An Official Website of the Commonwealth of Kentucky
History
Biology
Physical Characteristics
Wild Pig Signs
Habitat
Food Preferences
Photo Credit: USDA Wildlife Services
Wild pigs (Sus scrofa) are not native to Kentucky or North America. Their establishment in the southeastern United States dates back to the 1500’s. Early European explorers brought domestic pigs with them as livestock for their settlements. The historic practice of allowing pigs to range freely encouraged the spread and establishment of wild pigs throughout the southeastern United States.
Photo credit: USDA Wildlife Services
Wild pigs are extremely adaptable and can thrive in a variety of habitats. They eat almost anything, robbing our native wildlife of food and often preying on native animals as well. What’s most concerning, however, is their vigorous reproductive potential. In favorable habitat conditions, sows can breed as young as five to ten months old, and are capable of producing litters of 3-8 piglets twice a year! Leaving just a few females on the landscape can quickly result in a huge population increase.
Multiple generations of related females (sows) and piglets live in groups called “sounders”. By living in these sounders pig employ a safety-in-numbers strategy. Males leave the sounder around 16 months of age. These sub-adult males may associate in smaller familial groups, while mature males (boars) tend to be more solitary in nature. Boars temporarily join sounders to breed. Understanding this aspect of their biology is key to implementing effective population control.
Wild pigs are secretive in nature, often hiding during the day in thick cover. They have excellent hearing and sense of smell and typically avoid human contact. When faced with danger, their general response is to run away. However, if cornered or defending their young, wild pigs can be aggressive and dangerous.
Photo credit: Jamison Standard
All wild or domestic pigs are descendants of Eurasian wild boar and are not native to North America. The domestication of the Eurasian wild boar occurred about 8,000 to 10,000 years ago ultimately resulting in the many varieties of domestic pigs we see today. Consequently, both domestic pigs and the Eurasian wild boar are the same species, Sus scrofa. Wild pigs in Kentucky are the result of released domestic pigs and hybrids of domestic and Eurasian boar. There are no pure Eurasian boar in Kentucky.
Wild pigs show significant variability in color, body shape, and size. Most wild pigs are black or brown, but any color, or combination of colors can occur. In Kentucky, adult pigs usually weigh between 75-250 pounds. Piglets can be striped, spotted, or a solid color. Due to varied ancestry, some wild pigs have physical traits similar to Eurasian wild boar; such as long coarse hair, broad shoulders, and grizzled coat coloration; while others physically resemble domestic pigs or a combination of the two. Regardless of their ancestry, all pigs are an exotic, invasive species when living on Kentucky’s landscape.
Photo credit: Scott Smith
Wild pig tracks are very similar to white-tailed deer. It can often be difficult to differentiate between the two. However, deer tracks are spear-shaped with dewclaws directly in line with hoof print. Pig tracks are slightly rounder and wider with dewclaws angled outside of the hoof print.
Wild pigs create wallows in wet areas to get relief from biting insects and heat from the sun.
Wild pigs do not sweat and rely on shaded bedding areas and water to stay cool, especially during hot summer months. A behavior called “wallowing,” literally rolling in mud and water, allows wild pigs to stay cool while ridding themselves of biting insects. Trees near these wallows will become coated with mud as pigs rub off the mud and parasites.
Mud rubbed on trees is often indicative of a wild pig presence.
Scat can vary in shape and consistency depending on the diet and the season of wild pigs. Droppings are often round or tubular and contain grasses, hard mast, and other plant material. They mostly resemble dog feces with bits of grains, acorns, hair, or feathers.
Rooting often resembles a garden tiller. It usually covers a large area.
Wild pigs are extremely adaptable and able to thrive in a variety of habitat types. Habitat preferences include dense cover for shelter and concealment, coupled with permanent water sources. Bottomland forests and riparian areas along rivers and streams are the ideal habitat for wild pigs. Riparian areas are often used as travel corridors.
The home range of a wild pig is reported to vary from a few hundred to thousands of acres. Factors influencing home range size include the availability of food, quality of the habitat, number of pigs in an area, and human disturbance. Increased human activity will shift the movement of wild pigs, causing their home ranges to constrict or expand. More importantly, seasonal changes in food availability and abundance, as well as temperature influence home ranges.
Wild pigs may be active at any time of the day, numerous factors including human activity, food availability, and season may influence when they are most active. Disturbances associated with human activity, especially hunting pressure, is often sufficient to shift the movement patterns of pigs and make them nocturnal. Conversely, in times of food scarcity pigs may need to forage additional hours of the day and forage more widely regardless of other factors. Seasonally, extreme temperatures during the summer months generally results in pigs becoming nocturnal to avoid heat stress.
Photo credit: Jon MacGregor
The diet of wild pigs is classified as “omnivorous”, which means that they can and will eat almost any organic substance that is available. As a result, wild pigs can quickly establish themselves due to their ability to adapt to almost any food source. Vegetation dominates a pig’s diet, but animal prey is also common.
Wild pigs primarily feed by “rooting” or turning over the topsoil in search of roots, tubers, and invertebrates. They use an incredible sense of smell to locate food. In addition to rooting, wild pigs will graze, scavenge, and predate.
Seasonal changes in their diets greatly influences their selection of habitats. In the fall, for example, hard mast (i.e. acorns and hickory nuts) is a very common food item. Likewise, wild pigs consume the eggs and chicks of ground-nesting birds in the spring. Due to their affinity for wetlands and river corridors, wild pigs share habitat with many amphibian species, which they opportunistically feed upon. Amphibian populations can suffer severe losses in areas with high wild pig numbers. Unfortunately, the feeding habits and associated behaviors of wild pigs often results in extensive damage to agriculture, ornamental plantings, native wildlife, and their habitat. It is this adaptability, coupled with continued illegal releases for hunting opportunities, that has resulted in rapidly emerging populations throughout the United States.