Short-billed Dowitchers (Limnodromus griseus) swimming towards shore as the tide flooded the tidal flats in Bodega Harbor on 14 July 2012. (They're surrounded by the standing, longer-legged Marbled Godwits and Willets.)
Here's another view of a resting Short-billed Dowitcher (taken in the spring). The dowitcher is the bird in center, with short greenish legs. There is a Red Knot just in front and to the left of the dowitcher. They look similar at first, but note the difference in feather patterns.
An even closer view with a dowitcher (right) and knot (left) side by side. Compare the large red oblong spots on the knot's feathers with the thinner, jagged bars on the dowitcher's feathers.
Their bills are different, too. Look for the longer bill of the dowitcher, with a relatively uniform width throughout...versus the shorter bill of the knot, with a thicker base tapering to the tip.
(Dowitcher is lower left, knot is upper right.)
Dowitchers are known for their very regular up-and-down feeding motion (deep probing), sometimes likened to a "sewing machine."
The above picture was taken in April while dowitchers were migrating north. Remember that the first photo was taken in mid-July. Dowitchers have already finished their nesting season (in the muskegs of Canada!) and are now migrating south — a very quick turnaround. They will spend their non-breeding season along the Pacific Coast between northern California and Peru.
P.S. There's a fun connection between dowitchers and Bodega Head. Frank Pitelka, a UC Berkeley professor who was instrumental in establishing the Bodega Marine Laboratory, studied dowitchers in Alaska. He confirmed that there were actually two species — Short-billed Dowitcher (Limnodromus griseus) and Long-billed Dowitcher (Limnodromus scolopaceus) — and also described several races of Short-billed Dowitcher that have different breeding areas and migration routes (e.g., Pacific, Prairie, Atlantic).