WatchList Species Account for Rock Sandpiper (Calidris ptilocnemis)

Qualifies for the list as a Red List Species

Photo: USFWS

The Rock Sandpiper, whose numbers are estimated at no more than 100,000 individuals, winters farther north than any other shorebird. Breeding only in Alaska from the Seward Peninsula to the Alaska Peninsula and the Aleutian Archipelago and islands in the Bering Sea, it is found in winter on the Alaska coast from the south side of the Alaska Peninsula along the Pacific sparingly to central California. Outside North America, it breeds in parts of eastern Siberia winters south to Japan. A species seldom found very far from the coast, during breeding it favors tundra dominated by heath and other low vegetation, while during the non-breeding season it favors intertidal habitats, where it forages on mudflats and sandflats. In the southern part of its winter range, it is also found on algae-covered rocky intertidal habitats, as well as on piers and breakwaters. During breeding its diet includes terrestrial invertebrates in addition to seeds and berries, while in winter it feeds principally on marine invertebrates, including mollusks, worms and crustaceans, but also on algae. Estimates of the North American population put its numbers at around 150,000 individuals. Populations of the Pacific Northwest population have declined at some sites whereas its numbers have increased at others, including the Pribilof Islands. Threats include oil spills and the introduction of reindeer onto Bering Sea islands, which has led to dramatic habitat changes, though the effects on the birds breeding there are unknown. The Rock Sandpiper is one of the shorebirds of highest conservation concern, due to its limited breeding distribution and populations, and potential impacts to its wintering areas.