Thrasher ID - Part 2
I received 23 immediate responses within 24 hours of my query.
Clearly, the identification contest is between Brown Thrasher and Long-billed Thrasher, but which one is it? Here are your votes:
Brown Thrasher -- 11 e-mails
Long-billed Thrasher -- 12 e-mails
Interestingly, most that chose Brown Thrasher did not give any reasons for their choice. The three people with comments stated,
1) "That sure looks like a Brown Thrasher to me; I've never seen a Long-billed which had such a "rusty" dorsum."
2) "I see no contrast between a rufous-brown nape and a gray face. If the nape and back are concolor (brown) with the face, then I would say that the bird is Brown Thrasher. But I remain concerned that what I am seeing is an artifact of the photo, rather than a critical field mark."
3) "Based on how brightly colored it is and the fact that its bill looks relatively straight and short for a thrasher, I'd vote for a Brown over a Long-billed."
Comments from those favoring Long-billed Thrasher are:
4) "The photo shows white flanks rather than light brown, which would favor Long-billed and the bill appears a bit longer although that is not a great field i.d. mark."
5) "I find the main distinction between it and the Brown Thrasher seems to be the shape of the markings on the breast and belly. The Long-billed has almost teardrop shaped marks as opposed to the somewhat arrowhead shape of the marks on the Brown. Other than that, the Brown's eye looks to be a paler yellow and the beak a little shorter."
6) "This bird appears to me to be a Long-billed Thrasher. It may difficult at first to see the very substantial gray in the face, but careful attention reveals the bird as marked like Long-billed are here in the Rio Grande Valley. It cannot possibly be Curved-bill Thrasher, for virtually everything is wrong (e.g., the depicted bird's strong, very dark, bottom-side markings), and the fit seems to me substantially better for Long-billed than for Brown Thrasher, due to the gray in the face and the lack of widespread buffy coloration in the underparts. The Brown should have light buffy ground-coloration on the underside, the Long-billed, extensive white. (The bill, by the way, may seem a bit shorter than it is in reality because the bird would seem to have its head turned very slightly away from the observer. The intensity of dark markings in the throat area may be obscured by shadow, given the sun direction.) The intensity of orange in the eye might also be deemed to favor slightly the Long-billed Thrasher hypothesis, although eye color can be tricky, especially in photos. I hope this will be helpful. Here is a caveat: Judging species from a single photo--taken as it is at a single light angle and intensity--can be tricky!"
7) "It is a Long-billed Thrasher--look at eye color and more particularly the slightly deserved bill."
8) "Looks like a Long-billed at either Bentsen or Quinta Mazatlan. Too gray on the head and not bright enough for Brown Thrasher."
9) "The grey cheek, somewhat curved bill and the vegetation, mesquite, suggests a Long-billed Thrasher to me. LBT also have a darker malar stripe, but this is a little difficult to distinguish in this photo. However, the malar area does look dark."
10) "The photo clearly lacks any trace of a supercilium, and the overall body color is no where near rufous enough for Brown. With that said, both of these characteristics can be misleading in photos, and the undertail coverts are masked by the branch. Regardless, I think this is clearly a Long-billed based on the given photograph."
11) "First off, there are only two thrashers that fit this picture: Brown and Long-billed. Second, note the long, slightly decurved bill. Third, note that this bird is most likely an adult. it does not look to me to be a juvie. With all that in mind, take a good look at the eye. Adult Brown Thrashers display a YELLOW eye. This bird has a RED eye. Therefore, I think the bird is a Long-billed Thrasher.
12) "Just as an aside I have long considered the Brown Thrasher/Long-billed Thrasher situation a quite underrated ID issue. I wonder how many of us simply hear or glance a thrasher and check it off as the expected species. In central Texas where both are somewhat vagrant I look closely at every one I come across and quite often find myself walking away without any ID at all. Almost all the marks I saw discussed here in the last couple of days were things that in isolation can apply to either bird. ... The things I typically relied on -- color of face, color of crown, color and shape of belly/breast spots, and extent of spotting along the flanks are all belied somewhat by pictures I found [on the web], so right now I don't feel too comfortable claiming any ID ability. I strongly agree with the assessment of eye color (see (1) above). Further, the length and "curve" of the bill are also deceptive. Many folks I think are fooled by the curve of the culmen (which I think has a relative quality difference maybe, but even this is subjective and may overlap, as may length). I do think that most Browns have a "straight" (perhaps flat is the better term) lower bill, but Long-bills seem to vary from flat to slightly bowed. At best, there seem to be no single diagnostic characters. a "good" individual is probably easily identified by combinations of relative characters, but there are a significant number of difficult individuals out there. I would have said I was leaning toward Long-billed, for what appears to me to be a grayer crown than I would expect on Brown, what appears to me to be a sharper contrast between the color of the back and the color of the breast spots, and what I detect to be the curvature of the culmen on this bird which I believe is symmetrical lengthwise in Long-billed and more heavily weighted toward the tip in Brown. However, none of these things looks absolute to me and I don't think from the one picture I could rule out Brown.
13) "I took a long look at your thrasher and came to a couple of iffy conclusions. The brownish-gray legs, appearance of gray on the face, orange-yellow eye, and slender curved bill suggest to me that this may be Long-billed Thrasher. It also appears to be sitting in a Mesquite Tree, which suggests the correct range and/or habitat. But, you never mentioned exactly where this was photographed at. That's my best ID given the look. Then again, it could be just a dull looking Brown Thrasher."