Stones and Pipers

Black Turnstones (Arenaria melanocephala) with Least Sandpipers (Calidris minutilla)

Do birds play copycat off other birds? It certainly seems that way here, on the south shore of the North Basin, where a flock of Least Sandpipers not only followed a handful of Black Turnstones, but copied the bigger birds’ feeding habits. We’ve seen Least Sandpipers many times foraging on the mud. Here they were pecking at limpets and barnacles on the rocks, exactly like the turnstones. It almost looks as if the sandpipers were the chicks and the turnstones were the parents modeling proper foraging behavior for them.

Having written this, I went to the bird authorities, including the exhaustive Birds of the World subscription site, to see whether Least Sandpipers had been seen foraging on rocks. Negative. Least Sandpipers forage on mudflats or soft ground very near the tide line. Not on rocks. There is however another small sandpiper that fits the behavior pattern: the Rock Sandpiper, Calidris ptilocnemis. Rock Sandpipers, including a population that breeds on the Pacific shore of Russia, do migrate to Northern California from time to time. And it is typical for them to feed on rocks. However, they don’t look like the birds I saw. Rock Sandpipers often have some yellow in their beaks and regularly have spots or streaking on the breast, as well as more subtle differences. (But, say the sources, their appearance varies greatly.) Bottom line: The behavior says Rock Sandpiper. The appearance says Least Sandpiper. I’m going with the appearance. If you are a sandpiper expert please weigh in, using the Comment form below.

Least Sandpipers (Calidris minutilla)

More about the Least: Wikipedia Audubon Cornell In Chavez Park

More about Turnstones: Wikipedia Audubon Cornell In Chavez Park

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