[TN-Bird] Re: Nashville Warbler (???)

  • From: Bill Pulliam <littlezz@xxxxxxxxx>
  • To: csloan1973@xxxxxxxxx
  • Date: Sat, 30 Jun 2012 23:26:54 -0500

...which I think points out why it takes more than just a photo of a drab little green bird to document a first summer record for a boreal nesting bird. I'd like some descriptions or documentation about vocalizations and behavior that also appeared to exclude yellowthroat. When you have a choice between two little green birds, one of which occurs by the thousands, the other of which has never been documented before, you have got to consider than an odd looking or oddly-imaged individual of the former is probably more likely than a real occurrence of the latter.


Bill Pulliam
Hohenwald TN

On Jun 30, 2012, at 12:31 PM, Chris Sloan wrote:

This illustrates some of the challenges of photos for ID. We're clearly interpreting what we see in the photo differently. For example, I initially had the same reaction about the crown patch, but then when I zoomed in and studied it more closely, it doesn't seem to be there at all. It's an interesting issue. If had has any more photos of the bird, maybe he can post them.

Chris Sloan
Nashville, TN
http://www.chrissloanphotography.com


On Sat, Jun 30, 2012 at 11:12 AM, Richard Knight <rknight8@xxxxxxxxxxxxx> wrote: I can't believe we're discussing the same photo! To me the photos show little that even suggest Com. Yellowthroat. I have banded over 350 yellowthroats, so
am familiar with close-up, in-hand looks at them.

The head & bill shape are fine for Nashville, actually better than for yellowthroat.

The eye ring is a little weak in front, but still within range for Nashville & rather strong
for yellowthroat.

In both photos, the light seems fine to distinguish the shade of gray on the head.

You did not address the extensive, rather bright yellow underparts. A perfect fit for Nashville & all wrong for female yellowthroat. Immature male yellowthroat is,
of course, eliminated by lack of any trace of black mask.

In the second photo, looking at the top of the head, we can see what appears to be traces of the crown patch of Nashville, which is often partially or mostly
concealed.

While the null hypothesis is a good thing & should be part of our approach to ID, it doesn't always work in nature, otherwise we would never see a rare bird.

Rick Knight
Johnson City, TN


----- Original Message -----
From: Chris Sloan
To: rknight8@xxxxxxxxxxxxx
Cc: tn bird
Sent: 6/29/2012 6:37:18 PM
Subject: [TN-Bird] Re: Nashville Warbler (???)

Here's why I believe this is a Common Yellowthroat:

1. The bill and head shape are all wrong for Nashville. Nashville is one of the smallest warblers and has a very thin, sharply pointed bill with a dove-like, very rounded head. This bird shows the heavier bill and flatter head shape that is a typical of a yellowthroat.

2. The white eye-ring is nowhere near thick and prominent enough for a Nashville. Nashville shows a very thick, bright, uniform white eye ring. This bird shows a fairly weak eye ring. Admittedly it's more prominent than most yellowthroats, but it's nowhere near strong enough for a Nashville. Yellowthroats can show a pale eye ring like this at times.

3. The color or the head is misleading. Yellowthroats have a grayish brown head also, but the real test is the contrast between the head and the rest of the upperparts, which is uniform in yellowthroat and sharply contrasting in Nashville. We can't see that in these photos. I do not believe the color shown here is as gray as Rick interprets. It's hard to say for sure in that light, but to me it looks fine for a yellowthroat.

Remember that the null hypothesis here has to be Common Yellowthroat at this time of year, particularly in a location that is quite literally covered up with them as breeders. In my opinion, this bird shows no characteristics that are inconsistent with a Common Yellowthroat.

Chris Sloan
Nashville, TN
http://www.chrissloanphotography.com


On Fri, Jun 29, 2012 at 1:08 PM, Chris Sloan <csloan1973@xxxxxxxxx> wrote: I will post more substantive comments when I have time after work, but I stand by my response to Ed that, in my opinion, this is quite clearly a Common Yellowthroat for a number of reasons.

Chris Sloan
Nashville, TN
http://www.chrissloanphotography.com



On Fri, Jun 29, 2012 at 12:01 PM, Richard Knight <rknight8@xxxxxxxxxxxxx> wrote:

A few days back Ed Schneider posted a photo of a warbler for which he was unsure of the ID. In an off-list email conversation, he said the the consensus opinion was for female Common Yellowthroat. There has been no public discussion of the ID, so I am
weighing in.

I believe it is a Nashville Warbler.
My reasoning:
1) the head is too gray for female Com. Yellowthroat, which should be brownish-olive. 2) the eye-ring is a little too bold, but head color & eye-ring are right for Nashville. 3) the yellow underneath is too extensive & even-toned for yellowthroat, which should be shaded from fairly bright in throat to dull yellow on lower breast. 4) culmen shape appears to be straight, unlike slightly down- curved for yellowthroat.
The amount of yellow underneath & bill shape are good for Nashville.

While Nashville Warblers in spring migration usually occur higher up in trees than the bird in the photo, which is in blackberry brambles, I often see fall migrant Nashvilles in low shrubby stuff including goldenrod & ragweed. So habitat shouldn't be an issue.

Photo IDs are sometimes harder than in-life IDs, since there is only one angle per photo, no vocalizations or behavioral clues, etc. However, you can stare at the photo for as
long as you want & analyze visible details.

Apparently this would be the first summer record of a Nashville Warbler in TN, as Robinson (1990) lists none & I don't recall any since then. It could be a very late spring migrant or, more likely, an early fall migrant (perhaps a failed breeder) or a wandering non-breeder. Nashvilles do nest as far south as northern West Virginia.

Comments welcome.

Rick Knight
Johnson City, TN

----- Original Message -----
From: Ed Schneider
To: tn bird
Sent: 6/23/2012 3:39:54 PM
Subject: [TN-Bird] Nashville Warbler (???)

Bells Bend Park, Davidson Co.
23 June, 2012

I realize there are no summer records for this bird, and I wouldn't expect there to be. I of course thought I was photographing a female Common Yellowthroat, but the eye ring seemed WAY to strong compared to the female
and first year yellowthroats I've seen.

That being said, the bill shape doesn't scream Oreothylpis to me at all, and the habitat is of course all wrong for
Nashville even in migration.

Anyone care to share some thoughts on a bird that threw me for a small loop this morning? I imagine COYE can be extremely variable, and I'm still an advanced novice at best... always nice to get a photo of a questionable bird,
however.


Thanks,
Ed Schneider
Davidson Co.




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