Eurasian Collared-Dove, Forest Grove, Oregon, 2 January 2010 by Greg Gillson.
If you haven't seen it yet, you should take a look at the new blog by the American Birding Association. It has multiple authors, but Nate Swick is taking the lead in getting it going. It is at http://blog.aba.org/.
A recent article by Paul Hess asks: 'Where are the Eurasian Collared-Doves?' In a few short years these birds have expanded across the North American continent from Florida westward all the way from Mexico to Alaska, yet they seem slow to fill in the mid-Atlantic, Great Lakes, and New England areas.
The ABA article uses world-wide data from eBird to map the range of Eurasian Collared-Doves.
See my previous articles: What is eBird? and Coming to a backyard near you... Eurasian Collared-Dove.