Date: 10/27/17 6:02 pm
From: <5hats...>
Subject: [obol] Re: Provenance of the Portland gnatcatcher
So is there talk of splitting eastern and western Blue-gray Gnatcatchers into two species, or what?
Darrel



From: "Jay Withgott" <withgott...>
To: "OBOL" <obol...>
Sent: Friday, October 27, 2017 3:52:03 PM
Subject: [obol] Re: Provenance of the Portland gnatcatcher


To follow up on Shawneen's very helpful posting about Washington records of Blue-gray Gnatcatcher.... Ryan Merrill, also of the Washington Bird Records Committee, pointed me to a field mark that I was not aware of for distinguishing eastern vs. western gnatcatchers, which is shown in this photo collage that he compiled:
https://www.flickr.com/photos/rjm284/34906388555/
The field mark is the angle between black and white on retrix #5, the second tail feather in from the outside. As Ryan explains: "... the pattern of black on R5. In eastern birds the black makes a small angle in relation to the feather shaft (maybe 30 degrees), while on western birds the angle is much more extreme (like 60+ degrees). I made a composite photo showing the difference. I believe it was Peter Pyle who first pointed out this difference in the tail feathers after investigating the subspecies of the first Neah Bay BGGN "way back" in 2014 and it's held up in a small sampling of museum specimens plus a bunch of photos/Neah Bay birds I've looked at."

Here's wishing folks luck on getting a photo as nice as these of the spread tail on Nick's Kelley Pt. bird!

Jay Withgott, Portland


 
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