Sunday, January 29, 2012

A Tale of Two Teal

Digiscoped with HTC Incredible Android phone.
A couple weeks ago I found this teal in a small pond near my home.  I watched it swimming from both sides for over five minutes and didn't see any hint of the vertical white bar on the side of the breast that is distinctive for North American Green-winged Teal.  This made me wonder if it was a Common Teal, considered the Eurasian subspecies of Green-winged Teal by most American authorities, but considered a separate species by Europeans.  Common Teals have a white horizontal stripe on their sides, rather than the vertical white bar.  While watching this bird, I never did see a white stripe.  The breast seemed paler and more washed out, less brightly pattered than most Green-winged Teal, but otherwise I didn't see anything else that might tell me what it was.

Back at home, looking at David Sibley's page on how to identify Common Teal, he noted that the breast of the Common Teal is "paler and grayish, less buffy" than a Green-winged Teal and that the white stripe on Common Teal can be covered up by their scapular feathers.  Based on these two criteria, I put word out on the Jerseybirds listserv that there was an "apparent" Common Teal at the pond.

Well, over the next week I checked the pond every day and didn't see the bird.  Then I did see a Green-winged Teal with a very pale white vertical chest bar.  I did not think that was the same bird I had before, since though pale, the bar was fairly obvious.  Nobody else saw a Common Teal on that pond, while several others noted the teal with the pale bar--some even suggesting that this might be a sign that the bird was a hybrid or integrade Green-winged X Common Teal.

I didn't know what to think.  Were there really two birds, or had I just not seen this same bird well enough the first time?  Finally, this week, I saw a bird again with no bar or white stripe!  I watched it for five minutes from several angles as it swam around the pond.  Finally, at just the right angle I could see the faint vertical bar.  At this point, I had to conclude that I must have been seeing this same bird off and on, and that the faint vertical bar might be almost completely inconspicuous in some instances.  I had to send out a new message to amend my previous email and admit that the bird at Demott Pond was most likely just an odd Green-winged Teal.

A few folks emailed me to say that this pale-marked bird might be a hybrid.  Since there was a Common Teal and an apparent hybrid teal being reported in Newtown, PA about an hour away, I stopped by there on my way to work this week and took a look at them.  There was for sure a bird with a bright white horizontal stripe (Common Teal) as well as another bird that looks a lot like my Demott Pond teal--with only a pale white vertical bar on each side of the breast.  I don't know if that was the supposed hybrid bird or not.  I've got more research to do on that, I suppose.

So, a fun ongoing learning experience, even if it isn't fun to have to retract a public identification!

1 comment:

  1. Thanks for sharing that experience. We tend to learn so much more when we make bird identification mistakes. Its somewhat embarrassing to make public mistakes, but everyone learns from them too.