The spoon-billed sandpiper (Calidris pygmaea) is a small wader which breeds on the coasts of the Bering Sea and winters in Southeast Asia. This species is highly threatened, and it is said that since the 1970s the breeding population has decreased significantly. By 2000, the estimated breeding population of the species was 350–500. Taxonomy Platalea pygmea was the scientific name proposed by Carl Linnaeus in 1758. It was moved to Eurynorhynchus by Sven Nilsson in 1821. It is now classified under the calidrid sandpipers. Description The most distinctive feature of this species is its spatulate bill. The breeding adult bird is 14–16 cm in length, and has a red-brown head, neck and breast with dark brown streaks. It has blackish upperparts with buff and pale rufous fringing. Non-breeding adults lack the reddish colouration, but have pale brownish-grey upperparts with whitish fringing to the wing-coverts. The underparts are white and the legs are black. The measurements are; wing 98–106 mm, bill 19–24 mm, bill tip breadth 10–12 mm, tarsus 19–22 mm and tail 37–39 mm. The contact calls of the spoon-billed sandpiper include a quiet or a shrill . The song, given during display, is an intermittent buzzing and descending trill . The display flight of the male includes brief hovers, circling and rapid diving while singing. Distribution and habitat The spoon-billed sandpiper's breeding habitat is sea coasts and adjacent hinterland on the Chukchi Peninsula and southwards along the isthmus of the Kamchatka Peninsula. It migrates down the Pacific coast through Japan, Korea and China, to its main wintering grounds in south and southeast Asia, where it has been recorded from India, Bangladesh, Sri Lanka, Burma, Thailand, Vietnam, the Philippines, Peninsular Malaysia and Singapore. Through phylogenetic analyses for the complete mitogenome sequence, South Korean and Chinese C. pygmaea groups were indicated to be closely related to Arenaria interpres because of the similarity in the series of protein-coding genes. Behaviour and ecology Its feeding style consists of a side-to-side movement of the bill as the bird walks forward with its head down. This species nests in June–July on coastal areas in the tundra, choosing locations with grass close to freshwater pools. Spoon-billed sandpipers feed on the moss in tundras, as well as smaller animal species like mosquitoes, flies, beetles, and spiders. At certain points in time, they also feed on marine vertebrates such as shrimp and worms. Conservation This bird is critically