Feral pigs (Sus scrofa) have caused considerable damage where they have been introduced around the world. At Pinnacles National Monument, California, USA, managers were concerned that feral pigs were damaging wetland habitats, reducing oak regeneration, competing with native wildlife, and dispersing nonnative plant species through soil disturbance. To address these threats the National Park Service constructed an exclosure around 57 km2 of monument land and through cooperation with the Institute for Wildlife Studies eradicated all feral pigs within the area. Trapping, ground‐hunting, hunting dogs, and Judas techniques were used to remove feral pigs. Trapping techniques removed most pigs, but a combination of techniques was required to cause eradication. A series of bait sites and transects across the monument helped focus removal efforts and facilitated detection of the last remaining feral pigs in the exclosure. Consistent funding and cooperation from the National Park Service allowed for a seamless and comprehensive program that provided intensive removal of feral pigs. The successful eradication of feral pigs at Pinnacles National Monument should encourage managers in other areas to implement future control or eradication programs.

Our objective was to identify and evaluate mitochondrial diversity of wild pigs in the United States (U.S.). We obtained tissue samples from 81 individual pigs in 30 U.S. states and amplified a 403 base‐pair region of mitochondrial DNA. We then downloaded overlapping sequences (n = 904) from public repositories to create a global reference. We used parsimony and Bayesian techniques to evaluate phylogenetic relationships, and we used origins of published sequences from Eurasian wild boar to establish a phylogeographic reference. We then compared gene and nucleotide diversity measures for introduced pigs in North America with those of domestic swine, Eurasian wild boar, and feral pigs within broad‐scale geographic groupings. We identified 15 haplotypes for introduced pigs, representing wild and domestic animals from >30 countries spanning the indigenous range of S. scrofa. Mitochondrial diversity measures and phylogenetic relationships indicated a strong association between introduced pigs and European domestic breeds, reflecting the known history of human colonization, trade, and settlement in the United States. Based on the geographic distribution of haplotypes in North America, we found that range expansion is a product of translocation from historical populations and introduction from new genetic sources. Finally, haplotype network analyses provided evidence of past demographic expansions within lineages, contributing to observed mtDNA variation among introduced pigs in North America. © 2014 The Wildlife Society.

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Wildlife and humans are increasingly competing for resources worldwide, and a diverse, innovative, and effective set of management tools is needed. Controlling abundance of wildlife species that are simultaneously protected, abundant, competitive for resources, and in conflict with some stakeholders but beloved by others, is a daunting challenge. Free-ranging horses (Equus caballus) present such a conundrum and managers struggle for effective tools for regulating their abundance. Controlling reproduction of female horses presents a potential alternative. During 2009–2017, we determined the long-term effectiveness of GnRH vaccine (GonaCon-Equine) both as a single immunization and subsequent reimmunization on reproduction and side effects in free-ranging horses. At a scheduled management roundup in 2009, we randomly assigned 57 adult mares to either a GonaCon-Equine treatment group (n = 29) or a saline control group (n = 28). In a second roundup in 2013, we administered a booster vaccination to these same mares. We used annual ground observations to estimate foaling proportions, social behaviors, body condition, and injection site reactions. We found this vaccine to be safe for pregnant females and neonates, with no overt deleterious behavioral side effects during the breeding season. The proportion of treated mares that foaled following a single vaccination was lower than that for control mares for the second (P = 0.03) and third (P = 0.08) post-treatment foaling seasons but was similar (P = 0.67) to untreated mares for the fourth season, demonstrating reversibility of the primary vaccine treatment. After two vaccinations, however, the proportion of females giving birth was lower (P <0.001) than that for control mares for three consecutive years and ranged from 0.0–0.16. The only detectable adverse side effect of vaccination was intramuscular swelling at the vaccination site. Regardless of vaccine treatment (primary/secondary), approximately 62% (34/55) of immunized mares revealed a visible reaction at the vaccine injection site. However, none of these mares displayed any evidence of lameness, altered gait or abnormal range of movement throughout the 8 years they were observed in this study. Our research suggests that practical application of this vaccine in feral horses will require an initial inoculation that may provide only modest suppression of fertility followed by reimmunization that together could result in greater reduction in population growth rates over time.