Authored by Houston Chandler and Ben Stegenga
On a cool day in mid-March, we waded into one of South Georgia’s many blackwater swamps in search of Spotted Turtles (Clemmys guttata). This marked the beginning of our 3rd year studying Spotted Turtle populations in Georgia, the first extensive study of these diminutive turtles in the state. Spotted Turtles can be found all the way up the Atlantic Coastal Plain of the United States and in the Great Lakes region of the U.S. and Canada. Despite this large range, many Spotted Turtle populations are thought to be declining, primarily because of habitat loss and exploitation for the pet trade. The majority of research on Spotted Turtles has been conducted with northern populations, and the lack of research on Spotted Turtles in Georgia makes it difficult to assess whether populations are declining or not. We aim to provide new information about Spotted Turtle populations in southern Georgia by trapping, marking and radio-tracking turtles.
The trick to working with Spotted Turtles is that they can be difficult to find, even when they are most active in early spring (mating season), but virtually impossible to find during summer and winter when turtles are less active. Even when turtles are active in the spring, trapping is the best way to catch a large number of turtles. This is why we carried several large, custom-built traps (similar to a crab trap) specially designed to catch small turtles into the swamp. We baited traps with sardines and waited until the next day in hopes that many of the turtles captured in previous years would be back again this year. By the end of the first week of trapping, we had caught eight turtles, and one day in the second week, we caught four Spotted Turtles in a single trap! Off to a good start.
One of the fun things about any sort of trapping is that you are bound to catch species other than your target species. This season we caught a variety of other herpetofauna, including large bullfrogs (Lithobates catesbeianus), a Greater Siren (Siren lacertina), juvenile Snapping Turtles (Chelydra serpentina), Striped Mud Turtles (Kinosternon baurii) and plenty of Eastern Mud Turtles (Kinosternon subrubrum). Along with this interesting bycatch, we caught plenty of Spotted Turtles, both new individuals that we had not captured before and individuals that we had seen plenty of times over the last two years. We also caught both the largest and smallest Spotted Turtles that we had seen to date—the smallest turtle was likely last year’s offspring. We were relieved that we were catching a good amount of adult turtles because that meant that we could start the second part of our study: radio-tracking turtles for an entire year!
Tracking Spotted Turtles with radio telemetry requires us to attach a radio transmitter to adult turtles, which we can then locate in the field with a handheld receiver and antenna. It involves dialing the receiver to each turtle’s specific frequency, and by heading in the direction of the loudest “pings,” we eventually locate the turtle. Once we locate a turtle, behavioral and environmental data along with GPS coordinates are recorded, so we can map their movements and detect seasonal and behavioral patterns. It seems straightforward enough, but tracking any animal presents some challenges. Spotted Turtles, in particular, are incredibly shy, and locating an active one without spooking it can be tricky. There have been many times while out tracking Spotted Turtles when we have heard the very distinct “plop” of a basking turtle dropping from its perch into the safety of the water. We can only assume they were basking Spotted Turtles, as we usually only lay eyes on the ripples caused by their escape. Their cryptic patterning also provides us with another obstacle to overcome. It isn’t until you see a Spotted Turtle lying motionless in the shallows of a swamp that you truly appreciate how those bright yellow spots can allow them to virtually disappear.
The landscapes in which these turtles live can also present challenges. Sinking above your knees in muck, navigating through cypress knees and submerged logs, and trudging through briars and blankets of poison ivy are all part of the daily routine. Ticks, deer flies and the ever-present hum of mosquitoes are an added bonus on some days. However, being able to observe this secretive turtle species and spend time in these special wetland habitats is worth every flooded boot and drop of blood donated.
One of the best experiences tracking turtles came towards the end of a full day of tracking. The first turtle of the day was tracked to a small swampy pool, where she slowly ploughed through the leaf litter. While recording data, she poked her black and creamsicle head up through the substrate and out of the water for a breath, or perhaps to scan her surroundings. I remained motionless, and she pulled back under the leaves. She periscoped several more times during my short visit with her and even allowed me to take a few photographs. I then parted ways with her and moved on to find the rest of our tagged turtles. But the signal of my final target brought me back to that same pool.
I thought it was interesting to find this last turtle only a couple feet from where my first turtle had been just a few hours earlier. As I sat down to fill out my data sheet, a distinct pattern caught my eye in the leaf litter on the opposite side of the pool. Could it really be a third turtle? I walked as stealthily as I could through the water and snatched it up. Sure enough! It was an untagged Spotted Turtle! Almost immediately after I picked that turtle up, I saw another flash of golden spots dive beneath the leaf litter. I made a frantic grab and pulled up a fistful of leaves and yet another untagged turtle! In the following 60 seconds this series of events repeated itself three more times, leaving me with two handfuls of Spotted Turtles and a surge of adrenaline. I could not believe what had just happened! There had been a total of seven Spotted Turtles in this little pool, four untagged adults and one juvenile.
Now why were these turtles congregating? We can only speculate. Maybe it had to do with breeding. Maybe it was a choice spot for foraging or thermoregulating. Whatever the case, it’s one more piece of the puzzle that we now have to understanding the ecology of Spotted Turtles in Georgia, and we are excited to continue learning about these secretive gems of the Coastal Plain.