The southern U.S. state of Florida has the world's largest number of invasive species, mainly due to its subtropical climate. The latest invader could be the deadliest.
Three Nile crocodiles were captured in south Florida in the years between 2000 and 2014, from such varied locations as the Everglades and a suburban yard.
Frank Mazzotti, a University of Florida biologist who studies the state's reptiles, told VOA the animals are now in captivity, but that Nile crocodiles, in addition to being bigger than their American cousins, could potentially put humans on the menu.
Guess who's coming to dinner
"Nile crocodiles are more prone to view humans as food," Mazzotti said.
The three reptiles were juveniles when caught, but could grow to five-and-a-half meters in length and weigh as much as a small car. In sub-Saharan Africa, the huge reptiles feast on anything from zebras to small hippos to people.
According to a study published in April in the Journal of Herpetological Conservation and Biology, it's likely more of them are out there.
“The odds that the few of us who study Florida reptiles have found all of the Nile crocs out there is probably unlikely,” according to Kenneth Krysko, herpetology collections manager at the Florida Museum of Natural History on the UF campus.
“We know that they can survive in the Florida wilderness for numerous years," Krysko said. "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.”
Researchers from the University of Florida used DNA analysis to determine that the three crocodiles were genetically identical. That suggests they came from the same, so-far-unidentified source. They did not escape from zoos, since their DNA did not match the genetic profile of any Nile crocodiles in captivity.