Although Snail Kites (Rostrhamus sociabilis) in Florida and Venezuela fed mostly on Pomacea snails, I documented three alternative foods. In Florida, kites fed on five species of turtles, but especially on Sternotherus odoratus and Kinosternon bauri. During the height of a drought, one kite in Florida fed on a aquatic snail (Viviparus georgianus) for 5 weeks.- In Venezuela, freshwater crabs (Dilocarcinus dentatus) made up on average 10% of the Snail Kite's diet, but more than 25% during September and October. Kites consumed alternative foods with techniques that resemble snail-eating behavior, such as entering a turtle's body cavity by piercing the only leg shaped like a snail operculum. Handling times for turtles (76 min) and crabs (5.4 min) were much longer than for Pomacea snails (1.5 min). Viviparus snails required approximately one-third less handling time but contained one-fifth less body mass than Pomacea snails. Handling time (30 s) for V. georgianus did not differ between the Snail Kite and the Boat-tailed Grackle (Quiscalus major), a diet generalist. These findings are related to the factors that reinforce diet specialization and the ecological conditions that promote diet diversification in specialists. Like Pomacea snails, alternative foods have shells or carapaces and move relatively slowly. Alternative foods are probably less profitable than Pomacea snails, except for large crabs. Although crabs were regularly eaten by kites in Venezuela, turtles and Viviparus snails were eaten in Florida only during times of food scarcity. Received 9 June 1989, accepted 6 November 1989. DEPENDENCE on a single prey type is unusual among vertebrates, but may be more common in invertebrates (Bristow 1988). A notable ex- ception, the Snail Kite (Rostrhamus sociabilis), feeds almost exclusively on one genus of fresh- water snails (Pomacea). In Florida the kite eats only Pomacea paludosa (Howell 1932, Snyder and Snyder 1969, Sykes 1987), while in Central and South America several Pomacea species are eaten (Haverschmidt 1962, 1970; Beissinger 1983; Snyder and Kale 1983; Bourne 1985). Alterna- tive foods are taken on rare occasions. These include turtles (Sykes and Kale 1974, Woodin and Woodin 1981, Takekawa and Beissinger 1989) and a mammal (Sykes and Kale 1974). Other less carefully documented observations of nonsnail foods include a small yellowish serpent (Slud 1980), a ring-necked snake (Dia- dophis punctatus), and a dead American Coot (Fu- lica americana) (Sykes 1987). In Venezuela and Colombia, kites fed on freshwater crabs and