Impact of wild pig invasion on 13 years of crop planting in the contiguous United States

Abstract

Wild pigs (Sus scrofa) are an invasive pest that cause extensive damage to agricultural crops. We examined the extent that planting for five types of crops known to sustain damage from wild pigs (corn [Zea mays], cotton [Gossypium L.], peanuts [Arachis hypogaea], soybeans [Glycine max], and wheat [Triticum spp.]) was influenced by the expansion of wild pigs in counties of the United States (US) during 2009–2022. Specifically, we examined changes in planting anomalies (i.e., the amount planted relative to the long-term average) relative to two variables that could explain wild pig pressure: the proportion of a county with wild pigs and a trend in the intensity of management, while accounting for other variables that could influence decisions to plant. We found that greater overlap with wild pig range was associated with larger planting anomalies for cotton. However, removal of wild pigs did not influence planting anomalies for any crop. We also found that planting anomalies were influenced by return on investment, climate, and the amount of Conservation Reserve Program lands. For some crops, these other factors were more influential than pressures from wild pigs. Our results indicate that producers are planting more cotton in areas with greater presence of wild pigs, and current management efforts to reduce populations of wild pigs are not altering those decisions. Producers switching to lessor-damaged crops as wild pigs expand their range in the US could alter future crop yields, and more intensive efforts to mitigate wild pigs may be needed.