What is "red-backed sandpiper"

Dunlin \Dun"lin\, n. [Prob. of Celtic origin; cf. Gael. dun hill (E. dune), and linne pool, pond, lake, E. lin.] (Zo["o]l.) A species of sandpiper ( Tringa alpina); -- called also churr, dorbie, grass bird, and red-backed sandpiper. It is found both in Europe and Americ

n. small common sandpiper that breeds in northern or arctic regions and winters in southern United States or Mediterranean regions [syn: dunlin, Erolia alpina]