And even worse, they are devouring the much-smaller native treefrogs.
It’s pretty hard not to love a frog. But when a new kind of frog shows up where it doesn’t belong, and is the size of a human fist, and eats the smaller native frogs … well that’s not so lovable.
Such is the case in New Orleans, Louisiana, where a population of invasive Cuban treefrogs have become the first known breeding population in the mainland United States outside of Florida, according to a new study by the U.S. Geological Survey.
Adding to the unlove factor are the frog’s particular traits; which might be fine for a frog, but make it not so great for living in harmony with humans.
“Homeowners may be familiar with the nuisance species as they have noxious skin secretions, lay their eggs in bird baths and fish ponds, and they can clog plumbing and cause power outages by short-circuiting utility switches where they seek refuge,” says USGS Research Ecologist Brad Glorioso, the lead author of the study. “Cuban treefrogs grow much larger than native treefrogs, have been known to displace native treefrogs, and will even eat smaller frogs, often of their own species. A decline in native treefrogs could have consequences, since frogs act as both predator and prey in food webs.”
Native to Cuba, the Bahamas, and the Cayman Islands, Cuban treefrogs have been finding success in Florida since at least 1951. In March of 2016, palm trees were brought from Lake Placid, Florida and planted in the elephant exhibit at New Orlean’s Audubon Zoo. Elephant keepers began seeing the odd frogs shortly thereafter.
“In late 2016, reports of at least eight Cuban treefrogs of varying sizes on the grounds of the Audubon Zoo in New Orleans gave concern that a population may be establishing,” notes the USGS. “Following additional reports in 2017 of suspected Cuban treefrog tadpoles and recently metamorphosed juveniles in Riverview, a part of Audubon Park between Audubon Zoo and the Mississippi River, the USGS began investigating the likelihood of an established population.”
In a span of three months, between September and November of 2017, the USGS scientists collected 367 Cuban treefrogs in just four surveys. In addition, thousands of tadpoles have been discovered.
Nuisance to homeowners aside, the real threat is to native treefrog species, of which USGS scientists noted a lack of during their surveys, saying that “No native treefrogs were captured at Riverview, where the highest density of Cuban treefrogs were found.”
The local treefrogs are a lot smaller than their Cuban cousins, says Jeff Boundy, a herpetologist with the Louisiana Department of Wildlife and Fisheries’ Natural Heritage Program.
“The natives are about a quarter- to half-dollar-size on your kitchen window at night. These guys get up to 5½ inches (14 centimeters) in body length. You’re talking about a fist-sized frog now,” Boundy told the AP.
“Right now, the hope is that the Cuban treefrogs do not reach and become established in the large tracts of public land, including the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, just across the Mississippi River,” says Glorioso.
The moral of the story? Among other things, beware of the Florida palm trees and the secret gifts they deliver.
The study was published in the journal Biological Invasions.