All,

Hmm, that's discouraging since I consider the birds in
Grant to be among the best for illustrating most of my
points. I will try to come of with some body/head ratios
to illustrate the differences I see.

What I'm seeing has nothing to do with any psychological
misperception, it has to do with having closely studied 200+
GBBG photos, including birds in all possible postures, in
the last week or so and directly and objectively comparing
them with the best photos of the Renton bird.

The belly and rear end shape on the Renton gull are not
subject to posture, at least not to the point where they
would appear normal in a more extended posture. Even
with their necks compressed, GBBG typically look much
flatter-bodied and more attenuated than the Renton gull.
For a gull, the Renton bird looks a lot like a beach ball.

Many GBBG show a broken forehead, it's just typically
not quite so steeply angled or so far out in front of the eye.

The gulls Ryan referenced show certain features that seem
to be more similar than average to the Renton gull, but
they are still structurally different birds overall, and the features
that are more similar place them (apparently) in a small
minority of GBBG, particularly the culmen downslope on
the immature. I'd be interested if anyone can find a photo
of a second individual showing a similar downslope. I
sure haven't been able to. The adult shows the typical
blunt bill end that is very different than the Renton bird.

I agree that the gonydeal angle is within range of GBBG,
it's just on the shallow side compared to most photos
I've seen of that species. Mentioned that more as a
secondary point.

I agree and disagree with Mike - I agree that this bird shows
multiple structural features that are closer to GBBG than other
species, but IMO it is also odd enough where it could easily
be an F1 GBBG x Herring, or have a Glaucous grandparent
or whatever. I'm not arguing that it's not part GBBG, since that
appears to be by far the most likely possibility. I'm simply
arguing that the bird is unusual enough that it can't confidently
be called a pure GBBG, or necessarily even a mostly GBBG.
How that relates to listability or counting the gull as a first
state record are largely political side issues that I'm not
qualified to discuss.

Along with the culmen downslope, the body shape and
size are what I find strangest about this bird, so when he
can't vacuum again, for fun perhaps Mike should try
tracing body (and head) and comparing body/head size ratio,
and in particular body shape with multiple GBBG traces.

Yes, I should have said 2nd-summer (3rd-calendar year)
- ooops, I should know better.

Cheers,

Phil



> I just don't see what you report seeing. That's why I say these features
are
> subjective. I have some familiarity with the literature on the psychology
of
> perception and am aware that eye-witness testimony can be notoriously
> unreliable, that we tend to see what we expect to see. Only by physically
> measuring the features (as ratios, of course, and with careful attention
to
> the precise method of measurement and holding posture constant) can we
> entirely rule out these effects.
>
> Gene Hunn.