Cane toads bred in WA's Kimberley protect goannas from fatal consequences
Seemingly counterintuitive, the DBCA is breeding and releasing cane toads near Broome. (ABC News)
In short:
Scientists are deliberately breeding the invasive cane toad in Western Australia's far north as part of a strategy to protect native wildlife.
Exposing predators like goannas to small, non-lethal toads helps them develop a lasting aversion.
What's next?
Given the program's success in other parts of the Kimberley it is expanding into the Roebuck Plains outside Broome.
Scientists admit it might "sound crazy" to deliberately breed an invasive cane toad for Western Australia's northern outback.
Cane toads normally prove fatal to native flora and fauna, causing a significant impact since their introduction in Australia's east the 1930s.
Although seemingly counterintuitive, by exposing predators like goannas to small, non-lethal cane toads, they develop a "taste aversion".
The deliberately bred juvenile amphibians contain much lower toxin levels, so when goannas eat them they become sick but recover quickly.
The research group releases juvenile toads, known as metamorph cane toads, into targeted areas. (Supplied: DBCA)
It prevents goannas from fatal encounters with fully grown cane toads.
Program expands
The Department of Biodiversity, Conservation and Attractions (DBCA) has been running the exposure program for over a decade.
Cane toad program coordinator Michael Main said the mitigation strategy had been "incredibly successful" in preventing goanna deaths.
The Department of Biodiversity's Michael Main with cane toad eggs. (Supplied: DBCA)
He said he was optimistic about its effectiveness at a new location in Roebuck Plains, near Broome.
"We will go to sites that are at the frontline where the cane toads are arriving and we will release the eggs at those water bodies," Mr Main said.
"It sounds a bit crazy … but from previous studies we're very confident in our mitigation strategy working."
Cane toads are prolific breeders, with a single female laying up to 30,000 eggs twice a year.
"At sites where we were treating, 60 to 90 per cent [of goannas survived] after the main cane toad front arrived," he said.
"Whereas at the control sites, where we didn't engage in taste aversion training, populations dropped over 90 per cent."
Cane toads are introduced to treatment sites to teach native predators to avoid the species. (Supplied: DBCA)
DBCA will be working alongside the Nyikina Mangala rangers and the Yawuru community this year to release the eggs and monitor the goanna population.
Community involvement
Derby Landcare Group chairperson Robin Chapple helped organise a local cane toad muster to contribute specimens to the program.
The community caught 137 cane toads in 90 minutes.
A cane toad muster in Derby saw locals round-up toads for the study. (Supplied: Derby Landcare Group)
"The largest was a bit like a boxing glove and the other ones were about fist size," Mr Chapple said.
"You pick them up, it's as simple as that. They don't squirm away [but] you've got to be fairly quick and grab them by the hand and hind legs."
Mr Chapple said even though it was dark and pelting down with rain, one man caught 60 cane toads by himself.
Derby locals caught 137 cane toads, including 35 females. (Supplied: Derby Landcare Group)
"It's a fun night. Everybody comes out and tries to get the biggest bag, and we usually have ice creams for them," he said.
"It's a family outing. Quite honestly, the kids enjoy it immensely."