Some people spend their retirement traveling the world or relaxing at home. Sid Pennington spends his time trapping invasive lizards that threaten native wildlife in his community.

Pennington, 60, has single-handedly captured at least 117 black and white Argentine tegus in the woods and western neighborhoods of Fort Pierce where he lives.

In September, after the Florida Fish and Wildlife Conservation Commission saw how adept Pennington was at catching non-native tegus on his own, biologists lent him 20 traps and recruited him as a volunteer. He’s caught 31 this year alone.

“I grew up being a big reptile,” said Pennington, a former employee of the St. Lucie nuclear plant. His first catch was a female tegu in 2019, measuring just under 4 feet long. “I don’t want them here. But it’s fun.

Tegu populations spread to Florida

With sharp teeth and scaly black and white spots, the tegus can spread faster than biologists can trap them. The state doesn’t have a definitive population estimate, but residents have reported at least 132 sightings in St. Lucie County through 2021. Sixty percent of those sightings were from Pennington.

The South American lizard’s appetite for the eggs of native animals – such as killdeer, alligators and gopher tortoises – and its ability to thrive in cooler environments has elicited a strong response from FWC. If tegus begin to spread north, it could wreak havoc on native species already strained by habitat loss and overdevelopment.

This St. Lucie County population likely originated from escapes or releases resulting from the exotic pet trade, according to non-native FWC biologist Dan Quinn. The species now breeds successfully in three other Florida counties: Charlotte, Hillsborough, and Miami-Dade.

More than 12,000 tegus statewide have been removed from the wild to date.

“They’re starting to take hold here,” Quinn said of Fort Pierce at a press conference off Rock Road on Wednesday. “Since 2016, when the first tegu was reported, we have seen an increase in reports. We think it is possible that the population will increase in this area.

Most sightings have been recorded west of the Florida Turnpike, with a majority of reports south of Orange Avenue and north of Okeechobee Road, according to the FWC. The sightings were verified from over three miles away.

There have also been periodic sightings of individual animals in Martin and Indian River counties that are likely released pets and not part of an established population, Quinn said.

There is strong evidence that tegus affect native Florida species. A lizard captured in Charlotte County had gopher tortoise eggs in its stomach. Researchers from the University of Florida documented in 2014 a tegu eating alligator eggs.

In April 2021, the FWC deemed the tegus a “high risk” species and banned owning or raising them. Tegus remaining in captivity may live out the rest of their lives, but any future sale is prohibited.

Tegus are lured to traps by chicken eggs and are then humanely killed, Quinn said.

“The vast majority of sightings (in St. Lucie County) have been within the past two years,” Quinn said.

FWC is asking for the public’s help

When it comes to eliminating invasive species, wildlife biologists across the state have their hands full. The FWC has removed thousands of Burmese pythons from the Everglades, overseen a multi-year statewide effort to kill lionfish from Florida waters, and actively encourages the removal of iguanas.

Tegus is now the last animal on the list of problematic species, and the state has spent about $1.3 million since 2016 to reduce the population, according to FWC spokeswoman Lisa Thompson. A female tegu can lay about 35 eggs per year.

As temperatures rise with climate change, cold-blooded invasive species will spread wider and faster. A population of tegus, for example, has already been recorded in Georgia.

Last week, FWC outreach teams sent 3,800 letters to homes in St. Lucie County near where tegu sightings were documented and placed five information signs along busy roads . They also visited hundreds of homes in the area, handing out pamphlets that read, “How you can help stop the spread of an invasive lizard.”

The goal is to inform the public and encourage documentation of verified reports, Quinn said.

“We suspect more people are seeing them and not reporting them,” he said.