ABSTRACT
The establishment of wild pigs (Sus scrofa) in north-central North America has occurred relatively recently, with most detections identified after 1990. This reflects dispersal-based spread of wild pigs northward in the United States (Snow et al. 2017), and initial introduction of the first free-ranging wild pigs from domestic sources that began during the 1980s in Canada (Brook and van Beest 2014, Michel et al. 2017). From 1990 to 2019, the most notable expansion of wild pigs in this region was a dramatic increase in the 3 Prairie Provinces of Canada (Alberta, Manitoba, and Saskatchewan; Aschim and Brook 2019). At the same time, wild pigs expanded in Kansas and Missouri. However, wild pigs were greatly reduced through intensive control efforts in Kansas (Richardson et al. 1997, Hartin et al. 2007), but still occasionally cross into Kansas along the southern border from Oklahoma. Outside of Missouri, few populations of wild pigs currently exist in the US portion of the region. Several wild pig sightings along the Canadian-US border in Manitoba, Saskatchewan, and North Dakota have generated important concerns about cross-boundary movements.
