Subject: [Tweeters] Vireo With Notched Tail
Date: May 18 08:42:03 2005
From: Joy Markgraf - joymarkgraf at gorge.net


Hi Tweets;
The answer to my query about the vireo with a notched tail was a
unanimous Warbling vireo. Yesterday I saw and heard it in my yard
singing and I agree it is a Warbling vireo. If it claims the yard as
territory I may get a chance to see it's offspring and see if they have
notched tails? It will also be interesting to see if this adult vireo
grows a square tail this summer.
Joy Stickney-Markgraf
near White Salmon WA
email: joymarkgraf at gorge.net



Below is Brett Wolf's interpretation of why this individual has a
notched tail with information taken from the Bander's Bible by Peter
Pyle:

On May 16, 2005, at 6:32 PM, Brett Wolfe wrote:

> Hey Joy,
> ?
> One of my fellow field biologists and I just looked at the Nat'l
> Geographic bird book for N. America and the Pyle Guide. The Pyle Guide
> goes into some detail that I won't recreate here, but says that the
> bird is told apart from Philadelphia & Red-eyed Vireo by small size
> and longish tail (which this bird has). Also, of those two, only the
Red-eyed is a
> possibility in WA state besides the WAVI, and the facial pattern is
much different IMO. We both looked very closely
> at the pics, blown up on her faster computer, and at the vari! ous
texts
> and we both agree that you have a WAVI. The only thing that cropped
up
> in our discussion was that the tail, to me anyway, looks like it has a
> fine edging, suggesting new feathers, at least for the outer
> rectrices. This bird is not known (per Pyle) to molt any of the
flight feathers
> (which includes all tail feathers aka rectrices) during the
> pre-alternate molt it goes thru during Feb-Apr.It is possible that it
> lost them otherwise and replaced them only, without replacing the
> inner rects. Which could make it look notched I suppose. Also, the
> Nat'l Geographic book shows the ever so slightest difference in length
> between the central rects and the outers, not enough to look like a
> notch, but close enough to say that this bird you photographed is a
> WAVI. The only other way to really tell is by voice. Hope all this
> helps!
> ?
> Brett A. Wolfe


Species - From Philadelphia Vireo and Red-eyed Vireo by the combination
of small size but relatively long tail; bill small; crown and
upperparts fairly uniformly grayish olive; supercilium indistinct to
moderately distinct and dull whitish, contrasting indistinctly with the
dull grayish eye line, face, and lateral crown; loral area pale grayish
and uniform in color or only slightly darker than the supercilium and
throat. As you can see from your pics, most of this fits - long tail,
small bill, pale gray lores, distinct whitish supercilium stripe, crown
and upperparts uniformly grayish olive. But you can also see how dry
and confusing this book can be!
?
Molt - Pre-alternate limited (means some, but not all, body feathers
and no flight feathers are replaced). The PAs include no wing coverts
or flight feathers, although some inner secondaries might be suspended
until the PA (or next PB aka pre basic molt) in some ASY (after second
year) birds. More study is needed on molt of this species on the winter
grounds. I underline the last part as a precaution to what the text
states. This means that even someone like Peter Pyle, who has studied
countless thousands of skins in museums still isn't close to 100% sure
on some things. This molt section also gives you a bit of an idea of
some of the things banders have to try to find when ageing and sexing
birds in the hand. A lot of this work is all about subtleties...
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