Consequences Associated with the Recent Range Expansion of Nonnative Feral Swine

Feral swine (Sus scrofa) have been repeatedly introduced to locations around the world. Aided by both an adaptable biology and deliberate introductions by people, the range of invasive feral swine in the United States has expanded from 17 to 38 states over the past 30 years. The swine’s generalist diet combined with high population densities can complicate efforts to conserve threatened and endangered species, and losses from crop damage and livestock predation in the United States alone are estimated to be more than $1 billion. In addition, feral swine can be a reservoir for multiple pathogens, some of which are zoonotic. Management responses to mitigate these threats by reducing population numbers face resistance from groups that value feral swine for subsistence or sport hunting, which results in complicated policy actions that are extremely divisive and difficult to implement.