Effective use of radiotelemetry for studying tropical carnivores

Radiotelemetry has become one of the most valuable fi eld techniques in wildlife ecology because it allows biologists to collect location and other data remotely. This method is an especially important tool for studying the behaviour and demography of species that are often secretive, traverse large areas, and occur at low densities. Although use of radiotelemetry for studying tropical carnivores has been limited, this is changing rapidly. However, to maximise the value of radiotelemetry for learning about and managing tropical carnivores, biologists need to understand this technique and important considerations in its application. Radiotelemetry studies can provide useful information when biologists clearly articulate their objectives, carefully select study designs, evaluate important assumptions, apply appropriate analytical methods, and interpret the results properly. The choice of equipment and methods often must consider challenges such as remote study areas dominated by dense vegetation. Appropriate methods of attaching transmitters are critical, as is the assumption that transmitters have no signifi cant effects on study animals. The development of GPS radiotelemetry allows investigators to examine movements at high resolution, but VHF systems often remain the most appropriate or only feasible option for many studies of tropical carnivores. Methods for analysing radiotelemetry data also have expanded greatly in sophistication and explanatory power. Some of the most important analytical developments are in the shift from simple descriptive statistical approaches to process-based models that directly incorporate mechanistic hypotheses. Throughout this overview, we outline general advantages and disadvantages of various study options and emphasise the importance of testing key biological and methodological assumptions appropriate for each technique at all stages in the collection, analysis, and interpretation of radio-tracking data.