Images of three Willets (Tringa semipalmatus) taken at Nauset Marsh, East Orleans, MA, on 24 December 2006. These birds were discovered by Jeremiah Trimble and Rick Heil on the Cape Cod Christmas Bird Count on 17 December. One bird was suspected of being an eastern form (T. s. semipalmatus) due to its distinctly smaller size and darker appearance. This form apparently is undocumented in the United States during the winter, the wintering range lying almost entirely along the northern coast of South America.
The bird in question is the middle bird in the first two photos and the solo individual in the last two images. Although the size and coloration (note especially the much more pronounced "bib") are suggestive of the eastern form, the bill shape (exceptionally thin) is wrong for that form as is the more rounded body structure. Also, it seems likely that an eastern at this latitude would still retain at least some alternate plumage, as they don't molt until reaching the wintering grounds. Most likely, this is just a small male western form (T. s. inornatus).
These images were digiscoped from a considerable distance (>100 meters) with a Nikon Coolpix through a Leica Televid 77mm telescope. (The uncertainty over the identity of this individual was in part due to the considerable distance at which it has been observed; closer approach is not possible without crossing a deep channel.) The images have been cropped quite a bit and sharpened as much as reasonable.