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Invasive Species: Feral Swine in Ohio

Feral swine (Sus scrofa) are a combination of Eurasian wild boar and escaped or neglected domestic swine. Common names for this species include feral hog or pig, Eurasian or Russian wild boar, razorback, and piney woods rooter. Introduced to the United States in 1539, they are now present in at least 35 states. Feral swine cause significant damage directly to agricultural crops and property, as well as natural resources each year. Farmers and landowners can contact USDA Wildlife Services for technical assistance to deal with feral swine damage on their property.

Feral Swine Identification & Distribution

Feral swine can vary greatly in appearance, even within the same family unit. Typical fur coloration for true Eurasian boar can be gray to dark brown to black, while domestic breeds can display a wider variety of colors and even striping or spots. Piglets with strong Eurasian influence will display distinctive striping from nose to tail, while those with domestic lineage may appear as miniature versions of the parent.

As with coloration, the size of mature adults can vary greatly depending on the ancestral influence. In Ohio, adults range in size from 125 to 200 pounds. Larger individuals do occur, but rarely exceed 350 pounds in Ohio without supplemental feed.

Breeding Habits

Male feral swine are typically solitary, while females tend to live in family units called “sounders.” Sounders include adult breeding females, offspring that are weaned but not of breeding age, and piglets.

Feral swine typically reach sexual maturity at 8 months of age and can breed year-round. Under ideal conditions, feral swine can produce up to 2 litters per year. As with coloration and weight, litter size can also vary greatly depending on the ancestral lineage. Domestic breeds have the ability to produce much larger litters, sometimes of 10 piglets, while those of Eurasian lineage produce much smaller litters, averaging 4 to 5 piglets.

Distribution

The greatest concentration of verified populations can be found in the unglaciated region of southeastern Ohio. Currently, known breeding populations of feral swine have been confirmed in Adams, Ashtabula, Athens, Belmont, Gallia, Hocking, Jackson, Lawrence, Monroe, Ross, Scioto, and Vinton counties. Feral pig sightings can be reported by e-mail to the ODNR Division of Wildlife.

Damage & Disease

Feral swine cause significant damage directly to agricultural crops and property, as well as natural resources each year. In 2000, it was estimated that the total damage caused by feral swine in the United States was approximately $800 million annually. Since then, feral swine distribution has expanded greatly, increasing this figure significantly.

Farmers and landowners can contact USDA Wildlife Services at (614) 993-3444 for technical assistance to deal with feral swine damage on their property.

Crops

In Ohio, corn and soybeans tend to be the most sought after agricultural food source, but damage to other resources such as turnips, watermelon, squash, orchards, and timber have been reported.

Rooting

Feral swine are often referred to as “living rototillers” due to their destructive digging in search of roots, tubers, eggs, and invertebrates. Rooting can range from a depth of 2 inches to 2 feet (sometimes as deep as 3 feet), causing significant damage to roots and soil integrity.

Water Quality

As the summer months heat up, feral swine seek out wet areas to roll in the mud or “wallow.” These wallows range in size from small mud puddles to churned slurries exceeding 300 square feet, which severely damage downstream water quality through silt deposition and bacterial contamination.

Erosion

Whether by rooting or wallowing, disturbed soil from feral swine activity is subject to extensive erosion. The resulting poor-quality soil is often damaged so badly that it can only be colonized by invasive plant species.

Predation

Feral swine are omnivorous feeders and will eat almost anything in their path. As a predator, feral swine will consume invertebrates, small vertebrates, and even the young of larger animals such as white-tailed deer and livestock. Feral swine will also feed on the eggs and young of ground-nesting birds, reptiles, and amphibians.

Competition

Feral swine compete with native wildlife species for valuable resources, like food and shelter. Acorns that would normally be cached by squirrels and other rodents, or used to boost winter body fat by white-tailed deer, raccoons, and wild turkeys, are consumed at an alarming rate by feral swine.

Disease

Feral swine are highly mobile disease reservoirs and can carry at least 30 important viral and bacterial diseases and a minimum of 37 parasites that can affect people, pets, livestock and wildlife. In Ohio, two diseases of great concern are swine brucellosis and pseudorabies, which can infect both domestic and wild animal species.

Feral Swine Control in Ohio

Trapping and Disease Surveillance

Wildlife Services, a branch of the USDA’s Animal and Plant Health Inspection Service, conducts feral swine disease surveillance activities throughout the U.S. In 2009, Wildlife Services began collecting samples from trapped and hunter-harvested feral swine in Ohio. A wildlife disease biologist with Wildlife Services works with private and public landowners experiencing damage to agricultural and natural resources to collect blood and fecal samples from feral swine.

Control & Eradication Eradication

Thus far, eradication efforts have focused on smaller, emerging populations in the northern half of Ohio with great success. Currently, no large-scale eradication efforts are being conducted in those counties with known breeding populations. Hunters can aid in removal of swine and are encouraged to do so as opportunities arise. There is no closed season on feral swine.

Ridding Ohio of feral swine will take cooperation between wildlife managers, agricultural producers and hunters.

Feral Swine Hunting

Although hunting usually has little effect on feral swine populations, Ohio’s hunters are encouraged to harvest any feral swine they encounter in the wild to limit the spread of swine populations. Feral swine are primarily nocturnal, spending their days resting in dense vegetation or wallowing in mud holes. These nuisance animals may be legally harvested year-round by hunters with a valid Ohio hunting license or by landowners on their own property. During the deer gun and the statewide muzzleloader seasons, a valid Ohio deer permit is also required and hunters should use only firearms legal for the season.

Hunters interested in assisting with eradicating this highly destructive, invasive species can participate by targeting public access areas listed below. Names of private landowners with feral swine damage are not available to hunters. However, starting in key public access areas with known feral swine populations can serve as a starting point for obtaining access to adjacent privately-owned land. Always get permission from the landowner before hunting on private property.

Public access areas for feral swine hunting [pdf]

Feral swine meat is reportedly excellent to eat. As with any game, proper field dressing and thorough cooking are always recommended. Experts recommend cooking all types of meat to 165 degrees Fahrenheit to kill disease organisms and parasites.

Distribution Maps 

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