10 Things to Know About Feral Swine

Some consider them a nuisance, but they're highly intelligent.

Posted Sep 26, 2020

Way back in 2004, a Georgia hunter claimed to have shot and killed a feral hog that was 12 feet long and weighed 1000 pounds. The beast was of mythical proportions, and when its picture hit the Internet, an early meme was born. Later exhumation by National Geographic did indeed prove that "Hogzilla" was real, but somewhat smaller than initially claimed—at 8 feet and 800 pounds.

Swine were first brought to the United States in the 1500s by early explorers and settlers as a food source. Escapes from enclosures and from free-range livestock management led to pigs establishing feral populations. In the 1900s, the Eurasian boar was introduced to the United States for hunts, and this variant ended up breading with escaped domestic pigs to create some of the feral swine Americans know today.

Zamfir Cristian Ion/123RF
Source: Zamfir Cristian Ion/123RF

The United States Department of Agriculture (USDA) is plenty concerned about the repercussions of an ever-expanding feral hog population. These animals have no natural predators other than humans, they thrive in diverse environments, and they are highly intelligent: all factors that help with their continued survival.

Here are 10 facts about feral hogs.

  1. Range. Feral swine have been documented in at least 35 states, including Hawaii, and currently number more than 6 million.
  2. Breeding. Starting at 6 to 8 months of age, feral swine can breed year-round, thus producing up to two litters per year of between four and 12 piglets. Feral pigs can double their populations in four months, and harbor the greatest reproductive potential of any large, free-ranging mammal in the United States.
  3. Appearance. Feral swine resemble domestic hogs but are usually thinner, with thicker hides of coarse, bristly hair. They also have longer tusks than do domestic pigs. Feral hogs weigh on average between 75 and 250 pounds, but some can grow twice as big. They can grow up to 5 feet long, with boars (males) bigger than sows (females). Feral swine should not be confused with javelina, which are pig-like mammals of the American Southwest that are much smaller in size.
  4. Speed. Like deer, feral swine have cloven hooves that help them run up to 30 miles per hour. By comparison, Usain Bolt ran about 28 miles per hour in his prime.
  5. Social groups. Sows travel in groups with their young, with these sounders numbering up to 30 animals. Boars live either on their own or in bachelor groups.
  6. Signs. Because feral swine are usually nocturnal, the best way to identify them is by surveying their effects on the environment, including rooting/digging, tree rubbing, muddy wallows, tunnels/trails through the woods, and scat consisting of animal and plant matter, as well as hoof tracks near springs, streams, and ponds.
  7. Disease. Feral swine can potentially spread various infections to humans including brucellosis, leptospirosis, pathogenic E. Coli,  tuberculosis, salmonella, and tularemia, which are all bacterial. Viruses potentially spread to humans include vesicular stomatitis, porcine epidemic diarrhea, and influenza A.
  8. Destruction. While foraging for food, feral swine can destroy crops, pastures, orchards, and vineyards, as well as leveling private property and cultural/historical sites. They can also infect livestock with disease, eat feed, and even kill young lambs and calves—especially during the birth process. The USDA estimates that feral hogs end up costing Americans $1.5 billion in damages and control costs per year.
  9. Control. The USDA is on board with helping landowners and managers control feral swine populations, offering expertise in the form of wildlife biologists and field specialists. They wrote, “The most successful feral swine damage management strategies employ a diversity of tactics in a comprehensive, integrated approach. Factors to consider when choosing a management method(s) are overall objectives, landscape, environmental conditions, feral swine behavior and density, local regulations, and available funding. The appropriate method or combination of methods for the situation can be determined by utilizing the best information available which can be gathered from surveillance of damage and signs of feral swine on a specific property.” They added, “Nonlethal management techniques can be effective for limiting disease transmission, crop damage, and livestock loss. However, lethal techniques may be a more effective means for limiting population growth and achieving long-term suppression of damage.”
  10. Pork industry. Although feral swine can infect humans, livestock, and wildlife, they pose an existential threat to pork producers, who fear that their billions in revenue could be disrupted by pathogens that these animals carry, including pseudorabies and swine brucellosis. Pseudorabies is a viral disease that can interfere with sow fertility and kill piglets. Swine brucellosis is a bacterial disease that leads to weight loss, infertility, and piglet death. The pork industry in conjunction with the USDA pours tremendous resources into the detection of prevention of these infections among domestic herds.

It should be noted that there is considerable opposition to the lethal control of feral pigs. For instance, PETA “is encouraging wildlife refuges, as well as any other areas where pigs are unwelcome, to make simple adjustments, such as erecting inexpensive fencing and sealing trash containers in areas that the pigs frequent. As long as the environment is attractive for pigs, killing them will not solve the problem because more pigs will simply move in from surrounding areas,” per their website.

Finally, certain opportunists have made a tourist business of hunting feral pigs with semi-automatic weapons and the like. Others have captured wild piglets to be toyed with and slaughtered at rodeo events, per PETA.