Taste aversion training can educate free-ranging crocodiles against toxic invaders

Title	Taste aversion training can educate free-ranging crocodiles against toxic invaders
Authors	Georgia Ward-Fear, Miles Bruny, the Bunuba Rangers, Clare Forward, Ian Cooksey, Richard Shine
Magazine	Proceedings of the Royal Society B: Biological Sciences
Date	08/14/2024
DOI	10.1098/rspb.2023.2507
Introduction	Apex predators are vital for ecosystem health, thus their preservation is paramount. In tropical Australia, freshwater crocodile (Crocodylus johnstoni) populations have seen declines exceeding 70% due to consuming toxic invasive cane toads (Rhinella marina). Laboratory studies previously confirmed conditioned taste aversion (CTA) as an effective method to deter toad consumption. To implement this strategy at a broader scale, 2395 baits—comprising toad carcasses with toxins removed and infused with a nausea-inducing agent—were strategically placed across four gorge systems in north-western Australia. Remote cameras tracked bait consumption, and crocodile numbers were assessed through surveys. Wild crocodiles quickly learned to shun the toad baits, while continuing to consume control (chicken) baits. At a control site, toad invasion led to significant crocodile mortality, particularly among smaller individuals, a trend not observed at adjacent treatment sites. In regions with good connectivity to other water bodies, consistent bait deployment over several years sustained positive effects on crocodile survival. This intervention successfully mitigated the severe consequences of invasive cane toads on these apex predators.
Quote	Georgia Ward-Fear, Miles Bruny and the Bunuba Rangers et al. Taste aversion training can educate free-ranging crocodiles against toxic invaders. Proc. Biol. Sci. 2024. Vol. 291(2028). DOI: 10.1098/rspb.2023.2507
Element	Lithium (Li)
Industry	Research & Laboratory , Agriculture