The gregarious Snail Kite is a medium-sized raptor that ranks among the most specialized of the world's Falconiformes. Formerly called the Everglade Kite or Snail Hawk, it ranges from southern Mexico to northern Argentina and resides in the United States only in peninsular Florida. It is semi-nomadic and locally common on flooded freshwater marshes, around shallow lakes, and along freshwater courses. A dietary specialist, it feeds almost exclusively on freshwater apple snails of the genus Pomacea; its sickle-like bill is well adapted for removing these snails from their shells. This kite nests in loose colonies or solitarily, has an unusual mating system, and uses communal roosts, frequently in association with Anhingas (Anhinga anhinga) and colonial wading birds.
The species was first described in 1817 from near the Rio de la Plata and the Corrientes District of Argentina ( Vieillot 1817 ), but it was not discovered in Florida until April 1844, when Edward Harris ( Harris 1844 ) collected an immature male at the head of the Miami River in what is now downtown Miami. Although three subspecies of Snail Kite have been recognized in the past, current research suggests none are valid (see Systematics).
Since 1950 the Snail Kite has been widely studied in North America, but has received less attention in Central and South America. In Florida, it was classified as an Endangered Species in 1967. Unless otherwise specified, all material presented in this account refers to Florida populations.