Spotting native alligators and crocodiles in Florida is common, but anyone who sees a large reptile may want to take a second look -- human-eaters that can grow to 18 feet long and weigh as much as a small car have been found in the Sunshine State. 
 
 Using DNA analysis, University of Florida researchers have confirmed the capture of multiple Nile crocodiles in the wild. 
 
 The ancient icon eats everything from zebras to small hippos to humans in sub-Saharan Africa. Now three juveniles of the monster crocodile, have been found in South Florida, swimming in the Everglades and relaxing on a house porch in Miami. 
 
 The invasive crocodiles were captured between 2000 and 2014, leading UF scientists to analyze their DNA, study their diet and one of the animal's growth. Scientists verified the animals were Nile crocodiles linked to native populations in South Africa, and confirmed the species can survive in Florida -- and potentially thrive, said Kenneth Krysko, herpetology collections manager at the Florida Museum of Natural History on the UF campus. 
 
 In other words, there likely are more. 
 
 "The odds that the few of us who study Florida reptiles have found all of the Nile crocs out there is probably unlikely," said Krysko, co-author of the study published in April in the Journal of Herpetological Conservation and Biology. "We know that they can survive in the Florida wilderness for numerous years, we know that they grow quickly here and we know their behavior in their native range, and there is no reason to suggest that would change here in Florida." 
 
 Nile crocodiles, Crocodylus niloticus, were responsible for at least 480 attacks on people and 123 fatalities in Africa between 2010 and 2014. They are generalist predators and eat a wide variety of prey. In Florida, everything from native birds, fish and mammals to the state's native crocodile and alligator would be fair game for the carnivorous croc. 
 
 The study found one juvenile grew nearly 28 percent faster than wild Nile crocodile juveniles from some parts of their native range. 
 
 DNA analysis revealed the three similar-size Nile crocodiles were genetically identical, suggesting they were introduced via the same source, but Krysko said the source has not been confirmed. Prior to graduating in 2013, former UF doctoral student and co-author Matthew Shirley extensively sampled DNA of live Nile crocodiles housed in U.S. zoos, including Florida. The DNA of the three crocodiles did not match any of those Shirley sampled, suggesting they were either acquired by a permitted source later, or introduced by someone without a permit. 
 
 Study scientists note that over the last decade, large groups of Nile crocodiles have been imported from South Africa and Madagascar for display at places like Disney's Animal Kingdom and to supply Florida's flourishing pet trade, with the latter being the most likely introduction pathway, according to the study. 
 
 While there is currently no evidence of an established population, study scientists recommend a scientific risk assessment to evaluate the potential for Nile crocodiles to breed and spread across the state. According to the study, Florida's Atlantic coast and the entire Gulf of Mexico coastline provide favorable climate for Nile crocodiles. 
 
 Florida's subtropical climate is one reason the state has the world's largest number of invasive species -- from the Burmese python that has infested the Everglades to the Cuban tree frog, which has been found as far north as Jacksonville on the East Coast and as far north as Cedar Key on the Gulf Coast. 
 
 "My hope as a biologist is that the introduction of Nile crocodiles in Florida opens everyone's eyes to the problem of invasive species that we have here in our state," Krysko said. "Now here's another one, but this time it isn't just a tiny house gecko from Africa." ||||| FORT LAUDERDALE — Step aside, Burmese python — you may no longer be Florida's scariest invasive species. 
 
 Researchers have confirmed that three Nile crocodiles were captured near Miami, and they say it's possible more of the man-eating reptiles are still out there, although no one can say for sure. 
 
 The big question now: How did they get to Florida? 
 
 "They didn't swim from Africa," University of Florida herpetologist Kenneth Krysko said. "But we really don't know how they got into the wild." 
 
 Krysko and his co-authors just published a paper showing that DNA testing proved the three animals captured in 2009, 2011 and 2014 are Nile crocs, a species whose males grow to over 16 feet long and weigh upward of 1,600 pounds. 
 
 Nile crocs are believed to be responsible for up to 200 fatalities annually in their native sub-Saharan Africa. Compare that with an annual average of six reported shark attack deaths globally. 
 
 Krysko, who works at UF's Florida Museum of Natural History, said the captured crocodiles matched genetically, meaning they are related to one another, but didn't match Nile crocs kept at Disney's Animal Kingdom and other licensed Florida attractions. 
 
 That means they probably were brought to Florida illegally by an unlicensed reptile collector who either didn't contain them properly, allowing them to escape, or, more sinisterly, planted them in the Everglades in hopes they would multiply. 
 
 The Nile croc, if it became established in the Everglades, would pose another invasive threat to its teetering ecosystem. Through crossbreeding, they could endanger the smaller, less aggressive American crocodiles, which have never been responsible for a confirmed human death in the U.S. 
 
 About 1,000 American crocodiles live in South Florida, mostly in mangroves and estuaries. Any hybrids would degrade the genetic integrity of the endangered American variety. 
 
 Nile crocs also are known to attack livestock, which would be bad news for cattle farms that border the Everglades. 
 
 Krysko and two co-authors, independent wildlife biologist Joe Wasilewski and UF wildlife ecology professor Frank Mazzotti, think more Nile crocs lurk unfound in the Everglades, but they aren't certain. 
 
 Allyson Gantt, a spokeswoman for Everglades National Park, where one of the reptiles was found, disagrees, saying no Nile crocs still roam the park. 
 
 Some Everglades visitors might not be aware of the differences between crocodiles and alligators, complicating efforts to confirm any remaining crocs. Crocodiles have angular snouts, and their lower teeth are exposed when their mouths are closed. 
 
 Alligator snouts are rounded, with few exposed lower teeth. Nile crocs are usually bronze or brownish yellow; alligators are blackish green. 
 
 All three Nile crocodiles were captured in extreme South Florida. 
 
 The first, a hatchling, was found on a front porch and sent to a Louisiana reptile exhibit. The second, a female measuring 4 feet, was captured at a park. Wasilewski kept it, but later gave it to another licensed researcher. The third was captured twice. The first trapper didn't have the proper permit, so he released the female. The croc was recaptured two years later 18 miles away by water in Everglades National Park. It was euthanized.
– Huge, man-eating crocodiles may be hiding throughout the Florida wilderness, according to a study published last month in Herpetological Conservation and Biology. The Orlando Sentinel reports that DNA testing on three young crocodiles caught between 2009 and 2014 confirmed them to be Nile crocodiles native to Africa. Nile crocodiles can grow up to 18 feet long and weigh as much as a car, according to a press release. They eat everything from hippos to humans and are believed to be responsible for up to 200 human fatalities a year in Africa. The Florida Everglades have long proven to be a haven for nonnative species—including the Burmese python and Cuban tree frog. “Here's another one," study co-author Kenneth Kysko says. "But this time it isn't just a tiny house gecko." Researchers say the Nile crocodile could thrive in Florida, which is bad news for the already tenuous ecosystem in the Everglades. Nile crocodiles could eat and mate the smaller and less-aggressive native alligators and crocodiles out of existence. Not to mention what they could do to livestock and human populations. Analysis of one of the captured Nile crocodiles—it grew 28% faster than Nile crocodiles in Africa—showed they can thrive in Florida. And researchers believe there are likely more living in the Everglades. It's unclear how the Nile crocodiles got to Florida. As their DNA doesn't match up with Nile crocodiles at Disney's Animal Kingdom and other attractions, it's most likely they are escaped pets. "They didn't swim from Africa," Krysko tells the Sentinel.