Nile Crocodiles Have Moved to Florida

Three “unusual” crocodilians turned out to be more closely related to South African crocs than American ones

Nile crocodile
Paul Kane, (CC BY 2.0)

Florida is home to a variety of both alligators and crocodiles, and in the states alligators are considered the more ferocious of the two. This isn't the case everywhere in the world, however. Nile crocodiles have a considerably fiercer reputation than their American cousins.​

So there's no need to worry about Florida's crocodiles, right? Well, maybe ten years ago. Recent DNA analysis has confirmed that three crocodilians captured in southern Florida between 2009 and 2014 were actually Nile crocodiles, reports Oliver Milman for The Guardian.

One was a hatchling, spotted on a porch and the other two were larger crocodiles from near Homestead, writes Sara Laskow for Atlas Obscura. Scientists analyzed genetic material from the trio and found that they were Nile crocodiles, closely related to those in South Africa. Two were related to each other. The third probably was as well, but problems with the quality of DNA kept the researchers from figuring this out for sure.

Scientists were first alerted to the presence of "unusual looking crocodilians" by private citizens, the team reports in a paper for Herpetological Conservation and Biology. The largest of the three wasn't even three-feet long yet. Contrary to some headlines, these little crocs are not "man-eating." But "Largemouth Bass-eating crocs" doesn't sound as exciting even if that's what lingered in the the largest specimen's stomach.

While it sounds like the discovery of only three individuals isn't much cause for alarm, the researchers suspect there might be more 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,” Kenneth Krysko, a herpetologist from the University of Florida and lead author for the paper tells The Guardian.

The group also reported on a fourth individual had escaped from its enclosure at Billie Swamp Safari in 1996 or 1997, and was probably 4 to 5 feet long at the time. By the time it was recaptured in 2000, it had grown to almost 10 feet. Full-grown Nile crocodiles can be 16 feet long. The team didn't get genetic samples from this animal, but they do think that case means Nile crocodiles can thrive in Florida.

How did these creatures get to Florida, nearly 8,000 miles from South Africa? The DNA analysis shows that they didn't match animals kept at Florida attractions such as Disney's Animal Kingdom, so they must have been brought to the state illegally, reports Terry Spencer for the Associated Press (via the Orlando Sentinel). 

Already Florida is grappling with the ecosystem-upsetting effects of invasive feral pigs, lionfish and giant pythons. Not only could Nile crocodiles pose a threat to humans and native animals, but they could threaten the approximately 1,000 American crocodiles that already call the Everglades home either through competition or interbreeding. 

At this point, however, no one knows whether or not there are more Nile crocs in the state of Florida.

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