Invasive Lizards are a Threat to Florida's Native Reptiles, Researchers Say

Invasive lizards are a threat to Florida's native alligators and turtles, researchers find.

According to researchers at the University of Florida, The Argentine black and white tegu has already established itself in several parts of Florida and is now threatening the existence of alligators, crocodiles and turtles in the region.

The lizard species, which can grow to four feet in length, is already seen in areas inhabited by Eastern indigo snake, Cape Sable seaside sparrow and gopher tortoise, researchers said.  In the past five years, tegus have established themselves in Miami-Dade, Hillsborough and Polk counties. Also, there has been at least one case of tegu surviving a winter in Panama City.

Increase in the number of tegus will lead to decline in native reptiles' already dwindling population, researchers said.

"The lesson is we've got to leap, we cannot wait," said Frank Mazzotti, a wildlife ecology and conservation professor in UF's Institute of Food and Agricultural Sciences and the study's lead author. "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."

The research began in March 2013. The study team was on routine surveillance work when they spotted old nests of an American alligator and an American crocodile. The scientists knew that tegus lived in the area and so set up cameras near the nests to monitor the lizards' activities. Similarly, they monitored turtle nests, according to a news release.

The study, which included scientists from the U.S. Geological Survey and the Florida Fish and Wildlife Conservation Commission, found that tegus destroyed turtles' and alligators' eggs, but not crocodile eggs.

According to Mazzotti, tegus  have an omnivorous diet and "there is no reason for us to think crocodiles wouldn't be in danger."

The study is published in the journal Biological Invasions.

According to IUCN Red List of Threatened Species, Argentine Black And White tegu or Salvator merianae is a species of Least Concern because it is widely distributed, tolerates a range of habitats and has a large population.