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 mA h 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±s.d., 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.
Footnotes
Author contributions
Conceptualization: J.F., K.H.; Methodology: J.F., K.H.; Software: J.F.; Formal analysis: J.F., K.H.; Investigation: K.H.; Resources: J.F., K.H.; Writing - original draft: J.F., K.H.; Writing - review & editing: J.F., K.H.; Project administration: K.H.; Funding acquisition: K.H.
Funding
Financial support was provided by Hawk Mountain Sanctuary Association, Falklands Conservation and the Falkland Island Government Environmental Studies Budget.
Data availability
A subset of data from our field test is available for readers to practice using the processing scripts, along with TWLogger instructions: https://github.com/jamesfahlbusch/TWLogger
