An invasive Cuban treefrog in New Orleans.
Photo: Brad Glorioso, USGS

It is a cannibalistic, fist-sized frog covered in a noxious mucous secretion that burns your eyes. Its affinity for human structures leads it to clog drains and short-out the utility switches in which they lurk. They are spreading through the U.S. and we can’t stop them. Several message board commenters report that this proliferation is part of a communist invasion.

This is how the internet describes the Cuban Tree Frog. But even though almost all of that description is accurate (Earther was unable to verify the communist invasion), they’re not actually so sinister—just native Caribbean frogs swept up by humanity’s constant transit. For decades, the only known established populations of Cuban Tree Frogs in the continental US were inside Florida’s borders. This changed in 2016, when the frogs were found at the Audubon Zoo in New Orleans some 430 miles away from the nearest known population.

Now, experts say it’s only a matter of time before the species proliferates throughout the Gulf Coast.

“They’re survivors,” Steve Johnson, a professor at the University of Florida and one of the foremost experts on Cuban Tree Frogs in America, told Earther. “I dislike them for the fact that they’re not native in Florida and they’re eating our native species. On the other hand, I have respect for them because they’re successful.”

In April, the U.S. Geological Survey published a study confirming that the frogs established a new population in New Orleans, and warning of their potential harm. The report has received a flurry of coverage, and Johnson thinks the attention is well deserved.

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“They’re probably the worst of the amphibians we have,” he said, adding that they’re part of “the top tier” of disruptive invasive species in Florida—the state with the most invasive species in the country.

A cuban tree frogs in New Orleans.
Photo: Brad Glorioso, USGS

The frogs, which were likely transported to Florida via trade ships in the 1920s, are great hitchhikers, traveling in the nooks and crannies of car wheels or exported plants. They’ve been found all over North America, as far north as Canada, but they are usually unable to establish a population because of the cold. The hot and humid Gulf Coast is a different story.

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After Brad Glorioso, an ecologist with the US Geological Survey, heard that the frogs were spotted at the Audubon Zoo in 2016, he went to see for himself. It didn’t take long for him to understand the situation.

The first place he and his team of scientists looked was a concrete bathroom in the park—prime real estate for the Cuban Tree Frog.

“We look behind the first electrical panel and saw tons of eyes looking back at us,” Glorioso told Earther. In only four surveys in one day, they found 367 Cuban Tree Frogs. The frogs have now endured two winters, an indication that they’re here to stay. “Eradicating them is probably never going to happen,” Glorioso said.

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There is now a concern that the frogs will start triggering the same expensive electrical and plumbing problems that Florida endures. But Glorioso is more worried about the ecological implications. In Florida, the frogs have decimated local tree frog populations. The same could happen in Louisiana, and their presence could reverberate up and down the food chain.

As a generalist predator, the Cuban Tree Frog will eat anything it can get in its mouth, including native tree frogs and even the occasional snake. This could potentially disrupt the food supplies that sustain other animals. As prey, one study suggests they’re not nearly as nutritious as Louisiana’s native tree frogs, meaning that native predators, such as garter snakes, could unknowingly apply the same amount of energy for a lesser meal. They could also carry diseases that threaten native amphibians.

But ultimately, a lack of research leaves scientists unsure of how the Cuban Tree Frog changes ecosystems. The money for invasive species research usually goes to the more notorious invaders, Johnson says. “The frogs aren’t as headline grabbing as a python eating an alligator.”

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Experts agree that it is nearly impossible to get rid of the Cuban Tree Frog once it’s established. The goal in Louisiana is now to keep them contained within New Orleans, and out of the natural areas that surround the city. Still, scientists predict this scourge will spread.

“I think before long, you’ll find more established populations all across the Gulf Coast. If they can survive in Gainesville and Jacksonville and New Orleans, they can survive a whole lot of places in between,” Glorioso said. He also suggests that more populations may have already formed throughout the Gulf without locals realizing what they are.

And as climate change warms the planet, scientists predict that the frogs will be able to move further and further north.

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Glorioso and Johnson both say that this dispersion is inevitable given the increasingly immense numbers of cars, trucks and merchandise that travel American roads at any given second. “It’s a symptom of the global economy,” Johnson says. “It would be next to impossible to stop them.”

Based in New Orleans, Michael Isaac Stein writes about criminal justice and the environment in the Gulf.