Florida has become home to a new invasive species over the last decade: the black-and-white tegu (Salvator merianae), a large, omnivorous lizard species originating from South America.
While sightings in Polk County remain relatively rare, breeding populations have established themselves in nearby Hillsborough County, Miami-Dade, Charlotte County, and recently – an emerging population was found in St. Lucie County.
Adults have few predators and can give birth to large numbers of offspring per year, increasing the risk of populations spreading beyond their established ranges and impacting surrounding areas. Tegus are continuing to be seen in the Southeast, with reports of them reaching as far as the Carolinas.
Tegus’ adaptability—including their ability to brumate (a form of reptilian hibernation)—gives them a unique advantage in surviving Florida’s occasional winter chills. As they spread, concerns have grown about the ecological impact of this invasive lizard, particularly in regard to its interactions with native and endangered species.
In April of 2021, Tegus (all species within genera Salvator and Tupinambis) were added to Florida’s Prohibited species list. Below, we’ll explore the tegu’s biology, habitat, and its impact on local wildlife, as well as what Polk County residents can do to help.
DIET AND FEEDING HABITS
The Argentine black-and-white tegu is an opportunistic omnivore, which means it can consume a wide variety of foods depending on availability. If they can catch it, or fit it in their mouth, they are likely going to try eating it. Tegus are known to eat:
• Fruits and Vegetables: Tegus have a particular liking for berries, figs, and other fruits they can forage from the ground or lowhanging plants.
• Insects and Small Invertebrates: They feed on insects, worms, and other small invertebrates, which makes them direct competitors with native insectivores.
• Eggs: Tegus are adept at finding and consuming eggs, especially those of ground-nesting birds and reptiles. This poses a significant threat to native and endangered species in Polk County, including the gopher tortoise and certain groundnesting birds.
• Small Animals: Tegus have been observed preying on small mammals, amphibians, and other reptiles, which further adds to their impact on the ecosystem.
This varied diet, combined with their ability to adapt to new food sources, allows tegus to survive in a range of habitats and significantly impacts Florida’s native species.
ECOLOGICAL IMPACT ON NATIVE AND ENDANGERED SPECIES
The spread of tegus in Polk County presents multiple ecological risks. Their diet includes the eggs of ground-nesting species’ eggs, putting native and endangered animals at high risk. They have been documented eating alligator eggs and gopher tortoise hatchlings. It’s currently thought they could also present a threat to sea turtle eggs and hatchlings, ground-nesting birds and shorebirds, and even American crocodile eggs.
The eggs of the gopher tortoise, a keystone species in Florida, are also at risk from tegu predation. Gopher tortoises play a vital role in their ecosystem, as their burrows provide shelter for more than 350 other species. By preying on their eggs, tegus could disrupt gopher tortoise populations, with cascading effects on the broader ecosystem.
Beyond these direct threats, recent research suggests that tegus may carry non-native parasites and pathogens, which they could introduce into Florida’s ecosystems. The potential for tegus to spread diseases to native wildlife could compound their ecological impact, adding another layer of threat to already vulnerable populations.
REPORTING TEGU SIGHTINGS IN POLK COUNTY
Tegus are established in some remote areas of Polk County, but sightings remain relatively rare, making reports valuable for tracking their spread. Residents are encouraged to report any tegu sightings by calling the IVE-GOT-1 hotline at 1-888-IVEGOT-1 or using the IVE GOT 1 app, available on most mobile app stores.
The hotline connects callers to local wildlife agencies, including the Florida Fish and Wildlife Conservation Commission (FWC), who use sighting data to track tegu populations and respond to new invasions. If you have trouble attaching photos to the IveGot1 online form or the IveGot1 smart phone app, you can email them to ExoticReports@MyFWC.com. Please note the animal’s exact location, date of sighting, approximate size, and, if possible, include a photo.
Although tegus are generally not aggressive, they may bite or scratch if cornered, so maintain a safe distance.
HOW POLK COUNTY RESIDENTS CAN HELP
The spread of invasive species like tegus is a growing environmental issue that requires both community awareness and action. By staying vigilant and reporting sightings, Polk County residents can contribute directly to conservation efforts.
Residents can also support native species by maintaining Florida-friendly landscapes and restoration of native ecosystems on public lands. Another important way residents can help prevent the spread of invasive species is to never release a pet into the wild – especially a reptile or other “exotic” wildlife. Surrender unwanted pet tegus or other “exotic wildlife” to the FWC’s Exotic Pet Amnesty Program.
For more information on invasive species and local conservation initiatives, contact us at the UF/IFAS Extension Office in Bartow. Our phone number is 863-519-1041 or you can reach me directly at scarnevale@ufl.edu or on Instagram at @PolkNR.
Photo by UF/IFAS Photo byTyler Jones
