Feral Swine

Photo Credit: Patrick Lamont

SCIENTIFIC NAME: Sus scrofa

DESCRIPTION: Feral swine are non-native descendants of domestic stock brought to the Southeast centuries ago by Spanish explorers.  Domestic hogs provided a major food source for early explorers and settlers. Hogs that escaped or were released adapted readily to the wild and prospered in a wide variety of habitats.  Feral swine are hoofed mammals, generally stocky, with short legs, long snouts, and four continually-growing canine teeth (tusks) that self-sharpen from movement of the upper and lower jaw.  Size and weight varies dependent on genetics and habitat conditions.  Typically, male hogs (boars) are larger than females with adults weighing from 200 to 450 pounds.  Adult males may be up to three feet at the shoulder and five feet in length from the tip of the snout to the tail.  Tusk length ranges from three to five inches typically.  Females average from 100 to 300 pounds and have relatively small tusks.  Feral swine typically have solid-colored black, grey, or reddish-brown hair either in solid or mottled patterns across the body.

DISTRIBUTION:   Feral swine range from South Carolina to California and as far north as Wisconsin and Canada.  Illegal trapping, transport, and release of feral swine are a major cause of population expansion and movement across the United States.  Current studies reveal feral swine populations in at least 35 states and Canadian provinces.

HABITAT:  Feral swine are an adaptable species that utilize a variety of habitat types from bottomland hardwoods forests, marshes, and swamps to agricultural lands. Feral swine prefer large forested areas with abundant hard and soft mast crops interspersed with marshes, ponds, drainages, dense cover, and limited human disturbance.

FEEDING HABITS:  Feral swine are omnivorous, opportunistic feeders with seasonal diets consisting of grasses and forbs in the spring, fruits in the summer and fall, along with roots, tubers, and invertebrates throughout the year.  Agricultural row crops, nests of ground nesting birds like turkey and quail, carrion, deer fawns, and turkey poults will also be consumed if the opportunity is presented.  Acorns are a preferred food source for feral swine in the fall.  Voracious appetites of feral swine combined with large home ranges cause direct competition with native game animals for this valuable food source.

LIFE HISTORY AND ECOLOGY:   Feral swine breed year round with peaks in the breeding cycle during fall and spring.  Females are sexually mature at six months, but typically begin breeding at one year of age.  Gestation lasts 115 days with an average of two litters per year.  Litter size ranges from four to 14 with an equal sex ratio. Litters are dropped in a nest constructed of grasses and other vegetation.  Hog mortality is greatest during the first six months of life due to disease, parasites, and accidents.  Adult hogs have higher survival rates due to a lack of natural predators in most areas.  Humans are the main predators of feral swine, as hunting of the species is very popular.  Control and eradication programs for feral swine include trapping, shooting, running with dogs, and hunting with the aid of bait.  Due to a high reproductive rate and a lack of natural predators, feral swine are quickly becoming a huge nuisance problem in the United States, causing millions of dollars in damage to agricultural crops, pastures, timber, and wildlife openings.  Control programs for feral swine are expensive and time consuming, but essential to protecting valuable habitats and food sources for native wildlife.

REFERENCES: 

Burt, William H., and Richard P. Grossenheiden. 1980.  A Field Guide to the Mammals.   Houghton Mifflin Company, Boston. Pp. 214.

Knopf, Alfred A., 1980.  The Audubon Society Field Guide to North American Mammals.  Chanticleer Press, Inc. New York.  Pp. 639-642.

http://edis.ifas.ufl.edu/UW220   Ecology of Wild Hogs in Florida

http://nsrl.ttu.edu/tmot1/sus_scro.htm The Mammals of Texas- Online Edition- Feral Pig

AUTHOR: Chris Jaworowski, Wildlife Biologist, Alabama Department of Conservation and Natural Resources.

ARTICLES: Hog Wild: Hunting Feral Pigs on Alabama's WMAs from Outdoor Alabama magazine;

                   Brucellosis and Hog Hunters hunting safety tips from CDC


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