Warbler ID - Michigan (1 Viewer)

[Ghostly Vision]

Tennessee for me - think the leg/feet colour is a trick of the light; it looks yellow in tone but is probably just brownish in reality.

The whole feel of the bird smacks heavily of Tennessee and not Blackpoll

GV

 

[atricapillus]

Joe, I think we have it boiled down to Blackpoll or Tennessee and the key characters in dispute are foot color and tail spots. I think the faint shine in the undertail feathers are unlike any Blackpoll. Of the Dendroica, only some female Black-throated Blue Warblers have tail spots as obsolete as in this bird. I think we can agree it's not a Black-throated Blue.

JanJ referred us to a site by Gif Beaton which has a Tennessee Warbler in a similar pose and I think the tail is dead on for our mystery bird, with a slight reflectivity causing vestiges of tail spots. Blackpoll and most other Dendroica have real obvious tail spots that do not have to be argued about. The photo linked above also seems to me to show a slightly yellowish cast to the feet, although not as evident as in our mystery bird. A somewhat more compelling photo showing a light yellowish color on the toes and back of tarsus is at the Mangoverde site

Interesting discussion.

_______________________
Sorry to be such a hard sell, especially in the face of an overwhelming tide of concensus. I was ready to concede, but, for those wanting to beat me over the head one more time, check out this picture--feet and tarsi, undertail coverts and undertail spots, and creamy tone to underparts, eyeline. (and compare).
www.gardenbuddies.com/forum/messages/1107219/1174044.html
CHEERS, JOE G

 

[jmorlan]

Joe,

On your gardenbuddies photo, the undertail is in deep shadow. Nevertheless, notice that the underside of the tail is exactly the same color at the tips of coverts. We know that color is white on the coverts and it is also white on the tail. Also that photo shows the white spots, contrasting with narrow black tips, even though it is in deep shade.

Now compare the original image. The gray tail is in good light and it contrasts noticeably with the white undertail coverts. Furthermore there is no contrast with black rectrix tips as evident on your Blackpoll photo.

 

[Thayeri]

I do not believe this bird is a Tennessee Warbler, and I do see a lot of them. Yes, fall TN is highly variable, but where are the specifics?

That sure looks like a dendroica bill, not a vermivora one. Overall facial pattern and coloration are both highly suspect for a purported TN. Tennessee tend to mix green, gray, yellow and/or white on the face, not yellow and brown. Brown can happen but it would be quite uncommon, and I've never seen it totally replace the green/gray.

Tennessee face should be dominated by a short, pale supercilium and an eye line that extends through the lores. This bird does not have a supercilium stripe to speak of, rather the supraloral area before (but not above) the eye, as well as the front half of the lores themselves is more or less concolorous with the throat, nape, malar and cheeks, while the single most prominent feature is the broken eye ring. A TN should categorically NOT have pale lores between eye line and bill.

Joe wants to see an unambiguous photo of a TN with yellow feet. With the right (wrong) lighting that could probably be found, but I want to see a Tennessee with:

1) exclusively brown and yellow face, head and shoulders
2) no supercilium stripe -- there is nothing above the eye here except the eye ring
3) front of lores and supraloral area concolorous with throat, malar area, cheek and nape
4) bold broken yellow eye ring as most dominant facial feature
5) eye line that is longer behind the eye than before it, with pale front half to lores
6) simultaneous bright yellow feet and dark legs with equal lighting -- like this bird
7) Nice rounded dendroica shape to the bill

I think that Joe has made some strong points for Blackpoll -- but I can't go that far on this one photo, not with the pale tail spots. I will add that the first fall female in Sibley has a pale patch in the lores between eye line and bill, and that the subject bird appears to be slightly darker in the "necklace" area where throat meets breast -- and as the whole area is shadowed, I do not believe this is a shadow. Call me leaning Joe's way, but in strong disagreement with Tennessee.

 

[atricapillus]

Well, first, thank you Thayeri. I had a hard time accepting that it could be a Tennessee, but was beginning to buckle under concensus--I mean how many times does one need to get beat on the head and not say 'uncle.'

The undertail seems to be the crux of deciding if this bird is a Dendroica or not. Once decided not, the best apparent choice is Tennessee. However, one then has to compromise on other characters--accepting the suggestion of a supercilium that really doesn't exist, and an eyeline that is faint at best, and a bill one also has to imagine is really tapered, pointy and blackish (the bill actually appears more blunt, and brownish with a paler tomium).

I floated around locating what pictures I might on Tennessee Warbler tail spots. The pale off-white tail spots (when they occur) on some Tennessees were all alike in that they were squared and included the inner half or 60% of the outer tail feathers with a straight longitudinal edge spaced from the shaft, and a straight transverse proximal edge pretty much just inside the tips of the longest undertail coverts. (this is pretty much as Dunn and Garrett picture them, except that outer proximal corner was actually more cornered. The tail spots on our unknown don't match up. The border of the whit(ish) at the tip wanders toward the shaft proximally.

If this were a Dendroica (and by plumage and bill, this bird appears most like Bay-breasted or Blackpoll), why don't the tail spots show up better. I also checked out Dendroica tail spots, and they are mostly pretty evident. But at some angles, they tone down, and there is a fair amount of variation in the extent of these spots, and their contrast with (some not so) dark areas (except in yellow-rumps--Magnolias were fairly consistent also). There is some variation between males and females of species such as Bay-breasted, Blackpoll, Cerulean; females can have less prominent spots, even if they mostly appear evident in clear view (or in hand).

One problem can be angle of lighting. I would agree that this doesn't appear to be an issue here except that the right half of the tail is partly shaded. The sun in slanting in substantially from behind the bird such that the undersurfaces of the primaries are very much in shadow. So there could be some toning down.
However, the reflectance can also be affected by what is under the feather, whether another white spot or not. White on dark doesn't appear as white as white on white. This (along with angle of light) may be the reason why the white in the tail may be duller than the white of the undertail coverts under almost the same lighting.
If you consider the shape of the pale areas (spots) on the undertail, they match up with the pattern of white shown for several Dendoica species shown in Dunn and Garrett (including Cerulean, Blackburnian, Blackpoll, Bay-breasted). The pattern is to have a dark long-sided triangle in the corner. In most of these Dendroica, the white of the spot goes to the shaft, but in a few, there is a very narrow break, as in the unknown.
While my experience (and a run through a photo series) first suggested Bay-breasted, the yellow in the feet and heel brought forward Blackpoll. I can't make out much of the possible wing-bar, except that it looks a little tan for either of these.
It seems like we should be able to ID this bird, but have a very hard time accepting it as a Tennessee, easier time with Blackpoll. Blackpoll should have whiter tail coverts than Bay-breasted, so leaning in again on Blackpoll.
CHEERS, JOE G

 

[Jane Turner]

I guess its all becoming speculative... see I'm happier saying that the bright reflection on the bill has affected the perception of bill shape and that there is something funny about the colour cast and shadow to the entire picture (especially about the head) than that there are tail spots that you can't see. You can see the full length of feather shaft in the outer TF's

 

[Thayeri]

Hi Joe, glad to be a contrarian with you on this bird, I truly respect what I've seen of your skills on some previous threads. That said, I need to start by disagreeing with how you start your last post! In the field, when it comes to warblers, I am very much an undertail kind of guy, particularly in fall. However, while I believe that the tail spots are enormously important, I don't believe that their presentation in one photo necessarily trumps every single other aspect of the bird.

As far as I can tell, the entire case for Tennessee here consists of short, low contrast tail with long white undertail coverts. Stacked against that are wrong leg color, wrong bill shape, suspect head coloration, inappropriate pale lores, no supercilium stripe (the supercilium feathers above the yellow orbital feathers appear concolorous with the crown), and overall, an unusually monotone head with the contrasts in the wrong places. I cannot see how this bird could be counted a Tennessee -- but that is just my opinion.

It looks to me like every other feature than the tail spots (or lack thereof) would point us towards Blackpoll Warbler, as you have documented so well at length. The key questions then are how wide of variation do we see in first fall female Blackpoll's tail spots (the light streaking is just fine for that age and sex), and could something in the photo be creating a false impression? I lack the specific knowledge to help here, other than I will say that I agree that the pattern we see is correct for Blackpoll, it just doesn't look bright enough.

If pushed to a vote, I would definitely go Blackpoll over Tennessee. However, while you have done a fascinating job of building the case, I am having trouble making the leap to definitive with that tail, so I remain leaning rather than committed.

 

[atricapillus]

I guess its all becoming speculative... see I'm happier saying that the bright reflection on the bill has affected the perception of bill shape and that there is something funny about the colour cast and shadow to the entire picture (especially about the head) than that there are tail spots that you can't see. You can see the full length of feather shaft in the outer TF's

_____________________
Howdy,
If we all agreed on everything, it would be pretty dull. But just looking at the thumbnail, does it not look like the un- or less-shadowed left-side tail feathers have a pale spot and dark corner. Then, also a similar, but faded effect on the the right more-shadowed side?
Its only there if you can see it; may just need to leave this one alone.
CHEERS, JOE G

 

[Thayeri]

Coincidence

By coincidence, a Blackpoll Warbler photo was just posted in another thread from western Canada, that nicely illustrates the Blackpoll theory. While not identical, note how similar the facial patterning is, particulary in those areas that would be problematic for claiming Tennessee. Not to mention the yellow feet on dark legs...

http://birdforum.net/showthread.php?p=412982#post412982

 

[jmorlan]

Sorry, but that's just a typical Blackpoll image which the subject bird is not. It's not possible to just hand-wave the lack of obvious white tail spots away. The light is very good, we can see the shadows and most importantly we can clearly see the gray underside of the tail bases contrasting with the white undertail coverts. There is a slight reflectivity to these feathers, but it is not possible (despite the heroic attempts in this forum to do so) to turn those highlights into the large distinctive and well outlined white tail spots of a Blackpoll Warbler.

Furthermore, the bird is well within normal variation of Tennessee Warbler. The face pattern is a little faint, but given the angle I don't think it is atypical at all. Much has been made of the supposed large pale bill by those arguing for Dendroica, but web photos referenced above show fall TEWAs with pale bills of equal size and pointedness. The difference in bill shape between Dendroica and Vermivora is over-rated in my view.

Having said that, I understand that people of good will can look at the same data and come to different conclusions and that's fine. But when in doubt, I prefer to trust characters that are "either/or" and unambiguous. Characters like degree of lore stripe intensity, or relative bill size/shape are matters of judgment and it is reasonable to disagree. But characters like tail spots on a Blackpoll are not like that. The bird either has them or doesn't. This bird does not have them.

 

[Larry Lade]

For what its worth...

from 2nd Ed. of National Geographic Birds of North America on Blackpoll Warbler.."Most migration is east of dashed line on map [i.e.,eastern US], overland in spring, along and off coast in fall." And from 3rd Ed. of NG, "Very rare in fall in most of south because much migration if off east coast".

John Terres,"Encyclopedia of North American Birds" simply states "[Blackpoll Warblers] winter from c. Equador, c. Colombia, and n. Venezuela south to Peru, Chile, and Brazil, migrates through West Indies."

Michigan is located in the central states of the US.

While this might be a Blackpoll Warbler, the above seems to indicate that it would be quite rare indeed in the fall of the year in central US!

I am still leaning towards the Tennessee Warbler camp.

 

[Thayeri]

Yeah, it's funny how one person's "normal variation" becomes another person's "wave of the hand", isn't it?

As far as I can tell, to go Tennessee, requires waving your hand at no less than six big problem items that I pointed out in my last post, and variously mumbling "normal variation", "shadows", "reflections on perceptions" and "colour cast". The reason for all that is the tail spots... except... except... there is something else that Joe G. has repeatedly pointed out, that no one else seems to be picking up on. The outer pattern on the tail feathers is not only the right shape for Blackpoll rather than Tennessee, but they are dark. In fact too dark for Tennessee, even if Joe stays away from making that statement.

Go back to the Giff Beaton photo that Jane links to and look at the underside of the tail. It is gray. Like it says in the field guides. Tennessees do not have blackish corners to the ventral side of their tail feathers.

So the answer then becomes shadows again, I am sure. Except... I thought the reason for dismissing Blackpoll white tail spots appearing gray was that the undertail was clearly not in shadow? So, if it isn't in shadow, how do we get a Tennessee with downright blackish corners on its undertail?

Or do we need a very special kind of shadow, that curves around and selectively turns corners of feathers at different angles to the sun selectively blackish along lines that only coincidentally are right for Blackpoll, while keeping the absolute true and unshadowed colors for Tennessee right down the center and basal regions of the retrices?

Gosh, that sure is getting to be a lot of hand-waving, in combination with the bill and feet color and facial color and patterning hand-waving....

(all of this post is of course meant in the spirit of good fun! B )

(And Larry, as discussed on page 387 of Dunn & Garrett "Warblers", Blackpoll are common around the Great Lakes during fall migration, I know that I have seen quite a few already here, and Michigan is certainly a Great Lakes state as well. Down south of the lakes in the Midwest, like your area around St. Louis, they would be rare during fall migration.)

Edited to say St. Joseph, and as a former Missourian, my apologies for misremembering your side of the state!

 

[Larry Lade]

Personally, I have seen Blackpoll Warbler scores of times here in Missouri during spring migration (April and May). I have never seen one in Missouri during the fall migration.

I have seen many Tennessee Warblers in both the spring and fall migrations through the central states.

 

[stuart winter]

It's a fantastic experience reading expert commentary on this issue. ID-ing birds on the web opens up a whole new dimension to our wonderful hobby and also provides
some salutory lessons on how things like compture-created colour tones and photographic stance can change perspectives. Watching you guys carry out a cyber autopsy has been illuminating.
One question re the Blackpool v Tennessee debate: as a long distance - over sea - migrant - do Blackpolls have longer wing length and would they reach a deeper point in relation to the undertail coverts? Hope this makes sense.

S

 

[Motmot]

Late on this debate I have to say I see a Tennessee on this pic, palish legs probably indicate a young bird, rest looks fine for TEWA.

 

[Larry Lade]

Yes,Thayeri, I just checked my Dunn & Garrett book on warblers and see that whereas the Blackpoll Warbler is "quite uncommon in the midwestern states", it is "more common around the Great Lakes" in the fall migration. Heretofore, I was not aware of their occurrance in the fall around the Great Lakes region. Thank you for pointing that out.

I still think we need to see some definite tail spots for this to be a Blackpoll.

I think for this forum if you get me located somewhere in Missouri, that is good enough!

 

[atricapillus]

Late on this debate I have to say I see a Tennessee on this pic, palish legs probably indicate a young bird, rest looks fine for TEWA.

____________________________
Well, sometimes you gotta know when to fold. I can accept the possibility that I am wrong, having been there before. The tail-spot issue really hasn't cleared up, and TEWA then seems like the appropriate concensus choice, even if I can't make it into one myself. Nobody bats 100%, but Motmot (and others) have maintained high reliabllity.
My overall first and even later impression was that it looked more like a Bay-breasted (excepting tail spots) than Blackpoll, using the yellow in feet and heel and near whitish undertail coverts to sway to Blackpoll.
Thanks for the patience.
CHEERS, JOE G

 

[Jane Turner]

I'd not fold Joe.. I'd leave this in the not proven one way or the other box and another lesson in the futility of I'ding from a single photo with no field notes.

 

[Motmot]

____________________________
Well, sometimes you gotta know when to fold. I can accept the possibility that I am wrong, having been there before. The tail-spot issue really hasn't cleared up, and TEWA then seems like the appropriate concensus choice, even if I can't make it into one myself. Nobody bats 100%, but Motmot (and others) have maintained high reliabllity.
My overall first and even later impression was that it looked more like a Bay-breasted (excepting tail spots) than Blackpoll, using the yellow in feet and heel and near whitish undertail coverts to sway to Blackpoll.
Thanks for the patience.
CHEERS, JOE G

Well Joe, I´m surely wrong sometimes! Many warblers breeding in NA winter or pass through Costa Rica, a few of them being very very common (Tennessee, Chestnut-sided, Wilson´s, Golden-winged, Yellow, Blackburnian, Black-throated Green, Bay-breasted, Black-and-White, Canada, both Waterthrushes), others aren´t that common but still seen regularly (Cerulean, Yellow-rumped, Townsend´s, Worm-eating, Prothonotary, Am. Redstart, Ovenbird, Kentucky, Mourning, Yellowthroat), and with luck and patience one may get one or a few of the rarer ones in CRica (Parula, Blue-winged, Nashville, Magnolia, Cape May, Black-throated Blue, Orange-crowned, Hermit, Golden-cheeked, Prairie, Palm, Pine, Blackpoll, Yellow-throated, Connecticut, MacGillivray´s, Hooded, Chat). That´s 40 (!) NA migrant warbler species for a small territory no larger than West Virginia, plus 14 resident tropical warblers.
I confess I´m addicted to warblers and spent my years birding in CRica paying special attention to them, finding all but seven. These hurt!
On the other hand I almost never get involved on debates about NA resident birds, my knowledge on them varies from regular to very bad (sparrows eek), but I love reading and learning a lot on those threads, many times with your interesting comments or explanations Joe.
Most of the times these pics aren´t good enough to be sure and ALL of us make mistakes. I guess most of us join the id threads to learn or help or both.
The thread bird looks to me a Tennessee but that doesn´t mean it is 100% sure, the quality of the pic is simply not good enough. How many times on BF a new pic appears and all our hot debate disappears! As Jane stated don´t fold, buddy!
Cheers
Eduardo