A single cane toad can take down a monitor lizard, so researchers are teaching them to avoid these invasive amphibians.Releasing 200,000 eggs and young of a toxic invasive species might seem to be a sure way to make a bad situation worse. But by doing just that in Western Australia, conservation biologists have begun to rescue the region’s largest lizard.
The lizards, known locally as goannas, are an important apex predator and a food source for the Bunuba and other Indigenous people who live in the region. “If we don’t act soon … we will feel in our own selves that we will have lost everything,” says Monique Middleton, vice chair of the Bunuba Dawangarri Aboriginal Corporation.
To put it to the test, Ward-Fear and Shine worked with the regional wildlife department and the Bunuba Rangers, who are co-authors on the paper, to locate seven large populations of lizards that cane toads were expected to reach soon. The team counted lizards at each site, then put out more than 200,000 cane toad eggs for three of the seven populations. “It’s an ecosystem treatment,” Ward-Fear explains.
Sean Doody, an invasive species biologist at the University of South Florida, is concerned the young toads will kill other predators such as snakes, as well as juvenile lizards, as they seem to be wiping out a smaller monitor species he studies in Australia. But given the rapid growth of newborn lizards and the timing of the life cycles of lizards and toads, by the time the young toads appear, Ward-Fear expects the lizards will be big enough to survive eating them.