Feral swine management for conservation of an imperiled wetland habitat: Florida’s vanishing seepage slopes

Only 1% of the original extent of Florida’s seepage slope habitat remains, with Eglin Air Force Base containing some of the largest tracts. Feral swine damage is one of the greatest threats to this wetland habitat. We conducted a multi-year study to evaluate the impacts of sport hunting and supplemental swine removal on damage to seepage slopes. Prior to initiation of removal in 2003, swine damage to seepage slopes in the portion of the base closed to hunting averaged 25.0%, over twice the 10.9% losses in the portion open to hunting. After less than one year of supplemental removal, damage in the closed-to-hunting area dropped to 7.2%. Although supplemental removal was not applied in the open hunting area, damage dropped significantly to 5.6%, statistically indistinguishable from the swine-controlled (closed) portion. After another year of removal, average damage in the closed hunting area dropped further to 5.6%, while the open hunting area dropped to 4.3%, again statistically indistinguishable. Even though removal was only applied to the area closed to hunting, it also produced damage reductions in the open hunting area, as swine were free to move among areas. Declines in damage following implementation of removal corresponded with large drops in swine population indices for the base. Economic valuations of seepage slope damage losses demonstrated substantial benefit-cost ratios for application of removal. Prior to removal, the combined value of swine damage to seepage slopes in areas open and closed to hunting was estimated at $5.3 million. After only 1.7 years of removal, the value of damage losses was reduced by nearly $4 million to $1.5 million. The benefit-cost ratio over the 1.7 years of removal was an impressive 27.5. Moreover, the economic benefits of removal exceeded the costs 55.2-fold for the first year, when management impact would be greatest.