Date: 10/3/17 7:55 am From: john flannigan <rublzrme...> Subject: Empidonax ID
Kenn Kaufman has a book in the Peterson Field Guide series: A Field Guide To Advanced Birding: Birding Challenges and how to Approach them. 1990. Has chapter on Empidonax flycatchers. Goes into detailed analysis of points you raised.