Diet of the Invasive Argentine Black and White Tegu in Central Florida

Abstract

Salvator merianae (Argentine Black and White Tegu, hereafter also ABWT) is a large bodied, omnivorous lizard native to South America. In Florida, where the species was introduced via the pet trade and is invasive, there are at least 3 established populations as well as numerous one-off observations. We collected ABWTs from public and private property to determine their diet in central Florida (Hillsborough County) from 2012 to 2016. We determined frequency of occurrence (FO) for items identified to various taxonomic levels, calculated niche overlap to check for an ontogenetic shift in diet, and evaluated seasonal variation in diet. Stomach contents revealed ABWTs (n = 93) in central Florida consume fruit, invertebrates, and vertebrates, including hatchling Gopherus polyphemus (Gopher Tortoise). Frequency of occurrence of food items varied seasonally. Vertebrate prey was most common in the spring, whereas invertebrates and plants were consumed most frequently in summer. Diets among ABWTs were very similar, as indicated by Pianka's measure of niche overlap, regardless of age or sex. A greater proportion of ABWTs in central Florida consumed vertebrates compared to other invasive and native populations (FOcentralFL = 81%, FOsouthernFL= 37%, FOBrazil = 27%, FOArgentina = 44%). Argentice Black and White Tegus in central Florida are generalist omnivores and consume a diversity of taxa across several trophic levels, including imperiled species.