Rarest are the Nordmann's greenshank, whose 1,000 surviving pairs breed on Sakhalin; the tiny but striking spoon-billed sandpiper from north-east Siberia; and the much larger black-faced spoonbill, whose population has doubled to over 2,000, thanks to better protection of its wintering sites.
But what does it mean for the Norwegian purple sandpiper?For people, sea is better without sewage.
The most notorious example, in South Korea, is a 20-mile (33km) seawall built to enclose a huge estuary and mudflats at Saemangeum, an area two-thirds the size of Singapore where 400,000 birds, including the spoon-billed sandpiper and Nordmann's greenshank, had fed.
In one plover (the wrybill, Anarhynchus frontalis) the bill curves to the right; in the spoonbilled sandpiper (Eurynorhynchus pygmeus) the tip of the bill is broad and spatulate.
There are about 220 species, varying in size from the least sandpiper, a sparrow-sized bird of about 20 grams (0.7 ounce), to large curlews of about 640 grams (1.5 pounds, near the body size of a small chicken).
Along the tideline all around the estuary you may spot a common sandpiper in summer.
Along with the spoon-billed sandpiper, a whole suite of migratory waders from Asia and Australasia which depend utterly on these sites are in increasing danger of extinction, in an emerging wildlife disaster to which the world is paying little attention.
There are thought to be fewer than 100 pairs remaining in the wild of this tiny, critically-endangered wader, which is doubly notable: it is the only sandpiper with a spatulate bill, giving it a faintly comic air, and it has dropped in numbers by 90 per cent in a decade, putting it on the fast track to extinction.
Russia's spoon-billed sandpiper, the Tachira antpitta of Venezuela; the Reunion cuckooshrike of Reunion; the Mariana crow, of the Guam and Northern Mariana islands; the Floreana mockingbird of the Galapagos islands; and the akekee of Hawaii.
Scientists have observed that shorebirds, such as the white-rumped sandpiper (Calidris fuscicollis), risk increased mortality from exhaustion and severe weather during the course of their long migrations.
On his polo shirt was a pin featuring a spoon-billed sandpiper, a bird that breeds in Russia and is near extinction.
