I wasn't able to feel confident I was measuring the right spot
on the back on birds like Grant 294 where the body was
angled away from the camera. Also head shape tends to vary
(more than usual) when at an angle to the body. For those
reasons I was trying to find and use only reasonably straight, close
profiles. Doing that on the Washington bird pretty much narrows
it down (from what I've seen) to Denny5, and although the body
is slightly angled perhaps also Denny1, because it's close and is
such a good detailed photo. I also get .48ish on Denny1
and a little less on Denny5, so .49 sounds like a reasonably
conservative possible high end for this bird.

I'm getting different ratios for some of the birds in Grant,
so I wonder if such small photos are the best examples to
use (I don't have the other two books). Maybe if they
were scanned and enlarged it would reduce the error margin.

All that said, Mikes measurements do suggest the even if
the Washington gull is on the small end of this ratio, there
is not enough room there to convince anyone that the
gull is as dangerously atypical as I feel it is.

Some of the photos I was using are at this site, which
in terms of photo quality is probably the best series of
GBBG shots of the web:

http://www.xs4all.nl/~calidris/gullindex.htm

Not saying the photos posted so far of the Washington gull
can't be misleading in this respect, but in comparison I find it
striking how dark the markings are on all the immatures at
this site.

Vacuum away, I'll try to come up with something better.

Cheers,

Phil