The invasion of a lizard species that is the size of a dog has sparked concern as it wreaks havoc on ecosystems across the South.
Central to experts' fears is the fact the roughly five-foot-long Argentine black and white tegu eats ‘truly anything,' University of Florida wildlife professor Frank Mazzotti told The Palm Beach Post.
They devour quail, chicken, turtle and even alligator eggs as well as turkeys, gopher tortoises and ground-nesting birds. They also feast on gopher fruit, vegetables, plants and pet food.
This insatiable appetite poses a threat to native wildlife, and now the beast has spread to more states, including Florida, Texas, Georgia, South Carolina and even Maryland.
‘Because they can live in many more places and eat everything, there is not going to be a whole lot to stop them,' Mazzotti warned.
It is not known precisely how many of these highly intelligent creatures are currently in the United States, but there have been nearly 10,000 sightings since 2002, according to a database created by the University of Georgia's Center of Invasive Species and Ecosystem Health.
The vast majority of reports were in Florida, specifically in the Southern Glades Wildlife and Environmental Area, which is south of Miami. There was one sighting in Maryland and five in Texas.
The Argentine black and white tegu lizard can reach up to five feet long, have a varied diet and can exist in a wide variety of environments
Pictured: The Southern Glades Wildlife and Environmental Area, where tegu lizards are thriving
While the Southern Glades Wildlife park seems to be their primary hangout, they have also been spotted in Miami itself and even the upscale city of West Palm Beach, where one resident found the lizard in a parking lot.
And as Mazzotti and others have pointed out, tegus can thrive in a variety of different environments, which makes controlling their numbers nearly impossible.
In 2019, Bryan Falk, who was the supervisory invasive species biologist at Everglades National Park at that time, called them ‘do-everything lizards.'
‘They are happy in many different environments, whether that is a natural or disturbed habitat. We once had a report of a tegu living in a dryer vent in someone’s house in Homestead,' said Falk, who is now a program analyst for the National Invasive Species Council, an agency contained within the US Department of Interior.
Another reason why tegus have been able to move so far north is because they can sustain their body temperature during different seasons.
This discovery was made by group of Brazilian and Canadian biologists at São Paulo State University in 2016, and scientists have since deemed the tegu the only warm-blooded lizard on earth.
All other reptiles are strictly cold-blooded, meaning they can neither generate body heat nor sustain their metabolism without being in a warm environment.
That's why when temperatures drop, alligators and snakes will either migrate to warmer places or hibernate to conserve energy.
A 115.2-pound female Burmese python is seen devouring a 77-pound white-tailed deer somewhere in Everglades National Park
Contractors with the Florida Fish and Wildlife Conservation Commission show off a Burmese python caught Tuesday, August 13, 2024, in the Everglades
Tegus don't have this same limitation, demonstrated by the fact that they can raise their body temperature up to 10 degrees Celsius above the ambient temperature during their mating season in the spring.
The extreme threat to local wildlife posed by tegus comes at a time when Burmese pythons are also steamrolling Florida.
Like tegus, Burmese pythons are an invasive species. Pythons, though, are on average 16 feet long and can devour foxes, bobcats, raccoons and other animals.
A recent study by the Conservancy of Southwest Florida discovered that pythons can also whole deer and certain alligators.
Both pythons and tegus are believed to have made landfall in the US through the exotic pet trade, with pythons being exported in the early 1980s.
Tegus only started seriously proliferating in the wild about 15 years ago, so experts believe their introduction came later.
Some measures have been taken by state authorities to limit the tegu populations, including banning residents from keeping them as pets.
Florida and South Carolina outlawed the reptiles a pets in the spring of 2021, while Georgia banned any tegus not registered with the Department of Natural Resources before December 4, 2023.
Those wetlands are just south of the Miami metro area (pictured)
The creatures have also been sighted in the upscale city of West Palm Beach (pictured)
Scientists can now track the movements of tegus and other animals through their environmental DNA deposits in water or soil samples
This discovery will allow wildlife officials to better control the populations of invasive species like tegus and Burmese pythons
All three states have grandfather clauses for current owners, and based on tegus' approximately 20-year life span, they're likely to be around in captivity for some time.
But when it comes to controlling tegus who have either escaped captivity or were born in the wild, scientists now believe they have discovered a much more reliable way to track them. And it has to do with DNA.
Environmental DNA (eDNA), which is constantly shed by all living organisms, can now be more precisely detected than ever before.
New technology, known as a tetraplex digital PCR assay, was developed by researchers with the University of Florida, and it can successfully detect the eDNA of four different species in a single water or soil sample.
University of Florida invasion ecology specialist Melissa Miller, the lead author of the study, told the South Florida Sun Sentinel that her team was able to see Burmese python DNA in a soil sample two weeks after the snake was removed from an outdoor enclosure.
This breakthrough was developed in the hope that if the tech was successful, it could be used to effectively track all of the more the 500 non-native species in Florida, including tegus.
Miller said eDNA tests will offer wildlife officials who engage in removal efforts of invasive species a cost-effective way to ensure that they are indeed gone, instead of having to periodically check large swathes of land for physical sightings.
