Landscapes of nausea: Successful conditioned taste aversion in a wild red fox population

Abstract

Predation by invasive mammalian species is one of the key drivers of nativespecies' population declines and extinctions. Current management of invasivespecies focuses on their removal from the landscape. However, total removalcan be difficult, costly and even impossible. If eradication is not achieved,reductions in predator numbers are often temporary. New tactics are neededto target predators in situ, to reduce their negative impacts. We test the efficacyof conditioned taste aversion (CTA), a tactic that could reduce the impact ofpredation on target prey species. By associating nausea with a specific foodsource, it may be possible to condition an aversion to a target bait, and ulti-mately to live animals in the wild. To assess if wild invasive red foxes (Vulpesvulpes) can be conditioned to avoid a specific food source, we used baits (frieddeboned chicken) containing encapsulated levamisole, an anthelmintic agentknown to induce nausea leading to emesis and/or diarrhea at high dosageswith no long-term side effects. We buried baits at 30 stations across an openlandscape. After treatment, reductions in control baits taken (at least 30%)were observed for 68 days, indicating the use of CTA had successfully reducedbait consumption by red foxes in a wild context. To our knowledge, this studyrepresents the first successful test of CTA to a meat bait in a wild red fox popu-lation. Our results suggest that CTA shows promise as a tool to reduce the pre-dation of vulnerable animals providing an alternative tactic to manage theimpacts of invasive mammalian predators where eradication is currentlyimpossible Show more