Assessment of Spilled Toxic Bait by Wild Pigs and Potential Risk to Non-Target Species

Authors

John C. Kinsey, Texas Parks and Wildlife DepartmentFollow
Justin A. Foster, Texas Parks and Wildlife Department
Nathan P. Snow, University of Texas at San Antonio
Jason D. Wishart, Animal Control Technologies Australia Pty Ltd
Linton D. Staples, Animal Control Technologies Australia Pty Ltd
Janis K. Bush, University of Texas at San Antonio
Kurt V. VerCauteren, USDA APHIS WS NWRC Colrado

ORCID IDs

Kinsey 0000-0002-3978-3685

Document Type

Article

Date of this Version

2023

Citation

Pest Management Sciences (2023) 79: 4,589-4,598

doi: 10.1002/ps.7658

Comments

United States government work

Abstract

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations could be reduced by > 90% when compacted in trays, as opposed to being manually crumbled into pieces. We documented a mean spill rate of 0.913 g of bait per wild pig. Conservative risk assessments for nine non-target species for which SN toxicity data exist indicate that there is relatively low risk of lethal exposure,apart from zebrafinches (Taeniopygia guttata) and white mice. Our results indicate that there may be enough spilled bait per feeding wild pig to kill 9.5 or 3.5 individuals of these species, respectively. Other species assessed range from 0.002 to 0.406 potential mortalities per wild pig.

Conclusion

We demonstrated that the amount of bait spilled by wild pigs during feeding and the associated risk to non-target animals can be minimized by presenting the bait compacted in trays within bait stations. We recommend that baits be tightly compacted and secured in bait stations to minimize risks to non-target animals from spilled bait by wild pigs.