Wild pigs have terrorized the southern United States for decades, destroying farmers’ crops, preying on native species and carrying a variety of pathogens that can spread to humans. The animals have mostly stuck to warmer regions, such as Texas and Florida, but they still manage to cause an estimated $2.1 billion in damage every year.
Now, colder regions of the U.S. could soon be staring down their own swine foes: Canadian “super pigs.” These giant, intelligent hybrids of domestic pigs and wild boars are poised to invade from the north.
“We have already documented pig occurrences less than ten miles from the U.S. border. Quite honestly, I think there have already been some in Manitoba going into North Dakota for the last five or six years,” Ryan Brook, who leads the University of Saskatchewan’s Canadian Wild Pig Research Project, tells Field and Stream’s Sage Marshall. “There is no physical, biological boundary at the U.S.-Canada border. There is hardly any kind of fencing to speak of. There’s a real risk of pigs moving south into the U.S.”
Wild pigs are not native to the Americas. They were first brought to the West Indies in 1493 by Christopher Columbus and then introduced to the continental U.S. in 1539, when conquistador Hernando de Soto landed in Florida to plunder and colonize the southeastern U.S. His small herd of 13 swine soon grew to 700. The animals that were left behind or escaped during these European excursions formed the continent’s first wild pig populations.
In the early 1900s, wild Eurasian boars were brought to the U.S. for recreational hunting. These boars bred with the existing feral pigs, forming hybrids. Today, wild pig populations have spread across the southeastern U.S. and are made up of boars, feral pigs and crosses of the two. Though these groups have differences, all share the same scientific name and are considered invasive. Now, the estimated population of wild pigs in the country has exploded to more than six million.
“They lived a benign existence up until, you know, probably three or four decades ago, where we started seeing these rapid excursions in areas we hadn’t seen before,” Michael Marlow, assistant program manager for the U.S. Department of Agriculture’s national feral swine damage management program, tells the Guardian’s Adam Gabbatt.
Compared with the U.S., Canada has been battling wild pigs since only recently, when they were brought over from Europe in the 1980s to be raised on farms. Farmers created the super pigs, breeding their hogs with feral populations to form larger varieties that provided more meat and were easier to shoot, per the Guardian. These pigs usually weigh between 120 and 250 pounds, though one was recorded at 661 pounds.
“All the experts said at that time: ‘Well, no worries. If a wild pig or a wild boar ever escaped from a farm, there’s no way it would survive a western Canadian winter. It would just freeze to death,’” Brook tells the Guardian.
But these pigs surprised experts. Their large size and ingenuity have made the animals resilient to Canada’s cold. “One of the things they do to survive is tunnel under the snow,” Brook tells Field and Stream. The animals line their snow caves with cattails for insulation, keeping them warm. “If you go early in the morning on a cold day, you can actually see steam pouring out the top of the nests.”
Now, wild pigs have a range of about 300,300 square miles in Canada, per a 2019 survey. In the last decade, they have been expanding their territory by almost 34,000 square miles per year. These hogs eat Canadian crops such as wheat, barley and canola, wrote Andrea Anderson for National Geographic in 2020, and they are opportunistic omnivores, meaning they’ll gobble up pretty much anything they can—small mammals, reptiles, eggs, nuts, tree saplings and even deer fawns. Their rooting causes soil erosion and can lead to the destruction of culturally significant sites, such as cemeteries. They also carry diseases such as swine brucellosis, pseudorabies, leptospirosis, and trichinosis.
“We should be worried, because we know the biology,” Brook told National Geographic. “They’re called an ecological train wreck for a reason.”