Evaluation of movement behaviors to inform toxic baiting strategies for invasive wild pigs (Sus scrofa)

BACKGROUND: Invasive wild pigs damage agriculture, property, and natural ecosystems. To curtail damage, an effective and humane toxic bait containing microencapsulated sodium nitrite is under development. Strategies for delivering the toxic bait are needed to establish adequate spacing of bait sites, and for simultaneously accustoming wild pigs to the novel bait and wild pig-specific bait stations designed to exclude non-target species. RESULTS: We monitored movements of 32 Global Positioning System (GPS)-collared wild pigs relative to 41 bait sites containing placebo bait. Among the bait sites, we compared three experimental baiting strategies (and a control) to evaluate which strategy led to the most wild pigs accessing the placebo bait inside bait stations. We found that bait sites should be spaced 0.5-1 km apart to maximize opportunities for all wild pigs to find and utilize the bait sites. Baiting strategies that allowed ≥ 15 days for accustoming wild pigs to bait stations were most effective and resulted in nearly 90% of wild pigs accessing the placebo bait inside the bait stations. Bait stations excluded all non-target animals, except one instance with a raccoon (Procyon lotor). CONCLUSION: These results demonstrate the potential for toxic bait to be an effective tool for reducing populations of wild pigs with minimal risks to non-target species, if optimized delivery procedures are followed. © 2018 Society of Chemical Industry.