Invasive Tegu Lizards Are Eating Their Way Through Southeastern US

Published December 3, 2020 at 12:52 PM CST

A black and white Argentine Tegu lizard sticks out its tongue at the Yebo Gogga exhibition at the University of the Witwatersrand in Johannesburg on May 13, 2015. (Denis Farrell/AP)

An invasive species of giant lizards are cropping up in the southeastern United States.

The Argentine black-and-white tegu is a stout lizard native to South America. Populations are now established in Florida, and researchers are finding more populations in Georgia, says Amy Yackel Adams, a research ecologist with the U.S. Geological Survey.

The resilient species has been known to resist removal efforts and has some state wildlife departments worried.

When these lizards have enough resources, they can get pretty large, Yackel Adams says — but the tegus found in Georgia are less than 2 feet long on average from the snout to the tail tip.

Hundreds of tegus already live in Florida, but this summer was the first that multiple U.S. states reported tegu lizard sightings. In Georgia, 30 documented tegus have been removed from the wild. Eight tegus were removed from the wild in South Carolina this past summer, she says.

How did this invasive species make its way to the U.S.? Some Americans raise tegus for the pet trade, and those animals are being intentionally or accidentally released into the environment, Yackel Adams says.

Yackel Adams, along with a team of scientists, created models in 2018 that determined all of Mexico and the southern portion of the U.S. could be a suitable habitat for tegus, and “if they are released, they could take a foothold,” she says. But she notes, those geographical boundaries could change as climatic conditions change.

In Georgia, scientists and wildlife departments are currently very concerned about tegus’ threat to other protected species, as well as ground-nesting birds like quails and wild turkeys.

“They’re omnivores, and they will eat a variety of plants and animals, and so they pose a risk to native species, especially native species that are already under protected status — something like the gopher tortoise in Georgia that then becomes at risk of displacement,” Yackel Adams says. “The tegus are very good predators and they have been documented eating all sorts of prey, from toads to crayfish to beetles to invertebrates.”

Tegus pose no significant risk to humans, though they can bite, Yackel Adams says. It’s also nearly impossible to catch a wild tegu because they’re fast runners.

States with tegu populations are encouraging citizens to report any sightings of the lizards so that state agents can be dispatched to place traps and remove them from the wild. The Georgia Department Of Natural Resources has provided guidelines for farmers and hunters.

“In their native range, tegus are hunted rather heavily for their leather and they can withstand really substantial harvests and still persist,” Yackel Adams says. “That is what has a lot of state agencies alarmed, is that there’s such population resilience in the face of really substantial removal efforts of this species.”

Chris Bentley produced and edited this interview for broadcast with Tinku Ray. Elie Levine adapted it for the web.

This article was originally published on WBUR.org.