To me, the wings appear to be extending past the tail in this photo. The two wing tips are on top, with the light edge of the tail visible on the bottom and ending well before either wingtip. This would suggest Baird's and a few comparisons with other photos on the web and in my guides haven't shown any evidence to rule this possibility out. I'm not a shorebird expert by any means but this bird doesn't look stocky or plump enough to be a peep.
Iain