 However , the toad was generally unsuccessful in reducing the targeted grey @-@ backed beetles , in part because the cane fields provided insufficient shelter for the predators during the day , in part because the beetles live at the tops of sugar cane – and cane toads are not good climbers . Since its original introduction , the cane toad has had a particularly marked effect on Australian biodiversity . The population of a number of native predatory reptiles has declined , such as the varanid lizards Varanus mertensi , V. mitchelli , and V. panoptes , the land snakes Pseudechis australis and Acanthophis antarcticus , and the crocodile species Crocodylus johnstoni ; in contrast , the population of the agamid lizard Amphibolurus gilberti — known to be a prey item of V. panoptes — has increased . 
