Big South American lizards infesting Florida, could spread

A black and white tegu in the Florida Everglades
(U.S. Geological Survey photo)

A huge -- and hungry -- kind of South American lizard has gained a foothold in Florida and may
spread across the southern U.S., Jon Herskovitz reports for Reuters.

Tegu lizards, which can grow up to four feet long, have established two large colonies in the Florida wilds after being brought to the country as pets, though there are no current estimates of the population of wild tegus in the U.S. A study published in July in the journal Nature said that tegus could expand from Central Texas to the Carolinas. 

"They are voracious, omnivorous predatory lizards that can live in a variety of habitats, but we can’t know what is going to happen or how intense this invasion is going to become until the effects are upon us," said study co-author Lee Fitzgerald, a Texas A&M professor and curator of its Biodiversity Research and Teaching Collections. He also told Herskovitz that it could take years for the lizards to spread, but new hot spots pop up as more of them escape or are released in the wild by owners. 

Tegus eat the eggs of alligators and grround-nesting birds, as well as insects, fruit and birds. Their potential as an invasive species depends on what resources are threatened in the areas where tegus might live, according to other study co-author Robert Reed, chief of the Invasive Species Science Branch at the U.S Geological Survey. 

The lizards have strong jaws and tails that they use to thump enemies. Tegu owners describe them as calm and indiscriminate eaters but sometimes ornery and tough to handle. "On private lands, Florida hunters without a license are allowed to kill tegu lizards if it is done humanely. On public lands, the state is trying to get rid of the lizards through traps," Herskovitz reports.