Australasian Science: Australia's authority on science since 1938

Toad-Proof Fence

Toad-proof fences around dams can prevent the pests from cooling down in the hot, arid zones of Australia, killing them in large enough numbers to stop their spread. “This is the first study to demonstrate long-term control of cane toads,” says A/Prof Mike Letnic of UNSW

Letnic, who was lead author of a study published in the Journal of Applied Ecology, explained that most of the areas that these toxic amphibians will invade in future are semi-arid or arid. “Cane toads need water to survive, and we have previously shown they use the dams as refuges in the hot, dry periods. They enter the water during the day to cool down and rehydrate. Then, when the rainy period returns, they move on from these dry season refuges into new territory.”

To determine the impact of restricting access to the water, the researchers constructed small fences from shade cloth around three dams in the Victoria River region of the Northern Territory and maintained them for a year. Toads could not jump over the fences or burrow under them.

“The toads were still attracted to the water but they died en masse while attempting to settle at the fenced dams. Their numbers remained suppressed for a further year. By comparison, there were 10 to 100 times more toads living at the unfenced dams that were used as controls in the study,” Letnic says.

“By excluding toads from dams, we converted their invasion refuges into ecological traps and thwarted their spread,” Letnic says. “If conducted strategically, excluding toads from man-made water sources could effectively control their populations across large areas of Australia and relieve the impacts that cane toads are having on native predators and dung beetles.”