PHOTO/ Courtesy of Florida Fish and Wildlife Conservation Commission.

Tegu lizards, native to South America, can grow up to four feet long.

 

Tegu lizards moving in numbers down the Keys

SEAN KINNEY

KONK LIFE STAFF WRITER

Everglades National Park and other parts of South Florida adjoining Monroe County are teeming with invasive species, generally animals that started as someone’s pet, including iguanas, pythons and, in ever increasing numbers, the tegu lizard.

Tegus, native to South American, particularly Argentina, have a black and white pattern and can grow up to four feet long.

Since 2008 the invaders have established in Polk, Hillsborough and Miami-Dade counties, according to new research out of the University of Florida, and some estimates peg the Florida City-area population at around 800 of the lizards.

Iguanas are a familiar site throughout the Keys and in Key West; they’re loathed by home gardeners as iguanas’ vegetarian diet can wreak havoc on a carefully tended yard.

Aside from the obvious size and coloring difference, Tegus eat everything from fruit to small rodents and they’re especially fond of eggs like those laid by the protected crocodiles and alligators that live and nest in the Crocodile Lake National Wildlife Refuge area near Ocean Reef in the Upper Keys.

Frank Mazzotti, a wildlife ecology and conversation professor at UF, and lead author of the new study, observed first hand tegu’s taste for protected eggs.

In March 2013, Mazzotti and other researchers set up cameras on one alligator nest and one crocodile nest in Miami-Dade.

The croc eggs successfully hatched by July. But between Aug. 12 and 18, the cameras recorded two tegus taking up to two alligators’ eggs a day until all 30 eggs had been eaten.

The tegus also ate 15 turtle eggs that were spotted near the alligator nest.

“There is no reason for us to think crocodiles won’t be in danger,” Mazzotti said.

“The lesson is we’ve got to leap, we cannot wait,” he said. “If we focus on answering all the questions about how many there are and what their impact will be, there will be too many tegus to do anything about them.”

Tegu sightings are tracked by the Florida Invasive Species Partnership. Records indicate some 732 encounters in the Miami-Dade area.

Two have been recorded in Key Largo, one on No Name Key and another in Key West.

Nancy Finely is the manager of the National Key Deer Refuge on Big Pine Key and the Crocodile Lake National Wildlife Refuge, the area traversed by Card Sound Road and home to many of the refuge’s namesake reptiles.

Crocodile Lake comprises 6,700 acres, including 650 acres of open water, and was established in 1980 to protect breeding and nesting habitat of the American crocodile.

The species is considered “threatened” and is protected from harassing, poaching or killing.

“The concern,” Finley told Konk Life, is there’s a large number of the tegus in Homestead and Florida City. That’s a hot spot. The belief is it’s just a matter of time,” before numbers in the Keys increase.

She called the tegus “voracious egg eaters. If they establish themselves it could affect the crocodiles.”

Finley also pointed out that, unlike iguanas and the other big-name invasive Burmese pythons, tegus can withstand colder temperatures.

“Whereas a cold snap could knock down the population,” of pythons, for instance, “tegus can handle the cold a little better.”

If you see a tegu, call the Florida Fish and Wildlife Conservation Commission at 888-483-4681.

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