The common sandpiper is a small Palearctic wader. This bird and its American sister species, the spotted sandpiper, make up the genus Actitis. They are parapatric and replace each other geographically; stray birds of either species may settle down with breeders of the other and hybridize. Hybridization has also been reported between the common sandpiper and the green sandpiper, a basal species of the closely related shank genus Tringa. It is a gregarious bird and is seen in large flocks, and has the distinctive stiff-winged flight, low over the water, of Actitis waders. The common sandpiper breeds across most of temperate and subtropical Europe and Asia, and migrates to Africa, southern Asia and Australia in winter. The eastern edge of its migration route passes by Palau in Micronesia, where hundreds of birds may gather for a stop-over. They depart the Palau region for their breeding quarters around the last week of April to the first week of May.
The common sandpiper forages by sight on the ground or in shallow water, picking up small food items such as insects, crustaceans and other invertebrates; it may even catch insects in flight. It is classified as least concern by IUCN.