Posted by Phil Pickering (208.46.229.76) on May 14, 2001 at 10:54:55:
Actually it's the lowest 2+ rows of scaps that seem to be most obviously missing, exposing much more of the coverts than is typically visible on a standing peep. It doesn't look like this is due to the scaps being mis-stacked or mis-folded because there seems to be exposed plain buff base color visible between the lowest scaps and coverts. I'm not sure how to interpret this, but it does seem something funky is going on there.
That said, Matthew's points are hard to get around. It does look like there are some rounded, plain-fringed upper scaps visible on edge that seem to be positioned where a juvenile Western should have the 2 rows of smaller, brightly rufous-fringed uppermost scaps. Also, I'm not sure if a molting Western would drop whole tracts of scaps or not. I seem to recall seeing basic-plumage feathers intermixed with worn juvenile feathers on birds that I noticed were molting.
The width of the pale fringing on the visible scaps and on the coverts does seem quite extreme for Western and more typical of Semi, particularly since it seems logical that the fringe width would decrease with wear rather than increase. The dark internal areas to these feathers seem quite solid in both Western and Semi, and they don't seem to fade that much, at least relative to the amount of wear.
As Matthew points out, the scaps that are visible are quite rounded and solidly-centered. The round shapes combined with the wide pale fringes are what give juvenile Semipalmateds their distinctive scaly look. Also, although I haven't noticed it on the few birds I've seen in Oregon, a diffuse rufous tinge to the scaps and back apparently isn't unusual in Semi. The amount and position of the color displayed by this bird seems to be at least within reason for a juvenile Semi, if not typical.
The bill does have a kink, but the slight upturn at the very tip of the lower mandible seems more typical of Semi. This is quite subjective to judge in a photo, but I think even short-billed male Westerns would typically have a little sharper, less blunt look to the bill tip than is apparent on this bird. Also, if a Semi, the pale face could be due to wear, or perhaps even partially to the lighting and angle of the photo.
This is one heck of a confusing bird (as intended no doubt) but after staring at it a couple more times it is starting to look much more like a Semi. Waffle waffle.
Phil