Florida can feel like an open-air reptile zoo. The state is home to dozens of nonnative lizard species, most of which are bigger, faster and stronger than native lizards. The reptiles range from 4-inch Cuban brown anoles to nuisance green iguanas to imposing 5-foot predators such as the Nile monitor.
Though some of these creatures look like mini Jurassic monsters, are they actually aggressive enough to be dangerous?
They can certainly be dangerous to one another: Foot-long rock agamas from Africa dine on smaller anoles, and the largest nonnative lizard here, Nile monitors, take down iguanas.
The South Florida Sun Sentinel spoke with biologists about the species you’re most likely to encounter in Florida to figure out which of these animals really pose a threat to humans.
The little guys and ear rings
Anoles and curly-tailed lizards: You can spot 4- to 8-inch long anoles in almost any neighborhood in South Florida. The green ones are native and tend to stay in trees while the Cuban brown anoles showed up about 100 years ago and the similar crested anoles landed from Puerto Rico in 2018. Cresteds have pushed the Cuban browns off prime tree trunks where their ranges overlap. Chunkier curly-tailed lizards arrived from the Caribbean in the 1940s.
“These little guys are really pretty much harmless,” said University of Florida wildlife ecologist Frank Mazzotti of these lizards under 10 inches long. Mazzotti has studied myriad Florida lizards and crocs over the decades. “Things like anoles probably won’t break the skin if they bite you. They’ll just leave little indentations.”
The only chance they’ve had to bite you is if you manage to catch one. They’re all extremely skittish. Biologists who study them have to use long fishing poles with tiny lassos on the end to reach them.
There’s also a tradition in Florida of children catching anoles and letting them clamp onto their ears like earrings. A picture of an anole on a kid’s ear on Facebook triggered a thread of nostalgia: “I grew up in FL , we used to do that all the time! Would catch them during recess and wear them in to class! So funny!” wrote one reader.
“We also use to tie a string around a lizard and then the other end tie around a button on our blouse and have a live brooch. Those were such fun days as a kid growing up in Florida,” wrote another.
Medium-size invaders
These lizard species, all invasive, can grow to a foot or even 20 inches or so, and all likely prey upon the smaller anoles. You’ll likely see more and more of them around, as they’re expanding their ranges all over the state.
Peters’s Rock agamas: The males of this east African species, which can grow to about a foot in length, are undeniably striking, with dark torsos and orange heads and tails. Females have more sensible earth tones. They were released by a single pet trader in 1976 in both Homestead and Palm City.
There are pros and cons to the presence of rock agamas. They eat roaches and flies, and may actually eat other nonnative reptiles such as brown anoles.
Pam Harting, Florida Master Naturalist
A flamboyantly colored male Peters’s rock agama climbing a palm tree. The species originated in East Africa, and was introduced to Florida ecosystems in 1976. Researchers have seen an uptick in Florida populations recently. (Courtesy Pam Harting, Florida Master Naturalist)
They also might end up as food for hawks, herons, foxes, feral cats and bobcats. In other words, they’re fitting into a food chain that’s already been vastly disrupted.
The odds of being bitten by a rock agama are extremely low, unless you can scamper up walls and climb trees as fast as, well, a rock agama. If you do get your hands on one, they do have teeth, but Mazzotti said they’re fairly mellow. He’s studying their relationship to mosquitoes. “We’re not having any particular troubles with them in terms of handling them,” he said.
Brown basilisk: These 2-foot lizards are lanky and athletic, and have a leathery crest on their head and down their back. When fleeing, they sprint away on their hind legs, and younger ones have the uncanny ability to run on water, prompting some to proclaim them the “Jesus lizard.”
Unlike iguanas, basilisks kill things for a living; think roaches, small snakes, other lizards. They hail from East Africa and were brought here in 1963 through the exotic pet trade. They like to hang near fresh water, so South Florida’s canal systems have not only provided habitat, but also routes by which they can expand their range. Canals serve as “a super highway for them,” says Ken Gioeli, a University of Florida natural resources extension agent who studies nonnative species.
Mike Stocker / South Florida Sun Sentinel
A brown basilisk lizard fleeing on its hind legs at the Mount Botanical Garden.
Joel Crippen, a display garden horticulturalist at Mount Botanical Gardens in West Palm Beach, sees them on a daily basis.
“They don’t bother us,” he says of the basilisks. “Our big problem are iguanas,” which feast on plants he’s trying to cultivate. When you get up to something like Peters’s rock Agama or Brown basilisk, they can break your skin, maybe cause a little bruising,” said Mazzotti, but good luck getting anywhere near one.
Bigger beasts, bigger teeth, tail whips
Green iguanas: A four-foot-long iguana can be intimidating, and they live among us, pooping on pool decks and roofs, burrowing through sea walls and snacking on gardens. If you do manage to catch one, they bite. Iguanas can also spread diseases such as salmonella and E. coli. “Green iguanas are mostly herbivorous, though big ones do occasionally eat meat,” said Mazzotti. “Either way, their jaws are not as muscular and strong as other large invasive lizards, such as tegus or Nile monitors.”
Mike Stocker / Sun Sentinel
Iguanas gather on the seawall in the Three Islands neighborhood of Hallandale Beach.
Mazzotti, who’s handled many iguanas, said the most dangerous part of an iguana just might be the spikey tail. “You know, you catch them and you’re always concentrated on the head so you don’t get bit. But they can whip the bejesus out of you with their tails. That stings.”
Another potential threat is to pets. Iguanas sometimes die in cold weather, and dogs have become ill after scavenging them.
Mazzotti said iguanas love the color red — biologists often lure them into traps with red flowers, strawberries or even red marbles. “You don’t want to paint your toenails red and walk out in your backyard and wiggle your toes in front of the iguana,” he said.
Black and white tegu: Omnivorous and often predatory, tegus, which can grow to nearly 5 feet, were brought to Florida from Argentina by the same industry that imported the highly destructive Burmese python — the exotic pet trade. They’ve thrived in the wild, feasting on insects, mice, rats, fruits and smaller reptiles.
They’re especially proficient at finding and eating eggs, including those of burrowing owls, gopher tortoises, alligators, American crocodiles and sea turtles. They’re now illegal in Florida. Though there are sightings statewide, the FWC said that established breeding populations are centered in Miami-Dade, Hillsborough and Charlotte counties. There’s also an emerging population in St. Lucie County.
Mark Randall, South Florida Sun Sentinel
An Argentine tegu is an invasive lizard making its home in Florida. The reptiles compete with native wildlife and consume eggs of threatened turtles and American crocodiles.
Mazzotti said that though they’re strong and have nasty teeth used for killing smaller animals, their mindset is to run, not bite. “If you make a mistake taking them out of a trap, it runs away. Biting you isn’t even on its mind.” But every lizard has its own personality and mood, he said. “That said, you might get one coming out of the trap that decides he’s gonna be defensive — you have to treat every animal like it’s the one that’s going to be defensive.”
Nile monitor: The most potentially dangerous of the invaders, Nile monitors are big, (up to 6 feet) fast and very predatory. A population lives along the C-51 Canal, which parallels Southern Boulevard in West Palm Beach, where the Florida Fish and Wildlife Conservation Commission works to control them. There’s another population lives in Cape Coral, west of Fort Myers.
Orlando Sentinel file
This 4-foot Nile monitor was trapped in Cape Coral, Florida, where the African lizard has an established, breeding population. Nile monitors also live in Palm Beach County, along the C-51 Canal, which parallels Southern Boulevard in West Palm Beach.
“Out of all of the nonnative lizards, Nile monitors are the most offensive,” said Mazzotti. He and his team have had trouble with the cantankerous reptiles when removing them from cages. “They just try to bite. They don’t quit. They can turn their bodies. You grab one fore and aft, and you think it can’t get you — that thing just turns around and bites you anyway. You really have to go through very careful measures.”
Nile monitors are not venomous, said Mazzotti but their mouths can contain dangerous bacteria, such as Aeromonas hydrophila, which alligators also carry.
Mazzotti’s diet studies on Nile monitors show they’re capable of killing water birds, rats and iguanas, but he said they likely wouldn’t tackle a dog. “Maybe the biggest male monitor, and I haven’t seen one yet, might be interested in a kitten. By and large a marine toad (cane toad, which can reach 9 inches) is a fairly big item for them to eat.”
Final word: They’re scared of you and can be tasty
“These things are not a huge danger to people unless you ask for it,” said Mazzotti. “The best thing to do is just don’t catch them. If you don’t catch them, you’re not going to get bit.”
As a general rule, all of these nonnative lizards are afraid of humans, and very skilled at not being caught, said Mazzotti. His team regularly catches alligators and American crocodiles by simply getting close enough to slip a lasso around their neck. “You cannot do that with these lizards. They run. I’ve only known one or two people with their reflexes quick enough to be able to catch a fleeing iguana or a fleeing tegu, and I am not one of them.”
If you manage to get bit, wash your wound with soap and water and apply betadine solution, said Mazzotti. Don’t use peroxide.
Like chickens, captive iguanas are known to carry salmonella bacteria in their gut, which can spread via feces to their skin. Mazzotti said it’s not clear how common this is in wild populations. Regardless, pooping is a defense mechanism for many of these lizards.
“And if you’re going to cook and eat iguana, cook it as you would a chicken. That destroys the salmonella.”
Mazzotti likes them in tacos and stews. “They’re good. I don’t know why more people don’t hunt them for their meat. It’s a nice light meat. Just a very good, versatile, nice, light, white meat. And no, it doesn’t taste like chicken.”
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