Invasive wild pigs (Sus scrofa) are considered one of the most damaging species globally, and once they become established in an area, they are notoriously difficult to eliminate. As such, identifying the potential pathways of invasion, especially in places with emerging populations, is critical for preventing new or continued invasion. Wild pigs have been reported in Ontario, Canada in recent years. We tested four non-exclusive hypotheses about the source of wild pigs in Ontario: 1) escapees from captive sources within Ontario; 2) invasion from neighboring jurisdictions; 3) existing wild populations within Ontario; and 4) translocation and illegal release. We found that sightings of Eurasian wild boar were closer to premises with wild boar than were random locations; wild boar sightings were an average of 16.3 km (SD = 25.4 km, min = 0.2 km, n = 20) from premises with wild boar. We also found that sightings of domestic pigs were closer to domestic pig farms than expected. Sightings of wild pigs in groups of more than four animals were rare. Our results suggest that wild pigs observed in Ontario are recent escapes from captivity, recognizing that there may be established groups of wild pigs that we have not yet detected. While not common, we also received reports indicating that in the past, wild pigs have been translocated and illegally released. Other North American jurisdictions that have been successful at eliminating wild pigs have removed existing populations and changed regulations to limit future invasion, such as prohibiting possession and transport of wild boar and prohibiting hunting of wild pigs.

Two dataframes within Rdata:
dryad - contains pig sightings and random locations (n=250)
dryad2000 - contains pig sighting and random locations (n=2000)

Both dataframes have the same seven columns
PigType - type of pig sighting (domesticated, wild boar, unknown)
DETECTED - factor; 0 - random location, 1 - pig sighting
dist_boar - distance (meters) to nearest known premise with wild boar (meters)
dist_pig - distance (meters) to nearest known premise with domestic pig (meters)
borderMI - distance (meters) to border with Michigan (excluding the upper peninsula)
borderNY - distance (meters) to border with New York (meters)
borderQC - distance (meters) to border with Quebec