The invasive Asiatic freshwater bivalve Corbicula fluminea is regarded as a pest in several countries including Brazil. Two water birds native to South America, the limpkin Aramus guarauna and the common gallinule Gallinula galeata, are herein recorded preying on C. fluminea in a pond of an urban park in South-eastern Brazil. The exotic clam is becoming increasingly common in the diet of both these water birds. This trend is likely due to its increasing population and the consequent rarity of the habitual prey (apple snails and native clams) for the mollusc-specialised limpkin, besides being an accessible animal protein source for the omnivorous gallinule.