Hi all:
I have a few comments about the bird, but first the usual caveats when talking about hybrids, particularly dabbling ducks. Caveat #1: When discussing the putative parent species of any hybrid, it should be taken as given that these parent species are presumed, as without genetic testing on which to base our statements, our assumptions can be wrong. Caveat #2: Hybridization within dabbling ducks has a tendency to throw in characters that are not found on either parental species, with the single most common odd character being white or other pale-colored bits on the head and even without those, hybrid dabblers tend toward a teal-like (Green-winged or Baikal) head pattern and this is felt by some to indicate an ancestral feature. Thus, just because a suspected hybrid dabbler has a teal-like head pattern does not necessarily mean that one of the parental species was a teal. Additionally, the features of the parental species that come through undiluted -- along with which parent's features come through in any particular patch -- and those that come through blended seem completely unpredictable. That said, Bruce makes a strong argument in the past two day's posts for American Wigeon x Green-winged (carolinensis) Teal and an even stronger one against Eurasian Wigeon x American Wigeon. I wanted to point out a couple of interesting features that he did not mention. -- The bird seems to have the pale inner secondary typical of wigeon, which can assist in identifying wigeons to species, with that feather being white in Eurasian and pale gray in American. I would argue that the feather looks gray rather than white, though I cannot be certain with the pictures that I have to ogle. -- In the blow-up that Bruce provided pointing out the important bits, the bird seems to sport long lower scapulars that are white -- these are the feathers lying on the rump underneath the elevated right wing -- at least, that is what I believe those feathers must be, as there is otherwise no way to explain them. This feature, too, differs in the two possible parental wigeon species, with Eurasian having the lowest scapulars long and white, and American having shorter ones that are not white. For illustration of this, just check the lower flying male depictions in Sibley, in which the white on the wing of Eurasian extends posteriorily along the scapulars to beyond the base of the wing, while in American, the white does not reach the base of the wing. This feature would seem to argue with Bruce's thesis as to which wigeon species is involved, and it does. But, it's the only feature that I can find on the bird that would argue for Eurasian rather than American. -- The bird seems to sport the chest pattern of Green-winged Teal, with gray sides to the chest, but mottled brown center. Granted the picture does not allow much in the way of certainty on this feature, but the picture is suggestive. The features that argue for American Wigeon (as vs. Eurasian Wigeon) are, in addition to that mentioned above: -- Reddish on head paler than one would presume with Eurasian as a parent, as both Green-winged Teal and Eurasian Wigeon have strong and rich rufescent head coloration (but note caveat #1, above) and -- Green on head not reduced in extent from Green-winged Teal parent. Even more basic, the features that seem to argue for a wigeon, of whatever species, as a parent include: -- long and pointed tail with pale sides, -- black undertail region abutting white flank patch, and -- blue on the bill. However, those features are not restricted to wigeons. In fact, there's another possible parental species that I have not seen mentioned in the various posts on Cobirds: Northern Pintail. Though I'm not pushing that as one of the parental species, there are some strong arguments to be made for it, including: -- bill pattern (it is perfect for a male Northern Pintail); -- the lack of white on the forewing; -- the white feathers lying on the rump; -- the black undertail abutting the white flank patch; and -- the long, pointed tail with pale sides. Yes, the bird sports that wigeon-like inner secondary which might be a deal-breaker, but Northern Pintail x Green-winged Teal makes just about as much sense as does wigeon x Green-winged Teal. And, yes, I'm fairly convinced that the head pattern is not just the result of hybridization producing an ancestral dabbling-duck head pattern, but that Green-winged Teal was one of the parents. Bruce just makes too strong of an argument for me to refute with any certainty. Additionally, if Northern Pintail is one of the parents, then the other one probably cannot have been a wigeon, as the bird's flank patch -- which is identical in Northern Pintail and the two wigeon species under consideration -- is too muted, too restricted, to have been produced by some pintail x wigeon combo. Additionally, the vague chest pattern is hard to explain without a Green-winged Teal parent. Anyway, that's my take: either American Wigeon x Green-winged Teal or Northern Pintail x Green-winged Teal. Sincerely, Tony Leukering Villas, NJ P.S. I have bcc:ed Steve Mlodinow in hopes that he'll enter the fray. Topic: more digiscope photos of hybrid teal - Cottonwood Marsh Pond, Boulder Bruce Webb <[email protected]> Mar 26 10:47PM -0600 ^ Cobirders: I put a few of my own distant and not sharp photos into a Picasa web album showing this week's Boulder County hybrid duck. I also point out a few field marks supporting why one parent is a Green-winged Teal and the other parent seems to be an American Wigeon, Here is an abbreviated link to the Picasa web album: http://bit.ly/gH7xb2 My first blowup image is a distant shot but I have superimposed some identification text to point out the teal characteristics: 1. Blue AND black bill = combined bill color patterns of Green-winged Teal and Am Wigeon, 2. Bold green blaze through head - undiluted shared characteristics of Green-winged Teal and Am. WIgeon (but, shaped like a G-w teal) 3. The pinkish not white vertical stripe (male G-w teal) and diluted head color is a dilution of teal characteristics by Am. wigeon genes. 4. no white upper wing patch of a wigeon. Not sure why such a bold wigeon characteristic is lost in a hybrid, but flight views show it is not present,. There is a comment area below each picasa photo. Feel free to offer comments. -- Bruce Webb Granite Bay, CA 'Have scope - Will travel' Topic: more digiscope photos of hybrid teal - Cottonwood Marsh Pond, Boulder Bruce Webb <[email protected]> Mar 26 10:47PM -0600 ^ Cobirders: I put a few of my own distant and not sharp photos into a Picasa web album showing this week's Boulder County hybrid duck. I also point out a few field marks supporting why one parent is a Green-winged Teal and the other parent seems to be an American Wigeon, Here is an abbreviated link to the Picasa web album: http://bit.ly/gH7xb2 My first blowup image is a distant shot but I have superimposed some identification text to point out the teal characteristics: 1. Blue AND black bill = combined bill color patterns of Green-winged Teal and Am Wigeon, 2. Bold green blaze through head - undiluted shared characteristics of Green-winged Teal and Am. WIgeon (but, shaped like a G-w teal) 3. The pinkish not white vertical stripe (male G-w teal) and diluted head color is a dilution of teal characteristics by Am. wigeon genes. 4. no white upper wing patch of a wigeon. Not sure why such a bold wigeon characteristic is lost in a hybrid, but flight views show it is not present,. There is a comment area below each picasa photo. Feel free to offer comments. -- Bruce Webb Granite Bay, CA 'Have scope - Will travel' -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
