Invasive Lizards Threaten Florida's Natural Species In The Everglades

There's a new, invasive species threatening Florida wildlife in the Everglades. It's the Argentine black and white tegu, which can grow to more than five feet and has teeth.

MICHEL MARTIN, HOST:

Now to the Florida Everglades, where a hunt is underway for lizards who are not just relatively new to the neighborhood, they're considered a threat to indigenous species. The Argentine black and white tegu can grow to be several feet long. They eat nearly everything. Since discovering these reptiles about a decade ago, wildlife officials hold an annual tegu search every February to trap, study and kill the lizards before they spread across the state. Topher Forhecz of member station WGCU went along to see how it's done.

TOPHER FORHECZ, BYLINE: University of Florida wildlife biologist Kyle Allen and Lindsey Garner walked down a small path on state conservation land about an hour south of Miami. Marshes and thick green bushes surround them for miles. Garner heads toward a foot tall metal cage tucked away in the brush.

Inside the cage, a two-and-a-half foot-long lizard thrashes back and forth. Tegus come from South America. They're popular in the pet trade, which is how biologists think they ended up in the wild. Garner says when people see little hatchling tegus in pet stores, they don't realize they can turn into a 5-foot long lizard with sharp claws and an unruly attitude.

LINDSEY GARNER: There's a lot of maintenance and care that goes into these animals.

FORHECZ: Part of that maintenance includes the tegu's diet. The animal eats almost everything, and that has Garner worried about Florida's native wildlife. They've recorded tegus eating eggs from an alligator nest, and that could be a problem for the threatened American crocodile population nearby. There's also the endangered Key Largo woodrat.

GARNER: That could be the final straw that - you know, then we no longer have the Key Largo woodrat; it's gone forever. So we want to protect our biodiversity that makes South Florida so unique.

FORHECZ: Garner and Allen are part of a joint effort to control the tegu populations. One's here in Miami-Dade County. The second population is on the other side of the state near Tampa. Federal, state and local partners trap tegus from roughly February to October. In 2014, they caught 410 tegus. Last year, they nabbed almost 650. Trapping helps biologists learn more about the tegu's population size. Jenny Ketterlin Eckles is a biologist with the Florida Fish and Wildlife Conservation Commission. She says they're also learning how the lizards live in Florida's environment.

JENNY KETTERLIN ECKLES: We oftentimes don't know about the life history of the animal when it's coming from another place. And so we have to learn that at the same time as well.

FORHECZ: Back in the Everglades, biologists Lindsey Garner and Kyle Allen check more traps. They find their second catch of the day.

KYLE ALLEN: I'd say he's closer to the 2-foot mark. He's smaller than the other one that we had recently caught.

FORHECZ: Scientists want to avoid what's happened with Florida's most famous invasive species, the Burmese python. They say it will be next to impossible to rid the Everglades of those large snakes. But tegus especially worry biologists because they do something pythons don't. Garner says they can do the reptilian version of hibernation, meaning they can survive in colder places.

GARNER: That's really scary because, you know, tegus not only have the potential to be a problem in South Florida - in our subtropical climate - but they can also spread into temperate climates, you know, much further north that we're seeing the pythons so far.

FORHECZ: They euthanize the tegus they've captured and perform necropsies to learn more about them.

GARNER: The euthanizing part, you know, it's the least favorite part of the job, but it's a necessary evil. There's absolutely no other viable option.

FORHECZ: Garner says the tegu population in South Florida feels sort of like a bomb, like the bomb that blew up with the pythons that can now no longer be contained. They don't want that to happen all over again. For NPR News, I'm Topher Forhecz in Florida City.

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