KEY LARGO -- A steady invasion of meat-eating Argentine lizards, like aliens from a science fiction movie, is threatening to alter the natural order in South Florida.
The giant black and white tegu (Tupinambus merianae), which resembles the monitor lizard, joins a host of former exotic pets that have been dumped into the South Florida wilds by their owners.
Like the Burmese python which has thrived in the Everglades, the predatory tegus eat small animals that are a food source for native snakes, raptors and other animals. Because they have no natural predators, other than man, these invasive species can out-compete natives and therefore threaten their existence.
More than 50 of these lizards have already been captured in Miami-Dade County and some have been collared to track their movement patterns. A few were found in South Dade crossing through animal culverts under the 18-Mile Stretch.
Local wildlife officials fear the tegus, which can grow to 4 feet in length, will soon invade the Keys and threaten endangered species that live in the subtropical hardwood hammocks of North Key Largo.
"These are more of a concern than the Burmese python," said Steve Klett, manager of the Crocodile Lake National Wildlife Refuge. "They climb trees. That means more critters are vulnerable. They eat any flesh ... as well as fruits and vegetables."
Klett is particularly concerned about tegus targeting the eggs of the endangered North American crocodile and small indigenous mammals such as the Key Largo woodrat and cotton mouse.
Fewer than 500 woodrats live almost exclusively in the refuge on County Road 905 between the Overseas Highway and Card Sound Road.
Since the tegu lizard is able to swim in salt water, the refuge would be on the front line of any invasion.
But to date, rural southwest Florida City has been "ground zero" for the tegu, according to Tony Pernas, regional invasive species coordinator for the National Park Service.
"They hibernate this time of year and we know they are just south of the Robert Is Here fruit and vegetable stand in Florida City, and have established themselves all the way down to the [Homestead Correctional Institution] prison," Pernas said. "When the weather changes and it begins to dry out and get warmer about March, we expect to see them on the move again."
Everglades National Park is just a few miles west of the prison.
Robert Moehling, 45-year owner of Robert Is Here, said he recently found a dead tegu near his home.
"Dogs apparently got to it," he said. "It was about three feet long."
Just south of Moehling's S.W. 192 Ave. market, Everglades Outpost Manager Desiree Dow has seen the lizards on her property.
"There are red tegus and black and white tegus," she said. "People have let them loose and a bunch of them are running around wild. When we catch one we cage it, but they are harmless [to humans]. They don't bite."
Larry Perez, science communications officer for Everglades National Park, is urging anyone who spots a tegu or other invasive species, such as Gambian pouch rats and pythons, to immediately call (888) IVE-Got1 or go online to IVEGOT1.org.