A simple method of attaching GPS tracking devices to free-ranging Lace Monitors (Varanus varius)

Effective and reliable methods of attachment for very high frequency (VHF) transmitters to animals are essential for radio-telemetric studies. However, attachment difficulties escalate when longer term studies requiring larger global positioning system (GPS) loggers and additional battery life are required, resulting in the use of larger, more cumbersome units. Lace Monitors (Varanus various) of Australia inhabit rugged terrain in the wild, and accurate portrayal of home range and temporal patterns of movement requires a remote data collection process. We developed a robust system of attaching GPS loggers to Lace Monitors, while allowing them to attain a full range of movement, level of activity, and foraging methods. We designed a denim pouch to house a large GPS logger with radio-transmitter, and this unit was then glued to the back of adult Lace Monitors. Fifteen males fitted with denim pouches containing GPS loggers were successfully tracked for 6–65 weeks to study home range and habitat utilization. None of the denim pouches were prematurely dislodged from the animals during the study and pouch design did not appear to affect the natural behavior of the animals. This paper provides a detailed description of the pouch design and the efficacy of its attachment.