TWEETS,
I have bothered Bill Tweit as a member of the establishment about this
problem. My memory of what he said is as follows: He feels you can only count
them from north of the Frasier River where AMERICAN CROWS do not come down to
the coast. From there to the northern limit of their range there is only one
small area where AMERICAN CROWS can comingle (that spot is in Alaska). He also
said (in relationship to a question about swans) that as he got older it
seemed the toughest birds to identify were the all white and the all black
ones. I liked that observation. In short the official line is that they
probably fraternize as freely as our WESTERN GULLS and GLAUCOUS-WINGED GULLS.
If they didn't you would have to prove it with specimen measurments, or even
better, DNA analysis.
That being said, out here on the end of the world, almost all crows seem
to me to be small and to make funny noises except that sometimes in the
nonbreeding season we see a few big crows that sound like those of my Iowa
boyhood days. I have yet to see a group of crows where there were different
sizes.
I do wish someone would do a study of crows with measurements and DNA
analysis. Someone claimed that it was scholastically sexy to prove that there
are two or more species where there were thought to be just one but that you
didn't get any credit for showing two species ought to be lumped.
Also I agree with Mike Patterson's observation. On the OR coast all the
crows seem small and they are also small around Eureka, CA. When I see birds
in OR that are the size of the pygmies around here it makes me very doubtful
that there are two species. I have not paid attention to what small crows in
OR & CA sound like.

Bob Norton
Joyce (near Port Angeles), WA
norton360 at aol.com