Classified as a nuisance species in many states and not native to the Americas, feral swine cause significant damage to our natural resources and negatively impact agricultural production across the country. Recent research highlights the growing negative impacts feral swine can have to our water, plants, wildlife communities (both game and non-game) and their habitat. The prolific reproductive capabilities of feral swine create an enormous challenge for effectively managing this invasive, exotic species and mitigating their damage. Many states have implemented transportation bans for feral swine as well as other measures to curb the spread of these animals, and further research is currently being pursued regarding the use of toxicants as a control technique.
As an invasive species, feral swine negatively impact our water, plants, wildlife communities (both game and non-game) and their habitat, causing significant damage to the health of our natural resources. Predominantly through competition for food and space, feral swine have been shown to displace deer and ground-nesting birds, such as turkey and quail. Predation is also a factor, as feral swine have been found to depredate on the eggs of ground nesting birds. In addition to their impact on native ecosystems, feral swine are a perpetual issue for the larger agriculture community and can be devastating to individual agricultural producers due to their rooting behavior, consumption of valuable crops, and property damage. If that were not enough, feral swine also serve as a vector for disease and are known to carry at least 30 viral and bacterial diseases and nearly 40 parasites that can be transmitted to game and non-game animals, livestock, and even humans, making feral swine a public health threat.
Due to the prolific reproductive capabilities of the species, damage mitigation and management of feral swine presents an enormous challenge. State and federal agencies continue to struggle to find both effective and cost-effective management techniques which impede further dispersion of feral swine into new areas and reduce the negative impacts associated with having a feral swine population. Throughout the country, state fish and wildlife agency regulatory approaches to the management of feral swine vary from liberal seasons to no take at all.
Non-native to the Americas, feral swine were first introduced by early European explorers in the 1500s as livestock/domestic pigs. The importation of these animals later included Eurasian wild boar, which were introduced into parts of the United States for hunting purposes. Over the years, escaped and open-range domestic pigs interbred with Eurasian wild boar, helping establish feral swine populations in North America.
Today, due to the popularity of feral swine hunting, many privately-owned, fenced hunting preserves and hunting destinations feature feral swine as a pursuable quarry. This has had a large impact on the feral swine expansion rate, due to hogs escaping from these privately owned operations, as well as the illegal translocation of feral swine to previously unoccupied areas in order to pursue them as game animals.
Points of Interest
- Feral swine are also known as wild boar, wild hogs, feral hogs, Old World swine, Russian wild boar, razorback, and Eurasian wild boar.
- According to Savannah River National Laboratory, in 1990 there were approximately two million feral swine in 20 states. By 2019, as many as nine million feral swine inhabited at least 39 states.
- Typically, 60% of an area’s feral swine must be killed each year to simply keep population numbers stable.
- In 2019, feral swine were responsible for a conservative estimate of approximately $1.5 billion dollars’ worth of crop damage in the United States.
- USDA Animal and Plant Health Inspection Service (APHIS) was issued $20 million in 2014 for the National Feral Swine Damage Management Program, dedicated to field operations, research, disease monitoring, outreach, regulation, and internal monitoring. Subsequently, the APHIS annual budget to address feral swine concerns has been increased to 30.5 million.
- A “sounder” is the terminology used for a family group of feral swine and on average consist of two sows (adult females) and their young. Sounders range from just a few pigs to as many as 30.
- “Whole sounder removal” is a management practice that allows for a greater chance of decreasing an area’s population efficiently, failure to remove the females that define the sounder permits the continued repopulation of the area.
- The use of sodium nitrite or warfarin as a feral swine toxicant is currently being explored by researchers and has shown promise as a cost-effective and efficient form of removal. However, further research is needed.
- Though the EPA approved Kaput Feral Hog Bait (which is a warfarin-laced toxicant) in early 2017, many concerns on toxicity, impact on non-target species, efficacy, distribution/dispensing, use regulations and others still exist within the conservation and academic communities. State wildlife and agriculture agencies, as well as the USDA, should be consulted when considering any approaches dealing with toxicants.
- On November 6, 2017, APHIS Wildlife Services (WS) received an Experimental Use Permit (EUP) from the U.S. Environmental Protection Agency to conduct sodium nitrite toxic bait field trials on free-roaming feral swine in Texas and Alabama. Subsequently, on November 20, APHIS signed a final environmental assessment and issued a Decision and Finding of No Significant Impact (FONSI) associated with conducting such field trials.
- Strict regulations with clear enforcement authority over feral swine transport can help reduce the spread to new areas or repopulating depleted areas.
- In the 2018 Farm Bill, a newly established program named the Feral Swine Eradication and Control Pilot program was authorized to receive $75 million over five years spilt between USDA APHIS and NRCS to establish a pilot program to eradicate feral swine and to help mitigate their damages to fish, wildlife, and their associated habitats.
- Several states, namely Texas and Florida, now allow sale of hog meat, after inspection, as they are considered and invasive and non-native species.
- CODE ANN §49-7-140(2) states that no person may transport or relocate within the state any live feral hog, wild swine or Russian Boar and release the hog into the wild. Wild hogs may not be caught or trapped and released into the wild at a location different from the location where the wild hog was caught or trapped. A violation of this section, upon conviction, is punishable as a Class I violation.
- CODE ANN. §49-7-141 states that any person who has been convicted of a Class I violation shall be fined not less than two thousand dollars ($2,000.00) nor more than five thousand dollars ($5,000.00) and shall be imprisoned in the county jail for five days. The person shall also forfeit all hunting, trapping, and fishing privileges for a period of not less than 12 consecutive months from the date of conviction.
- In 2013, HB 1478 of the Arkansas General Assembly prohibited the possession, sale and transport of any hogs not conspicuously identified by ear tag provided by the Arkansas Livestock and Poultry Commission.
- In 2011, Tennessee removed “feral swine” from defined big game species, and in order to remove the incentive to relocate wild hogs, they are now considered a destructive species to be controlled by methods other than sport hunting. It is illegal to possess, transport, or release live wild hogs (“wild appearing”) as defined.
- In 2017, Arkansas enacted legislation trying to combat explosive hog population growth throughout the state. HB 2063 created the Feral Hog Eradication Task Force, establishing an intrastate network of agencies, with a goal to extirpate hog populations through proven means of extermination.
- In 2019, Oklahoma HB 1150 was enacted, authorizing the Conservation Commission to grant conservation cost-share program funds to conservation districts to “reduce feral swine population by use of electronic hog traps.”
Current management methods have not properly addressed the explosion of feral swine populations occurring throughout the country. It is imperative that coordination and best management techniques be utilized to address this serious conservation challenge. Ideally, a strong, multi-collaborative strategy involving states, federal agencies, non-governmental organizations, and local stakeholders could be implemented to assess current management techniques, share best practices, and execute a multi-pronged approach to managing feral swine. Foremost, states need to work collectively with partners to slow the spread of feral pigs by implementing and enforcing a transportation ban of some type.