WatchList Species Account for Rock Sandpiper
(Calidris ptilocnemis)

Qualifies for the list as a Red List Species


Photo: Alan Wilson

The Rock Sandpiper is a shorebird of highest conservation concern due to its limited breeding distribution and low population (only 100-150,000 individuals), and potential impacts to its wintering areas.


This sandpiper winters farther north than any other shorebird, on the Alaskan coast from the south side of the Alaska Peninsula along the Pacific sparingly to central California. It breeds only in Alaska, from the Seward Peninsula to the Alaska Peninsula, and the Aleutian Archipelago and islands in the Bering Sea. Outside North America, it breeds in parts of eastern Siberia winters south to Japan.


The Rock Sandpiper is seldom found very far from the coast. It favors tundra dominated by heath and other low vegetation during breeding; 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.


Threats to this species 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. Populations of the Pacific Northwest population have declined at some sites, but numbers have increased at others, including the Pribilof Islands.