Florida Reef Gecko Faces Threats from Development and Climate Change

Beneath dried leaves and palm fronds, the Florida reef gecko lives in relative obscurity. The two-inch critters have speckled brown bodies that blend in with the forest floor, and they can dart off in the blink of an eye.

But for such a tiny reptile, it faces some large threats: notably, urban development in one of the fastest growing U.S. states and sea level rise due to climate change.

In February, Florida’s wildlife agency voted to list the reef gecko as a state-level threatened species. The agency’s proposed action plan includes provisions to increase and protect the gecko’s habitat and expand science-based research about the animal.

The decision comes five years after scientists first warned that its historic range has dwindled—and what remains is at high risk of going underwater by the end of the century.

“This species was so under-studied to begin with, so we just didn't know that we even needed to be worried about them,” says Stephanie Clements, a conservation biologist who led a 2021 study surveying the locations of reef gecko populations—data that informed the original listing petition filed in 2021.

These geckos have already disappeared completely from nine spots, and their habitat has been reduced to 41 percent of its original size in less than a century, according to recent research. At the same time, South Florida’s stretch of the Atlantic Ocean is predicted to rise between one and three feet by 2080, according to NOAA.

“Our concerns with the reef gecko are loss of entire populations,” Clements adds.

In a phenomenon called coastal squeeze, sea level rise will begin to swallow parts of the state, promoting people to move inland. But geckos can’t follow.

“If you can't travel more than a hundred meters in 10 or 20 generations, you're not really going to be able to outrun potential problems like sea level rise,” says Aaron Bauer, a biology professor at Villanova University who reviewed the Florida listing proposal as an outside expert.

If sea levels rise by seven feet, biologists expect 85 percent of the gecko’s habitat to go underwater.

But some scientists argued the reef gecko might not belong in Florida at all—a controversy that held up its listing as a threatened species for years.

In a state overrun with invasive reptiles, the Florida reef gecko is a rarity: It’s the only gecko native to the eastern United States and lives in small pockets of South Florida’s tropical hardwood hammocks, an ecosystem that provides a cool, dry refuge for the gecko and many other species.

At Miami’s Simpson Park, a protected hammock preserve, an entire reef gecko population lives within the confines of just eight acres, but “there's no guarantee that it's viable in the long-term,” says conservation biologist Christopher Searcy, a co-author on the 2021 study and head of the Searcy Lab at the University of Miami.

“Of course, coastal areas are where humans most want to develop, so the tropical hardwood hammocks along the coast are highly fragmented,” Searcy says.

This habitat is also right in the path of hurricanes, which are becoming more intense due to the changing climate.

By granting the reef gecko protections, the listing decision helps protect the geckos’ wider hardwood hammock habitat—and the other species that live there—from development as well, Clements says.

The at-risk rim rock crowned snake, for instance, shares habitat with the reef gecko and, as the result of a recent court ruling, will be listed for federal protections under the Endangered Species Act. Both are important predators in their ecosystems: Reef geckos dine on insects such as beetles, bees, wasps, ants, butterfly and moth larvae, and worms, keeping the hardwood hammock’s forest floor ecosystem in balance.

“It’s about so much more than just them,” Clements says. “It’s about their dwindling habitat.”

Although the Florida reef gecko is considered a Florida native, some scientists weren't always sure.

The earliest written record of reef geckos in Florida dates back to 1858 in Key West, a bustling port where geckos could have easily hitched a ride on cargo. But earlier genetic data trace to Key Largo, a more northern island where trade wasn’t as common. This would imply that the geckos rafted to Florida from the Caribbean on their own, if they weren’t already there.

The Florida populations are categorized as the subspecies Sphaerodactylus notatus notatus, but the main species occurs across the Caribbean. The populations outside of Florida aren’t as imperiled.

“I still think the jury is out,” says Tony Gamble, a herpetologist at Marquette University in Wisconsin who studies dwarf geckos—a group to which the Florida reef gecko belongs—and their evolution.

Resolving the controversy would require comparing genetic samples from South Florida with those in Cuba or the Bahamas, he says. Still, “it is better to err on the side of caution to conserve populations before we know the whole story,” he adds in an email. “We can always adjust species management later when new data comes to light.”

State officials declared in a public meeting this month that the Florida population is resident.

The plan for protecting the gecko will require habitat surveys before building permits are issued in locations where the geckos might appear, such as hardwood hammocks with lots of leaf litter.

Still, at the state level, developers can easily find loopholes for species like these that are hard to find, says Elise Bennett, a senior attorney at the Center for Biological Diversity, a nonprofit that advocates for endangered species.

Knowing where to find these obscure critters is key to protecting them, Clements adds. “If you know they're in an area, you don't want to clear all the leaf litter,” where the geckos often dwell, she says.

Microscale critters such as the reef gecko also represent a large gap in conservation, Gamble adds.

“Little things need conserving, and they are being affected just as much as the big, charismatic megafauna,” Gamble says.

“For every elephant or panda, you’ve got dozens or hundreds of these little things that are in the same boat.”