The Big Night Out: Experiences from Tracking Flying Foxes with Delay-Tolerant Wireless Networking

Long-term tracking of small-size animals with wireless sensor networks remains a challenge as only limited energy harvesting and storage is possible due to stringent size and weight constraints for animal collars. We present first experiences towards a perpetual monitoring system for free-living flying foxes. The high mobility of flying foxes requires a delay tolerant wireless network for data gathering: GPS positions and sensor data have to be stored locally until a wireless gateway deployed in bat congregation areas, so called roosting camps, comes within radio range. In this paper, we present the system architecture and discuss our design decisions towards sustainable and reliable monitoring of flying foxes with a limited energy budget for sensing, storage and communication. Using empirical data from three free-living flying foxes, we characterize the overall system performance in terms of energy consumption and latency.