Skip to main content
U.S. flag

An official website of the United States government

December 11, 2020

Research ecologist Dr. Amy Yackel Adams was recently interviewed on the invasive tegu lizard for National Geographic and NPR’s Here & Now. 

During both interviews, Dr. Yackel Adams shared information on where tegus are currently found in the U.S. and where they’ll likely spread, as well as what impact tegus may have on their surrounding ecosystems.

Tegu lizard trap baited with chicken eggs
Image of a trap meant to capture tegu lizards, an invasive species spreading throughout the southestern U.S. The trap is baited using chicken eggs. 

The black and white tegu, native to South America, has been documented as living and breeding in three counties in Florida for the last decade. However, the lizards have recently been spotted and removed in South Carolina and Georgia. Tegus present a unique challenge to researchers and managers, due to their unusual resilience. These voracious omnivores can withstand cold temperatures and extensive hunting pressure in South America. Tegu diet includes fruits, vegetables, small animals, and the eggs of many species. Species that are at high risk are those with threatened status such as gopher turtles and Eastern indigo snakes.

While tegus are having a moment in the spotlight, they’ve been a species of interest at USGS for more than a decade. Collaborative tegu research conducted by USGS, National Park Service, and University of Florida focuses on understanding the species to create effective management plans. In 2018, Fort Collins Science Center (FORT) scientists used species distribution models to predict suitable habitats in the U.S. (Jarnevich et al. 2018). These models suggest that much of the southern United States and northern México contain suitable habitat for tegus. So far, FORT scientists and partners, including Georgia Southern University and Georgia Department of Natural Resources, have also documented an incipient population of tegus in Georgia (Haro et al. 2020).

In addition to understanding where tegus may find suitable habitat, ecologists at the Fort Collins Science Center have contributed to research on tegu behavior and movement. Brumation, or reptile hibernation, is a largely unstudied area of tegu behavioral ecology. Three FORT-based studies have monitored brumation of black and white tegus in southern Florida (McEachern et al. 2015, Currylow et al., accepted at Ecosphere pending minor revisions) and Alabama (Goetz et al., in press at PLOS ONE). A FORT-based 2015 study by Klug et al. documented the use of tree and shrub habitat preferences and activity ranges that varied from 3.8 to 58.6 hectares. These studies provide a basis for future research, and could aid in management and control plans.  


Read Dr. Yackel Adams’ interview in National Geographic at “This dog-size lizard is spreading through the southeastern U.S."  

Listen to Dr. Yackel Adams on Here & Now at “Invasive Tegu Lizards Are Eating Their Way Through Southeastern US.”  

Get Our News

These items are in the RSS feed format (Really Simple Syndication) based on categories such as topics, locations, and more. You can install and RSS reader browser extension, software, or use a third-party service to receive immediate news updates depending on the feed that you have added. If you click the feed links below, they may look strange because they are simply XML code. An RSS reader can easily read this code and push out a notification to you when something new is posted to our site.