Impact of Invasive Wild Pig on White-Tailed Deer and Eastern Wild Turkeys in Southwest Georgia

Abstract

Wild pigs (Sus scrofa) are a highly destructive invasive species and reported to be present in 77% of counties in the southeastern U.S. Wild pigs may negatively affect white-tailed deer (Odocoileus virginianus; hereinafter, deer) and eastern wild turkeys (Meleagris gallopavo silvestris; hereinafter, turkey) via competition over forage or exclusion from preferred areas. To explore effects of wild pigs on spatial distribution of these species within a mixed agriculture-forest landscape, we developed models predicting camera trap detections of deer and turkeys as a function of landcover, calendar season, and wild pig presence. We deployed 147 passive camera traps and collected data for one month during each calendar season during 2020 to 2022 in southwestern Georgia (32,760 camera nights). We observed a negative association between turkeys and wild pigs during summer and within mixed forests, and a negative association between deer and wild pigs in pecan (Carya illinoinensis) orchards during summer, fall and winter. However, there was a positive association between deer and wild pigs in forested wetlands and mixed forests during fall and winter. The negative relationships between turkeys and wild pigs or deer and wild pigs may be from adverse interactions or simply species-specific landcover preferences. Similarly, the positive correlations with deer are likely the result of common landcover preferences, as it seems highly unlikely that deer benefit from wild pigs. Our results highlight how the relationship between invasive species and native species may be confounded by differences in land cover preferences and suggest further, manipulative experiments, may be necessary to better assess the effects of wild pigs on native wildlife.