Oklahoma State University
Banner
Oklahoma Invasive Species
Oklahoma State University

Wild Boar
Sus scrofa

Common Names: Wild Hog, Feral Pig, Feral Hog, Old World Swine, Razorback, Eurasian Wild Boar, Russian Wild Boar

wild boarImage of: Sus scrofa (wild boar)
Country of Origin: Eurasia
History: It was introduced into the United States with European settlers during the 1500s.  This was the domesticated pig, which humans use as a food source.  Most of the wild populations in the United States are animals that have escaped enclosures. During the 1900s, populations of wild boar from Eurasia were also released in the United States as game source for hunters.
Intended Use: Food use and a game source for humans.
Mode of Invasion:

Human release and natural dispersion

Species Description:

Color- variable (combinations of black, white, red, and brown or belted)

Size - three feet in height and over 300 pounds in weight; however, the average sow weighs approximately 110 pounds and the average boar weighs 130 pounds.

Reproduction – can have two litters per year, 4-10 piglets per litter, gestation is 115 days, piglet sex ratio is 1:1 male to female.

wild boar

Home Range – 0.4 – 19 square miles

Activity –  summer – nocturnal, cooler months – dusk and dawn.

Food - omnivorous, opportunistic feeders, with a diet that varies by season: spring consists of grasses, forbs, roots, and tubers; summer and fall consists of soft and hard mast, including grapes, plums, prickly pears, mesquite, acorns and persimmons.  Other food categories of importance in hog diets are: mushrooms; carion; and live animal matter, such as birds, eggs, snails, insects, earthworms and other invertebrates.  Agriculture crops also provide a primary food source

 

Map of Occurrence:

map
Feral Hog densities in Oklahoma and Texas, 1996.

A recent telephone survey performed by the Noble Foundation in 2007, contacted four agencies within the state of Oklahoma:  Oklahoma Department of Wildlife Conservation Game Wardens, Natural Resource Conservation Service, USDA Wildlife Trappers, OSU County Extension Office for each of the 77 counties.  The results were that 74 counties reported populations of feral hogs within the county.  There have been no population estimates to date.

Effects of Invasion: They compete for food with deer, turkey, waterfowl, squirrels, raccoons, opossums, foxes, bobcats, javelinas, bears, sandhill cranes and chipmunks. Rooting effects can change soil properties such as water and mineral cycles, and can also alter plant community succession sequences. Positive effects include increased quality of seed beds, increased water infiltration, shift in plant succession toward increased diversity, accelerated decomposition of organic matter and increased mixing of soil horizons. Negative effects include soil erosion, consumption of native seed crops, consumption of threatened or endangered species, altered plant succession in monocultures or native rangeland and reduction of overall species diversity. 
Control:

Trapping: variety of live traps to catch and either remove or kill hogs

Hunting: in Oklahoma there are no regulations on feral hog hunting (no spotlighting except with proper permit)

Fencing: documented to be somewhat effective, although costs are very high

Predators: coyotes, owls, hawks, and bobcats predate on young hogs but usually cannot control an entire population

 

References:

The Feral Hog in Oklahoma. 1996. Published by The Noble Foundation.

Species profile: wild boar. USDA National Invasive Species Information Center.    www.invasivespeciesinfo.gov/animals/wildboar.shtml

http://www.noble.org/Ag/Wildlife/FeralHogs/

www.invasivespeciesinfo.gov