Killer Nile crocodiles in Florida? It’s possible

FORT LAUDERDALE, Fla. — 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 the crocs 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.

Wasilewsi said people are likely to notice the difference, or at least take photos that researchers can check later. And no, crocs and alligators can’t interbreed.

Florida already has more non-native amphibians and reptiles than any region worldwide, according to the UF paper, published April 30 in Herpetological Conservation and Biology. They include Burmese pythons, a menace that quickly reproduced into the thousands and is decimating the Everglades’ small mammal population.

Giant toads, iguanas and another species of crocodilian, the spectacled caiman, also live in the state. But that species grows to only about 80 pounds and feeds on fish, crustaceans and the occasional small mammals.

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.

The UF paper said all Florida wetlands and coastal areas of Alabama, Mississippi, Louisiana and Texas would be hospitable to Nile crocodiles. They require fresh water, abundant prey and year-round warm weather.

“Doesn’t that sound like Florida?” Krysko said.

Fortunately, Nile crocodiles don’t reproduce rapidly. Still, the researchers said, it might only take one adult male and female finding each other for an Everglades population to become established.

“I have two words: Burmese python,” Wasilewski said. “If you would have told me 15 years ago we would have an established population in the Everglades, I wouldn’t have believed you.”

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Local News

Trader Joe’s customers walk in and out of the store on Monday, Nov. 20, 2023 in Everett, Washington. (Olivia Vanni / The Herald)
New Trader Joe’s opens this week at Everett Mall

It’s a short move from a longtime location, essentially across the street, where parking was often an adventure.

Ian Bramel-Allen enters a guilty plea to second-degree murder during a plea and sentencing hearing on Wednesday, March 6, 2024, at Snohomish County Superior Court in Everett, Washington. (Ryan Berry / The Herald)
‘Deep remorse’: Man gets 17 years for friend’s fatal stabbing in Edmonds

Ian Bramel-Allen, 44, pleaded guilty Wednesday to second-degree murder for killing Bret Northcutt last year at a WinCo.

Firefighters respond to a small RV and a motorhome fire on Tuesday afternoon in Marysville. (Provided by Snohomish County Fire Distrct 22)
1 injured after RV fire, explosion near Marysville

The cause of the fire in the 11600 block of 81st Avenue NE had not been determined, fire officials said.

Ashton Dedmon appears in court during his sentencing hearing on Tuesday, March 5, 2024, at Snohomish County Superior Court in Everett, Washington. (Ryan Berry / The Herald)
Everett Navy sailor sentenced to 90 days for fatal hit and run

Ashton Dedmon crashed into Joshua Kollman and drove away. Dedmon, a petty officer on the USS Kidd, reported he had a panic attack.

A kindergarten student works on a computer at Emerson Elementary School on Wednesday, Feb. 28, 2024, in Everett, Washington. (Ryan Berry / The Herald)
‘¡Una erupción!’: Dual language programs expanding to 10 local schools

A new bill aims to support 10 new programs each year statewide. In Snohomish County, most follow a 90-10 model of Spanish and English.

Cassie Franklin, Mayor of Everett, delivers the annual state of the city address Thursday morning in the Edward D. Hansen Conference Center in Everett, Washington on March 31, 2022.  (Kevin Clark / The Herald)
At Everett mayor’s keynote speech: $35 entry, Boeing sponsorship

The city won’t make any money from the event, city spokesperson Simone Tarver said. Still, it’s part of a trend making open government advocates wary.

Logo for news use featuring the Tulalip Indian Reservation in Snohomish County, Washington. 220118
Woman drives off cliff, dies on Tulalip Reservation

The woman fell 70 to 80 feet after driving off Priest Point Drive NW on Sunday afternoon.

Everett
Boy, 4, survives fall from Everett fourth-story apartment window

The child was being treated at Seattle Children’s. The city has a limited supply of window stops for low-income residents.

People head out to the water at low tide during an unseasonably warm day on Saturday, March 16, 2024, at Lighthouse Park in Mukilteo, Washington. (Ryan Berry / The Herald)
Everett shatters record high temperature by 11 degrees

On Saturday, it hit 73 degrees, breaking the previous record of 62 set in 2007.

Snohomish County Fire District #4 and Snohomish Regional Fire & Rescue respond to a motor vehicle collision for a car and pole. The driver was pronounced dead at the scene, near Triangle Bait & Tackle in Snohomish. (Snohomish County Sheriff’s Office)
Police: Troopers tried to stop driver before deadly crash in Snohomish

The man, 31, was driving at “a high rate of speed” when he crashed into a traffic light pole and died, investigators said.

Alan Dean, who is accused of the 1993 strangulation murder of 15-year-old Bothell girl Melissa Lee, appears in court during opening statements of his trial on Monday, March 18, 2024, at Snohomish County Superior Court in Everett, Washington. (Ryan Berry / The Herald)
31 years later, trial opens in Bothell teen’s brutal killing

In April 1993, Melissa Lee’s body was found below Edgewater Creek Bridge. It would take 27 years to arrest Alan Dean in her death.

Logo for news use featuring the municipality of Snohomish in Snohomish County, Washington. 220118
Man dies after crashing into pole in Snohomish

Just before 1 a.m., the driver crashed into a traffic light pole at the intersection of 2nd Street and Maple Avenue.

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.