Feral swine, often called wild pigs, feral hogs, or wild boars, are an invasive species descended from escaped domestic pigs, Eurasian wild boar, or their hybrids. These animals are highly destructive, causing an estimated $1.5 billion in annual damages across the United States. They inflict severe ecological harm through rooting, which disturbs soil and native vegetation, and by preying on native wildlife like ground-nesting birds and reptiles. Feral swine also pose a public health risk by acting as vectors for more than 30 viral and bacterial diseases. Successfully managing these populations requires an integrated approach utilizing a variety of removal and exclusion techniques.
Preventing Access Through Exclusion and Habitat Modification
Physical barriers are an effective first step to block pigs from entering specific areas, focusing on the animal’s tendency to root and push rather than jump. A successful exclusion fence is typically constructed from high-tensile woven wire, often standing at least four feet tall with small mesh openings to prevent penetration. The lower edge is the most vulnerable point, so it must be secured firmly to the ground by burying the wire six to twelve inches deep or by installing an L-footer apron.
Electric fencing offers an extra layer of deterrence, as pigs learn quickly to associate the area with a sharp shock. The most effective electric fences utilize multiple strands, with the lowest wire positioned approximately eight inches from the ground to target the pig’s sensitive snout. These fencing methods work best when combined with habitat modification, which removes the attractants drawing the pigs in the first place. This involves eliminating artificial food sources like improperly stored garbage, pet food, and livestock feed, and draining or fencing off standing water sources that pigs use for wallowing.
Trapping Strategies for Large-Scale Removal
Trapping is considered the most efficient method for large-scale removal because it targets the entire sounder, which is the family group of pigs. Unlike smaller box traps that typically catch only one or two animals, large corral traps, often circular and constructed from five-foot-high livestock panels, are designed to capture a whole sounder at once. Circular designs prevent pigs from piling up in corners and escaping over the top.
A crucial phase of the trapping process is pre-baiting, where the trap is initially set up with the door open and baited for several days or weeks. This conditions the entire sounder, including wary adult sows and boars, to feed comfortably inside the enclosure without fear. The most successful bait is fermented or “soured” whole-kernel corn, which is highly attractive to pigs due to its pungent odor but less appealing to non-target species like deer.
Remote monitoring systems, using cellular cameras and remote triggers, have revolutionized trapping efficiency. These systems allow the operator to observe the trap site constantly and wait until the entire sounder has entered before remotely closing the gate via a cell phone command. This targeted, whole-sounder removal prevents the survival of trap-shy individuals, who would otherwise become educated and difficult to catch later. This strategy increases the overall success rate compared to traditional triggers like trip wires or root sticks.
Direct Removal Methods and Regulatory Requirements
Direct removal involves active pursuit and shooting, often used to complement large-scale trapping efforts or for quick response to localized damage. Since hunting pressure can cause hogs to become nocturnal, specialized nighttime operations using thermal or night vision optics are effective for locating and removing animals. Aerial gunning from helicopters is another highly efficient technique for rapid population reduction in large, open landscapes.
Aerial gunning operations are capable of removing a significant percentage of a localized population in a short time. This method is often the only practical solution for inaccessible or heavily infested areas. Compliance with the law is mandatory for all direct removal methods, as regulations vary widely by state and local jurisdiction. Landowners must verify local laws regarding legal firearms, night hunting restrictions, and whether a special depredation permit is required to remove nuisance animals outside of designated hunting seasons.
Safety and Disease Concerns When Handling Feral Swine
Feral swine present safety concerns due to their unpredictable temperament and aggressive defense mechanisms. Sows are highly protective of their young, and large boars are territorial, possessing razor-sharp tusks capable of inflicting severe wounds if they feel cornered or threatened. Any interaction with a live or freshly dispatched hog requires extreme caution.
The primary health risk comes from the zoonotic pathogens they carry, such as swine brucellosis, leptospirosis, and pseudorabies. Pseudorabies is particularly dangerous as it is fatal to dogs and cats that come into contact with an infected carcass. To minimize exposure, protective gear, including sturdy gloves, eye protection, and a mask, should be worn when field dressing or handling a carcass. Carcasses must be disposed of properly through burial at least four feet deep, composting, or rendering, to prevent disease transmission to other wildlife and domestic animals.