Posted by Charlie Wright (205.188.197.182) on October 18, 2000 at 19:22:54:
Ok, I've been staring at these interesting photos for over 11 days now, 3+ hours each day, and I am now thoroughly confused about the left-hand bird. I've been zooming way in on certain parts of the photo, and have gotten a lot of detail.
#1. Western Bell's Vireo?
My first reaction was Bell's Vireo (BEVI), and that is still my first choice. But there are some major marks that make me think that this might be something else. After looking very hard it seems the bird could well be a Bewick's Wren (BEWR). But there are things that point away from that also. I'm convinced that it is not a gnatcatcher. The legs are very large, gray, and scaly. All gnatcatchers that I've seen (Black-tailed and Blue-gray) have tiny, black, warbler-like legs. So I'm going to rule out California Gnatcatcher. I believe BEWRs usually have pinkish or brownish legs, but I'm certainly not ready to rule out this species yet. The posture of this bird looks good for both BEWR and BEVI. Juvenile Vermillion Flycatcher was an interesting thought also. The face pattern looks almost identical to the mystery bird. But of course there is no spotting on the breast or belly. From what I can see of the tail it is dark with a couple white blotches. As far as I can tell all the black could easily be shadows. The tail appears to be fairly squared off and quite long, like a BEVI. I cannot see the undertail coverts, which would be a very useful mark. The bill is obviously broad, espesially at the base, and not very decurved. The upper mandible is dark and the lower mandible appears half bluish-white and half dark. The facial pattern of the bird is what has really got me confused. It has a broad, but not clean white, eyebrow. The eye closest to us looks like it has a strong lower eye cresent but little if any upper eye cresent, which looks very good for BEWR. However, after zooming in on the eye farthest from us, it looks very much like it has an almost complete eyering, like a BEVI. Maybe I'm just looking too hard. The lores are darkish, but not too dark to be a BEVI in my opinion. The auriculars also appear to be dark, but I bet this has something to do with shadowing. The cap doesn't seem to contrast greatly with our view of the coverts, which seems to point a bit to BEWR. But the cap looks to me to be a much grayer color than the rufous cap I'm used to on Bewick's. As far as the coverts go, I see no wingbars, which would point to BEWR and away from BEVI. But this area seems to be greatly shadowed, so maybe there are wingbars and I just can't see them. The underparts seem to have a very slight yellowish tinge to them, but this could also be shadowing. So I'm going to stick with western Bell's Vireo for now, but it could easily be something else.
#2. 1st fall female MacGillivray's Warbler.
At first glance this is an easy ID. But then a couple strange marks show up when you look hard enough. Easiest to see are the faint greenish streaks on the side. I think this could be an elusion of the way we're viewing the bird and the way it's feathers are ruffled. Next is the seemingly broken black bib. I think this could be due to overexposure. The supralore is very bright whitish on this bird, brighter than I have ever seen on a MacGillivray's Warbler (MGWA). But it HAS to be a MGWA, doesn't it? Do any other warblers ever have the very bold eye-cresents like this bird? The throat color looks overexposed, not yellow as it would in a Mourning Warbler (MOWA). The legs are pink, as they should be for an oporornis warbler. So it has to be a MGWA, right? But it is a pretty strange looking MacGillivray's!
Thank you Joe Morlan for another fine mystery bird, and thanks to everyone else who has commented. I've learned a lot. I'm looking forward to more comments and the answers next month.