Data loggers to monitor activity in wild freshwater turtles

A data logger originally developed for the study of homing routes in birds was adapted for monitoring the activity patterns of the European pond turtle Emys orbicularis and tested on wild specimens from a Central Italian population. The set of sensors included a compass, water switches, an activity sensor and a thermocouple. The compass allowed us to record the orientation of the turtle's body axis, but also provided information on the temporal pattern of activity, thus adding to the information from the activity sensor. The water switches allowed us to distinguish between immersion and complete or partial emersion, while the thermocouple furnished data on surface temperature. The system provided new detailed information on the behaviour of wild E. orbicularis, in particular the daily patterns of activity, including basking, and overwintering habits.