Hanging Rock: feather ID please!

[stevep@receptor-biol.duke.edu (Stephen J. Perry)]

Hi folks,

Just got back from Hanging Rock where there were many good sightings 
of black throated green, pine and black and white warblers. Also got 
great looks at a pair of phoebes, a spotted sandpiper on the bathing 
beach, a red-tailed hawk scouring the cliffs, and ravens. But the 
thing I want to ask you about is a rather fine feather I found 
between rocks at the very top of Cook's Wall. My knowledge of feather 
anatomy is nonexistent, so excuse any misused terms: by shaft I mean 
the central "vein" from which sprout the "bristles" (the fine 
interlocking bits that we all associate with the feathery part). Here 
goes...

It is 10.6cm long from the base of the shaft to the very tip of the 
feather. At its widest point (2.1cm back from the tip) it is 1.8cm. 
It looks to me like either a wing primary or secondary or a tail 
feather. The "bristles" start 1.5cm from the base of the shaft. It is 
shaped gradually increasing from 1cm in width to its widest point, 
then rapidly narrows to a forked point of courser short bristles. 
Coloration is striking: it is generally very dark gray/black on the 
upper surface, but on the lower section of bristles it starts out 
lighter gray/brown and fades to gray/black. There is a hint of olive 
or yellow to the gray. The shaft is bright yellow from the base to 
7.0cm, then it is gray/black. On the underside, the shaft is yellow 
for 8.4cm then goes to gray/black. The bristles are yellow, dulled 
slightly with gray, from the base to within 7.4 cm of the end, where 
they immediately change to gray/black. It is really quite a 
distinctive feather and I have browsed through Sibley's flight 
pictures for the nearest fits. I came up with a female Am redstart 
central tail feather or secondary wing feather, or maybe a Scott's 
oriole  central tail feather (based on geography I realize this is 
exceedingly unlikely). The problem with the Am Redstart is the size: 
to me, this feather at 10.6cm seems awfully long for a  5.5" (14cm) 
bird. If anyone has a good feeling about what this might be I could 
arrange to email a scan of the feather to you for further ID.

regards

Steve Perry

Receptor Biology Lab, Duke Uni Med Center, Durham, NC

stevep@receptor-biol.duke.edu