| Since early 2012, there has been a steady and dramatic increase in feral swine (Sus scrofa) activity in Southeast Missouri, notably on Mingo National Wildlife Refuge. Feral swine have an adverse effect on any environment in which they have been introduced. In these environments, one or more methods of feral swine control must be implemented in order to protect delicate habitats from complete degradation and/or destruction. This project represents an extension of an earlier baseline study of seasonal habitat use by feral swine, which used camera trap stations across the refuge. Control techniques were then employed in an effort to test the efficacy of 3 commonly used feral swine removal techniques (trapping, snaring, and shooting) and management plans for ongoing swine control were developed. These plans called for targeting specific groups within the population to reduce the numbers of feral swine. These groups were the younger age classes, and more specifically, females within those age classes. I established baited camera trap sites across the refuge in areas with extensive swine sign, and monitored these sites for activity. When activity was detected, traps or snares were deployed. I tabulated numbers of swine removed via traps, snares, and shooting over a period of 115 weeks, and used these data in an autoregression time series analysis to assess the effectiveness of each method. I then used estimates of effort and cost to assess the relative cost effectiveness of each method. The results suggest that specific trapping methods are the most effective, and also the most cost effective. At the same time, some control methods may reduce the effectiveness of trapping efforts, and other activities on the refuge may reduce the effectiveness of efforts to control feral swine populations on Mingo National Wildlife Refuge. |
