Florida scientists ask people to watch out for potentially invasive ‘Jesus lizard’ that can run across water

There are reports of brown basilisks from the Florida Keys to Gainesville

The brown basilisk, a nonnative lizard, is gaining ground across South and Central Florida, and University of Florida IFAS scientists need more data to determine its status and potential impacts. (UF)

GAINESVILLE, Fla. – Scientists from the University of Florida are asking people to be on the lookout for the brown basilisk, a nonnative lizard also known as the “Jesus lizard,” because the reptiles have the potential to become invasive in Florida.

UF said the species is gaining ground across South Florida and scientists said they need more data to determine its status and potential impacts.

“We receive anecdotal reports of brown basilisks in areas where the reported sightings are thin and sporadic, but we know they are thriving in South and Central Florida. There are reports of brown basilisks from the Florida Keys to Gainesville” said Ken Gioeli, a natural resources and environment agent at UF/IFAS Extension St. Lucie County. “Residents and visitors can enhance the data by taking photos of brown basilisks and uploading them to EddMapS or the IveGot1 app.”

The lizard has prominent markings and characteristics that distinguish it from other reptilian species, most notable is the head crest. They also appear to run across water, leading to their nickname.

There remains a mystery to scientists about how far and wide they have spread and what they are consuming and disturbing, according to UF.

Currently, numbers indicate that the reptiles are primarily in South and Central Florida.

“It is important for us to determine where the invasion front currently is, where it might be heading, and the numbers likely to be found,” Gioeli said. “Right now, we can work with the limited reported sightings on EddMaps, but scientists need more accurate numbers.”

Of particular interest is the space between Orlando and Palm Beach County, said Gioeli.

“We know the brown basilisks are on the Treasure Coast, and we can see there is a likely move northward and west,” he added.

Florida’s west coast has also seen sporadic reports.

“There is still a lot we don’t know about the impacts of brown basilisks in south and central Florida,” Gioeli said. “We don’t know enough about their diet, reproduction or environmental impacts, but fortunately, we have dedicated UF/IFAS research and Extension specialists studying these issues.”

While not all nonnative species evolve to become invasive, those that become established can impact waterways, wildlife, agriculture and urban areas — a concern for scientists, wildlife organizations and communities.

Among the concerns, a study published in Frontiers in 2022 by UF/IFAS Florida Medical Entomology faculty found that Culex mosquitoes prefer to feed on nonnative lizards. The brown basilisks are among five identified nonnative lizards that could potentially serve as significant hosts for West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) vectors in Florida.

As of February 2023, more than 160 specimens have been collected and recorded at the Florida Museum of Natural History Herpetology Collection database.

A brown basilisk on trees in urban areas of South Florida. Photo courtesy of Steve Johnson. (University of Florida)

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