December 1, 2025 by Joshua Rapp Learn TWS
While other areas struggle against an overwhelming invasion, one state’s holistic approach to control has revealed that control is possible
In some ways, the spread of invasive wild pigs across the U.S. resembles the path of a hurricane. They are nearly impossible to stop, destroying entire crops and ruining human property. The widespread destruction they engineer in native ecosystems may be even longer lasting than a tropical storm.
What’s more, new research shows that Missouri’s strategy of responding to the pig problem like it’s a hurricane with a collaborative task force is part of the reason for the state’s unique success in pig control.
“The incident command systems are really born out of disaster response systems,” said Megan Cross, a social scientist with the U.S. Department of Agriculture’s Wildlife Services, describing the holistic program created for wild pig control.
In a study published recently in the Wildlife Society Bulletin, Cross and her co-author, Keith Carlisle, also with Wildlife Services, examined the reasons for Missouri’s unique success in controlling wild pigs (Sus scrofa).
Wild pigs can devastate human infrastructure, agriculture and the native ecosystem when they take hold. They are found in more than 30 states and populations are well-established in many, including some that border Missouri. But a bevy of new rules and measures have beaten back the rising tide of wild pig invasion in Missouri, turning the Show Me State into more of a We’ll Show You How State.
A change in pig perspective
As Cross and Carlisle began to look into the reason for the state’s success, they found that Missouri was unprepared when wild pigs started to appear there in the 1990s. Interviews with wildlife managers who were around in the early years revealed that Missouri approached the problem in much the same way as other states now overflowing with swine. They used limited state funds to trap and remove some animals while encouraging hunters and trappers to pick up the slack.
But this method has proven not to work. Other research has shown that states that open up hunting laws to allow for the public harvest of wild pigs may inadvertently create an economic incentive to promote the spread of wild pigs, especially when rules prohibiting the transportation of wild pigs are lax or nonexistent. Outfitters and guides can earn a lot from these kinds of hunts. In some cases, the potential for big money leads to political lobbies that seek to weaken anti-swine regulations.
In Missouri, it took more than a decade for the Missouri Department of Conservation (MDC) to change their approach. Cross and Carlisle conducted surveys with 37 people from 15 agencies and organizations in Missouri to determine what changed and how they achieved success.
The MDC began to realize that its current plan was not working by 2007, when the agency partnered with private landowners, the federal government and nonprofit organizations and began to get a handle on the growing problem. As part of Missouri’s strategy, the state banned the transport of pigs, which started a process to help control their spread.
By 2015, the Feral Hog Elimination Partnership had begun to form between the various stakeholders.
These partnerships were incredibly important, Cross said, as the MDC wouldn’t have been able to accomplish what they have without broad buy-in. It involved entities like the Missouri Farm Bureau, the U.S. Fish and Wildlife Service, the U.S. Army Corps of Engineers, Wildlife Services, the Nature Conservancy, private landowners, the U.S. Forest Service and the National Park Service.
By the end of 2019, most partners had banned wild pig hunting on their lands, but perhaps the most consequential move came when the U.S. Forest Service moved to stop the practice in the Mark Twain National Forest—a place where pig-hunting enthusiasts had already begun to transfer the animals for the sake of sport.
Cross said this move was critical due to the sheer size of Mark Twain, which is about 1.5 million acres of land across 29 counties. But the move was controversial, and the partnership needed to produce results that proved that the move, unpopular among some hunters and trappers, would actually work. The MDC began to implement pig removal via staff and partners in Mark Twain and other areas.
Wild pig strike team
The partnership created an incident command system (ICS)—a management team that coordinated pig removal efforts across lands managed or owned by the various state, federal, private and nonprofit stakeholders involved.
The group divided the whole state into territories that “blurred the lines” between the stakeholders. Responding to hotline calls or other reports of pigs or pig damage, strike teams made up of MDC and staff from Wildlife Services could move freely onto lands managed by organizations participating in the Partnership. They conducted removal efforts and responded to reports of damage from private land owners.
“If you’re in Missouri and you have pigs on your property, the ICS is going to handle it,” Cross said.
The team created systematic baiting in the Mark Twain National Forest and other areas, set up traps on a grid system, and shared resources between partners in the ICS. They also shared information on best practices and strategies and the movement of pigs across the land. Finally, the ICS developed agreements with stakeholders in some neighboring states, allowing the strike teams to cross borders while tracking pigs. This helps to reduce the likelihood of the animals crossing the border and establishing populations in Missouri.
The ICS has been successful in reducing wild pig numbers in Mark Twain National Forest—perhaps their main stronghold 20 years ago—and in other parts of the state. “Full-time specialists were much more effective than people who were only trapping pigs part-time,” Cross said.
In effect, this system worked similarly to those set up to manage and respond to natural disasters like hurricanes or tornadoes. But while those systems are usually formed for a short period of time to respond to the disaster, Missouri’s swine control ICS has been around for years now—the longest such ICS that Cross and Carlisle could identify in scientific literature.
Aside from directly controlling wild pigs on the landscape, the ICS also coordinated with law enforcement officers in Missouri, which helps in the enforcement of laws against hunting and transporting the animals. The inability to hunt pigs on public land had already reduced the incentive for people to pull up with a trailer full of pigs and release them on public lands, Cross said.
“Missouri was a standout in the effort,” Cross said. “These laws and hunting closures are one piece of the puzzle. Their operations on the ground are also quite sophisticated.”