Yes, wild hogs are present in Illinois, but they are not native wildlife. They are classified as an invasive, exotic species known scientifically as feral swine (Sus scrofa). These unrestrained animals, which include Eurasian wild boar, domesticated escapees, and hybrids, pose a threat to the state’s natural resources and agricultural interests. Illinois maintains an active program aimed at complete eradication, which keeps the state’s population relatively low compared to other U.S. states. Feral swine are highly adaptive omnivores that can rapidly establish breeding populations if left unmanaged.
Current Status and Geographic Distribution
Feral swine were first reported in Illinois in the early 1990s, concentrated in several southern counties. Their presence often stems from escaped domestic livestock, free-ranging practices, and illegal intentional releases for hunting. Although over 30 counties have documented feral swine over time, the Illinois Department of Natural Resources (IDNR) and the U.S. Department of Agriculture (USDA) actively work to eliminate these populations before they become self-sustaining.
Sightings are most common in the forested and agricultural habitats of southern Illinois, which provide necessary cover and food resources. While self-sustaining breeding groups were previously identified in counties like Fulton, Fayette, and Pike, these have been successfully removed through targeted programs. Today, reported sightings are aggressively investigated to prevent the establishment of permanent sounders, the family groups in which these animals live. Monitoring efforts are continuous to prevent re-establishment or expansion from transient animals crossing state lines or escaping local farms.
Ecological and Agricultural Damage
Feral swine pose a significant threat to Illinois’ ecosystems and agricultural industry due to their destructive foraging behavior. Their habit of “rooting”—using their snouts to dig up soil and vegetation for food—causes extensive damage to crop fields, pastures, and sensitive natural habitats. This activity destroys native plant communities and can flatten several acres of crops in a single night.
Rooting and wallowing also lead to significant soil disturbance, increasing erosion and contributing to sedimentation in waterways. This runoff degrades water quality, impacting aquatic life and potentially introducing bacterial contamination like E. coli into streams and rivers. Feral swine compete directly with native wildlife, such as white-tailed deer and wild turkeys, for food sources like acorns and nuts. They also prey upon vulnerable native species, including reptiles, amphibians, and the eggs and young of ground-nesting birds.
Disease Transmission
The animals carry a variety of diseases and parasites, with over 30 types known to be transmissible to livestock, wildlife, pets, and humans. The potential for feral swine to spread diseases like pseudorabies and brucellosis to commercial domestic hog operations represents a serious economic threat to Illinois pork producers.
State Control and Eradication Efforts
Illinois maintains a proactive, coordinated approach to feral swine management, aiming for complete eradication. This effort is primarily a collaboration between the Illinois Department of Natural Resources (IDNR) and the USDA Animal and Plant Health Inspection Service (APHIS) Wildlife Services. These agencies provide free assistance to landowners for identification, monitoring, and removal of feral swine.
The legal status of feral swine is clear: they are not classified as wildlife and are not protected. It is illegal to transport, release, or establish populations for hunting purposes. Landowners who discover damage should report sightings immediately to the IDNR or USDA Wildlife Services rather than attempting removal themselves. Uncoordinated shooting can scatter a sounder, causing the animals to disperse and establish new, harder-to-find populations.
The most effective removal technique is advanced trapping, specifically large corral-type traps designed to capture an entire sounder at once. Controlled aerial removal operations using helicopters may also be implemented to quickly eliminate large numbers of animals in isolated, accessible populations. These methods maximize the removal rate, which must be around 60 to 70 percent annually just to prevent population growth due to the swine’s high reproductive rate. Landowners may also obtain a free nuisance wildlife removal permit from the IDNR to take action outside of the firearm deer seasons.