The Terek sandpiper (Xenus cinereus) is a small migratory Palearctic wader species and is the only member of the genus Xenus. It is named after the Terek River which flows into the west of the Caspian Sea, as it was first observed around this area.
Slightly larger than the common sandpiper at 22–25 cm (8.7–9.8 in) length, its long upcurved bill – somewhat reminiscent of an avocet's, but not as strongly curved – makes it very distinctive. As the scientific specific name implies, this wader has a grey back, face and breast in all plumages; a white supercilium may appear more or less distinct. The belly is whitish and the feet yellow; the bill has a yellowish base, with the rest being black.
The call is a high whistle.