Adult poison frogs can capture and consume aquatic tadpoles

Cannibalism is common in animals, and its expression is shaped by a suite of costs and benefits beyond the caloric content of meals made of conspecifics. We report here on fortuitous observations of cannibalism of tadpoles by unrelated adult Oophaga pumilio made during experimental assays of tadpole begging. This cannibalism was rare, but performed by adults of both sexes and from six populations in the Bocas del Toro archipelago. Only tadpoles at the earliest free-living stages were cannibalized, and those that were cannibalized begged more often than tadpoles at the same developmental stages that were not eaten by adults. This newly documented proficiency at capturing and consuming food in water is impressive given that O. pumilio adults are terrestrial and not known to consume aquatic prey. This ability, if employed in nature, may also afford additional reproductive opportunities to adults. The nurseries used for tadpole deposition are often limiting, and a parent could make an occupied nursery more hospitable for its young (or attractive to a potential mate) by consuming the occupant, or could even parasitize the parental investment of another mother by replacing her tadpole.