Movement responses inform effectiveness and consequences of baiting wild pigs for population control

Abstract

Wild pigs (Sus scrofa) damage agricultural and natural resources throughout their nearly global distribution. Subsequently, population control activities (e.g., trapping, shooting, or toxic baiting) frequently involve the deployment of bait to attract wild pigs. A better understanding of how wild pigs respond to bait sites can help maximize efficiency of baiting programs and identify any potential pitfalls. We examined the movement behaviors of 68 wild pigs during three stages of intensive baiting programs (i.e., 15 days each: prior, during, and post baiting) spread across two distinct study areas in southern and northern Texas, USA. We found that bait sites needed to be within1 km of where females were located (1.25 km for males) to achieve ≥0.50 daily visitation rate. Deployment of bait increased movement distances and erratic movements for both sexes, but did not influence their foraging search area. Home range sizes increased and shifted during baiting, especially for wild pigs on the periphery of the baiting area. After baiting ceased, wild pigs moved away from bait sites and began using new space (i.e., less overlap with previously used home ranges), suggesting that baiting could facilitate the spread of wild pigs. We recommend that baiting programs should be coordinated to reduce the number of wild pigs left on the landscape following baiting. Bait sites should be spaced every 1–2 km, and should be actively relocated if visitation by wild pigs is not consistent. Uncoordinated and passive baiting for recreational hunting and trapping likely exacerbates the negative consequences of baiting identified in this study, such as expanding the space-use and facilitating the spread of wild pigs.