Feral Swine in Ohio

History - Introduced to the continental United States in 1539, feral swine (Sus Scrofa) are rapidly becoming established throughout the country.  It is estimated that wild breeding populations of feral swine are now present in at least 35 states.  Feral swine are a combination of Eurasian wild boar and escaped/neglected domestic swine. Some have escaped from hunting preserves or have been illegally released. Having many common names such as: feral hog or pig, Eurasian or Russian wild boar, razorback, and piney woods rooter, feral swine are all considered to fall under the same ancestral genus and species of Sus scrofa which have become established in several areas of Ohio.  

Biology - 
Identification- Depending on ancestral lineage and cross-breeding among breeds, feral swine can vary greatly in appearance.  Typical fur coloration for true Eurasian boar can be grey to dark brown to black, while domestic breeds can display a wider variety of colors with many defining patterns of striping or spots.  Several generations of cross-breeding between domestic and Eurasian lineages can make the physical appearance of these animals drastically different within the same family unit.  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 typically range in size from 125-200 lbs, but larger specimens do occur.  Truly wild feral swine, which receive no supplemental feed, rarely achieve weights greater than 350 lbs in Ohio.
  
Breeding- Male feral swine are typically solitary, while females tend to live in family units called “Sounders.”  Sounders are composed of 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 = 10 piglets) while those of Eurasian lineage produce much smaller litters, averaging 4-5 piglets.

Distribution- While unconfirmed sightings of feral swine are reported periodically throughout the State, 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 also be reported by e-mail (wildinfo@dnr.state.oh.us).

Damage and Disease - 
Feral swine cause significant damage directly to agricultural crops and property, as well as natural resources each year.  Due to inexperienced investigation, feral swine damage is often incorrectly linked to white-tailed deer and other larger mammals and birds.  Therefore, losses associated with this species are often underestimated.  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 (USDA publication, 6Mb PDF).  Farmers and landowners can contact USDA Wildlife Services for technical assistance to deal with feral swine damage on their property.

Crops- With an appetite for practically anything in their path, feral swine are responsible for considerable damage to agricultural crops, with national estimated annual losses in the hundreds of millions. 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 consume 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.  Additionally, feral swine will feed on the eggs and young of ground-nesting birds, reptiles, and amphibians.

Competition- In addition to predatory impacts, feral swine compete with native wildlife species for valuable resources. 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, 2 diseases of great concern are swine brucellosis and pseudorabies, which can infect domestic and wild animal species indiscriminately (read more: USDA bulletin 799).

What is being done about feral swine 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. each year.  In April 2009, the Ohio Program of Wildlife Services began collecting samples from trapped and hunter-harvested feral swine to participate in this national effort.  A wildlife disease biologist with Ohio Wildlife Services works with private and public entities experiencing damage to agricultural and natural resources to collect blood and fecal samples from feral swine.

Control/Eradication- Thus far, State and Federal eradication efforts have focused on smaller, emergent populations in the northern half of the state with great success.  Most of these efforts have been addressed through disease surveillance efforts. Currently, no large scale eradication efforts are being conducted in those counties with known breeding populations. Hunters can aid in removal and are encouraged to do so as opportunities arise. An integrated approach supported by wildlife managers, agricultural producers and sport hunters can have the most beneficial impact in battling this invasive species.

What you can do

Although hunting usually has little effect on feral swine populations, Ohio’s hunters are still encouraged to harvest any feral swine they encounter in the wild in order to limit the spread of this destructive wild animal species in the state.  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 the firearm legal for the season.         

Hunters interested in assisting with eradicating this highly destructive, invasive species can participate by targeting public access areas listed below.  USDA, Wildlife Services is not permitted to share private landowner information with the general public and the Ohio Division of Wildlife does not maintain a list of landowners with reported feral swine on their property.  However, starting in these key public access areas with known feral swine populations can serve as a foot-in-the-door for obtaining access to adjacent privately-owned land.  Always obtain permission from the landowner before hunting on private property.

LIST OF PUBLIC ACCESS AREAS for feral swine hunting

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 (read more Wild Hog Hunting).

For further Information on wild boars and disease:

Southeastern Cooperative Wildlife Disease Study

USDA Animal Plant Health Inspection Service

Swine Brucellosis and Pseudorabies

Video: A Pickup Load of Pigs: the Feral Swine Pandemic