Lyall Grieve was among the first to see the carnage return to Mark's Dam last December. It was another sunbaked afternoon on the Kimberley plateau in northwestern Australia when the khaki-clad herpetologist stepped out of his Toyota Hi-Lux and onto the red soil. He hiked up a dry, grassy hill to the top of the dam when he spotted the skeleton under a tree. A Merten's water monitor - a meter-long lizard whose nostrils sit atop its head like a crocodile's - was contorted in what Grieve called a "position of pain." Continuing along the edge of the waterhole, he and his companions found three other monitors in various states of decomposition. Then, there was the dead jabiru - a robust stork that breeds in Australia and Asia - along with the empty shell...
This dam is on the frontline of the cane toad's invasion, and Grieve was joining a mission with the Kimberley Toadbusters - a volunteer group that wants to stop the toad before it leaps across the boundary between the Northern Territory and the state of Western Australia. The jabiru and the monitor lizard commonly feast on native frogs, and they were likely poisoned when they tried to munch on the toxic cane toad. Although some scientists contend that some animal populations will adapt to the cane toad's presence in the long-term, the can-do folks in Kununurra, the town of 6,500 where the Toadbusters are based, are not content to wait and see. The group, which boasts volunteers ranging from Vietnam veterans to aboriginal schoolchildren, heads out every weekend mapping, trapping, and killing the invasive pests. Lee Scott-Virtue, who founded the Toadbusters with her husband in September 2005, says that to date, they've bagged more than 200,000 toads.
At the first of four waterholes, toads of all sizes are bounding through the grass, heading down to a muddy cattle pond for their nightly courtship ritual. Grieve snatches toads along the way as Sister Del Collins holds an outstretched green garbage bag. The bag soon grows heavy with their weight. By the end of the night, the modest team of four will have snagged over 100 full-grown toads.
After midnight, Collins, a 61-year-old nurse and nightclub bouncer whose toadbusting attire includes a cap embroidered with the words "The Slayer," will gas them with carbon dioxide. "You have to admire the toad," she says. "Awesome creature to hunt and bloody hard to kill." Collins, like many of the Toadbusters, says she enjoys the camaraderie and sense of a mission that comes with toadbusting. But she's also heard reports of what the toad has done to Queensland and the Northern Territory, and she doesn't want it to happen to Western Australia. "There's still a lot of wildlife," she says, gazing at a rust-colored escarpment breaking through the tea trees to the south. "Just gotta stop these bloody toads."
Not everyone believes toadbusting is having an impact. Last July, Tony Peacock, the CEO of the Invasive Animals Cooperative Research Centre, prepared a report on the Toadbusters and the Darwin-based rival, Stop the Toad Foundation, which also enlists volunteers to battle the toads. Peacock's analysis found that neither effort was slowing down the toad's advance of 40-60 km/year. "The evidence doesn't show it works," he says. "Having said that, no one has tried what they are trying. It's fantastic that they are so concerned about their wildlife." The groups' leaders admit that they cannot halt the toad's progress, but they believe they can temper its blow by reducing population explosions on the front lines. They hope to hold out until these scientists come up with a solution.
Grieve himself is both a scientist and a toadbuster. He is a master's student at Macquarie University in Sydney, and he joins the toadbusters for part of the year because it's the quickest way to gather specimens for his thesis work. The next morning, he pulls 25 limp toads out of plastic grocery bags and lays them on a picnic table one at a time. Data on the toad's stomach contents will go hand in hand with his pre- and post-cane toad surveys of the Kimberley's small vertebrates. So when the toads do arrive, Kununurra will know what they lost, or what the Toadbusters have saved.