Effectiveness and target-specificity of a novel design of food dispenser to deliver a toxin to feral swine in the United States

Abstract

There are no registered toxins available for use on Feral Swine (Sus scrofa, Linnaeus) in the United States. HOGGONE® is a proprietary bait matrix under development in Australia that delivers toxic levels of sodium nitrite to feral swine. However, one challenge is to develop a species-specific oral delivery system to deliver toxins to feral swine in the USA while minimizing non-target wildlife exposure. The HOGHOPPER™ is a lightweight and portable bait delivery system that could overcome this problem. Our objective was to compare non-toxic HOGGONE removal by wildlife that visited HOGHOPPERS during acclimation periods (doors open; free-feeding stage) and activation periods (doors closed; simulated toxic stage) at sites throughout the United States. We conducted 38 HOGHOPPER trials on private and public land in Alabama, Florida, Oklahoma, and Texas, and determined species-specific visitation and HOGGONE removal rates using motion-sensing digital camera systems. We found activated HOGHOPPERS to successfully exclude all wildlife except feral swine and Raccoon (Procyon lotor, Linnaeus). For raccoons the number of baits removed per 24h was reduced by 92% during the HOGHOPPER activation period. No other wildlife removed HOGGONE from HOGHOPPERS. During trials in which raccoon breaches occurred, an extended acclimation period was used. To minimize raccoon exposure risks, an abbreviated acclimation period of ≤ 14d should be used with the HOGHOPPER. This will decrease the likelihood that raccoons learn how to access HOGGONE from the HOGHOPPER. Further experimentation is needed to demonstrate the efficacy of toxic HOGGONE at controlling feral swine populations.