Wild Pigs: Nature’s Unwanted House Guest!

A Little Bit of History

We have all seen the movies of horrible roommates or relatives that make life miserable and overstay their welcome. They end up destroying a house, terrorizing friends and family, or worse yet, refuse to leave. Meet the real-world wildlife equivalent. The wild pig (Sus scrofa; also referred to as feral swine, wild hog, razorback, Russian boar, and a variety other names) is an extremely destructive invasive species. With an estimated 6 million pigs inhabiting more than 35 states, the damage they inflict can be staggering. Conservative estimates place damage and control costs at 2.5 billion dollars annually.

Unlike the collared peccary (aka javelina, which is not a member of the pig family; Suidae), wild pigs are not native to North America. Wild pigs were originally brought to the continent by explorers as early as the 1500s to serve as a food source for new settlements, many of which were located in the southeastern United States. Over the centuries these pigs escaped or were managed as free-range and multiplied, establishing populations of wild pigs. As more people settled the United States they brought with them domesticated pigs and other native pigs, most notably Eurasian wild pigs (also called Russian Boars). In many parts of the country the Eurasian pigs and wild semi-domesticated populations hybridized and led to more pigs of differing size, shape, and color. This occurred to varying degrees throughout much of the Southeast, Texas and West Coast.

However, during the late 1900’s and early 2000’s wild pigs began appearing in more northern states (i.e., the Midwest and Northeast). While pig populations had slowly grown and expanded over several centuries in the South and West, many of these more recent pig populations appeared hundreds of miles from nearest known populations. This recent, significant expansion of their range is largely attributed to translocation of animals for recreational hunting interests and escapes from fenced farming/shooting operations, which has been corroborated through multiple legal cases as well as genetic studies.

With the majority of states incurring varying degrees of damage from wild pigs, the need to manage this non-native species was elevated to a national level. Funding to implement a collaborative, national feral swine damage management program came in the form of the 2014 Farm Bill. The overarching goal of the National Feral Swine Damage Management Program is to protect agricultural and natural resources, property, animal health, and human health and safety by managing damage caused by feral swine in the United States and its territories. The national program is led by the United States Department of Agriculture’s Animal and Plant Health Inspection Service; however, this is a cooperative effort with other agency partners, tribes, organizations, and local entities that share a common interest in reducing or eliminating problems caused by wild pigs.

The Threats

Wild pigs are known to carry at least 30 viral and bacterial pathogens and many different parasites that can cause disease in humans, pets, livestock, and wildlife. Disease transmission can occur through direct contact with wild pigs, their feces and bodily fluids, contact with contaminated food or water, and the consumption of undercooked, infected wild pig meat.

Pseudorabies (PRV) is one example of a highly impactful disease that could be devastating to domestic livestock should it be transmitted from wild pigs, which are considered the reservoir for this disease in the U.S. Thankfully, the U.S. domestic swine industry is considered PRV free. Similar concern exists for other diseases though. Fortunately, our livestock industries do a good job of preventing the spread of disease, but wildlife and humans are equally susceptible to many diseases carried by wild pigs. Therefore, monitoring and testing of wild pigs for a myriad of diseases is crucial to knowing what threats are out there.

The impact wild pigs have on agricultural crops, natural resources, and property is devastating. Wild pigs could be described as miniature bulldozers. They are built tough, have a lot of power, are designed to tear up the ground, and are just plain hard to stop. Wild pigs will systematically root up freshly planted seeds, overturn pastures and lawns, damage expensive nursery stock, and overturn woodland soil in search of nature’s finest delicacies. While the monetary loss of some of these damages may be calculated, it’s the ecological damage that is hard to assign a dollar value to, especially when it may take years or decades for a resource to recover. Natural wetlands, one of our rarest habitats, are preferred locations for wild pigs to create deep wallows, damage streams, and lead to long-term erosion issues. All these impacts have a profound influence on the ecosystem and the other wildlife inhabiting those ecosystems.

What Can Be Done

Fortunately, we have identified the damaging agent (the wild pig) and we know how we got to this point (human interests). The challenge is fixing the problem. We need to remember a few things: 1.) they are a non-native species; 2.) they pose a lot of threats to people, animals, and the environment and; 3.) because of their distribution and population size, especially in their historical range, it will take a committed effort over a long period of time to get to a manageable level.

In many states the population of wild pigs is relatively low, and the chance for removing them from the landscape is favorable. Several states with wild pigs just 5-10 years ago are now wild pig free with monitoring programs in place to detect any new occurrences. As the range and population levels of wild pigs are reduced, so in turn should their impact (i.e., damage) on other resources. The advantage of having a national program is that resources can be shared and redistributed once states eliminate their respective pig populations.

Additional information about wild pigs and the National Feral Swine Damage Management Program can be found at: https://www.aphis.usda.gov/aphis/resources/pests-diseases/feral-swine. If you see signs or hear reports of wild pigs, please call the Indiana Wild Pig Report Hotline at 1-855-386-0370.

Lee Humberg is the Indiana State Director for USDA-APHIS Wildlife Services. The mission of Wildlife Services is to provide Federal leadership and expertise to resolve wildlife conflicts to allow people and wildlife to coexist.