C H A P T E R 1 6

Wild HogsJames G. Dickson’ John J. Mayer

US Forest Service WestinghouseSouthern Research Station, Smtrnnah River Company,

Nacogdoches, TX Aiken, SC

Wild hogs or swine aremedium to large-sized,stout-bodied, and propor-tionately short-leggedhoofed mammals withthick skin covered withsparse to dense coats of

John D. Dickson*Texas WingsAustin, TX

of the country at present(Mayer and Br i sb in1991). In this chapter,these different types ofwild hogs will be treatedtogether unless otherwisenoted.

coarse bristles. These ani-m a l s h a v e e l o n g a t e dheads and snouts ending in a disc-like pad throughwhich the external nares open. The only other species inthe southern United States that resembles the wild hogis the collared peccary or javelina, found in Texas, NewMexico and Arizona.

Two primary types of wild hogs, Eurasian wild boarand feral swine (wild hogs solely of domestic ancestry),have been established in the southern United States.These 2 types are conspecifics and will readilyhybridize (Wood and Barrett 1979, Mayer and Brisbin1991). At present, there are only populations of feralswine and wild boar x feral swine hybrids found in theSouth. No pure populations of Eurasian wild boar areknown or have been documented to exist in this region

Feral hogs resembledomestic hogs, but usual-

ly are leaner, and generations in the wild have honedadaptations for life in the wild. Eurasian wild boar, alsoknown as European wild hogs or Russian boars, areabout the same size as feral hogs, but have a grizzled,sleeker appearance, with light tipped hair, and longerlegs and snout. Specifically, there are both physical andmolecular differences among the 3 types of wild hogs.Of these, the morphological differences are the mostuseful in differentiation. Variation in coloration patterns,cranial differences, and snout and hind foot length havebeen used to tell the different types of wild hogs apartwith a far degree of accuracy. In addition, mitochondri-al DNA techniques are beginning to show promise inidentifications (Mayer and Brisbin 1993). In contrast to

‘Current Address: School of Forestry, Louisiana Tech University, Ruston, LA‘Current Address: Texas Parks and Wildlife, Austin. TX

191

192 WILD HOGS

Recently, wild hogs have become a more prominent part of the southern landscape (J. Mayer).

earlier beliefs, the presence of striped coloration patternsin piglets is not a reliable character for identifying eitherEurasian wild boar or hybrids (Mayer and Brisbin 1993).

In general, male wild hogs are somewhat larger thanfemales. This size relationship is true for both externalphysical dimensions and total body mass. These differ-ences are initially evident at about 15 months of age,and increase with age. Average adult males are about 5feet from the snout to the end of the tail, stand 3 feet atthe shoulder, and weigh between 180 and 200 pounds.Exceptional animals can weigh in excess of 500pounds. Wild hogs have an excellent sense of smell andfair to good senses of hearing and vision. Tusks orcanine teeth in males are much larger than in females(Mayer and Brisbin 1988), and have trophy value tosome hunters.

In many areas of the southern United States. wildhogs are considered to be an important recreationalresource as a big game animal (Mayer and Brisbin199 I ), with recreational sport hunting having substantialeconomic impact. In Florida alone. this has annually rep-resented a multi-million dollar industry (Degner 1989).Particularly in Florida. North Carolina. Tennessee. and

Texas, the opportunity to hunt wild hogs has attractedlarge numbers of nonresident hunters and has an eco-nomic impact (Conley et al. 1972, Degner 1989).

HISTORY

Being a non-native or exotic species, the origin of wildhogs in the western hemisphere is attributable solely toeither the intentional or accidental release of these ani-mals by man. The earliest presence of this species in thesouthern United States can be traced back to the intro-duction of domestic swine into Florida by Hernando DeSoto in 1539. Along De Soto’s route through 13 states,domestic swine escaped into the wild. SubsequentSpanish and French colonies in the South introducedmore domestic swine. By the 17OOs, feral populationsof swine were established throughout the region (Towneand Wentworth 1950, Mayer and Brisbin 199 1).

In addition to these early introductions, colonial set-tlers in the South released domestic swine into unfencedwoods to fend for themselves, foraging on mast andother foods. Whenever the settlers wanted pork, the ani-mals were either caught with dogs. trapped. or shot.

physiographic Regions of the South

a Coastal PlainMiss iss ipp i R iver Va l ley

m Blue Ridge Mountains

q Ridge and ValleyAppalach ian Pla teauIn ter io r Low P la teau

l Ouachi ta Uplands[ZI Ozark Plateau

l Central Lowlands

q Miscellaneous

Major Forest Types of the South

---. ____‘,

‘,._.i1

Longleaf-Slash PineLoblolly Shortleaf Plne

Oak-Gum-CypressNonforest land

Forest Type Groups of the SoutheasternLambett-Azimuthal Equal Area Projection

Top: Forests of the South have always been diverse as well asciynamrc (G. Sm~fh).

Left: Southern forests have been contrnually molded by a variety ofdiverse natural and anthropogenic forces (J. Walker).

Above: In the era of explortation in the late 1800s and early 1900s :Ifew specres. such as this ivory-billed woodpecker, apparently wereeliminated from southern forests (G. Sutton, Cornell Lab ofOrmthology).

A number of species whose future oncewas in doubt have been successfullyrestored to southern forests.

expanding where there is extensive habitat in the Appalachian and

The white-tailed deer, a premier game species.Populations were once decimated by the new southernsettlers and relegated to a few locations. Now it thrivesthroughout the South and is found in every county(B. Lea).

Mourning doves may have declined from theloss of traditional habitat, but seem to be doingwell in suburban situations with ample nestingsites and bird feeders (17 . Mirarchi).

Top and above: The beaver is widespread today. It’s capability to flood forests and cropfields often puts it at odds with man and his land use objectives (J. Dickson, OutdoorO k l a h o m a ) .

The northern bobwhite was once a verypopular game bird in the South. But as smallweedy fields disappeared and southernfOreStS aged the call of the bobwhite hasbecome increasingly rare (J. MacHudspethi.

H u f f e d grouse populations in the southern Appalachians appear to have dwindled due tothe loss of early successional habitat (R&fed Grouse Society).

197

Several species and groups of southernwildlife are the focus of special interest.

Population viability of some forest interior species may be negativelyimpacted by forest fragmentation (M. Hopiak, Cornell Lab ofO r n i t h o l o g y ) .

Red-cockaded woodpecker populations declined as old- growth pinestands were harvested. Now there are substantial efforts, particularlyon federal land, in behalf of this species (P Moore, OK Dep. Wildlife).

We don’t know very much about the life historyor habitat requirements of some vertebrates,such as bats, reptiles, and amphibians. TheRafinesque’s big eared bat shown here is aspecies of special concern. Origtnally it hiber-nated and reproduced in large cavity trees.Now it uses man-made structures such asbuildings and wells (0. Saugey).

Sandhill crane chick and egg. There is some concern for a few species ofbirds such as the sandhill crane (D. Hancock).

Wildlife foods

Oak acorns wherever they occur are a principle food in fall and wrn-ter for a number of wildlife species. Parent nutrition, and productionand survival of young often depend on the previous season’sacorns. However annual production is very erratic (US forestS e r v i c e ) .

Fruits from shrubs are important wildlife food for a number ofspecies in summer and fall (US Forest Service, H. Ho/brook,

J. Dickson~.

Protection and particular management is needed for some sen-sitive plant species and communities. Coastal plain bogs andseasonally wet longleaf pine flatwoods are among the mostdiverse communities in the world, supporting many differentplants, top. Among the plants of interest found here are a vari-ety of orchids, such as this rosebud orchid, left (J. Walker).

Big-leaf geranium, above. The rich cove forests of the southernAppalachians are renown for displays of spring wild flowers.Many are ephemeral, growing and flowering each seasonbefore the canopy leafs out (J. Walker).

T h e nature of the South’s p e o p l e and their relationship with theforest continue to change. One of the biggest challenges will b e t omanage for varied products, w h i l e protecting a n d a l l o w i n g use ofsouthern forests. It is important to help an increasingly urban p o p -u l a t i o n understand n a t u r a l resources and their management(K. Cordell, S. Thompkins, M. Staten).

s,llOk&O~~ses to cuse posk wer-e 3 common feature ofeilr~y rural southern settlements. Many of these swinedrifted away from the fXmS and eventually lxc~ullefel.:l], or wild-living (Towne and Wentworth 1950,Hanson and Kar::tad 1959, Mayer and Brishin 199 I ).Free-l;ulging d o m e s t i c i lOgS ill th.? ,~Ollth WL’l’e Wide-

spr& in the early 1900~. But with the increasinghutnan population in the I-CgiOll. open range was lqeiy

ejiminatcci in the mid I9OOS when most southern stateslegislated cl~secl range laws (Mayer and Brisbin 190 I ).

Eurasian wild boar were introduced in the South inthe early 1900s to provide new huntable big game ani-mals. The earliest documented introduction of‘ wild boaIwas into a fenced shooting preserve located on HoopelBald, Graham County, North Carolina in 1913.Following a period of about 10 years of confinement,these animals escaped during a large-scale hunt. Thewild boar dispersed into the surrounding mountainousterrain and over time interbred with local feral hogs.Hybrid stock from this area have either spread or werelive-trapped and relocated into portions of California.Texas, Georgia. Florida. Kentucky, North Carolina.South Carolina. and Tennessee (Mayer and Brisbin1991).

Additional stockings of hybrid animals of unknownorigin have reportedly taken place in Arkansas.

Mississippi, and Louisiana. Although prohibited byboth federal and state regulations, the additional intro-duction or release of feral hogs and hybrids continues inmany ;IIEIS of the So~~th today (Mayer and Brisbin199 I ). Also, wild hogs have keen introduced and popu-lations have become e&blished in numerous areasacross the central United States.

Wild hogs currently are found in scattered popula-tions and vat-yin g densities in all of the southern states.Most populations are fwncl in the Coastal Plain region,however. substantial populations are also found in someportions of the Appalachian Mountains. They are wide-spread in eastern Texas, Louisiana, and Florida. Thecurrent regional population estimate for this species inthe southern United States is between 1 and 2 millionanimals (Mayer and Brisbin 1991, Miller 1993).

H A B I T A T

Throughout the southern states. wild hogs use a varietyof habitat types. The most commonly used habitat in theSouth is riparian forest associated with a year-roundwater source (Sweeney and Sweeney 1982). However,the types of habitats successfully occupied by thisspecies range from the mountainous hardwood forestsof the southern Appalachians; to the bottomland forests

With adequate nutri-tion sows are veryp r o l i f i c , p r o d u c i n gseveral litters eachyear (J. Mayer).

202 WILD HOGS

along rivers in South Carolina, Georgia, and easternTexas; to the marshy palmetto and oak flats of centraland south Florida, (Mayer and Brisbin 199 I).

The general habitat requirements for this speciesinclude a mast-producing cover type during the fall andwinter months, and both well-distributed water andescape cover on a year-round basis (USDA 1981). Bothhard and soft mast play an important role in the nutri-tional status and reproductive biology of this intro-duced species. The importance of hardwoods, particu-larly oaks, to wild hogs is evident wherever these ani-mals are found. For example, in the AppalachiansEurasian wild hogs used mixed oak stands during falland winter of years of high mast production, but usedother hardwood stands when little mast was available(Singer et al. 1981).

Wild hogs are found only in areas that are associat-ed with either permanent drainages or widespread mesichabitats. The absence of water in an area will effective-ly preclude establishment of this species. Habitat use bywild hogs is related to cover density (Barrett 1978).Cover habitat also functions as a preferred beddinglocation for this species. In cooler weather wild hogsusually make beds where they will get warmth from themorning sun. In the southern Appalachians, most bedsare found on slopes or areas with a south, east, or south-eastern exposure. In addition, dense cover affords wildhogs some measure of protection from hunting (Conleyet al. 1972).

Seasonal changes in habitat use are related to foodavailability and dietary shifts (Sweeney 1970, Kurz andMarchinton 1972, Graves and Graves 1977). For exam-ple in South Carolina, an abundant mast crop in the fallconcentrated feral hog activity in bottomland hard-woods, but they moved to upland pine plantationsaround thickets of ripe plums during summer (Kurz andMarchinton 1972).

Movements of wild hogs are variable and depend-ent. to some extent, on food availability and sexualactivity. In general, males travel more than females, andsexually active males traveled more than sexually inac-tive males. Also, movements were least during yearsand season of high acorn production; hogs moved moreto find food during periods of food shortage (Singer etal. 1981).

REPRODUCTION

Compared to all other native or introduced big gamespecies found in North America. wild hogs have thehighest reproductive potential. This species sexually

matures at an early age, produces the largest litters ofany ungulate, can farrow 2 litters within a twelve-monthperiod, and breeds throughout the year. Reproductivesuccess in wild hog populations depends on food avail-ability, particularly the annUd mast crop (Matschke1964, Scott and Pelton 1975).

Sexual maturity in wild hogs can be reached asyoung as 5 months in males and 6 months in females.Excluding unusual circumstances or pathological con-ditions, all individuals of both sexes become sexuallymature before the end of the first year of life (Sweeney1970, Barrett 1978). Wild hogs in the South are sexual-ly active and will breed throughout the year. Althoughvariable by area, there are usually 2 peaks in the annualreproduction among wild hogs. a major one in late fallto early winter and one in late spring to early summer(Sweeney 1970, Conley et al. 1972, Johnson et al.1982).

The gestation period of wild hogs ranges from 110to 140 days. with an average of 114-l 16. Estrous cyclesare resumed and sows may breed soon after their youngare weaned at about 3 to 5 months of age (Asdell 1964,Barrett 1978).

The fetal litter size in wild hogs varies from 1 to 16,with a mean of between 5 and 6. The observedintrauterine mortality varies from 23-40 % (Asdell1964, Baber and Coblenz 1986, Hellgren 1993).

The pregnant sow builds a farrowing nest approxi-mately 2 to 3 days before giving birth. These nests tendto be shallow depressions lined with grasses, leaves orother plant material. After the litter of piglets is born,the young stay in or near the nest for about a week, evenwhile their dam leaves to forage. The basic social groupamong wild hogs is a sow with her offspring; matureboars are usually solitary except when breeding.Juvenile mortality in wild hogs can be high, with obser-vations varying from 9 to over 90 % in any given year(Crouch 1983, Barrett 1978).

FOODS

Wild hogs are both omnivorous and opportunistic intheir dietary preferences (Sweeney and Sweeney 1982).In general, however, most recent studies have shownthat wild hogs consume far more plant than animalmaterial on an annual basis. The specific diet of a wildhog population is largely dependent upon what foodsare available in a local area at any one time of the year(Barrett 1978, Belden and Frankenberger 1990), andcan change as new forage species become available.

W ILD HOGS 203

The list of plant material eaten by wild hogsincludes a wide variety of both above and below groundstems, leaves, fruits, roots/tubers, forbs, fungi, andwoody vegetation. Hard mast such as acorns and hicko-ry nLlts is important and preferred food when it is avail-&[e (Henry and Conley 1972, Scott and Pelton 1975,Matschke 1964). In general, wild hogs feed on grassesand forbs in the spring, fruits in summer and fall, androots and tubers throughout the year (Hellgren 1993).The opportunistic food habits of this introduced speciesalso often result in the depredation of a variety of com-mercial grain and vegetable crops.

Although typically low in volume and frequency(both less than lo%), the consistent use of and apparentdetermined searching for high protein animal foodresources may indicate the importance of this compo-nent within the diet of wild hogs (Barrett 1978, Scottand Pelton 1975). On islands where food resources aremore limited, the seasonal volume of animal material inwild hog diets has been documented to be as high as26% (Baron 1979). Wild hogs eat a variety of animalmatter. such as insects, crustaceans, mollusks, worms,fish, amphibians, reptiles, birds, and mammals. Thiscomponent of the wild hog’s diet includes consumptionof both predated animals and carrion that is found. Eggsof a number of vertebrate species are also consumedopportunistically.

Wild hogs feed mostly at night, but also may feedduring daylight hours. For example, in theAppalachians radio-instrumented Eurasian wild hogswere more active during twilight and at night than dur-ing the day in all seasons (Singer et al. 1981).

DISEASES AND PARASITES

Wild hogs are susceptible to a wide range of diseasesand parasites. Some of these diseases are specific toswine, while others are shared by other wild and domes-tic mammals as well as by man. In general, wild hogshave the potential to contract and transmit all of theviral. bacterial, and fungal diseases of domestic swine(Payeur 1989). In some cases, wild hogs may carry andbe resistant to diseases, but are capable of infectingdomestic livestock, native game species such as white-tailed deer. or hunters. For this reason there is concernover the potential of wild hogs functioning as diseasereservoirs in areas where they are abundant (Nettles1989, Davis 1993).

The list of diseases which can infect wild hogsincludes but is not limited to the following: psuedora-bies. hog chol era, swine brucellosis, bovine tuberculo-

Sk, VeSiCLlklr StOmatitiS, vesiclllar exanthema, trichi-nosis, foot-and-mouth disease, African swine fever, lep-tospirosis, bubonic plague, anthrax, transmissible gas-troenteritis, rinderpest, porcine encephalomyelitis,porcine eIIterOVirLlS, reOViruS, Swine influenza, andVenezuelan equine encephalitis (Davis 1993, Mebus1989, Nettles 1989). Of particular concern are swinebrucellosis and psuedorubies because these diseases area threat to the domestic swine industry and are subjectsof major control programs by both federal and stateagricultural agencies.

Brucellosis is an infectious bacterial disease of ani-mals and humans caLlsed by members of the genusBruceh. The effects of this disease are generally limit-ed to abortions and reproductive organ infections. Inhumans bmcellosis may clinically mimic severe flu andmay resemble crippling arthritis or meningitis. There isno cure for brucellosis in either animals or humans(Davis 1993). The occurrence of bmcellosis infectionsin wild hogs in the South has been found to vary from 6to 53% of animals tested (Becker et al. 1978, Zygmontet al. 1982). The areas of highest brucellosis incidencein the South have been in Florida (Becker et al. 1978).Bigler et al. (1977) reported that 22% of human cases ofbmcellosis in Florida were attributable to hunter contactwith wild hogs.

Psuedorabies is an infectious, alphaherpes viral dis-ease of the central nervous system in wild hogs that isalso found in domestic livestock, cats and dogs (Davis1993). Transmission is through animal to animal con-tact or contact with contaminated media such as foodand water. Most swine remain latently infected follow-ing clinical recovery. Except for swine, the disease isalmost always fatal (Payeur 1989). Small pigs are moreseverely affected, but more virulent strains have recent-ly developed and fatalities among adult swine havebeen observed (Davis 1993).

A variety of parasites infect wild hogs, but typical-ly do not cause direct mortality. Endoparasites thatappear to be well-established in wild hog populationsinclude lungworms, kidney worms, liver flukes, thorny-headed worms, stomach worms, intestinal roundworms, hookworms, nodular worms, coccidia(Sorcocystis spp.) and threadworms (Smith 1981,Nettles 1989). Kidney worms and lung worms areknown to cause severe debilitation in domestic swine:and in conjunction with other unfavorable conditionscould represent significant morbidity/mortality factorsto wild hogs (Smith 1981). Dog ticks, hog lice, andmites (Sarcoptes scnhiei) are the most typical ectopara-sites focind on wild hogs. With the exception of sarcop-

Wild hog rootings are a problem in disrupting plant communities (J. Mayer)

tic mange, none of these ectoparasites constitutes a pub-lic health threat (Smith 198 1 j.

INTERACTIONS

Although considered beneficial in some areas. abun-dant wild hogs usually are regarded as a significant lia-bility (Lucas 1977, Tisdell 1982). Federal and stateagricultural and environmental agencies and interest

groups consider wild hogs to be serious economic pestsand an undesirable exotic species that GILIS~S ecologi-

cal damage.In this species sebaceous b(Tlands do not function as

sweat glands. so hogs cannot cool themselves physio-logically. Therefore wild hqs need to w:dlow through-

out the year, especially during hot weather. Wallowingserves to reduce their body temperature and provides ;Iprotective coating of mud that functions to eitherexclude or immobilize ectoparasites. Wild hog wallowscan be fotknd in almost any type of low-lying. wet al-ea.and can be found in either isolated sites or in association

with bottomland drainages and streams (Conley et al.1972. Belden and Pelton 1975). Wallowing can degadewater quality of riparian streams. In the Appalachians,siltation and contamination of streams from rooting andwallowing are suspected of beins detrimental to thenative brook trout populations (Howe et al. 1981).

Another common activity of wild hogs is rubbing.This behavior involves an animal rubbing or scratchingagainst a tree trunk. post. or other stable vertical struc-ture. Rubs appear to provide comfort. remove excesstnud obtained during wallowing, and to mechanicallyrid the body of ectoparasites. However. not all rubbingis associated will1 mud wallows. Wild hogs also will rubagainst pines and creosoted telephone poles. whose pineresin or creosote seems to serve as a repellant for liceand ticks.

Rooting is the most obvious ;uxi widesprexl dnm-

age cat~ecl by wild hog in areas where these animalsoccur. Ho2 rooting is most often observed in the winterand e a r l y spriny m o n t h s w h e n o t h e r I’ood r‘eso~irces a r enot plentiful (Baron 1979). The location of wild hog

WILD HOGS 205

rooting in different habitat types appears to be related toseasonal movement, food availability, and reproductiveactivities (Belden and Pelton 1975). Excessive hogrooting can destabilize surface soils and increase soilerosion that can be particularly damaging to streamchannels, roads, rail beds (LLUXS 1977). Singer et al.(1982) found that rooting mixed the top two soil hori-zons and reduced ground vegetative cover and leaf lit-ter. In some areas, the entire herb understory wasremoved by rooting activity (Bratton 1977). Rootinghas also been shown to damage tree roots and increasethe amount of sprouting and root suckers (Huff 1977).Although claimed by some to benefit in forest regener-ation, disturbances caused by rooting may enable theestablishment of undesirable weed species in someareas. Extreme rooting by wild hogs can also influencenutrient cycling within the forest floor (Lacki andLancia 1983).

Wild hogs may negatively affect native plant com-munities (Wood and Barrett 1979), from both rootingand direct foraging. These animals have been an espe-cially difficult problem with respect to protecting frag-ile plant communities in high elevation ecosystems inthe Great Smoky Mountains National Park. Wild hogrooting reduces ground cover and negatively affectssome sensitive herbaceous species. Within the park,over 50 non-woody species are known to be eaten,uprooted, or trampled. Hog activities change plantspecies composition in favor of plants with deep orpoisonous roots (Bratton 1977). In contrast to otherstudies, Baron (1982) concluded that the feral hog root-ing and foraging did not disrupt a barrier island’s plantCommunities.

Wild hogs have long been known for their depreda-tions to both agricultural crops and forest plantations.The list of crops impacted by foraging wild hogsincludes corn, milo, rice, watermelons, peanuts. hay,turf, wheat and other grains. Wild hog-caused damageto these crops results from feeding and related tram-pling and rooting. Wild hogs on national wildliferefuges also damage crops specifically planted forwaterfowl (Thompson 1977). Wild hogs have been aProblem in their damage to pines (Wakely 1954). Theyroot uP and chew the roots of planted loblolly and slashPine seedlings, sometimes destroying entire pine‘egeneration areas (Lucas 1977). Wild hogs also feedOn the grass stage of longleaf pine, and chew on the lat-eral roots of mature pines (Conley et al. 1972. Lucas1977). They also root up and consume newly-plantedcherrybark and swamp chestnut oak seedlings, andProbably other hardwoods where available.

A number of vertebrate species are preyed on bythe omnivorous wild hog. Typically this predation isdirected at young animals and less mobile species, butthe effects on populations are unknown (Wood andBarrett 1979). Adult hogs can also be effective preda-tors of both domestic livestock and ungulate gamespecies. While hogs will readily prey on healthy new-born lambs, kids, calves, and fawns, it should also benoted that wild hogs will also attack, kill, and eat adultsheep and goats (Beach 1993). Wild hogs also oppor-tunistically prey on the eggs of ground-nesting birdspecies, such as the ruffed grouse, wild turkey, andnorthern bobwhite (Conley et al. 1972, Hanson andKarstad 1959, Stegeman 1938), particularly where wildhog densities are high (Henry 1969, Matchske 1965).Recent observations in eastern Texas suggest that highdensities of hogs may preclude wild turkey nesting suc-cess (J. Burk: pers. commu.). Wild hogs inhabiting thecoastal barrier islands of the southeastern United Stateshave also been found to be a significant predator ofboth the eggs and hatchlings of loggerhead and greensea turtles (Hanson and Karstad 1959, Thompson 1977,Baron 1982, Mayer and Brisbin 1995).

Although man is the most significant predator ofwild hogs in the United States (Sweeney and Sweeney1982), other species of wildlife prey on wild hogs.Documented predators of wild hogs include black bearand cougar for all age classes, and coyote and bobcatfor immature individuals (Stegeman 1938, Young1958, Conley et al. 1972). American alligators will alsoopportunistically prey on wild hogs (Shoop andRuckdeschel 1990).

One of the concerns about the introduced specieshas been competition with native species for availablefood, particularly mast. Acorns are a primary diet itemof wild hogs as well as several species of native south-ern wildlife, such as white-tailed deer, black bear, grayand fox squirrels, wild turkeys, and woodrats. Studieshave shown annual acorn production is highly variableand in some years is very low. It has been demonstrat-ed that low acorn production can negatively affect deeroverwinter survival and subsequent fawn survival(Rogers et al. 1990); and other species are probablynegatively affected as well. During these years of min-imal acorn production, wild hog consumption of acornsprobably negatively affects mast-consuming species inoak forests.

A general dietary overlap also suggests some com-petition between wild hogs and other species, such asrange cattle, striped skunks, common opossums, redand gray foxes, raccoons, bobcats, muskrats, nutria,

206 WILD HOGS

eastern cottontails, swamp rabbits, hawks, owls, andwaterfowl (Conley et al. 1972, Brutton 1974,Thompson 1977, Baron 1979).

C O N T R O L

Because wild hogs are very prolific and become warywith hunting pressure, once populations are establishedthey usually are difficult to control. To be effective.control efforts must be intensive and continuous (Woodet al. 1992). Control techniclues include fencing, snares,trapping, shooting, and hunting with trained dogs.Although inexpensive and widely used in Australia(Hone and Pedersen 1980), poisons or toxicants such asCompound 1080 or Warfarin for controlling wild hogshave not been approved for use in the United States(Littauer 1993).

A variety of fence designs have been described forrestricting wild hog access into crop fields and lambingpastures (Littauer 1993). Electric fence designs inAustralia have been shown to exclude hogs 94% of thetime (Hone and Atkinson 1983). Nonelectric fence mustbe of net wire or diamond mesh construction with aspacing of vertical wires of 6 inches or less to be hogproof (Hone and Atkinson 1983, Littauer 1993). In addi-tion, these fences must be at least 3 feet tall and buriedbeneath the ground at the bottom to be effective (Littauer1993). However, hog-proof fencing is difficult to erect

and maintain in uneven terrain (Littauer 1993), and gen-erally, is not economically feasible in most situations.

The use of snares can be effective in controllingwild hogs. For example, in the last decade over half ofthe wild hogs removed by the Texas Animal DamageControl Service were accounted l‘or by the use oi’snares.Snares consist of a loop of steel cable that is attached toa secure object so that the loop catches the hog as itpasses through ;I small area or opening. Snares for tak-ing wild hogs are typically placed over holes in fencesthat hogs have been using (Littauer 1993). Although ofrelatively low cost compared to other control methods,snaring has several disadvantages including the abilityto capture only one animal at a time, being inappropri-ate to use in some situations, the ability of very largehogs to occasionally break snares and escape, and thecapture of nontarget species (Littauer 1993). In addi-tion. the use of snares for controlling wild hogs in someareas has met with public opposition (Anderson andStone 1993).

Large cage or pen/corral traps can be a very effec-tive method for controlling wild hogs. Traps are avail-able or can be constructed in a variety of designs. Somedesigns are made of takedown panels that are easilymoved and set up. Trapping is usually more effectiveduring winter when food is in short supply, and beforespring green vegetation is available. Corn is one of themost common baits used for trapping wild hogs; soured

C o n t r o l l i n gis a frequeimethod is 1Mayer).

hog POi IUlin t p r obk trn.:rapF Qng /J:

ttionso n e

WILD HOGS 207

Hunting wild hogs with dogs is a popular activity and can be an effective control method (J. Mayer)

or mash corn has been found to be especially attractiveto hogs. The primary advantage of using traps is thatmore than one hog can be captured at a time (Belden andFrankenberger 1977, Littauer 1993). The drawbacks ofusing traps are: traps are cumbersome, require someeffort to set up, hogs can become trap shy, and trappinggenerally is less effective during summer months whenthere usually is ample food (Littauer 1993).

Shooting wild hogs can be a very useful controlmethod. This method can be carried out through pedes-trian, vehicular or aerial means, and typically useseither a high-powered rifle or shotgun. Opportunisticshooting of hogs on the ground is less expensive thanmost other means of control, but it is typically less suc-cessful in removing large numbers of animals (Fox andPelton 1977). In some situations large numbers of hogscan be removed through aerial shooting from a fixedwing aircraft or helicopter. but it is expensive (Littauer199.1). The primary advantage of shooting is the abilityto select specific target animals for removal.Disadvantages of shooting include both a potential forWounding ;lnimals and safety concerns associated withthe discharging of firearms in some areas.

The use of experienced hog dogs for removing wildhogs is an age-old technique that is still very effective.This control method also allows the hunter the option ofselecting individual animals, and of killing or carryingcaptured hogs out alive. An advantage of using traineddogs is that many hogs can be taken in a relatively shorttime. However, experienced hog dogs are very expen-sive and dog casualties from hunting hogs may be high(Littauer 1993).

H U N T I N G

Wild hog hunting is a popular pastime in many areas ofthe South. In some states (North Carolina, Tennessee,and West Virginia), they are considered game animalswith associated seasons and bag limits. However- inmost other states they can be hunted at all times of theyear on private land and can be taken in ways that areillegal for game animals (Mayer and Brisbin 199 I ). Wildhogs can be located by scouting for rootings. tracks,rubs, wallows. and scat. If not limited by state regula-tions. wild hogs may be still-hunted. stalked. huntedover bait such as corn, and hunted at night with lights.

208 WILD HOGS

A popular form of hunting in the South is with hogdogs. It is an exciting activity and has a dedicated fol-lowing. Dogs. such as Catahoulas or blackmouth curs,can function as both trail and bay dogs. Other breeds ofdogs. such as pit bulls or pit bull/cur crosses, are used tocatch and hold the hogs. Hogs are killed or caught,thrown and tied up after they have been bayed.Captured hogs often are held in pens to be fattened forlater consumption. In huntin,17 wild hogs with dogs, avariety of weapons are employed. including guns,bows. knives. and even spears.

In still hunting, standard centerfire rille calibers of,733 or larger that are adequate I‘or deer are normallyused. Sllotpm loaded with either l~~~cksliot or slrigs

may also be used for both still and drive hunts. Decausewild 1102s are often easier to stalk than white-tailed

Wild hogs can be located by wallows in the ground or rubs on trees(J. Mayer).

deer, many hunters in the South hunt hogs with eitherhandguns or archery gear. Hog hide and the subcuta-neous gristle pad on the shoulders and upper sides ofmature boars are thick and can be diff%zult to penetrate.

Care should be taken when dressing wild hogs toavoid infection with swine brucellosis. It is advisable towear disposable plastic or rubber gloves, to avoid directcontact with blood or reproductive organs (especiallythe uterus and uterine fluid from mature sows), and towash hands thoroughly when completed.

Feral hogs are very good to eat. The meat is tastyand has more natural fat than native game animals, suchas deer, but normally is not as fatty as domestic hogs.Care should be taken to fully cook the meat to kill anypossible pathogens.

CONCLUSION

Because of their trophy and table qualities, wild hogshave been introduced throughout much of the South.But there are substantial problems associated with theseanimals. Wild hogs may negatively impact naturalecosystems and vegetation. They compete with nativespecies for food when these forage resources are in lim-ited supply. They harbor diseases, which may be athreat to both man and domestic livestock. They are aproblem in a variety of Iand management activities.Populations of wild hogs are very difficult to controlonce they are established. Because of these problems, itis recommended not to introduce wild hogs into newareas, and to control populations where they and relatedproblems are excessive.