Potential landscape connectivity for invasive wild pigs (Sus scrofa) across the northern prairies of North America

Abstract

Understanding landscape scale connectivity is an essential component in the management of invasive species since connectivity facilitates their invasion potential. Invasive wild pigs (Sus scrofa) are among the most prolific invaders on the planet, causing billions of dollars in agricultural and environmental damage annually. Newly introduced to Canada in the 1980s, we examined wild pig invasion potential across the northern prairies from western Canada into the currently wild pig-free northern U.S. states. We used GPS collar data collected in the Canadian prairies to quantify resource selection and incorporated results into an electric circuit theory framework to evaluate potential regional landscape connectivity. While available landcover types in this region were dominated by crops and grasslands, wild pigs were predominately located in deciduous forest, crops, and wetlands. Resource selection modelling indicated wild pigs selected deciduous forest and wetlands over other landcover types. These selection tendencies resulted in areas at greater risk of occupation in an intermixture dominated by crops interspersed with waterbodies and deciduous forest fragments, which facilitated movement. Given the pervasiveness of this intermixture across the northern prairies, there was a high potential for invasive wild pigs to move throughout much of the region with areas in southern Saskatchewan and Manitoba, northeastern Montana, North and South Dakota, and western portions of Minnesota being particularly vulnerable. Our work highlights a need for monitoring and science-based response strategies for likely southward spread of this invasive species to prevent or reduce potential crop damage, risks to native species, and disease transmission to humans, pets, livestock, and wildlife.