1. Has anyone ever before seen, in the carolinas, a female goldeneye with an all-yellow bill?
I have only seen maybe two or three goldeneyes total in the Carolinas. They’re very scarce in South Carolina, so this question is not really the relevant standard. What is relevant is that people who are in areas where both goldeneyes occur said (in the Facebook advanced ID group thread) that they saw Common Goldeneyes with bills like that, and that it did not look like a Barrow’s Goldeneye to them.
2. Does anyone have any published information refuting Jamie's info about the 3rd mottled white patch on the upper wing for Barrow's?
Because his pictures clearly show the mottled patch.
What I like about this ID card is more in relation to the number of white wing panels, not so much the number of feathers or the amount of white within each panel since Sibley clearly thinks it is not too important.
For an adult female, which I am fairly sure my bird is, the middle left picture is what I was looking for in confirmation. Unfortunately yesterday I was not successful in getting an overhead shot of the wing only the under wing.
That line there, “for an adult female, which I’m fairly sure my bird is.” I disagree. I had just played “match the picture” with the scan of the ID card that Jamie included, and based on that, not even pulling out other references, this is an immature female. Adult females of both species have two black lines across the white patch, formed by broad dark tips to the median and greater secondary coverts. The photos of the NC bird show no such lines, only the tiniest dark tip to the greaters. So this looks like an immature female, which makes the “third mottled patch” argument moot.
And again, the two questions above pull out only the points in support of BAGO and ignore or dismiss the clear points against it. There are 7 (more like 7 1/3) white feathers in the secondary patch: Common. Just because Sibley says that is useless in the field and of limited value in photos is not reason to dismiss it. Of course on a flying bird through binocs, or in many photos, you couldn’t count feathers. In THESE photos the white feathers are clearly visible, and there are 7 or 8, depending on how you count that outermost one (there’s even a 9th with a white tip). Also on the card (don’t know how reliable this is) it says for Barrows “able to see through the nostrils.” In a near-perfectly positioned profile photo of the NC bird, you can’t see through the nostril. And in the whole collection of comparative photos, the head profiles are essentially identical. I’ve seen lots of Barrow’s females, and in my opinion the difference would be obvious if it actually were a Barrows. It’s not THAT hard. As Harry pointed out, and I just confirmed by scanning the photos quickly without focussing on the beaks, the black-and-yellow billed bird has the more “Barrows-like” head profile in about half the photos.