Land cover attributes affect the distribution of rooting damage by wild pigs (Sus scrofa)

The rapid expansion of invasive wild pig (Sus scrofa) populations over the past several decades has resulted in an increased distribution of damage to native systems throughout their introduced range. Despite the extent of wild pig damage and growing concerns among land managers, there is limited published data regarding the variability of damage in relation to season and fine-scale land cover attributes. We assessed wild pig rooting damage during the winter (January-March) and summer (June-August) of 2020 along 36 km of 10-m-wide transects on the Savannah River Site (SRS) and 34 km of 10-m-wide transects on privately owned agricultural (POA) properties in South Carolina, USA. We recorded fine-scale land cover attributes at damage and control sites to determine the factors that were most closely associated with wild pig rooting damage. We reported 6,825.5 m² of rooting damage over 36 km of survey transects on the SRS and 3,146.9 m² of rooting damage over 34 km of survey transects on the POA properties over winter and summer seasons. The average depth of rooting damage was 11.8 cm on the SRS and 11.2 cm on the POA properties. Our modeling results suggested rooting by wild pigs was more likely to occur in earlier winter months, in hardwood stands, proximal to water, and in areas with less ground vegetation and greater stem density, and less likely to occur in areas with greater tree density and near roads. Our results can help facilitate early detection of wild pig expansion by highlighting key areas to monitor for wild pig presence.