A low-cost, open-source inertial movement GPS logger for eco-physiology applications

Abstract

Open-source technology has been increasingly used for developing low-cost animal-borne bio-loggers, however, a gap remains for a bio-logger that records both inertial movement and GPS positions. We address this need with the Tapered Wings Logger (TWLogger), an archival bio-logger that records high-resolution (e.g. 50-Hz) tri-axial accelerometry and magnetometry, temperature, and GPS. The TWLogger can be built for 90 USD, accepts user-defined sampling parameters, and with a 500-mAh battery weighs 25-g. We provide publicly available build instructions and custom analysis scripts. Bench tests recorded 50-Hz inertial movement and 2-min GPS for 31.8 ± 2.2 h (mean±SD, n=6) with GPS accuracy within 10.9±13.6 m. Field deployments on a medium-sized bird of prey in the wild achieved similar results (n=13). The customizable TWLogger has wide-ranging application across systems and thus offers a practical solution for eco-physiology applications.