[order] Charadriiformes | [family] Scolopacidae | [latin] Calidris acuminata | [UK] Sharp-Tailed Sandpiper | [FR] Bécasseau à queue pointue | [DE] Spitzschwanzstrandläufer | [ES] Correlimos acuminado | [IT] Piro piro siberiano | [NL] Siberische Strandloper

Siberische Strandloper determination

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Similar in size and shape to the more common Pectoral Sandpiper, the rare Sharp-tailed Sandpiper can be distinguished by its rufous cap and distinctive white eye-line. Adults in breeding plumage are heavily spotted overall. Non-breeding plumage is lighter gray and less boldly streaked. Juveniles, the form most often seen in Washington, are redder than adults, with a buff-colored, lightly streaked breast, which often serves as their most distinctive field mark.
In areas where they are more abundant, Sharp-tailed Sandpipers are typically seen in large flocks. In Washington, they are often seen with Pectoral Sandpipers. They feed by moving steadily along in dense grass, heads down, picking up surface prey and probing lightly. They are seen on mudflats slightly more often than are Pectorals.

Sharp-tailed Sandpipers breed in wet Siberian tundra. During migration, they usually stop at grassy, coastal salt marshes, although they can also be found in coastal lagoons and mudflats, especially those adjacent to salt marshes.

Accidental in Europe with sightings in Northern, Central en west Europe (almost annually in Belgium and Finland).
The Canadian Wildlife Service estimates the worldwide population at 166,000 birds, with 1,000 birds traveling down the Pacific Coast south of Alaska each year. Because such a small percentage of the population ever makes it to the Pacific Northwest, local conservation issues involving the Sharp-tailed Sandpiper are few. Population trends are unknown.

On their breeding grounds, Sharp-tailed Sandpipers eat primarily mosquito larvae. Other invertebrates, including mollusks and crustaceans, are also part of the diet.

This species has a large range, with an estimated global Extent of Occurrence of 50,000-100,000 km². It has a large global population estimated to be 160,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern [conservation status from birdlife.org]

Sharp-tailed Sandpipers are polygynous. Males with good territories mate with more than one female. Each female builds a nest out of grass on the wet, peaty tundra, or on a drier hummock. She incubates the clutch. After 19-23 days of incubation, the young hatch and leave the nest within a day or so. They find their own food immediately, but the female protects and tends them. The young birds begin to fly at 18-21 days.

Migratory. Leaves breeding grounds Jul-Sept. Main flyway via Transbaikalia, E of L Baikal, with smaller numbers in broad front from E Kazakhstan to Sea of Okhotsk; continues over E Mongolia and China, including Manchuria, to Japan, Korea, Philippines and New Guinea; probably overflies New Guinea during N migration. Juveniles on passage also occur regularly down Pacific coast and even into Alaska. Arrival in Australia Aug-Nov, and 25,000 birds arrived in single night mid-Sept 1984; birds leave S Australia early, mid-Feb to early Mar, undertaking rather prolonged N migration to breeding grounds, with series of short flights. Movements within Australia seem to be dispersive, with birds leaving when wetlands dry. Most of population migrates to Australia, mainly SE; few 1 st-year birds spend N summer in winter quarters.