A comparison of cane toad and native tadpoles as predators of native anuran eggs, hatchlings and larvae

Few quantitative data exist regarding the impact of the introduced cane toad, Bufo marinus, on native Australian fauna. This study investigated predation by tadpoles of B. marinus and two native anurans (Limnodynastes ornatus and Litoria rubella) on eggs, hatchlings and larvae of native anurans that co-occur with these tadpoles in temporary and semi-permanent water bodies in northern Queensland. During controlled laboratory experiments, neither small nor large B. marinus tadpoles were significant predators of native anuran eggs, hatchlings or tadpoles. Small tadpoles of L. ornatus also did not prey significantly upon native anuran eggs, hatchlings or tadpoles. However, large tadpoles of L. ornatus and, to a lesser extent, L. rubella were often significant predators of native anuran eggs and hatchlings, but were not significant predators of native tadpoles. The results suggest that native tadpoles are often likely to have a greater impact on the survival of early life history stages of native anurans via predation than areB. marinus tadpoles.