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Hungry invader: Tegu lizards are living happily in the Everglades, but their taste for reptile and bird eggs has biologists concerned. Reptile breeders and weary owners are letting them run free. Below, biologist Joy Vinci coaxed a tegu to move from a cage into a cloth bag.

Handout photo (above), RACHEL NUWER • New York Times, below,

Joy Vinci, a wildlife biologist, encourages a black-and-white Argentine tegu to move from a cage into a cloth bag, in an undated handout photo. Originally from South America, the tegu is now considered by biologists to be one of the most troublesome invasive species in the Everglades. (Rachel Nuwer via The New York Times) -- NO SALES; FOR EDITORIAL USE ONLY WITH STORY SLUGGED SCI INVASIVE LIZARDS BY RACHEL NUWER. ALL OTHER USE PROHIBITED. ORG XMIT: XNYT93

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Rise of invasive lizard species has Florida on alert

  • Article by: RACHEL NUWER
  • New York Times
  • August 8, 2014 - 6:10 PM

Deer flies swarmed around Frank Mazzotti and Joy Vinci as they stooped to get a closer look at the creature thrashing around in a metal trap. Inside it was what some biologists consider the most troublesome invasive species in the Everglades: not a Burmese python, but a 24-inch lizard, the Argentine black and white tegu.

It thumped its long tail like a snare drum — a tactic to shift predators’ attention to that expendable appendage (it can grow a new one). Vinci, a wildlife biologist, was not fooled. Wiping her brow in the 91-degree Florida heat, she attached a cloth bag to the end of the cage and then carefully opened it, shooing the tegu inside.

The creature went limp, playing dead. That did not work either: The tegu, along with three others trapped earlier, would be taking a one-way trip out of the marsh to the University of Florida’s Fort Lauderdale Research and Education Center.

Tegus (pronounced TAY-goos) came from South America through the pet trade. They are smart, attractive animals, patterned like an abstract Moroccan rug. They have a nasty bite, but with enough handling, they grow docile.

“They’ll crawl on you — the reptile ­version of interacting,” Mazzotti said.

But like pythons and other invasive species first brought here as pets, tegus eventually found their way into nature. Warm weather, bountiful food and an absence of natural predators allowed them to thrive in the wetlands.

Wild tegus were first spotted in 2008, scuttling around a trailer park south of Miami. But they quickly spilled into the nearby Everglades.

The lizards have a taste for eggs — reptile and bird — but also eat small mammals, insects and fruit. “Everything they get their jaws around, plant or animal, they seem to swallow,” Mazzotti said.

Rare freezes in southern Florida kill nine out of 10 pythons, but tegus have successfully wintered as far north as Panama City. Some of the lizards escaped or were set free by owners who no longer wanted them; many may have been released by reptile breeders on the theory that harvesting them in the wild is cheaper than breeding them in captivity. “We know in those two areas they’re reproducing,” said Kristen Sommers, head of exotic species at the Florida wildlife agency. “We’ve really been increasing our trapping efforts.”

Mazzotti said the number of tegus trapped around Florida City has risen to 400 a year, from just 13 in 2009 and 21 in 2010; he thinks that represents less than 10 percent of the population. A time-lapse map he created to track the invasion resembles the progression of a disease outbreak.

He and his colleagues each day check 30 live traps baited with chicken eggs. They have fitted several tegus with tracking transmitters and set up cameras to monitor colonization patterns.

“We cannot wait until an invasive species demonstrates negative impacts to act, because then it’s too late,” he said.

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