The common sandpiper (Actitis hypoleucos) is a small Palearctic wader. This bird and its American sister species, the spotted sandpiper (A. macularia), 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.

Source: Wikipedia