2020: A Banner Year for Turtles on our Islands

31 Dec 2020

This has been an extraordinary year for turtle research on Sanibel despite the setbacks from the global pandemic. All 10 known species of freshwater, brackish, and terrestrial species that have been recognized on the islands in the past were documented this year. Three of the four marine turtle species known to nest on Sanibel nested this year.
 
The highlight was the leatherback (Dermochelys coriacea) that returned to nest more than once. Of the non-marine turtles, the two rarest species known to live on Sanibel—the Florida chicken turtle (Deirochelys reticualria chrysea) and Florida mud turtle (Kinosternon steindachneri)—were documented multiple times during 2020.
 
“More than one observation of these turtles in a single year has never been recorded,” said SCCF Director of Wildlife & Habitat Management and herpetologist Chris Lechowicz. There are a few possible reasons for this anomaly, Lechowicz said, such as extreme high water lasting for a long period of time that caused these two ephemeral species to spend more time wandering on land or fewer disturbances by human activity due to lower numbers of people circulating during the pandemic.
This year, the Wildlife & Habitat Department formed the SCCF Terrestrial and Freshwater Turtle Volunteer Group, pictured here, to help survey and document species throughout the island. This has been quite successful because it ensures that many areas of the island are covered.
 
The first documented chicken turtle nesting event on Sanibel was discovered in January and this species was recently found more than three miles from its known range on the island. Two of these turtles were tracked with radio telemetry throughout the year noting their active and inactive (aestivation) cycles and preferred habitat. The rarest Sanibel turtle, the Florida mud turtle, was documented three times this year and two of them are being actively tracked with radios to determine their preferred habitats and periods of dormancy.
Many Florida box turtles (Terrapene carolina bauri) from the confiscation from a turtle trafficking bust in August 2019 are being tracked with radio telemetry and GPS transmitters on Sanibel. A lot of valuable information is being gathered on translocated versus repatriated box turtles from a hard release (immediate release) that occurred on the island.
 
This information is being compared to a soft release (in which turtles are penned and acclimated to a new environment before release) of confiscated box turtles in South Carolina. This data will be used to aid future releases of confiscated box turtles from trafficking busts. 
 
The department would like to thank Mike Mills and Juliana Koller, pictured here with a box turtle, for their hard work and diligence to detail in their field work in challenging conditions, including traversing through heavy vegetation, extreme amounts of poison ivy, and lots of biting insects.