Evidence for an Established Population of Tegu Lizards (Salvator merianae) in Southeastern Georgia, USA

Daniel Haro^1,*, Lance D. McBrayer¹, John B. Jensen², James M. Gillis³, Lea’ R. Bonewell⁴, Melia G. Nafus⁴, Stephen E. Greiman¹, Robert N. Reed⁴, and Amy A. Yackel Adams⁴

¹Georgia Southern University, Department of Biology, 4324 Old Register Road, Statesboro, GA 30458. ²Conservation Matters, LLC, P.O. Box 662, Monticello, GA 31064. ³1147 Say Road, Santa Paula, CA 93060. ⁴US Geological Survey, Fort Collins Science Center, 2150 Centre Avenue, Building C, Fort Collins, CO 80526. *Corresponding author.

Southeastern Naturalist,Volume 19, Issue 4 (2020): 649–662

Abstract
Documenting emergence of invasive species in new areas is vital to understanding spatiotemporal patterns of invasions, propagule pressure, and the risk of establishment. Salvator merianae (Argentine Black and White Tegu) has established multiple unconnected populations in southern and central Florida, and additional sightings have been reported elsewhere in the state. In 2018, land managers in Georgia received >20 reports of this species in the wild. To evaluate the probability of establishment, we assembled verified records of the non-native Argentine Black and White Tegu in Georgia over the past 9 years. We report on 47 tegu observations throughout Georgia, with a concentration of sightings (n = 38) in Toombs and Tattnall counties. In 2019, we used modified Havahart® traps and captured adult male and female tegus at 1 of our 3 locations during 3085 corrected trap nights. While we did not find evidence of a well-established population (i.e., varied size structure of tegus captured) with our limited trapping effort, we suspect Argentine Black and White Tegus are breeding in Toombs and Tattnall counties due to the concentration of captures and reports of adult males and females, the consistent reports of adults across years, the confirmed presence of the species in 2018, 2019, and 2020, and the reproductive capacity (i.e., turgid testes and secondary follicles) of individuals captured. Ongoing introductions of tegus from captivity are likely to maintain high propagule pressure in the southeastern United States. Effective early detection, funded rapid response networks, and public outreach to solicit reports of sightings of Argentine Black and White Tegus are critical to prevent establishment and associated ecological impacts of this invasive species elsewhere in the southeastern US.

Download Full-text pdf (Accessible only to subscribers. To subscribe click here.)