DNA tests on crocodiles found in Florida swamps have confirmed that African-originated reptiles are indeed living and growing in state. They are of the species famous for man-eating along the Nile. And so the questions arise: How many are there? What can be done to control them? Will these crocodiles become Florida’s next ecosystem-busting invasive species?
BBC News reported May 21 that University of Florida researchers, using DNA taken from three crocodiles discovered in 2009, 2011, and 2014, have confirmed, publishing their findings in the journal Herpetological Conservation and Biology, that the reptiles are the Nile variety, beasts that are far larger than the regular Florida alligator. In fact, while the American alligator grows to roughly four meters (13.1 feet) in length, the Nile crocodile can grow to six meters (19.7 feet) in length.
Of particular concern, though, is that they could soon become a problem in the Florida Everglades, where recent history has shown that an apex predator with a virtually unlimited food supply and nothing to prey on it in return can see its population explode, endangering the local ecosystems in which it proliferates.
How do they know? Several decades ago, the Burmese python was unknown to the United States except as an exotic pet or simply a snake seen on a wildlife program on television. However, through pet owners losing or releasing their pet snakes into the wild over time, the Burmese python, having no natural predator in the southern swamps, became an ecological menace in and around the Florida Everglades. It is estimated that some 30,000 of the massive snakes inhabit Florida at present, prompting the state to endorse “python round-ups” in order to hopefully reduce the large snake population.
Unlike the Burmese pythons, experts are unsure how the Nile crocodiles made their way to the United States. But, as University of Florida herpetologist Kenneth Krysko told the Associated Press, they didn’t swim all the way to the Peninsula State. Krysko speculates that the crocodiles were most likely brought to the U. S. illegally by unlicensed collectors. Then the beasts were either intentionally released or somehow escaped from their owners or handlers.
And just like the Burmese pythons, not knowing how long the Nile crocodiles have been on the loose in Florida poses a problem, because their numbers cannot be calculated on three confirmed DNA cases. Krysko noted the problem in a University of Florida press release via Science Daily.
“The odds that the few of us who study Florida reptiles have found all of the Nile crocs out there is probably unlikely.”
And, just like the pythons, if you cannot find them, you cannot control the population. This becomes even more troubling considering that, along with an appetite for shrimp, insects, and birds, the Nile crocodile enjoys mammals as well, including livestock and the occasional human being. Whereas pythons can pose somewhat of a risk to human life (especially to children), Nile crocodiles are famous for being man-eating machines of nature. In their natural habitat in sub-Saharan Africa, the massive reptiles kill an estimated 200 people every year. That kill number far exceeds the number of shark attack deaths globally (six in 2015).
As the Associated Press points out, the Nile crocodile, should it become established in the Florida Everglades, could presumably introduce further deterioration in the already tenuous ecosystem. It could also cause degeneration in the American alligator population, an already endangered species numbering about a thousand in all of South Florida, through cross-breeding. That smaller, less aggressive species has never been the confirmed killer of a human being.
Although Krysko and the two co-authors of the Nile crocodile paper, independent wildlife biologist Joe Wasilewski and University of Florida wildlife ecology professor Frank Mazzotti, believe that more of the potentially massive reptiles are to be found in the Everglades, they cannot be completely certain. At the same time, Allyson Gantt, speaking for Everglades National Park, where one of the crocodiles was recovered, disagrees with the researchers’ conclusions, saying that no Nile crocodiles are still in the park.
But how can she be certain? Regardless, what about the other swamps and waterways in the region?
Said Kenneth Krysko in the press release: “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. Now here’s another one, but this time it isn’t just a tiny house gecko from Africa.”
Nor is it a Burmese python. It is far worse; it is a man-eating crocodile, and experts believe the species is now on the loose.
[Image via Shutterstock]