked...
concluding it was a more Westerny hybrid, with a mantle shade like
occidentalis (northern Western Gull)-- then I saw a very dark
backed adult gull on to the right that I must have overlooked as a
shadow of an air vent or something. From that distance, it looked
as dark as intermedius Lesser Black-backed (which I've seen in
Norway), slightly darker than southern wymani Western Gulls.
I could also see some streaks on the neck and pink legs, but not
much more from that distance.

The next day, Ruth Sullivan and I located it on a rooftop about
a block north of the wetlands and got good scope views from about
40 yards. Here are some comments on the standing bird:

-mantle nearly black from a distance, more like wymani through scope
-large white tertial crescent, almost bill length
-at one point, it showed 2-3 scapular crescents (the last may have
been a tertial), the upper pair nearly 1/2 bill length; from the
back, these produced a "white staircase" up the bird's back
-rather fine light brown or dirty gold streaks over crown, nape,
and neck sides, coming across breast, though fainter; these streaks
are hard to see from a distance-- except for the neck ones, as they
are thicker;
-that charcoal mascara-- a gray smudge around the eye, somewhat pointed
in front and behind-- again, hard to see from a distance; I was
surprised that this smudge was a completely different color than
the streaks--- in Herring, the eye smudge is a concentration of the
streaks, matching the streak color.
Note that Sl-Bs may be white-headed by late January, so all these
head markings may be molting away.
-the eye was a bit darker than I expected-- a light amber or pale
gold-- appearing dark through binos but pale through the scope--
Note that southern (and even, rarely, northern Westerns and even
one pure Gl-W that I saw at Gog-le-hi-te) can match this eye color!
Of course, Gl-W/Western will not show fine brownish streaks on the
head and neck-- only gray smudging with delicate barring.
-the bill was a tad smaller and straighter than Gl-W/Western with
a smaller gonydeal angle and less steep curve of the culmen to the
tip; it was pale yellow with a reddish spot.

Alas, I never got a good look at the primaries in flight, but the
trailing edge of the secondaries was quite large.

Ruth later got many many photos at point blank range (I missed that!);
these show brighter pink legs than Gl-W and a thin red orbital ring.
No photos of the open primaries yet.


thanks to Rick Romea, Richard Rowlett, Eric Kraig, Rob
Conway, and others for suggestions for my trip. I did see
Ancient Murrelets, but missed many other targets. I was not
allowed in the Thurston Co landfill, but saw the gulls well from
the fence via the subdivision north of the landfill -- nothing
but Gl-W and 2 Californias there. Also, thanks to Steve Mlodinow
for suggesting Gog-le-hi-te--- I saw about 100 Thayer's there of
all plumages-- wonderful place!


Steve Hampton

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hampton at primal.ucdavis.edu
http://www.agecon.ucdavis.edu/homepages/hampton/index.htm

Dept. of Ag. and Resource Economics
UC Davis, Davis, CA 95616 USA