The Terek Sandpiper (Xenus cinereus), is a small wader and the only member of the genus Xenus. This bird breeds near water in the taiga of Finland and northern Asia, and lays three or four eggs in a lined ground scrape. These birds migrate south in winter to tropical coasts in east Africa, south Asia and Australia, usually preferring muddy areas. This wader is a rare vagrant in western Europe.

The Terek Sandpiper feeds in a distinctive and very active way, chasing insects and other mobile prey, and sometimes then running to the water's edge to wash its catch.

This bird is slightly larger than the Common Sandpiper at 22-25 cm length, and it its long upcurved bill makes it very distinctive. As the scientific specific name implies, this wader has a grey back, face and breast in all plumages. The belly is whitish and the legs yellow. The call is a high whistle.