U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version

May 2005


Swine adversely affect the environment in most places around the world where they have been introduced into the wild. In many of those places swine removal is key to protection of a variety of special habitats, wetlands in particular. We have pursued several avenues of research and technique development to enhance swine removal efforts, primarily in Florida. An easily-applied passive tracking index (PTI) with good statistical properties has been effective for monitoring swine distribution and relative abundance, thus aiding the location of control method applications and the evaluation of control results. A quadrat sampiing methodology used in conjunction with the PTI population surveys was developed to estimate the amount of habitat damaged by swine in an area. Another method employs a series of transects specially developed to efficiently estimate damage to the exposed portions of the last remnant of a formerly extensive basin marsh system in Florida. Besides estimating damage levels, we developed credible means for monetarily estimating the value of the damage based on the dollar amounts that wetland regulators have allowed permit applicants to spend in mitigation attempts to replace lost wetland resources. Estimation of damage levels and their associated economic values before and after swine control permitted economic analyses of the removal efforts. Universally, the economic analyses demonstrated enormous benefit cost ratios for swine removal, as well as large values per swine removed.