The curlew sandpiper is a small wader that breeds on the tundra of Arctic Siberia. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. These birds are small waders, having a longer down-curved bill, longer neck and legs and a white rump. The breeding adult has patterned dark grey upperparts and brick-red underparts. In winter, this bird is pale grey above and white below, and shows an obvious white supercilium. Juveniles have a grey and brown back, a white belly and a peach-coloured breast. Of all shorebird species, the curlew sandpiper has the smallest breeding range in relation to its non-breeding range. After breeding these birds migrate south to Africa, Australasia or India. South Africa is at the southern limit of the migration path from Siberia, 15,000 km (9,300 mi) or 130° of latitude away.
This wader is highly gregarious, and will form flocks with other calidrid waders, particularly dunlin. Despite its easterly breeding range, this species is regular on passage in western Europe, presumably because of the southwesterly migration route. This species is classified as Near Threatened by IUCN.