1 The Eradication and Prevention of Feral Swine in Pennsylvania Comments and recommendations prepared for the Pennsylvania Game Commission by the Western Pennsylvania Conservancy January, 2008 I. Background Feral swine (also known as wild hogs, wild boars, feral hogs or feral pigs) is an injurious invasive species that has recently been introduced in Pennsylvania and has serious potential to become permanently established. Although the same species as the domesticated agricultural swine (Sus scrofa), the invasive form is often an entirely wild, undomesticated strain imported from Europe or Asia, and which can weigh up to 400 lbs. Hybrids of wild and domesticated swine exist, and thus the focus is on free-roaming uncontrolled swine in general and on wild strains imported for sport shooting at enclosed facilities. Invasive feral swine is a problem in many areas across the nation, and while some 25 states have established populations, Pennsylvania is one of 16 new states where introduction is more recent and may still be countered. Feral swine is recognized as one of the most serious and damaging invasive species by many sources, and it impacts both natural resources and other human interests (World Conservation Union 2007). Impacts Wildlife and Habitats Numerous studies (Sweitzer and Van Vuren 2002, Mayer and Brisbin 1991, Lipscomb 1990, Wood and Lynn 1977, Lucas 1977, Springer 1977, Wood and Brenneman 1977) address the impact of feral swine on wild ecosystems. Feral swine are efficient and adaptable, eating almost any plant or animal for food and are able to live in a wild range of habitats, so long as water is available. Their behavior includes rooting and digging through the soil for food. Food items include roots, tubers, stems, leaves, fruit, nuts, bark, bird eggs and small (salamanders, snakes, mice) to medium (fawn deer) animals. In addition to eating some wildlife, feral swine also compete for wildlife foods, for example, mast crops (acorns, etc.). Feral swine wallowing impacts small streams, wetlands and riparian areas, destroying habitat and creating sedimentation. Invasive plants benefit and expand into areas where swine have disturbed habitats. Thirty diseases can be carried by feral swine, some of which are transferable to wildlife. There are no significant feral swine predators. In addition, feral swine also have a detrimental impact on many native game species, such as ruffed grouse, wild turkey and white-tailed deer. Their presence also adds another threat to the viability of rare and endangered species (Mapston 2004). Agriculture and Forest Products Feral swine are of great concern to agricultural industries with damage estimated to be more than $800 million per year (Pimental et al. 2000). Oregon determined that 35 top agricultural crops could potentially incur damage from feral swine (Rouhe and Sytsma 2007). Agricultural damage includes direct crop loss as well as transmission of diseases. Certain diseases known to be carried by feral swine (e.g. pseudorabies, swine brucellosis, foot and mouth disease) can require the sacrifice of entire domesticated swine herds if an infected animal is detected. Feral boars will also invade domestic herds to breed with sows. Forest regeneration and the establishment of tree plantations may also be potentially impacted by swine by the consumption of seeds and seedlings, and exposure of tree roots during rooting and wallowing.2 Health and Human Safety Several of the diseases feral swine can carry are transmittable to humans. Feral swine were recently implicated in a 2006 California Escherichia coli outbreak resulting in three deaths and 200 people inflicted. Feral swine-related automobile collisions in USA in one year recently totaled 35 million dollars (Mayer 2007). Some states now install feral swine crossing signs on problem roads. As feral swine have increased in some states, homeowners complain about damage to lawns and gardens. Other states Pennsylvania is not alone in the recent concern over invasion of feral swine into northern states. Other states include Maryland, Ohio, Michigan, Wisconsin, Nebraska, Kansas, Missouri and Oregon. Examples of some actions underway: Michigan stakeholders are regrouping given their initial reaction was limited and inadequate, and feral swine have quickly spread. Wisconsin will pass 2008 legislation listing feral swine as a prohibited animal. Nebraska has outlawed possessing feral swine and shooting feral swine. Kansas has outlawed possessing feral swine and shooting feral swine. Missouri is assessing options and might follow NE and KS. Oregon has developed an action plan, with the intent of eradication (Rouhe and Sytsma 2007). In several southern states, feral swine have become established with no hope of eradication, and in some areas great efforts to control damage is undertaken each year. There are 2 million feral swine in Texas covering most of the state (Mapston 2004). In some national parks (Great Smoky Mountains-TN/NC, Congaree-SC) long term programs are underway to reduce impacts. II. Current Situation in PA Pennsylvania has experienced some free-roaming swine since at least the mid-1990’s, but the records were only occasional until 2002. As of 2007, U.S. Department of Agriculture Animal and Plant Health Inspection Service has gathered evidence that feral swine have established breeding populations in five counties (Bedford, Bradford, Butler, Indiana, Cambria). Breeding populations are also likely in two others (Crawford, Tioga). The status of feral swine in three more counties is unclear (Erie, Somerset, Wyoming) (H. Glass, personal communication, 8 Jan 2008). Sources of feral swine in Pennsylvania are: 1) escapes from shooting preserves 2) intentional releases by swine hunters (presently illegal) 3) domesticated swine that escape enclosure and mingle with feral swine Shooting Preserves Many of the records of feral swine come from areas near shooting preserves. These facilities buy swine (usually wild boars) for paid hunting. Experts state that fencing will not contain swine and escapes are inevitable (Mayer 2007). APHIS reports at least one preserve operator maintaining escaped swine on adjacent leased land. In some other states, swine are now outlawed for use in these businesses. Swine Hunting Culture In some southern states, hunting feral swine is considered a cultural heritage right. If this attitude develops in Pennsylvania, the eradication and