GREAT SMOKY MOUNTAINS Status of the European Wild Boar Project Management Report No. 6

Elimination or control of the exotic wild boar is outlined by the policies for natural area management if it can be done by methods which preserve wilderness qualities. Additional reasons for control effort include: 1) damage to native vegetation, 2) increased soil erosion. Potential, but as yet unverified, effects of the exotic boar include: 1) competition with other species, 2) overexploitation of native amphibians and reptiles, 3) alteration of water quality through rooting and wallowing in or near streams, and 4) disruption of successional relations and the timing and sequence of energy flow.

Vegetation effects in high-elevation beech gaps is described by Bratton (1974) and include: 1) low species counts and low cover of herbs in plots with the longest history of rooting, 2) reduction of herbaceous ground cover to 5 percent of the expected undisturbed value, 3) incidental damage to nearby plants from being turned out of the soil to dry or by being plowed under, and 4) frequent heavy disturbance to a plant community composed of perennials adapted to a normally stable environment ,i.e. , with low reproductive potential. The severe reduction in cover and disturbance of the leaf litter was accompanied by surface soil erosion.

Bratton (1974) also speculated on other effects of boar upon the ecosystem. These effects included: 1) reduction of individual plant populations, 2) damage to tree roots and seedlings, 3) damage to grass balds, 4) soil erosion, 5) predation on native animals and 6) competition with native species. Any effects in these areas are undesirable since the boar is an exotic species. There is little data, however, to substantiate any major effects. Research on damage to tree roots and seedlings (Mark Huff, M.Sc., Duke University) and on soil mixing by rooting, is under way. S. P. Bratton and J. R. Buchanan (pers. corres.) feel that white-tailed deer may avoid wild boar trails. Dearden and Cherry (1974) ran simulations of animal diets and found that the boar potentially could compete for certain foods, particularly acorns, with a number of animals. Competition is only hypothesis, however, until the habitat relationships, interspecific associations, timing and sequence of feeding, and the supply of the forage in question is determined. J. Claybo (pers. corres.) feels that rattlesnakes have declined in the past 20 years in the southwestern corner of the park due to overexploitation by boar. John L. Boaze (pers. corres. to Superintendent, Great Smoky Mountains National Park, July 1, 1970) reported that extensive rooting by hogs along Meigs Creek was causing increased silt loads in the stream and damage to the stream as brook trout habitat. In addition, rooting and wallowing damage to watersheds has been suspected by the observations of many other people.