>I've finally, unequivocally, found a Northwest(ern?) Crow in Seattle.
>Pioneer Square to be exact:
>
>My wife and I were walking along 1st Ave, about a block N of Elliot Bay
>Bookstore, and I noticed a small crow scrounging about in the gutter. It
>was so small I commented to my wife that it could be the nefarious NW Crow.
>A Rock Dove promptly came in to see what was so interesting (to the crow,
>not us), and I was excited to note that this crow couldn't have been an
>inch or two longer than the dove (all in the tail). To confirm my now
>certainty that this was indeed a NW Crow, the dove drove off the crow with
>a mere lunge at it!
>
>These guys are quite noticeably smaller than the usual crows seen in this
>area, and interestingly enough this one was all alone (lost, or just out
>on a foraging mission?).
>
>Michael Patrick

Although people talk about seeing differences in crows all the time, this
would have to be backed up by some sort of bimodal size distribution in our
crow populations, and it just ain't so. Some crows look small to me, too,
but I've examined all those in the Burke and Slater Museums, and there is a
1961 publication on crows in North America based on much larger series of
specimens, and no one has found two different-sized populations of crows
living side by side in this region.

Crows average smaller in western than eastern WA, but not a whole lot. For
the most part, crows just get smaller and smaller as you come north from
Oregon and toward the coast from eastern Washington, with no dramatic
break. It may be that the size variation we see in this area comes from
the relatively recent mixing of genes of the smaller crows of the northwest
coast and the larger crows of the interior and farther south, which would
produce a bit more variation than in areas where only "pure" types occur.

I don't deny that you saw a small crow, but--notwithstanding the available
guide books--the evidence for a distinct small species of crow on the
Northwest coast is not convincing.

To follow up on your Rock Dove comparison, I checked in David Johnston's
"Biosystematics of American Crows," the book I mentioned above, and his
weights for male crows are: AK 414 g, western WA 413, CA 418, interior BC
& ID 449, Ontario/Michigan 504, Georgia 447. Unfortunately no weights
given from interior WA or OR.

I then checked our collection records on the computer for Rock Dove
weights, which averaged 307 grams (N=13). From Johnston's table, female
crows from western WA averaged 364 g, indicating an average for the species
of about 390 g (halfway between 364 and 413). Thus adult crows in this
area average about 25% larger (heavier) than Rock Doves--and, I would have
thought, could dominate the latter easily. Maybe you indeed found a new
species--Corvus wimpii.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416