Snail Kites have a diet restricted to apple snails of the genus Pomacea. The slender, curved beak of Snail Kites seems to be beneficially specialized for the consumption of these type of prey in which the body of the mollusk must be extracted from its hard shell. There is a high percentage of hunting success (76%) compared to other accipiters (Bergmann et al., 2013) and larger prey are selected at sites with high prey densities despite the cost this could potentially mean in terms of handling time (Tanaka et al., 2006). However, the study of Bergmann et al. (2013) found that on average handling time is double that of the time spent hunting. As they forage, Snail Kites depend on visualization of the snails from a perch or in flight and so are favored by shallow waters with vegetation that is not too dense (Bergmann et al., 2013).
Only in cases in which snail abundance might be low, such as in extreme dry seasons, or in situations of captivity, do Snail Kites feed on different prey. In their natural habitat, the broadening of a specialist diet may not be optimal due to longer handling times and less energetic supply (Beissinger et al., 1994), but foraging plasticity probably is essential when apple snails are scarce. Accounts of alternative prey items include turtles, crabs, other snail species and small mammals (Beissinger, 1990; Sykes et al., 1974).