Large, slimy, cannibals: Invasive Cuban tree frogs gobbling up Florida’s native wildlife

Cuban tree frogs can hide in your toilet, in your gutters, in crevasses around your yard.

On warm nights, they hang on walls and windows near lighted areas and wait for insects to eat. They’ve adapted to living among humans — and have been known to jump on people as they enter and exit their homes at night.

The non-native frogs can lay up to 1,000 eggs during the spring and summer months, especially after heavy rains. They remain tadpoles for only a few weeks before they morph into frogs, preying on native wildlife. During drier months, they’re less active.

A Florida statute prohibits releasing invasive species into the wild, even if one finds its way into your home.

It’s not only illegal, it’s irresponsible to let the frogs go because of their impact on native wildlife, said Steve Johnson, a wildlife ecology and conservation professor at the University of Florida.

One solution: euthanasia.

Yes, you can hit a Cuban tree frog in the head with a hammer. Any accurate and quick blunt force that results in instant death is considered humane.

Johnson, however, doesn’t promote this method to mitigate the population.

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The most approachable way to kill these amphibians is to capture one in a plastic bag, tie the bag tight and place it in the refrigerator for a few hours, then in the freezer overnight. The cool air acts as a natural anesthetic, and the frog will die a painless death, according to Johnson. In the morning, throw the bag away.

Many Floridians, however, find it hard to take a seemingly harmless, big-eyed frog and kill it. Plus, the frogs secrete a slimy film that can irritate some people’s skin and eyes, and it’s not like the Florida Fish and Wildlife Conservation Commission has “Cuban tree frog cops” to enforce the law, Johnson said.

“Some (people) are like, ‘I can’t bring myself to do it. Can you come get them?’” Johnson said. “‘No.’ I’d be spending all my time trying to pick up frogs from people.”

Cuban tree frogs are thought to be responsible for the decline of native species such as the southern toad and green and squirrel tree frogs. They eat lizards and snails, and they compete with other tree frogs for habitat and food, according to the wildlife commission.

“Every frog has beautiful eyes, so they got that redeeming quality,” Johnson said. “But the fact that they’re eating our native tree frogs … I’m advocating for native species.”

There’s another school of thought: Let the frogs be.

“Through the range of South Florida, they can be virtually in every neighborhood, potentially every yard,” said Sean Doody, associate professor of integrative biology at the University of South Florida.

It’s like swatting a mosquito and thinking you’ll make a difference in mosquito populations, Doody said.

He acknowledges his opinion is unpopular. But he looks at the invasive brown anoles that scurry across all of Florida: “There’s nothing we could do,” Doody said.

Cuban tree frogs spread rapidly from Cuba and other parts of the Caribbean to Florida over the last century. The first ones most likely hitched a ride on shipping crates in the 1920s, and by the 1970s, they had inhabited most of southern Florida, according to Johnson.

Adult Cuban tree frogs are hard to identify and can be confused with native species like barking tree frogs and Cope’s gray tree frogs. Their warty skin often ranges from creamy white to light brown, though they can be green, yellow, dark brown or a combination of the three. Some have patterns on their backs while others remain a solid shade, according to the wildlife commission.

The simplest way to identify a Cuban tree frog is by its toe pads, which are larger than those of native tree frogs, the wildlife commission said. And they have “bug eyes,” according to Johnson. Plus, any tree frog in Florida that grows longer than 3 inches is almost certainly a Cuban tree frog, which can grow up to 6 inches.

They do have natural predators: Several Florida snakes will eat them, like black racers, pygmy rattlesnakes and garter snakes. Owls, crows and wading birds have also been seen feeding on the frogs, Johnson said.

Kelly Cockerham, a nonprofit grant writer living in Riverside Heights in Tampa, has at least two Cuban tree frogs in her yard. One lives behind a flower pot on the side of her shed, the other in lemongrass by her fountain.

“I don’t personally like frogs very much. They creep me out,” Cockerham said. “But I was like, that’s the cutest freaking frog I’ve ever seen.”

Cockerham tailored her yard with native plants to attract monarch butterflies, and she seeks advice from Little Red Wagon Native Nursery for what’s best to grow. When she learned Cuban tree frogs are invasive, she felt conflicted.

The species found their niche among humans, Doody said, and they can breed in lily ponds, bird baths and kiddie pools.

“I just created a wonderful environment for them,” Cockerham said with a laugh; she has two fountains and “a lot of pots back there.”

The frog near the blue fountain keeps her up at night with its loud call, a nuisance that Johnson said peaks in the hours before dawn.

But a few days ago, Cockerham’s son saw a black racer come out of the lemongrass. She hasn’t heard the frog’s ribbit since.