Hi All,
This is an interesting conundrum. I must confess a western bias when thinking of small Calidris ID, but there are some puzzling attributes to these birds. The bird in the foreground can be assessed for shape, but the bird behind it is somewhat hidden from our view. One can see well the scapular and wing coverts patterns of both, however. The underexposed nature of the picture gives a more uniform feel to the upperparts, but there is really some contrast there. One thing that is apparent on both of the peep is that they exhibit rather rufous-edged upper scapular tracts. While this is apparent on some Semipalmateds (as I have seen when visiting huge Semipalmated Sandpiper stopover sites in New Brunswick), it is also certainly typical of juvenile Western Sandpipers too. The bill of the foreground bird looks okay for Semipalmated, but could also be found on some male Westerns, IMO. What about this bird really does differentiate it from a short-billed Western? When I'm looking for Semipalmateds in the west, I certainly feel much more comfortable with those that are lacking rusty fringed scapulars and possessing short, blunt tipped bills. I would certainly want to see more images of this bird from different angles before settling on Semipalmated Sandpiper, especially in an area where they are outnumbered by hundreds to one by Westerns.
Now the bird in the background could be a any of several possibilities, but again, I suspect that Western would be the most likely.
Chris