The on-ground feasibility of a waterless barrier to stop the spread of invasive cane toads in Western Australia

Abstract

Modeling suggests that excluding invasive cane toads from artificial water points (e.g., pastoral dams) along an arid coastal corridor in Western Australia would create a “waterless barrier” halting their spread. In this study, we explored one critical assumption of these models: that toads cannot persist in the corridor during the dry season without access to artificial water points. We explicitly tested this assumption by translocating and radio-tracking 78 male cane toads in the proposed barrier region during the dry season. Telemetered toads moved substantial distances (maximum distance >2.5 km/night) and were adept at finding shelter. Nonetheless, toads experienced high water loss rates (1.89%/hr) and rapid mortality in both desert (mean ± SD = 43.6 hr ±1.4) and coastal (24.5 hr ±1.2) habitats. Survival analysis suggested that toads could survive a maximum of 5 days without access to surface water and would move a maximum of 5.35 km in this time. Our results confirm that artificial water points are a critical resource for toads in the proposed barrier region and provide further evidence that the waterless barrier could successfully halt toad expansion in Western Australia.