Cannibalism in anurans is well known, both on eggs, tadpoles, and post-metamorphic specimens.
Among adult anurans, however, less is known about cannibalism in the terrestrial phase of the anuran life cycle. We report an in situ observation of Leptodactylus macrosternum preying on an juvenile of L. macrosternum. During fieldwork in a rapid amphibian and reptile assessment at a flooded area, municipality of Santana, State of Amapá, Brazil, we found an adult male L.
macrosternum trying to swallow a juvenile of L. macrosternum. The initial observation was prompted by following a distress call, revealed to be emitted by an individual of L. macrosternum which was biting the hind limbs of the L. macrosternum male. The stomach contents included two anuran species: L. macrosternum and Rhinella major. This record presented herein presents further evidence of the generalistic feeding behaviour of L. macrosternum and the first report of adult cannibalism in this species.