mystery bird names offered by many folks:

BREWER'S BLACKBIRD, dark eyed female: Size is an issue. Foraging behavior is
different.

BUSHTIT: Subject bird is 1 to 1-1/2 inches larger than Sibley describes. The
bill is larger than illustrated in the guide and this bird's neck is
noticeable, unlike Bushtits. Bushtits are regular (daily) visitors to our
yard and readily recognizable for their chatter and groupie behavior. Small
and constantly moving they are difficult to photograph. I've not been able
to nab one. The bird pictured was solitary and clearly larger to the naked
eye. It made a sound I can't describe, different from Bushtit chatter. (I'm
okay with a camera but my ears are worthless.)

COWBIRD (female): Size is a problem, cowbirds are a bit larger, unless this
is a young one. Also, the bill should be stouter. Notice elsewhere on this
pbase page a photo of male cowbirds [http://www.pbase.com/image/28754873].
But if it's a young bird maybe the bill changes during the first year.

GRAY CATBIRD: Nope, not a chance. Catbirds I know well from growing up in
the Midwest. Wish we could see them in Seattle but I don't think that's
going to happen often.

GRAY JAY: Size, wow, Gray Jays are big, unless it's a young one, and several
people have said young or juvenile jay. But in the city how often can we
expect to see one? I leave that topic to someone more knowledgeable. Other
Gray Jay markings seem absent.

OLIVE-SIDED FLYCATCHER: Nope, not down low picking through backyard trees
and bushes. Markings are not there.

PHOEBE: No dark tale. Behavior; not a backyard city kid.

SPOTTED TOWHEE very young, just fledged. This suggestion from someone who
recently observed this elsewhere. But I would expect to see some backside
pattern and although the lighting is poor the eye appears black not red,
unless red appears later.

SEATTLE GREATER BUSHTIT: Can't be anything else, says Mike Denny: "I am
amazed at what I am looking at in this photo. This bird is not your run of
the mill bushtit. I do not believe it to be a bushtit as we know the species
today. It has some Siberian Jay looks to it and yet that tail is out of
reach when looking at the measurements for that species. I do not believe it
to be a Brown-headed Cowbird unless the species can morph into a near
likeness of its host. So are we looking at a as of yet Unknown North
American species? A member of a remnant population that has lived under our
noses undiscovered until now ? If it is a "super sized" bushtit and God
knows just about everything and everyone is that today, then from where did
these genes arise? Great discovery! So I am still baffled and will simply
call it the Seattle Greater Bushtit."

Thank you, Mike. I agree. Mystery solved, I'm going back to bed.

Before retiring though here's a second look at the same photo (Canon RAW
image tweeked for color saturation and some brightness added). This is isn't
cheating but it's easy to overdo. Head color (brown) is clearly different
from back (gray) color.
http://www.pbase.com/image/30137628

Good night.
Bill F.