Pine Siskins can also be albinistic, which may explain some of the 
lightness on the bird you saw. I've posted a photo of an albinistic 
siskin from northern Minnesota for comparison.
http://junetvee.smugmug.com/Nature

-- 
June Tveekrem
Columbia, Maryland
tweekiebird|AT|southernspreadwing.com
http://SouthernSpreadwing.com


Claire Wolfe wrote:
> Today at my thistle feeder I had an unusual looking Pine Siskin.  My original impression of the bird was of a somewhat light siskin with very extensive yellow in the wings and tail.  In fact, when this bird settled down on the feeder the yellow was clearly visible on the folded wing and tail, not just the typical hint of yellow at the base of the flight and tail feathers.  The lightness of the bird was due to it being very faintly and diffusely striped compared to the other siskins it was feeding with.
>  
> Looking in my field guides I found that Sibley has a picture of what he calls a "Yellow adult" with the comment "scarce; most frequent in southwest".  That picture is a fairly good representation of the bird I saw, although the bird at my feeder did not have a noticeable yellow wash along the sides as this picture depicts.  I did not get a good look at the undertail coverts to see if they were yellow as this picture shows.
>  
> At any rate, it was an interesting bird.  I live at the edge of Black Hills Regional Park, not far from the visitor center, as the siskin flies.  If you are at Black Hills, it is worth keeping an eye out for this bird.
>  
> Claire Wolfe
> Germantown