What Is the Balkan Terrapin Up To?

To better guide our efforts in restoring and improving the habitats of the Balkan Terrapin as part of work packages WP2 and WP4, it is crucial to understand how this species uses freshwater habitats and the surrounding agricultural landscapes — fields, meadows, and gardens (WP5).

To achieve this, we equipped several individuals with small telemetry devices and released them back into their natural habitats — ponds, rivers, and canals. These are lightweight transmitters originally designed for tracking birds, which have been adapted to function underwater and to be safely attached to the turtle's shell without interfering with its movement or natural behavior.

This method introduces an innovative approach to Croatia to studying the behavior of freshwater turtles. For the first time, we are using satellite tracking to continuously collect data on their daily and seasonal movements, replacing the traditional capture-mark-recapture technique. The capture-mark-recapture method involves capturing individuals in the field, marking them, and recapturing them over time to gather data on movement and survival. While valuable, this approach requires a great deal of field effort, frequent site visits, and significantly more time. In comparison, telemetry allows for simpler, more accurate, and continuous monitoring with fewer resources.

And the first results are already providing valuable insights!

For example, one female we are tracking in the Konavle area was recorded crossing a road — likely heading to a nearby lawn to lay her eggs. Thanks to this data, we now know where to look for her nesting site and assess whether it needs additional protection. We are also considering installing road signs such as "Watch out – turtles crossing" in the future to alert drivers and increase safety during this important, but risky, period for females.

This is just one example of the kind of valuable information we can gather through this method. We hope that this technology will become an integral part of future conservation projects for freshwater and land turtles in Croatia, helping us to more effectively protect endangered species and their precious habitats.