This Semipalmated Sandpiper is showing quite a bit of rufous on its head and back but the bill shape gives the ID away. Heavy, evenly tapered to a blunt end. The rufous on the back or scaps on these birds is located along the tips or edges of these feathers. On a Western the rufous on the scaps is always located at the bases of these feathers, just the opposite from Semis. There are occasional Semis with slighter bills and these birds require a lot of looking to prevent a stint from slipping by you;o)