WHAT: Expose native predators to small doses of Cane toad toxin that make them sick but don't kill them ('teaching' them that toads are bad)
WHEN: Just before these animals meet the oncoming Cane toad invasion in the wild
HOW: Distribute small Cane toads or Cane toad sausages (i.e. made of toad flesh) in areas of the landscape with high predator abundance
It's likely that all vertebrate species (even us) have the ability to develop taste aversion. This is because taste aversion enables animals to: i) detect that an ingested substance was toxic; ii) create a strong physiological association between taste and toxicity; iii) shift their foraging behaviour to avoid these dangerous meals in the future (substance aversion). Taste Aversion, therefore, is a powerful protective response that enables animals to survive alongside poisonous substances in the wild.
The only caveat - the initial dose can't be fatal!
VIDEO: Premise of CTA toad aversion and CTA deployment on the landscape scale
Teacher toads and CTA deployment
Putting it into practice
Our field studies have shown that we can harness an animal's natural ability to develop taste aversion to affect its own conservation when faced with the cane toad invasion. Animals can develop strong aversions after only one experience with a small cane toad.
Here is an example. In the video below 'Macca' a wild floodplain monitor has his first trial with a small toad. This is the first time he has seen one so he gobbles it down. The next clip shows Macca a month later, in a subsequent trial. He investigates the small toad extensively but recognises it by sight and smell, then leaves it alone. Macca survived in toad-infested areas until the end of the study (three years later). If the first toad he had met was a big one at the invasion front, he wouldn't be here today!
VIDEO: Macca's CTA trials in the wild