On a humid mid-June morning, John Mayer and I drove deep into Gum Swamp near Aiken, South Carolina — classic feral pig habitat, he assured me. Pigs could have it, I thought. Whenever I stepped out of Mayer's SUV, sweat instantly soaked my shirt and dribbled down my spine. Squadrons of piranha-like deer flies dive-bombed us if we ventured even a few yards into the boggy bottomland forest, an impenetrable tangle of oak, pine, tupelo, bald cypress, saw palmetto, swamp ferns, and prickly greenbrier vines. The placed reverberated with the squeaking, chirping, and trilling of insects, and periodically some hidden creature would bellow a frightening cwah, cwah, cwah. A panther, perhaps, or an angry feral boar? But Mayer, who goes by the name of Jack, told me it was just a tree frog. "They are borderline deafening some times of the year," he said.
I had traveled to Aiken expressly to see a wild pig. Unique among animals that humans commonly raise to eat, pigs can abandon domesticity and revert to lives exactly like those of their wild ancestors. These feral creatures constitute a porcine underground, animals that survive in the wild, abide by their own rules, go wherever their curiosity takes them, and flaunt their essential piggyness. They remind us that this is the way a pig goes about life, given its druthers. And they are doing just fine. More than fine. Wild pigs now live on every continent except Antarctica — and what pig would want to live there? An all-out war is raging, with farmers, ranchers, wildlife officials, and conservationists on one side and a guerrilla army of wild pigs on the other. The pigs are winning.
But Mayer and I weren't having much luck finding a feral pig. Thunderstorms had walloped the area the previous night, and nasty black clouds lingered, making the morning dull and muggy. For over two hours, he and I raised the back roads that crisscrossed the floodplain, or as he said, "the boonies," on the South Carolina side of the Savannah River about an hour from Augusta, Georgia. We had seen deer, rabbits, armadillos (both scurrying across the road and run-over), barred owls, wild turkeys, cattle egrets, a coyote, and perhaps the world's largest turkey vulture. But not a single wild pig, even though more than 2,000 supposedly lived in the area, and possibly had called the swamp home for 450 years. The Spanish conquistador Hernando de Soto crossed the Savannah River not far away and lost some pigs in the process.
"They are down here somewhere. And it's not a bad day for spotting pigs," Mayer said. "One might be in the trees looking at us right now, but we'd never see it. But they gotta cross the road sometime. If we're lucky, they'll cross right in front of us."
If you want to do some serious hog watching, you could pick no better guide than Mayer. Officially, he is in charge of the environmental sciences group that oversees 310 square miles of swamp and forest that serves as a buffer around the Savannah River Site, a nuclear facility that was built in the 1950s to make tritium and plutonium-239 for US bombs and missiles. Although he is too modest to claim the title, Mayer is the country's foremost authority on wild pigs — the "guru of wild pigs," according to one colleague. He did his PhD on feral pigs in the mid-1970s, at a time when virtually no one else thought the animals worthy of serious study. In addition to writing scores of scientific papers, Mayer has led international wild-pig symposiums and cowritten the definitive book on wild pigs in the United States. He has trapped wild pigs, hunted them with dogs, and has tackled more than one 200-pounder by the hind legs. He bears a four-inch-long scar on his calf, acquired when he accidentally came between a sharp-tusked sow and her path of escape.
A trim, sixtyish man with close-cropped graying hair, Mayer has spent four decades patrolling the forests and swampland surrounding the Savannah River facility. As part of their mandate, people who work for the federal government like him must reforest higher areas of the buffer zone with longleaf pine trees. They also have to mitigate the damage caused by invasive species, the most troublesome being feral hogs. One pig can unearth as many as 1,000 recently planted pine seedlings in a single night. Pigs compete with deer for forage and can kill fawns. They are even a threat to people trying to manage them. Collisions between pigs and trucks damage government vehicles and injure drivers.
Mayer hit the brakes and leapt from the vehicle. By the time I joined him he was bent over, poking a cloven hoof stamped into the wet sand that passed for road surface. The track was the circumference of a tennis ball. "These are fresh. Very fresh. No question about it," Mayer said, following the tracks across the road. "Oh my goodness, look here. We have a mom and her kids." He pointed to dozens of fifty-cent-piece-sized replicas of the big track. "That's quite a brood. She'd go close to a hundred pounds from the tracks we're seeing. That's a good-sized pig. Her piglets are probably a month old." We followed the tracks until they turned off the road and disappeared into the swamp on a muddy, well-beaten hog trail.
During the early years, Mayer waged war on the pigs by hunting them and luring them into penlike traps. The pigs soon learned to avoid hunters and, after seeing their comrades locked into the fenced enclosures, steered clear of traps, no matter how alluring the bait. Mayer turned to using trained hog dogs to cull his porcine foes. That worked like a charm, for a while. The first year they used dogs, hired hunters took 1,000 pigs — half the population. "We thought, This is great. This is going to be our salvation. We're going to get things under control," he said.
Instead, Mayer inadvertently educated the Savannah facility's wild pigs on how to outsmart dogs. Normally, a pig runs from an approaching pack of hounds until it reaches a defensible patch of ground, often up against a tree or boulder, where it "comes to bay." Instinctually, the pursued animal stops and prepares to fend off the dogs. The dogs are trained to get close enough to the pig to keep it from resuming its flight until hunters arrive to kill it. But after taking so many casualties the first year, the Savannah pigs changed the fundamental rule of hound/pig relations. They kept running, never coming to bay. "They just don't stop anymore," said Mayer. "I never saw that one coming. And I have talked to others who have experienced the same thing." The pig population at the site today is larger than ever. "You can kill them until you're blue in the face," said Mayer, "and they just keep putting more little pig feet on the ground."
The story is the same across the country, where wild pigs are undergoing a population explosion, what Mayer calls the "pig bomb" and "a national crisis." Twenty-five years ago they lived in nineteen states. Today they have spread to forty-eight states, and it's only a matter of (very little) time before they call all fifty states home, according to Mayer. Because of their secretive, stealthy ways, no one knows exactly how many wild hogs live in the United States. The best guesses are that their numbers have surged from between 1 and 2 million in the late 1980s to between 4 and 8 million today. That's a lot of pigs, but nothing compared to Australia, home to over 23 million wild hogs as of 2007, outnumbering its human population of 21 million. It's a cautionary tale about what happens when wild pig populations go unchecked.
As long as they have water to drink, pigs survive in the most unlikely places. Big-game enthusiasts brought wild pigs to the Canadian prairie province of Saskatchewan to populate commercial hunting reserves. Conservationists expressed concern about what would happen if the animals escaped from the fenced reserves, but pig-hunting advocates belittled the worrywarts. Surely, no wild boar could survive a bitter Saskatchewan winter with temperatures dropping to 60-degrees Fahrenheit. When too few hunters proved willing to pay to bag a boar, the scheme was abandoned — and so were the pigs. Calling what happened next an ecological disaster, Ryan Brook, an assistant professor at the University of Saskatchewan, said to Canadian Geographic writer Harry Wilson, "They have a tremendous impact on agricultural and native vegetation, harass livestock, and can spread disease. They're as close to an ideal invasive species as one could find." Not only have the pigs adapted to life on the Canadian prairies, tunneling into rolled bales of straw and digging caves in snowdrifts to remain snug during blizzards, but some have migrated across the border, giving slightly balmier North Dakota its own unwelcome permanent wild pig population.
It's hard to imagine a more formidable candidate for America's most destructive invasive species than the feral pig. A pig can run 30 miles per hour and leap over three-foot fences. They are virtual breeding machines. On average, a feral sow has one litter of six piglets per year, but can have up to twelve. The young typically begin breeding at around one year old. Unguarded piglets are susceptible to predation, but once a wild pig has matured, humans are the only major predator it faces. Bears and panthers do take the occasional hog, at some risk to themselves. Mature pigs have killed black bears.
Even though 10,000 years have passed since humans first domesticated Eurasian wild boars, all pigs — Eurasian wild boars, feral hogs, and modern agricultural breeds — are the same species, Sus scrofa, and can freely interbreed. Most wild pigs today are hybrids between gone-wild farm pigs and introduced wild boars brought over a century or so ago for sport hunting. And new recruits to the porcine life of liberty still abandon farms and join their free-roaming cousins. Unlike other livestock, pigs, even pigs raised in the confined conditions of industrial agriculture, retain the instincts and physical traits necessary to survive in the wild. A sow can make a successful break for freedom, feed herself, find a wild mate, and within a couple of generations her descendants will be smaller, hairier, darker, and more pointy-snouted — more-wild-boar-like in all ways — than the original escapee.
Pigs are ideally suited to lives on the lam. They can and do eat anything that is edible. Wild hogs in a single area have literally hundreds of food items on which to dine, from earthworms (up to three hundred have been found in the belly of a dissected wild pig) to the carrion of deer, and even the corpses of humans. Feral pigs devour domestic grain crops such as wheat, barley, and corn; vegetables such as potatoes, squash, cabbage, beans, and peas; and fruits such as pumpkins, grapes, and watermelons. They eat kid goats, calves, and lambs and spread diseases such as pseudorabies, swine brucellosis, tuberculosis, bubonic plague, foot-and-mouth disease, and anthrax to livestock. Coastal pigs love to head to beaches to root up the eggs of endangered sea turtles. In forests, they scarf eggs of ground-nesting game birds such as turkeys, quail, and grouse, and destroy the habitat of the golden-cheeked warbler and black-capped vireo and other endangered songbirds. Pigs' rooting erodes riverbanks and turns pristine trout streams into turbid waterways better suited for carp. They eat red-cheeked salamanders and slurp huge numbers of hapless male spade-foot toads as they sing in shallow breeding ponds. They can swim well and will dive for crabs. Their propensity to overturn sod destroys native vegetation and clears the ground for invasive weeds. Pig rooting can make hayfields impassable to tractors. In urban areas, pigs destroy yards, parks, golf courses, and sports fields.
Pigs can sniff out a food item at a distance of seven miles. If that item is buried, their well-adapted snouts have little difficulty unearthing it. In addition to two wide, sensitive nostrils, their noses come equipped with a pre-nasal bone that is attached to the skull and works in conjunction with a cartilage disk. It's like having a spade and a pickax. A rooting pig is an excavating marvel. I once gazed awestruck as a herd of escaped sows churned up the grass around the rural building that housed a publishing company where I worked. The pigs moved along at a brisk walking pace with their snouts planted in the ground. The upturned earth in their wake looked like a half dozen rototillers had churned it.
On their own, pigs are perfectly equipped to expand their range as an invasive species. But Mayer says they have had help from misguided hunters who intentionally introduce wild pigs into pig-free areas so they'll have a new quarry. Despite the damage they wreak, the animals have a powerful human constituency that resists wildlife managers' efforts to cull populations. "That's the conundrum of wild pigs that you don't see with other invasive species," said Mayer. "You've got one of the worst invasive species on Earth and you've also got one of the world's most popular big-game animals. You're not going to find people willing to pay hundreds of dollars an hour to go up in a helicopter to shoot fire ants and zebra mussels. But people line up to shoot wild pigs. And landowners like the extra money pig hunters bring them."
Shooting a pig that day was far from my mind. I would have been happy to settle for a fleeting glimpse of one of the critters, but the hogs of Gum Swamp remained hidden. Mayer and I saw their signs everywhere. He pointed to the base of a telephone pole. Bristles clung to waxy black creosote. Pigs love to rub themselves against creosote — Mayer suspects the smelly gunk may repel ticks and lice. In clearings, they had upturned swaths of earth and dug depressions about the size of hot tubs for mud wallows. Hog paths fanned out into the swamp. "We've probably driven right past any number of pigs just standing there, and we didn't pick up any movement," said Mayer. "It's amazing how stealthy they are. We once put a radio collar on a big white boar — two hundred pounds. We were out trying to track him, shoot him, and get the collar back. We thought it was going to be like shooting fish in a barrel. The signal led us to an open cypress flat. The signal was really strong, but there was no sign of this pig until I took a step toward a log and the boar exploded from beside it and disappeared into the timber before we could get a shot off. I'm convinced he knew we were there, but he just mashed himself down behind that log so that he was hidden."
Despite suffering humiliation in his efforts to control the resident hog population, Mayer genuinely respects his adversaries. "They are just such cool critters. I find them fascinating from a biological perspective. That's what floats my boat."
The clouds that had been lurking around us all morning let loose with a torrent of rain that ended our quest to see a wild pig. "You never know when you're going to encounter them here. With the heat we've been having, they are mostly active at night when it's cooler," Mayer said. "If you really want to see wild pigs, you should go to Texas. The state is overrun."
From Pig Tales: An Omnivore's Quest for Sustainable Meat by Barry Estabrook. Copyright 2015 by Barry Estabrook. Excerpted by permission of W. W. Norton & Company.