Semipalmated Sandpiper - Calidris pusilla

When birding along the east coast one sees a somewhat different cast of characters than what we get in Northern California. Least Sandpipers are the most common small shorebird, but Western Sandpipers are much less common, and their niche seems to be filled with the Semipalmated Sandpiper, Calidris pusilla.

Western and Semipalmated Sandpipers both have black legs and gray back. You would think that the webbing between the outer toes of the Semipalmated would serve to separate these 2 species, but actually the Western Sandpiper also has webbing there, so we have to look elsewhere, and in particular we look at the bill shape and size. The Sibley Guide (old version), has a good discussion ("Identification of Peeps:, p. 187) with excellent illustrations of the bills. Suffice to say that often these 3 peeps can be ID'd by bill alone (short and stubby for Semipalmated, long and droopy for Western, and thin and slightly droopy for Least.

Here's a Florida peep (Fred Howard Park, Tarpon Springs) that looked good for Semipalmated. Photo selected for bill shape, but also shows the webbing of the toes, including even the web of the inner toes.

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Here's the same bird, with an alternate plumage Least Sandpiper in the background:

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Most of the Semipalmated Sandpipers were starting to show a few rufous feather in the crown, but none exhibited much in the way of color. Some of the feathers on the back and wing show black centers, indicating transition to breeding plumage.