Lance McBrayer, Ph.D., a professor in the biology department at Georgia Southern has been studying the Argentine black and white tegu lizard for over 10 years.
As the name suggests, originally from South America, Argentine tegus’ popularity has risen exponentially in the past 20 years because of human interaction and the attraction for them as common household pets.
As an adult ,the tegus can grow to over four feet and can be compared in size to a small dog as their owners have put them on leashes.
Prior to the foreign lizard being recently found in its early stages of environmental invasion in the Georgia and more recently South Carolina, it was only found in Florida where eradication efforts have failed.
McBrayer, along with his student researchers , have been studying the tegus since the spring of 2020 and have since caught around two dozen tegus .
The researchers observe the argentine native species in what he calls natural experiments where he explores the environmental parameters of the tegus by researching them in the field, where the lizards actually live.
“With much of my work we look at the interaction between that ,” said McBrayer.
“Let’s say the sandy substrate versus the amount of leaf litter , the amount of closed canopy where there’s no sunlight versus open sun, how do those types of environmental parameters affect what that lizard does on a day to day basis.”
Since 2019, McBrayer has worked in collaboration with the United States Geological Survey along with the Department of Natural Resources and Georgia Southern to capture and remove argentine tegus from the environment.
Researching these tegus in the field, where the lizards actually live, is normally difficult according to McBrayer.
The tegus can perform well in the American Southeast because its location is at the same latitude of their native range and the lack of cold temperatures in the places like Georgia or Florida makes for a suitable environment to them.
Though an adaptable pet to human life and a docile, poor human care and an introduction to an unfamiliar environment have caused concerns to rise of if these foreign lizards can have a negative effect on the native wildlife around them.
“Tegus threaten native wildlife since they eat a wide variety of things, ” said Jada Daniels ,a graduate biology researcher and student of McBrayer.
Since the tegus are in the early stages of invasion researchers hope to keep the numbers of the species down by capturing, studying them, and preventing them from breeding and killing already endangered species in Georgia .
“They’ll pray on the eggs of ground nesting birds like quail and turkey and other wildlife such as gopher tortoises and alligator , so this new predator that the native wildlife is not adapted to can be catastrophic.”
Daniels has aided McBrayer in the focus and the early detection of these invasive lizards and facing the issue of eradicating of the species before its population becomes established in Georgia.
“ This animal has a really good smelling tongue,” said McBrayer. “ They find the nests with their tongues and eat the eggs.”
The run-ins with these tegus, whose weight can reach up to 10 pounds, have been primarily found in two rural counties in Georgia, Tattnall and Toombs , though few reports have been found in other places of the state.
The student researchers apart of this research studying the population of tegus and trapping them are paid through a grant from the USGS called the Evaluation of Status of Tegu Population in Southern Georgia.
Michael Brennan, senior biology major at Georgia Southern University, is another one of the student researcher McBrayer advises through the grant.
"Fortunately, capturing tegus is rare, we hope this means they aren’t abundant, " said Brennan .
"We have a standard method of conducting a necropsy to gather gut contents to assess diet and parasite loads as well as collect tissue samples for genetics analysis on top of many other data points like weight, length, sex, reproductive stage et cetera. This can be used to answer many questions about how they live here. "
The $45,000 grant allows students like Jada and Michael to conduct research at sites where the lizards have been seen and remove the tegus from the environment for further exploration.
According to McBrayer, one of the hardships of the research on Tegus by Georgia Southern is having the money to pay students and to get to field sites.
Another hardship in their research would be the weather because of how researchers conducted their sampling in the field.