SREL Reprint #3608

Multi-level movement response of invasive wild pigs (Sus scrofa) to removal

Guillaume Bastille-Rousseau1,2, Peter E Schlichting3, David A Keiter3, Joshua B Smith3, John C Kilgo4,
George Wittemyer2, Kurt C Vercauteren1, James C Beasley3, and Kim M Pepin1

1United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, Fort Collins, CO, USA
2Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, USA
3Savannah River Ecology Lab, Warnell School of Forestry and Natural Resources,
University of Georgia, Aiken, SC, USA
4United States Department of Agriculture, Forest Service, Southern Research Station,
New Ellenton, SC, USA

Background: Lethal removal of invasive species, such as wild pigs (Sus scrofa), is often the most efficient approach for reducing their negative impacts. Wild pigs are one of the most widespread and destructive invasive mammals in the USA. Lethal management techniques are a key approach for wild pigs and can alter wild pig spatial behavior, but it is unclear how wild pigs respond to the most common removal technique, trapping. We investigated the spatial behavior of wild pigs following intensive removal of conspecifics via trapping at three sites within the Savannah River Site, SC, USA. We evaluated changes in wild pig densities, estimated temporal shifts in home-range properties, and evaluated fine-scale movement responses of wild pigs to removal.
Results: We observed a significant reduction in the density of wild pigs in one site following removal via trapping while a qualitative reduction was observed in another site. We found little evidence of shifts in pig home-ranging behavior following removal. However, we did observe a nuanced response in movement behavior of wild pigs to the removal at the scale of the GPS locations (4 h), including increased movement speed and reduced selection for vegetation rich areas.
Conclusion: Our work provides a better understanding of the impact of removal via trapping on wild pig movement and its implications for management. The lack of shift in home-range characteristics observed illustrates how targeted trapping could be used to provide temporary relief for species sensitive to wild pig consumption such as ground nesting birds or agricultural crops.

Keywords: animal movement; GPS telemetry; step-selection functions (SSF); spatially-explicit-capture-recapture (SECR); swine; wild boar

SREL Reprint #3608

Bastille-Rousseau, G., P. E. Schlichting, D. A. Keiter, J. B. Smith, J. C. Kilgo, G. Wittemyer, K. C. Vercauteren, J. C. Beasley, and K. M. Pepin. 2021. Multi-level movement response of invasive wild pigs (Sus scrofa) to removal. Pest Management Science 77(1): 85-95.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).