Photograph by Malcolm Gay
Skimming along the Sac River, the motorized johnboat picks up speed, pushing the February air deep into your face, chilling the cells, making it difficult to blink.
It’s midmorning, and Matt Hill, well built in Carhartt coveralls and a knit cap, pushes the flat-bottomed rig ever faster as he scans the icy waters. He’s looking for a small brown protuberance—the sort of thing most anglers would disregard as a piece of driftwood making its way toward a southern arm of Truman Lake, about 65 miles north of Springfield.
But Hill, a wildlife biologist with the Missouri Department of Conservation, knows better.
Three weeks earlier, the biologist used a foul-smelling mixture of sour corn and yeast to capture a herd of six feral hogs in a corral-like trap. As the young boars and sows angrily rooted around the 20-foot-diameter wire-fence enclosure, Hill and his colleagues studied the herd carefully.
“It’s really a guessing game,” says Hill, part of a statewide effort to exterminate the wild swine. “You’re judging them on hoof when they’re banging around in the trap. The first trick is, you’ve got to get the tranquilizer dart in her while they’re running around. The second trick is getting the other ones shot while she’s still settling down from the dart.”
Hill and his colleagues were looking for a hog that was neither too large nor too small. It needed to be able to fit easily into one of the harnesses the MDC had outfitted with a radio transmitter. But most important, it needed to be female: Whereas boars are solitary animals that interact socially only to mate, females are more social and will easily attach to a new herd. Ideally, they were looking for a gilt—a juvenile pig that has yet to produce a litter. In MDC parlance, they were looking for a “Judas pig.”
“It’s kind of a double-edged sword,” says Hill. “You don’t want her popping out pigs right away, but being sexually mature is also a good thing, because the boars will come around when she comes into heat.”
Hill ended up settling on a brown-bristled gilt weighing about 70 pounds. After dispatching her five companions with quick shots to the brain, Hill and his associates strapped the radio collar onto the hog, which they eventually came to call “Lulu.”
For the next three weeks, Hill would head out once a day with telemetry equipment to track Lulu as she roamed the Sac River valley. Though Hill, traveling to remote spots by pickup truck and four-wheeler, wasn’t able to determine her exact coordinates, his antenna picked up the scratchy “click-click” of her radio collar, reassuring the biologist that she was in the area, alive and rooting.
Of course, the hope was that the Judas pig, so named for the role foisted upon her by the treacherous radio transmitter, would join a new group of wild hogs, an invasive species known to carry disease, destroy habitat, and eat everything from acorns and mushrooms to turkey eggs and deer fawns. There are thought to be 5,000 to 10,000 wild pigs living in Missouri, and MDC officials say they not only threaten the existence of certain game animals and endangered plant species, but also are vectors for disease that threaten to cripple the state’s $1.1 billion swine business.
The stakes are high, and Hill and his associates had limited time for Lulu to lead them to other hogs. Don’t wait long enough, and she wouldn’t have sufficient time to meet other animals; wait too long, and Lulu, whose gestation period would be just under four months, might be shot by an enterprising hunter or, worse, give birth to a litter of her own.
“I don’t want a collar on a pig much more than three weeks,” says Hill. “If she doesn’t group up in three weeks, she’s probably not going to.”
As Lulu traveled the area, Hill continued to venture out each day to check in on her. He continued to bait the trap he’d caught her in, and each day he heard the reassuring “click-click” of her collar.
Then one night, Lulu wasn’t there.
Hill started losing sleep. He’d been orchestrating a party to retrieve the hog for more than a week. The helicopter was scheduled to arrive that Thursday, and the MDC had devoted six men to the operation.
“Monday, Tuesday, I couldn’t hear anything,” says Hill. “The possibilities start going through your mind. Did somebody shoot her and take her home? Is she out there but just laying in a hole? Did the transmitter quit working?”
In mid-February, the Sac River valley is a stubbly expanse of leafless willows and barren cocklebur stalks. Now strapped into an MDC helicopter and accompanied by a shotgun-toting gunner, Hill struggled to locate the hog amid the landscape’s study in brown. Sweeping the river valley about 80 feet above the ground, Hill used the chopper’s antenna to triangulate the collar’s radio signal. Still, it wasn’t until he softened his eyes that he saw Lulu standing alone by the river.
“She was in a bad spot for her; she was really out in the open,” says Hill, adding that Lulu froze as the chopper lowered down on her. “She knew we had her, but I think they’ve learned that if they stand still, they’re harder for us to see. She stood there for a while, but then she decided her best escape was across the river, so she took off swimming. I had no idea they could swim so fast.”
But by then it was too late for Lulu. The gunner fired, and the pig, already halfway across the river, died midstroke when the buckshot ripped through her rib cage.
Now, half an hour later, Hill pilots the johnboat toward a tangle of driftwood. It’s his final search for Lulu, and as he pulls the boat alongside her hump of brown bristles peeking from the water, he has only one regret: “I hate that she was by herself.”
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No one really knows when feral hogs first arrived in Missouri. Thought to be a legacy of the free-range pig-farming culture that held sway for many years in the Ozarks, wild pigs have been roaming the Missouri countryside for decades.
But when the hog market tumbled in the 1980s, many farmers found that it cost more to raise and feed pigs than they could sell them for, and wildlife biologists suspect that many farmers simply opened their gates.
Released into the wild, those pigs began interbreeding with escaped Russian and Eurasian boars, two nonnative species that were often released as game animals on private reserves. Add a few pot-bellied pigs that grew too large for their owners’ liking, and the resulting hybrid blend, Sus scrofa, is a sturdy animal built low to the ground. It sports a rough coat of dark brown bristles, two tusks—outsized canines, really—and a sheet of tough, armor-like tissue above the shoulders.
Pig farmers normally clip their swine’s tusks, but after one generation in the wild, a domestic pig will produce a litter of leaner, more muscular hogs that will eventually grow tusks and a coat of long bristles.
“The offspring are going to take on those Russian or European traits—and from there it’s all over,” says Rex Martensen, who, as the MDC’s private land services field programs supervisor, coordinates the state’s antihog efforts. “Those first- or second-generation pigs may have some of the spotting, but boy, by the third generation, they’re all black or dark chocolate brown. Those wild genes really dominate the domestic genes.”
What’s more, they breed like rabbits. A typical sow first comes into heat at about nine months. From then on, she can have as many as two litters per year, with a typical litter containing six piglets. That’s a theoretical 12 piglets per year, and the general rule is that, given the right circumstances, a feral hog population can triple in one year. And the circumstances are almost always right.
“Nothing really preys on hogs,” says Martensen. “The piglets could be taken out by a coyote or a bobcat, but once they reach 15 to 20 pounds, there’s not a whole lot out there that’s going to go after them. They can fend off a coyote or a bobcat pretty easily.”
By the 1990s, the wild boar population was booming. As an invasive species, they were not considered a game animal and therefore went unregulated by the MDC. Hunters could stalk them all year long—with no limit on how many they could take.
Although Missouri’s hog population is concentrated in the counties south of I-44, as word spread that feral hogs were not only good hunting, but also good eating, people began rounding them up and trucking them to other areas of the state. Today, the hogs live in 20 of Missouri’s 114 counties.
“If you look at a hog map between 1998 to today, the population hasn’t naturally expanded out from a core,” says Martensen, noting that there is a pocket of hogs living in the northeast corner of the state. “It’s a patchwork, where there’s a core and all of a sudden we’re seeing pigs 40 miles or 150 miles away. These pigs aren’t just cutting across country and setting up camp in a new area. They were hauled there and released.”
Although the MDC began its involvement with feral hogs after receiving complaints from farmers and property owners in the late 1990s, it wasn’t until 2002 that the Missouri Department of Agriculture adopted a statute making it illegal to release any unconfined pig on public or private land. Even then, the law was an imperfect device. It wasn’t incorporated into the state’s wildlife code, making it difficult for conservation agents to enforce it on land not managed by the MDC.
In 2007, former Gov. Matt Blunt brought together members of state, federal, and private agencies to form a feral hog task force. The task force, which recommended ongoing public education and eradication efforts, also recommended changing the laws governing the release of hogs. Its proposal, which has broad legislative support, would effectively bring all the laws governing feral hogs under one statute, allowing any conservation agent to enforce it throughout the state.
Even so, a ban on releasing animals is hard to enforce unless you catch someone red-handed, which has happened only a few times in the past seven years.
The more effective approach by far is on-the-ground extermination, i.e., hunting and trapping. MDC literature instructs private hunters to “shoot ’em on sight.” And by using a variety of techniques that include corral-style traps, Judas pigs, snares, aerial gunning expeditions, and occasionally the services of a professional hunter and trained dogs, the MDC has managed to slow their proliferation a bit.
Still, it’s a tall order. Biologists estimate that, given the animal’s prodigious capacity to reproduce, the MDC must exterminate 70 percent of the feral hog population each year just to keep the animal’s numbers static. With an estimated 10,000 hogs in the state, that would mean that wildlife officials may have to remove as many as 7,000 per year.
“When it comes to eradicating hogs, ‘efficiency’ isn’t a word we use much,” says Martensen. “Nothing is very efficient when it comes to these critters.”
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One reason hogs are so difficult to control can be seen in a series of black-and-white photos captured by a trail camera in rural Wayne County. The photos show a large boar that has just been captured in a corral-style trap.
The circular traps are about 20 feet in diameter. Their walls are about 6 feet tall, and the hogs enter the trap through a gate suspended by a trip wire. As the hog, or, as the MDC would prefer, hogs, enter the trap and begin feeding on the bait, they eventually brush up against the trip wire, causing the gate to crash down and trapping the hogs inside.
The gate only swings inward, and theoretically, at least, once it’s down, hogs can still push on it to enter the trap, but it would be very difficult for any animal without opposable thumbs to pull the gate open from the inside.
Unless, that is, that animal happens to be the feral hog trapped in Wayne County on the night of May 6, 2008.
“This hog took a bait bucket, carried it over to the door in its mouth, propped open the door with his mouth, and then pushed the bucket under the door so he could get his nose in. He then lifted it up and got out,” says Tim Turpin, a steward with the Department of Natural Resources. “That’s using a tool.”
Not only do hogs use tools, they’re also smart enough to modify their behavior if they feel pressured. Whereas most game animals will flee if they feel threatened, they will continue to eat and sleep at normal hours and eventually will return to their previous range of habitat.
Hogs, on the other hand, will change their behavior if they feel endangered: If they sense they are being hunted in one area, they will take up residence in another. If they suspect they’re being stalked at night, they’ll become active only during the day. And so on.
“Hogs, being one of the smartest animals on the face of the earth, go to where they’re not being hunted,” says Turpin. “Any time you pressure a hog, they’ll move or they’ll adjust their schedule to avoid that pressure, so if we don’t keep pressure on them in state parks [where hunting is prohibited], the parks actually become a reserve for the pigs.”
They’re also quick studies, and MDC officials have learned to set out bait for weeks before building a trap. Once the trap is built, conservation agents will often wire the door open for a week or two so the hogs become comfortable coming and going in the trap. Only then, after the pigs have been inured to the trap’s presence, will wildlife agents set the trap.
Even so, many hogs have become familiar with the MDC’s methods and will bolt from an area the minute a trap appears.
“We’ve had some pigs coming in to the bait every night. Then, after we’ve set the trap up, they’ll come in the next night, see the trap, and they’ll leave—that’s the last we’ll see of them,” says Martensen. “We’ve actually built the traps one piece at a time over a period of a week. We’ll take just the gate and set it there. We’ll let them get used to that, and then we’ll put another panel up. It can be very frustrating.”
Meanwhile, the hogs, fast-moving and omnivorous, are wreaking havoc on the state’s ecosystem. They may have no predators of their own, but their wide-ranging eating habits put them in direct competition with many of the state’s game animals, such as deer and turkeys. Not only will they eat the acorns these animals rely on for much of their nutrition, they will also eat the animals themselves, feasting regularly on quail and turkey eggs and even the occasional deer fawn.
“They devour anything they can get their mouth around,” says Turpin. “Every wild animal is hungry all the time. They’re always looking for food, and they’re always avoiding predators. If you’ve limited how much food they have, you’ve made them hungrier, so you’ve made them take more risks. They’ll change their feeding strategy, and that opens them to more predation.”
Meanwhile, as the hogs root around looking for food, they leave deep gashes in the earth, destroying the glades and glens that often serve as other animals’ habitat and costing farmers thousands when they light upon a field of soybeans or corn.
But it’s not merely their eating habits that have detrimental effects on the environment. Hogs lack functioning sweat glands, meaning one of the only ways for them to cool off in the hot summer months is by wallowing in mossy creek beds.
In southern Missouri, many of these creek beds grow sphagnum, a moss that is home to the four-toed salamander. As its name suggests, the four-toed salamander is a small amphibian with only four toes on each of its hind legs. While not endangered, the salamander has a limited range in Missouri and is dependent on sphagnum to survive.
Of course, sphagnum, being cool, moist, and spongy, offers ideal wallowing possibilities, and hogs often make the creek beds into their own personal mud baths.
“They completely modify their environment to suit them,” says Turpin. “Now those salamanders can’t live there anymore. There are millions of examples like that.”
But the biggest threat from wild hogs is economic.
Wild boars are known carriers of brucellosis and pseudorabies, diseases that can cause a sow to abort a litter, as well as lead to high mortality in piglets. While pseudorabies cannot be transferred to humans, brucellosis causes undulant fever. What’s more, various studies have documented that wild hogs can carry up to 30 viral and bacterial diseases and 37 parasites.
The real fear, though, is that either brucellosis or pseudorabies will jump to the domestic swine population. The U.S. Department of Agriculture mandates that commercial pork be free of both brucellosis and pseudorabies. If a state has two documented cases of either disease in its domestic swine population, the USDA will revoke its status, prohibiting the state’s pork producers from selling their products nationally or internationally.
“It would put our swine guys out of business,” Dr. Taylor Woods, Missouri’s state veterinarian, says, noting that any infected herd would have to be destroyed. “We’d have to go back to testing swine again to get that status back. It would take three or four years, and our swine producers would suffer greatly because they’d have no place to move their animals.”
So far, there’s been no instance of either disease in the state’s commercial swine population. The feral population, however, is another matter. Conservation officials take a blood sample from each hog they kill. So far they have discovered four cases of pseudorabies and brucellosis in the wild population.
Obviously, feral hogs do not respect state boundaries, and Missouri is not alone in its battle against the pest. There are thought to be roughly 4 million hogs roaming the U.S. countryside. Nearly half of those are in Texas, where researchers estimate they cause
$52 million in crop damage each year. And though the pigs are concentrated in the South, they are moving northward, prompting state wildlife officials in New Jersey to sponsor a feral hog hunt last December. Hunters killed 56 of the beasts, roughly half of the state’s estimated wild hog population.
The animals also plague Australia, where researchers are reportedly working on a species-specific poison, and there’s even talk of genetically engineering diseases that would affect only feral pigs.
“The hog industry definitely doesn’t want that,” says Turpin. “It’s space-age stuff.”
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Missouri’s southern region around Iron and Reynolds counties boasts some of the state’s most beautiful natural environments. Two-lane roads give way to dirt tracks as they dive into lush forests. Drained by clear springs, the verdant hills are rife with microecosystems that are home to several endangered plant species and many limited-range animals like the four-toed salamander.
It’s also ground zero for Missouri’s hog population.
“To us Missouri boys, this is pretty new,” says Jay Simpson, a resource assistant with the MDC. “It’s not like hunting anything we ever hunted before.”
All modesty aside, Simpson and his partner, Howard King, are something of legends in MDC hog-eradication circles. The two have worked together for more than a decade. They finish each other’s sentences, and last year they pulled more than 300 hogs out of the region (giving much of the resulting hog meat to area families to eat).
Like many MDC employees involved in hog eradication, they have a conflicted relationship with some hunters. On the one hand, they welcome any hunter who’s able to gun down a hog or two. On the other hand, some hunters will lurk around MDC traps, either driving hogs out of the area or poaching hogs from the trap so that officials are unable to take blood samples.
To guard against this, Simpson and King talk in code.
“We try to talk in acronyms over the radio because everyone in this country has scanners,” says Simpson, a burly man with a full gray beard. “People will listen in. They’ll run our traps for us. Or sometimes they’ll kill one or two hogs and let the others get away, but we’re not trying to kill one or two—we’re trying to kill all we can.”
To do so, Simpson and King spend their days patrolling the area in a slightly distressed Polaris six-wheeler. Crossing streams and rocky outcroppings, they use snares and traps to battle the hogs. They’re also always on the lookout for fresh signs of hog activity, such as rooting or wallowing. To keep other animals away from the bait, they’ll often douse their sour corn with a splash of diesel fuel. If they’re uncertain what type of animal is visiting their bait, they’ll string a piece of barbed wire between trees to snag a few strands of fur. To determine whether hogs are in the area, they’ll place bait deep in holes where only hogs would venture to get it. To keep hogs coming to an area, they’ll fill a sealed plastic drum with bait. After punching a few small holes in the drum, it becomes the sort of feeding device that only a hog is smart enough to use.
So it is that on a recent morning, the pair forge a trail through the hilly terrain made muddy from an intense downpour the night before. Crossing swollen creeks, Simpson signals King to stop the vehicle several times as he steps out to investigate fresh signs of hog activity. Last night’s rain is making it difficult to determine just how fresh the tracks are, and like many MDC employees, they marvel at the animal’s toughness and intelligence.
Stopping at one of their empty traps, King points out a spot in the wire fencing where an angry boar once rammed it, causing the wire to bow. What’s more, King says that while most of the MDC’s traps have 9-foot walls, this trap’s walls are barely 6 feet tall, and the pair has seen hogs jump on the backs of others and nearly escape.
Experiences like these have taught the pair to approach trapped pigs with caution, especially if there’s a large boar in the trap.
“If we have a big male, we won’t come up on him, we’ll snipe him from a distance,” says Simpson, adding that last season King and a fellow MDC employee shot a 250-pound boar with two rounds from a 12-gauge shotgun.
“The pig got up and looked at Jay,” says King, picking up the story.
A third round finally finished the boar off. “He was pretty healthy for having two rounds of buckshot in him,” says King. “To me that’s pretty darn tough.”
But while last year they captured a bumper crop of hogs, their efforts this year have been stymied by bad weather and plentiful acorns. This may be a sign that their previous efforts were successful and that there are simply fewer hogs in the region. But that’s unlikely, and like many MDC employees, Simpson and King fear they aren’t catching as many hogs this year because the animals are getting wise to the sour corn bait they use.
“This year’s been slow,” says King, walking away from the empty trap. “Everything we think of, they’ll figure out.”
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Malcolm Gay, SLM’s editor-at-large, wrote about Metro’s budget cuts last issue. Winner of a James Beard Foundation Journalism Award, he writes frequently for The New York Times.
