One of Africa’s Most Dangerous Predators Is Invading Florida

Three captured crocs have been confirmed to be feral Nile interlopers.
May 22, 2016, 8:12pm
Image: Tim Muttoo

From alligators to sharks to venomous snakes, Florida is known for supporting a lush variety of deadly creatures. Now, researchers based at the University of Florida have confirmed that a new killer has rolled into town, and it's a real heavyweight. Watch your backs, Floridians, because odds are that there are invasive Nile crocodiles roaming around the swamps of your state.

Of course, Florida is no stranger to the crocodilian clan, and many native alligators and crocodiles dwell in its rich wetlands and swamps. But Nile crocodiles, which are endemic to Sub-Saharan Africa, are not only larger than their North American brethren—reaching lengths of at least 18 feet—they are also more aggressive, and their attacks are deadlier.

As generalists, pretty much anything is on the menu for these apex predators, including hippos, zebras, birds, fish, and yes, even humans. Between 2010 and 2014, Nile crocodiles attacked at least 480 people, 123 of whom died from their injuries. You do not want to mess around with these old world biters.

Naturally, that's why it's so disturbing that DNA analysis on three crocs captured in Florida revealed them to be Nile crocodiles, raising the troubling question of how many more of these people-eaters are eking out a fresh start in the Florida wilds.

File:Nile croc couple 690V1510 - Flickr - Lip Kee.jpg

"The odds that the few of us who study Florida reptiles have found all of the Nile crocs out there is probably unlikely," said Kenneth Krysko, herpetology collections manager at the Florida Museum of Natural History and a co-author on the DNA research, in a statement.

"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," he said.

Yes, you read that right—it looks like Nile crocodiles are particularly well-suited to the Everglades lifestyle, with one study finding that juveniles can grow 28 percent faster in Florida than in their native African environment. As if this enormous, grouchy, invasive, human-eating carnivore needed another boost, it turns out they are flourishing in their new digs.

So, who spilled the crocodilian beans? At the moment, the origins of these feral crocs remains as murky as their current numbers. Study co-author Matthew Shirley compared the DNA of the captured animals to many Nile crocodiles kept in zoos, and found they were not closely related to those found in the wild. The most likely backstory, according to the team, is that the animals leaked through the seams of Florida's exotic pet trade.

"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."

Tread carefully, Sunshine State.