Saving an Endangered Species by Creating a Conditioned Taste Aversion The endangered northern quoll is a small Australian marsupial that seems to have a particular fondness for cane toads, a highly invasive, nonnative species. Quolls and other native species have been decimated by cane toads, whose skin, glands, and internal organs contain a deadly poison.University of Sydney ecologist Stephanie O’Donnell and her colleagues (2010) successfully created a conditioned taste aversion to teach quolls to avoid eating cane toads. They fed young quolls tiny, dead cane toads that were laced with a nausea-inducing drug. The juvenile cane toads, weighing less than a tenth of an ounce, did not contain enough poison to kill the quolls, but the drug made the quolls extremely nauseous. Did a taste aversion develop? Yes, and the quolls with taste aversions survived up to five times longer in the wild than control group quolls who were not exposed to the sickness-inducing toads.
Ultimately, the scientists hope to develop ways to produce cane-toad taste aversions in entire populations of quolls and other endangered species whose survival is imperiled by their habit of munching on the poisonous toads. One idea is to spread drug-laced toad carcasses over a wide area, possibly from the air by plane or helicopter.
