Bob,



I think your understanding of the situation must be incorrect. Around
Vancouver, BC, ALL of our crows seem to be pure Northwesterns, based on
measurements, vocalizations, etc. Same for Vancouver Island. They certainly
do not all turn into pure American Crows as soon as one crosses the US
border. All of the crows in Whatcom & Skagit Counties (which I bird very
frequently), as well as San Juan County, appear to me much closer to
Northwesterns than Americans.



Around Seattle and southern Puget Sound, there is no question that crow
populations are hybrids between American and Northwestern; they are NOT pure
American Crows.



Larry is correct; to sort out the situation, it may well be necessary to
take DNA samples from many crows in many different localities. However, I'm
sure that any such study would conclude that there is one species of crow,
not two. Unfortunately, the study hasn't been done yet.



Wayne C. Weber

Delta, BC, Canada

contopus at telus.net







From: tweeters-bounces at mailman2.u.washington.edu
[mailto:tweeters-bounces at mailman2.u.washington.edu] On Behalf Of Bob Norton
Sent: December-22-09 9:00 PM
To: Jon Leland; tweeters at u.washington.edu
Subject: Re: [Tweeters] NW vs AM Crow



The people who examine crows at the University of Washington say there
are no Northwestern Crows in Washington. They have not been able to find any
Crows in Washington with the correct measurements. North of the Frasier
River in British Columbia they are all Northwesterns except for one area in
Alaska where the American Crows get to the salt water.

If anyone else knows otherwise, please expound and quote your sources.

Bob Norton
norton36 at olypen.com
Joyce (near Port Angeles), WA