Invasive wild pig (Sus scrofa) diets on barrier islands in the southeastern United States.

BACKGROUND: Biological invasions are a leading cause of reductions in global biodiversity. Islands are particularly sensitive to invasions, which often result in cascading impacts throughout island communities. Wild pigs (Sus scrofa) are globally invasive and pose threats to numerous taxa and ecosystems, particularly for islands where they have contributed to declines of many endemic species. However, the impacts of wild pig diet on the flora and fauna remain understudied in many island systems.

RESULTS: We used DNA metabarcoding of wild pig fecal samples to quantify the seasonal diet composition of wild pigs on three barrier islands in the southeastern USA. Wild pigs exhibited a diverse diet dominated by plants but also including marine and terrestrial animals. The diet composition of plants varied seasonally and between islands. Consumption of invertebrates also changed seasonally, with a shift to coastal invertebrates, particularly crabs, in spring and summer. Vertebrates were found in <10% of samples, but spanned broad taxa including amphibians, fish, mammals, and reptiles. Species consumed by wild pigs indicate wild pigs use a variety of habitats within barrier islands for foraging, including maritime forests, saltmarshes, and beaches.

CONCLUSIONS: An observed shift to beach foraging during sea turtle nesting season suggests wild pigs have potential to hinder nesting success on islands without established management programs. These findings provide insight into the diverse diets of wild pigs on barrier islands and highlight the need for removal of wild pigs from sensitive island ecosystems due to their potential impacts to native plant and animal communities. This article is protected by copyright. All rights reserved.