Do Pigs Have Wings?

By Tom Hutton | November 2, 2004
From Missouri Conservationist: Nov 2004

You may have heard the old saying, "When pigs fly!" It's a way of describing something that can never happen.

However, recent discoveries of feral hogs many miles north of Missouri's previously identified feral hog sites may make Missourians wonder whether pigs do indeed have wings. Or, perhaps, more to the point, whether pigs have wheels.

They have neither, of course. Wild, crossbred swine are appearing in places where they have not been before not by flying, driving or walking. The hogs aren't taking it upon themselves to move into the country-side. Instead, people are releasing hogs to the wild. Some are even importing hogs into Missouri and releasing them.

Why would anyone import and release feral swine given the damage those animals can do to Missouri's crops, economy, livestock industry, lawns and gardens, and natural resources? We hope the people doing this are unaware both of the consequences of their actions and that their activities are illegal. We also hope they'll stop it.

Against the Law

In 2002, the Missouri General Assembly updated Missouri's "stray hog" laws. These statutes define a feral hog as "any hog, including Russian and European wild boar, that is not conspicuously identified by ear tags or other forms of identification and is roaming freely on public or private land without the landowner's permission."

It is illegal to release hogs on public land, or anywhere else where they can roam freely. The statutes allow landowners to kill such hogs on their land and protect landowners from liability for doing so. They also allow any person to kill feral hogs on public and private land with the consent of the landowner, except as regulated by the Wildlife Code of Missouri during the firearms deer and turkey seasons, and holds them harmless from liability for doing so. The law also prohibits the take or kill of feral hogs with the use of an artificial light except by a landowner or their agents on their own property.

The Wildlife Code allows feral hogs to be taken in any number throughout the year. During most of the year, no permit is required and any method is allowed. However, permits are required and special regulations apply during the firearms deer and turkey hunting seasons. People pursuing feral hogs during these seasons should study the regulations closely.

Resident landowners and lessees, as defined by the Wildlife Code, are not required to have any permit. They may use any method on their land to take feral hogs throughout the year.

Feral or Domestic?

Feral or "wild" hogs generally involve a combination of blood lines that include Russian or Eurasian Wild Boar (razorbacks) and an assortment of domestic varieties. Most of these are Yorkshire, Hampshire and Duroc. Some feral hog populations even acquire potbellied pig genes after people tire of their pets and abandon them in rural areas. All of these swine interbreed, and the offspring display a variety of sizes and colors including gray, red, black, spotted, and black and white belted.

Most feral hogs are released intentionally by people who want to hunt them. Hogs that escape from inadequate or damaged enclosures can also go wild, as can swine that are abandoned when pork prices periodically hit bottom, making it unprofitable to take them to market. Once in the wild, they multiply rapidly.

Missouri is not the only state suffering from this situation. Kansas, Arkansas, Colorado, Illinois, Wisconsin, Indiana, Ohio, Pennsylvania and Washington now have free-ranging hogs within their borders, as do the Canadian provinces of Saskatchewan, Manitoba and Ontario. Of course, substantial numbers of wild hogs already exist in Texas, Oklahoma, Georgia, Alabama, Florida, Mississippi, Louisiana and California.

Hog Problems

Wild hogs have the potential to spread diseases that affect people, pets and livestock. Currently, the diseases of most concern are trichinosis, leptospirosis, swine brucellosis and pseudo-rabies. In southern states, feral hogs frequently have infection rates of 10 percent for swine brucellosis and 30 percent for pseudo-rabies. One domestic hog operation in Georgia was invaded twice by diseased wild boars that infected the stock. As a result, all of the domestic hogs had to be destroyed.

Feral swine could also spread foot and mouth disease, anthrax, or various swine fevers. An outbreak of any of these diseases could be catastrophic. In 2001, for example, an outbreak of foot and mouth disease caused $7 billion in economic losses, including a quarantine on all English beef. Entire herds were condemned and destroyed. A similar outbreak in Missouri could devastate the state's cattle industry. It's also conceivable that feral swine could provide a reservoir for various other viruses to mutate and eventually affect people.

Rooting and Feeding

Feral hogs primarily eat plants, roots, acorns and earthworms. In pursuit of food, they may substantially damage pastures, hayfields, grain and truck crops, vineyards, forest land and archeological sites. Their rooting plows the earth to depths of 2-8 inches, much as a rotary tiller or an offset disc. This disturbs native plant communities and affects survivability of some plant species. In just one county in Texas, feral hogs cause an estimated $100,000 in crop damage annually. In southern states, feral hogs substantially damage lawns, gardens, parks and golf courses.


Because hogs lack sweat glands, they cool themselves by wallowing in seeps, springs, ponds, lakes and streams. Their wallowing contributes to soil erosion and sedimentation that smothers aquatic life, sometimes degrading rare natural communities.


Hogs also prey on newborn lambs, goat kids and deer fawns. They eat turkey and quail eggs, and they devour reptiles and amphibians that they uncover. Some Texas sheep ranchers annually lose 15 percent of their lamb crop to feral hogs. On the other hand, feral hogs have few natural predators.

Competition with Wildlife

Feral hogs also compete with native wildlife for food, especially for acorns. Telemetry studies have shown that turkey hens in Missouri's Ozarks lay small clutches, or fail to nest at all, in the year after failed acorn production. Any acorns consumed by feral hogs are at the expense of Missouri's turkeys, deer and other native wildlife.


Feral hogs, whether mature boars or sows with pigs, can be dangerous. Although most hogs run away at the sight of people, they have been known to charge. They also bully cattle, horses and deer away from feeders, sometimes causing them to run through fences.

Road Hazards

Any wild swine constitutes a potential road hazard. They are built "low to the ground" and are active at night. They lack the reflective layer (tapetum) at the back of their eyes that deer have, so their eyes don't shine when hit by artificial light. This and their generally dark coloration make them difficult for drivers to see.

Hogs in Missouri

Feral hog populations in Missouri are relatively small, localized and thinly scattered. However, feral hogs reproduce at a high rate. Each adult sow can wean 10-12 pigs per year. Their numbers easily can double twice a year. It's estimated that 70 percent of the hogs must be removed annually just to stabilize the population.

Because of their reproductive potential and limited number of predators, it's essential that we quickly identify occurrences of hogs and eliminate the animals before they begin to cause problems.

Though eradication or control of feral hogs is difficult, it has been accomplished at some sites in Missouri. The effort requires the cooperation of private landowners, federal and state agencies, agricultural organizations and hunters.

It's to the benefit of Missouri citizens and wildlife that everyone recognize the potential danger associated with these animals and prevent further releases and escapes. People should report sightings of feral hogs to the Conservation Department by calling (573) 751-4115, ext. 3147, the APHIS-Wildlife Services at (573) 449-3033 or their local Conservation Agent.


Missouri's feral hogs move frequently in response to food supplies and hunting pressure so they are difficult to find.

Private landowners and their neighbors generally kill feral hogs that appear on private property. You can help by hunting on public areas near where feral hogs have been spotted.

Many hunters don't target feral hogs, but take them while hunting other game. To find feral hogs, hunters must scout areas to locate fresh sign. They can then devise strategies to intercept them along trails to feeding areas, bedding sites and watering holes.

This Issue's Staff

Editor - Tom Cwynar
Managing Editor - Bryan Hendricks
Art Director - Ara Clark
Artist - Dave Besenger
Artist - Mark Raithel
Photographer - Jim Rathert
Photographer - Cliff White
Staff Writer - Jim Low
Staff Writer - Joan McKee
Circulation - Laura Scheuler