Wild pigs negatively impact water quality: Implications for land and watershed management

Authors: Josh Helcel, Forrest Cobb, Dr. James Cathey

Growing populations of wild pigs (Sus scrofa) pose a challenge to both landowners and wildlife managers by threatening crop and livestock production, as well as native wildlife and their habitat. While these concerns are commonly known, the impacts of wild pigs on water quality are less apparent. Introduced to North America in the 1500s as a reliable food source by early European settlers, free-ranging domestic pigs established initial feral populations. Later, the Eurasian wild boar was released primarily onto hunting preserves in the early 1900s, but they escaped to hybridize with free-ranging pig populations. Intentional (illegal) and accidental releases since have further contributed to wide-ranging and growing wild pig populations. In Texas, these animals are classified as free-ranging exotic livestock and regulatory authority falls primarily under the jurisdiction of the Texas Animal Health Commission, who established rules regarding their transportation and release.

Today, wild pigs occur in 3 varieties: feral hogs (those originating of domestic stock), Eurasian boar, and domestic-Eurasian hybrids. As of 2016, the National Feral Swine Mapping System (NFSMS) in collaboration with state natural resource agencies and the U.S. Department of Agriculture, Animal and Plant Health Inspection Service (USDA-APHIS) reported that wild pigs occurred in at least 36 of 50 states including Hawaii5 (Figure 1). In 2007, the estimated economic toll of these animals in the U.S. exceeded $1.5 billion30; an economic impact likely to be much larger today.