Invasive caiman may pose new challenges for Everglades restoration

UF researchers pieced together the first comprehensive review of the spectacled caiman, a small invasive crocodile-like reptile.
Introduced into South Florida more than 45 years ago, researchers have suspected caimans compete with native species for food and habitat.
Scientists say the species could complicate the Comprehensive Everglades Restoration Plan, the largest hydrologic restoration in U.S. history.

In the canals, wetlands and marshes of the Florida Everglades, the spectacled caiman has quietly expanded its foothold threatening an already-vulnerable ecosystem.

A University of Florida study synthesizes more than 70 years of research on the invasive species native to Central and South America that has firmly established itself across the most vulnerable part of the Sunshine State – the Florida Everglades.

Researchers at UF’s Institute of Food and Agricultural Sciences (UF/IFAS) in Fort Lauderdale say the reptile may further complicate the Comprehensive Everglades Restoration Plan (CERP) – the largest wetland project in the history of the United States.

“We want people to be aware that this species is present in the Everglades. Reporting sightings can help agencies and researchers respond quickly and better understand where populations are expanding.” —Sergio Balaguera-Reina, Ph.D., research assistant scientist at the UF/IFAS Fort Lauderdale Research and Education Center and a co-lead of The Croc Docs

At a multibillion-dollar price tag, the project is designed to restore, preserve and protect Florida’s most sensitive ecosystem. The Everglades ensures water supply and flood protection and serves as a habitat for valued wildlife species.

The study compiles the spectacled caiman’s documented establishment, detailing what scientists know about the species’ biology, ecology and distribution while identifying major unanswered questions about its environmental impacts.

a baby caiman, a crocodile-like reptile, stands on leaves and twigs at night

“We now know the spectacled caiman is established in more areas than we previously thought. We also know that spectacled caimans are more adaptable than we previously understood,” said Sergio Balaguera-Reina, lead author of the study, a co-lead of The Croc Docs and research assistant scientist at the UF/IFAS Fort Lauderdale Research and Education Center. “We still lack basic information about how this species may affect Everglades ecosystems. That is one of the most striking findings from this work.”

Researchers say the findings underscore the need for continued management and expanded scientific research before the species becomes even more difficult to control.

The spectacled caiman was introduced into Florida through the exotic pet trade with established populations documented since the 1980s.

“At the beginning, we thought Colombia was the main source and genetic work conducted with samples from 1980s and 1990s also pointed to Colombia,” he said. “However, using more recent samples from the 2000s, we got a genetic signal pointing to Brazil and the Guayana area as an additional new source of caimans.”

These mixed origins may boost their adaptability, making it tougher to control, he said.

Researchers don’t know whether Everglades restoration efforts might create more or less suitable habitat for caimans. More study is needed to see how spectacled caimans will respond to restoration and affect native alligators, crocodiles and wildlife. Researchers also know little about where these reptiles nest, how far they travel during seasonal periods or whether restored waterways could accelerate their spread into protected natural areas.

“We think caimans in Florida may move more than populations in their native range because of dry-down conditions in the Everglades,” Balaguera-Reina said. “This could potentially mean that they can disperse faster than we expect.”

To address those questions, researchers continue to track spectacled caimans to better understand their movements and how they use habitats. Future projects include satellite tagging of female caimans to locate nesting areas and developing environmental DNA tools to identify new populations before they establish. These efforts are critical as wildlife managers try to reduce the spread, while protecting the Everglades restoration.

Researchers also hope the public can play a role in slowing the species’ spread.

“We want people to be aware that this species is present in the Everglades,” he said. “Reporting sightings can help agencies and researchers respond quickly and better understand where populations are expanding.”

Researchers encourage the public to report any spectacled caiman sightings through the IVEGOT1 app or calling 1-888-IVEGOT1 (483-4681) or reporting on the EDDMaps website.