A medium-sized (9 inches) wader, the female Wilson’s Phalarope in summer is most easily identified by its gray crown, black face, white throat, pale rust-red breast, and light gray wings with dark edges. The male Wilson’s Phalarope is similar but duller, especially on the back and face. Winter birds of both sexes are light gray above and pale below with a light gray head, and forehead and faint gray eye-stripes. This species is unmistakable in summer; in winter, it may be separated from the related Red Phalarope (Phalaropus fulicarius) and Red-necked Phalarope (Phalaropus lobatus) by its plainer wings as well as its longer bill and legs. Wilson’s Phalarope breeds primarily in the west-central United States and southwestern Canada, with smaller populations in the Great Lakes and further north and east in Canada. In winter, this species migrates south to southwestern South America, being most common from southern Peru to northern Argentina. This species’ temperate-zone breeding grounds, terrestrial wintering grounds, and exclusively New World distribution separate it from the other two phalarope species, which breed across the arctic and winter at sea. Wilson’s Phalaropes breed in a number of wetland habitat types, primarily in freshwater across most of its summer range but in brackish or salt-water marshes at a few coastal breeding sites. During the winter, this species primarily inhabits shallow saltwater lagoons. Wilson’s Phalaropes mainly eat aquatic invertebrates, especially small crustaceans. As this species’ breeding grounds are more accessible than those of the other two phalarope species, Wilson’s Phalaropes are comparatively easy to see during the summer. At that time of year, it is possible to observe individuals walking in shallow water while picking food out of the mud or from the surface of the water. On migration and during the winter, this species forms large flocks at a number of suitable saltwater lakes. Wilson’s Phalaropes are most active during the day.