Invasive lizards threaten Florida's turtles, alligators

An invasive lizard first spotted in southern and central Florida about a decade ago has become the latest concern for wildlife officials after the four-foot-long, black-and-white tegu was caught on video stealing alligator and turtle eggs from their nests.

Scientists from the University of Florida during the spring and summer of 2013 planted several cameras in the Everglades around nests containing dozens of eggs.

“We captured images of tegus removing (up to) two eggs per day until an examination of the nest on Aug. 19 revealed no remaining eggs,” University of Florida professor Frank Mazzotti wrote of one alligator nest in a forthcoming study, conducted with the U.S. Geological Survey and the Florida Fish and Wildlife Conservation Commission, to be published in journal Biological Invasions this summer.

Mazzotti said the species, found naturally in Argentina and parts of South America, is thought to have first arrived in the U.S. via pet traders sometime in the early 2000s. Since then its population has boomed thanks to an ability to withstand cold and large clutch sizes containing up to 30 eggs.

“Any species that is a predator and eats high up the food chain and is introduced into a novel environment has potential for causing serious ecological damage,” said Mazzotti, a member of the UF's team of wildlife researchers known as the "Croc Docs."

Florida, and particularly the Everglades, is home to dozens of invasive species that have escaped into the wild or been released by pet owners after growing too large. Most famously wildlife officials have struggled to contain Burmese pythons, and occasionally encountered some nearly 20-feet (6-meters) long, even preying on adult alligators.

Mazzotti said tegus are split into two groups, one in the Everglades and another near Tampa on the state’s west coast. The Florida Fish and Wildlife Conservation Commission estimated the size of the South Florida group in the low thousands, and Mazzotti said more than 400 have been trapped in the last year.

“We can’t contain them,” he said.