Modeling the distributions of tegu lizards in native and potential invasive ranges

Catherine S Jarnevich,Mark A Hayes,Amy A Yackel Adams,Bryan G Falk,Lea’ R Bonewell,Page E Klug,Lee A Fitzgerald,Michelle A M Collier,Robert N Reed,Sergio Naretto

doi:10.1038/s41598-018-28468-w

Abstract

Invasive reptilian predators can have substantial impacts on native species and ecosystems. Tegu lizards are widely distributed in South America east of the Andes, and are popular in the international live animal trade. Two species are established in Florida (U.S.A.) - Salvator merianae (Argentine black and white tegu) and Tupinambis teguixin sensu lato (gold tegu) – and a third has been recorded there— S. rufescens (red tegu). We built species distribution models (SDMs) using 5 approaches (logistic regression, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy) based on data from the native ranges. We then projected these models to North America to develop hypotheses for potential tegu distributions. Our results suggest that much of the southern United States and northern México probably contains suitable habitat for one or more of these tegu species. Salvator rufescens had higher habitat suitability in semi-arid areas, whereas S. merianae and T. teguixin had higher habitat suitability in more mesic areas. We propose that Florida is not the only state where these taxa could become established, and that early detection and rapid response programs targeting tegu lizards in potentially suitable habitat elsewhere in North America could help prevent establishment and abate negative impacts on native ecosystems.

Highlights

The impacts of invasive predators on native biodiversity are increasingly acute and recognized as principal drivers of biodiversity loss[1]
Salvator merianae populations appear to be expanding in Florida, and ongoing programs are aimed at understanding and confronting the conservation challenges of eradicating and controlling S. merianae[17]
This would be informative because we do not know whether the distributional boundaries between the species in South America are due to purely physiological responses to environmental conditions, or are based on historical biogeography and/or biotic interactions

Summary

Introduction

The impacts of invasive predators on native biodiversity are increasingly acute and recognized as principal drivers of biodiversity loss[1]. Our first goal was to model and map the native-range distributions of the 3 large-bodied tegu species that have been documented in Florida. We used a suite of five species distribution models (SDMs) based on presumed biologically meaningful input variables to create maps of potentially suitable habitat for these species in South America. The second goal was to project these native range models of potentially suitable habitat for tegus into North America, providing the ability to assess relative invasion risk for each species and for tegus overall.

Methods

Results

Conclusion