A medium-sized (16-20 inches) gull-like bird, the Black Skimmer in summer is most easily identified by its black upperparts, white underparts, and bizarre black and orange bill. In winter, the Black Skimmer becomes slightly grayer on the head and body. Male and female Black Skimmers are similar to one another in all seasons. The Black Skimmer breeds along the Atlantic coast of the United States south of Massachusetts, on the Gulf coast from Florida to northeastern Mexico, and along the coast of southern California south to central Mexico. In winter, this species withdraws from the U.S.Atlantic coast north of North Carolina, and may be found from there south on both coasts to Central America. Other subspecies occur along coasts and on large rivers in South America. Black Skimmers in North America breed on sandy beaches and barrier islands in colonies near those of other seabird species, utilizing similar habitat types during the winter. In South America, inland populations also exist which inhabit sandy river banks. Black Skimmers eat a variety of small fish and crustaceans. In appropriate habitat, Black Skimmers may be observed flying low over calm water. They feed by lowering the bottom half of their bill (which is much longer than the top half) into the water as they fly, quickly closing their bill when the submerged half of the bill touches a small fish. Black Skimmers are primarily active during the day.