Nashville or Orange-crowned Warbler ID problem

Warbler ID

02 December 2007
Dartmouth, Nova Scotia, Canada

I first (and quickly) identified this bird as an Orange-crowned Warbler, but I confess to not paying much attention, as I was looking for a reported White-eyed Vireo. I did manage one photo of the warbler, which I posted on the NS-RBA web site. Upon seeing the photo Ian McLaren wrote me the following:

"Your Orange-crowned Warbler is an exceptionally drab 1st Basic female Nashville - a plumage not well depicted in field guides. That thorough eye ring and lack of dark eyeline and lighter (often yellowish) supercillium give it away. It may be the one [earlier observers] are calling a "western." It does seem to have a lot of gray in the back, but I don't think it's safely ridgwayii on plumage alone. Maybe they're going on tail-bobbing." [Note: a Nashville Warbler had been reported about 500 metres away within the previous two weeks, and reported as a possible ridgwayii, though without explanation or description.]

I come to this question from the background of having lived for many years in Arizona, where observers tried to turn Orange-crowns into Nashvilles every winter; we had to look critically at a lot of Orange-crowns there. The bird in Blake's photo is a tricky individual and I believe there are some tricks of light happening here as well, but taking all that into consideration, I think it's an Orange-crowned Warbler. It looks much too long-tailed for a Nashville and perhaps too square-headed as well. There is a lot of bright light shining on the bird, coming from a position low and to the right of the observer -- look at the position of the shadow of the twig on the bird's side and even across its belly, suggesting that the source of light was very low. (Blake, was there snow on the ground reflecting light up at the bird?) Taking that lighting into account, I think the white on the belly is an illusion, and I think the chest was probably moderately dark (more so than it appears here) and not the very pale lemon yellow that we usually see on the drabbest Nashvilles. Admittedly the eye-ring looks more complete than on the typical Orange-crown, but it's not outside the range of normal variation, and I also see a hint of a pale supercilium (which you can also get on the dullest Nashvilles, I know). The shape of the bird and the overall distribution of color as I judge it to be both suggest Orange-crowned Warbler. In this case I'm inclined to think that the effects of lighting fooled the camera, so to speak, but didn't fool the observer, who compensated for momentary illusions and identified the bird correctly.

I would have to go with Orange-crowned Warbler. Structurally, the proportionately large head and long tail suggest OCWA. Plumage-wise, the low-contrast plumage, slight supercilium, and slightly darker gray lores points to OCWA although I admit I have no experience with western NAWA. To my eye, the eye ring does not look complete and appears slightly broken on each side. Similarly, the "surprised" look as a result of a bright, full eye ring on NAWAs does not seem to be apparent here. Though as mentioned numerous times on this list, you can only do so much with one photo.

Those of us who live on the left coast are likely to balk at the idea of an Oronge-crowned with that much white around the eye. We're used to lutescens which invariably have yellow eye-ringsand even orestera which at least migrate through in large number are never immaculately white. But celata, well those are eastern vagrants to us. We're likely to lean toward personal experience too much on this call. I agree with those who are calling this an Orange-crowned. Pull the white eye-ring out of the equation and find me any other field marks that point to Nashville....

However, I will comment about Blake's photo, and make a few observations . The light is coming in from the right, at a fairly low angle, but not too low - look at the sun reflection in the bird's eye, as well as the shadow of the small stick crossing the larger branch at 6 o'clock in the photo. If there were significant light reflecting from snow cover, we would see more detail and possibly highlights on the undersides of the branches. The dark mark at the rear of the eyering appears to be a shadow of the upper feathers (eyelid?) cast on the lower feather. I will have to say I've never seen an OCWA with such a strong eyering.

The near-vertical shadow across the bird's body retains the same tone throughout, and looking at a large version of the photo (nice shot, Blake!) the whitish belly definitely carries through the shadowed area and even sticks out to the left. I am certain that the belly is whiter than the sides and breast. The dark-ish area behind the bird's eye is enhanced by shadowing created by the contour of the feathers, while there does appear to be a slightly darker feather color immediately behind the eye. Do all OCWAs show a post-ocular dark line / spot composed of feathers that are darker than the nearby cheek and temple? Do any NAWAs? Checking a few specimens should answer that. Also, I cannot make out any definite streaking on the underparts that are pigment, not contour shadows - Dunn & Garrett say "usually" streaked, but I'd be interested to hear if there are specimens that are totally unstreaked.

Here's where I have a definite failing - I am a white male that has trouble with greens and reds, but aren't the primaries atop the base of the tail (to the right of the branch) grayish in comparison? Here's a knucklehead observation - looking at the plates in Dunn & Garrett, my eyes think the fall female Virginia's Warbler looks pretty inviting. Yes, the head looks blocky, but if I was up there at this time of year, I'd pull my head back and fluff my feathers, too. This is where a series of photos would be nice.

I vote for Nashville Warbler, although I agree with Ian that it's "exceptionally drab". I've never seen an Orange-crowned with such a distinct eye-ring, and the bird also lacks an eye-stripe, which should be evident on most if not all Orange-crowns. The bill also looks quite slight to me, which would fit Nashville better, although the measurements in "Birds of Canada" suggest that the difference in bill length is quite small.

I am in the Orange-crowned Warbler camp. The white eye ring IS broken. All fall Orange-crowned Warblers we see in Newfoundland have quite strong broken white eye rings. It may be that fall Orange-crowned Warblers from the Labrador breeding range (where common) have whiter eye rings than birds even in central parts of the breeding range of celata. In breeding season eye rings of breeding Labrador OCWA are yellow. The gray wash across the breast is right for OCWA but should be yellow on Nashville. Even dull Nashvilles look brighter and cleaner yellow on the under parts than this bird. The dull yellow under parts is right for OCWA. The long tail, long bodied look is good for OCWA and not like the stubby more rounded Nashville shape. There is a hint of a dark lore and a faint but definite hint a pale supercilium extending slightly rear of the eye which is right for OCWA but not for Nashville. If the bird wasn't so brightly exposed this might show up more.

It seems that either "Dunn" or "Garret" should chime in, and I guess it's me since Dunn does not usually follow these discussions. As with any single photo ID issue, I have nothing definitive to say, though I have to agree with the Orange-crowned Warbler camp that this bird looks more like that species than a Nashville. Take away the striking eyering, and there is really little to suggest this is anything other than an Orange-crown. And I agree with those who have observed that Nashville eyerings are not likely to be (are never?) broken in front and back; nor should Nashvilles show even a hint of a dark transocular line as in this bird (though a slight pale supraloral is fine for Nashville). Furthermore, the grayish on the chest, if really present, certainly does not fit any Nashville. Even the dullest Nashvilles should show rather bright yellow undertail coverts (which are always at least tied for the brightest yellow part of the bird in Nashville); I see rather pale yellow there in Blake's photo.

I did want to make one comment about Nashville subspecies. In most respects, western (ridgwayi) Nashvilles (aka "Calaveras Warblers") are like nominate Nashvilles that are tweaked a little bit toward a Virginia's Warbler. By this I mean that they are longer-tailed than nominate Nashville (though shorter-tailed than Virginia's), they bob their tails more (nearly as much as Virginia's), they are intermediate in grayness of the back, and their yellow tends to be clearer (less suffused with greenish). Furthermore, ridgwayi Nashvilles tend to have more extensive whitish on the lower underparts than nominate birds, but there is so much variation and overlap in this character that I wouldn't put much weight on it. Even calls of western Nashville are somewhat scratchier (towards Virginia's) than those of the nominate subspecies. Though the above doesn't expand much on what is in "Warblers", I did want to stress that the perplexing appearance of the Nova Scotia bird should not be explained by its being a Nashville of "western" origin. I chalk the confusion up to photographic conditions that over-emphasized the boldness of the eyering.

Kimball’s information on Calavera’s Warbler are interesting, and entirely congruent with my experience. I am no expert on the subject, but my gut feeling is that ridgwayi (Calaveras Warbler) is actually sister to Virginia’s, and this clade is sister to Nashville. The fact that ridgwayi and Nashville look an awful lot alike is one of those wrenches that evolution has thrown in to confuse us. I know that there is a team diligently working on parulid systematics, I hope they sample all members of this group.

I posted earlier and said thought it looked like a Nashville- now I also am convinced by the arguments of others, as well as seeing that the eye-ring of your bird IS in fact broken, that it's an Orange-crowned. I had not seen this before, and (rightly) could not imagine an Orange-crowned with an unbroken eye-ring! The point that others make--take away the eye-ring, and there is nothing left to support Nashville--is one I follow, and will agree with. Good way of examining it.

I guess I'll have to switch to the O-c Warbler camp. I do see, now, a hint of yellowish supercilium, although try as I might, don't see an eyering splt beyond some hints on one on Nashville's. I'm unsure about shape criteria in such a fluffed bird, although agree the tail is long. Although I've seen some large and bright eye features on numbers of Orange-crowneds here in late fall and winter, they've always been crescents rather than eyerings. There have also been some markedly and uniformly gray-headed birds, bright-yellow below, that might answer to orestera. This one is quite bright yellow below (given the breast in shadow), and doesn't look like to me our usual dull fall celata from the eastern boreal/taiga.

One footnote. Following up Kimball G's authoritative pronouncement, I do note that his and Jon Dunn's "Warblers" mentions that OCWA legs are "slaty brown, grayish, or pale brown, palest on soles of feet and toe pads" whereas NAWA they are "dark gray-brown to dull blackish; soles of feet dull yellow." If you look closely at the NS bird, you'll see blackish legs and yellow soles, whatever that means.