This is one non-native animal that has infiltrated Sanibel Island very, very slowly.
A turtle, the invasive pond slider, first appeared on the barrier island more than 60 years ago.
It never was one of the more visible turtles until Hurricane Ian in 2022 battered many of the native freshwater turtles when storm surge flooded or over-washed the island.
After the hurricane, sightings of native turtles such as the live peninsula cooters, red-bellied turtles, softshell turtles, and snapping turtles declined.
Herpetologists blame not the slider, but the former freshwater ponds in the interior of the island spiking in salinity after being inundated with saltwater storm surge during Hurricane Ian and again during hurricanes Milton and Helene a few years later.
The pond slider can handle higher salinities.
“Scientists have documented higher salinity tolerance in other parts of the world, but we have not seen this here until now. For the last four years, people have been sending us photos of aquatic turtles basking, crossing roads, and laying eggs — most of them are sliders,” said Chris Lechowicz, the Sanibel-Captiva Conservation Foundation’s director of wildlife and habitat management. “They are survivors.”
The SCCF documented yellow-bellied sliders being introduced to Sanibel in 1963, and red-eared sliders, probably released pets, found by 1975. The turtles later interbred and spread.
Pond sliders today remain common across much of Sanibel, even in the small lakes made salty by the hurricanes where they continue basking in the sun. It’s how they earned their name.
As cold-blooded reptiles, they climb out of the water to bask in the sun to regulate their body temperature.
Highly alert and wary of predators, any sudden noise, movement, or approaching person sends them sliding down the rocks, logs, and banks into the safety of the water.
Environmental reporting for WGCU is funded in part by VoLo Foundation, a nonprofit with a mission to accelerate change and global impact by supporting science-based climate solutions, enhancing education, and improving health.
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