PIGS GONE WILD

There are as many as 9 million feral swine across the U.S., their populations having expanded from about 17 states to at least 39 over the last three decades. Canada doesn't have comparable data, but Ryan Brook, a University of Saskatchewan biologist who researches wild pigs, predicts that they'll occupy 386,000 square miles across the country by the end of 2020, and they're currently expanding at about 35,000 square miles a year.

Wild pigs are now the United States' most abundant free-ranging introduced ungulate. The term ungulate refers to animals which have hooves. From 1982 to 2016, the wild pig population in the United States increased from 2.4 million to an estimated 6.9 million, with 2.6 million estimated to be residing in Texas alone. The population in the United States continues to grow rapidly due to their high reproduction rate, generalist diet, and lack of natural predators. Wild pigs have expanded their range in the United States from 18 States in 1982 to 35 States in 2016. It was recently estimated that the rate of northward range expansion by wild pigs accelerated from approximately 4 miles to 7.8 miles per year from 1982 to 2012.