Hi,

First let me start out by saying this is in no way an attempt to identify
the Conneaut mystery gull.  It is however meant to be instructive in how
photoshop can be used to to give good side by side comparisons of features.

I have posted a composite image here:

http://www.flickr.com/photos/haans42/7297429564/in/photostream

This uses the Slaty-backed Gull picture from its Wikipedia article and a
photo by my friend Frank Buck of the mystery gull.  I picked the Wikipedia
image because it seemed to be a good match to Frank's image in both
lighting and posture. Also because everyone agreed the Conneaut bird was
the size of a typical Slaty-backed Gull and much smaller than a typical
Greater Black-backed Gull.

The top row shows overall coloration and structure.  The first thing that
strikes me is how close the mantles are.  This shows the absolute need to
have comparisons combined with references as in the image I posted
yesterday.  It defies imagination that anyone could accurately judge theses
shades of gray from the picture of the individual by itself or even a
Herring or Ring-billed Gull.  Second the overall structure of both birds,
proportions, leg length etc are very similar. The Conneaut individual looks
a little more bulky. Its head is a different shape from the SBGU as well.

The second row concentrates on the head and here we see how the eye
structures are completely different.  The Conneaut bird has a much smaller
eye.

The third row compares bill shape and structure. With the Slaty Backed
below the Conneaut gull. I heard from several self proclaimed "experts"
outside of this forum that the bill structure was all wrong and was that of
a Greater Black-backed Gulls blah blah blah.  I think this image shows that
claim is utter nonsense as the size proportion and shape are nearly
identical.  For all I know a GBBG matches as well but I wanted to show in
comparison to Slaty-backed.

This was a fun little exercise that took maybe 30 minutes.  I did something
similar last fall to show the Ross's Goose found by Jerry Talkington, at
Ashtabula, was indeed a Ross's and not the same individual as in the more
widely circulated photos of a white goose on the water

I wish there was more of this.  It is both instructive and creates solid
evidence rather than useless banter about what people think.  I could have
also included pictures of wing tips and patterns of white, (which do not
match at all) but I think this effectively conveys the idea of what I would
consider good evidence in these sorts of discussions.

Haans Petruschke
Kirtland

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