SensorDrop: A system to remotely detach individual sensors from wildlife tracking collars

K Rafiq; R G Appleby; A Davies; B Abrahms

doi:10.1002/ece3.10220

SensorDrop: A system to remotely detach individual sensors from wildlife tracking collars

Ecol Evol. 2023 Jul 4;13(7):e10220. doi: 10.1002/ece3.10220. eCollection 2023 Jul.

Authors

K Rafiq^{1

2}, R G Appleby^{3

4}, A Davies⁵, B Abrahms^{1

2}

Affiliations

¹ Department of Biology, Center for Ecosystem Sentinels University of Washington Seattle Washington USA.
² Botswana Predator Conservation Maun Botswana.
³ Centre for Planetary Health and Food Security Griffith University Brisbane Queensland Australia.
⁴ Wild Spy Pty Ltd Brisbane Queensland Australia.
⁵ Arribada Initiative Cheshire UK.

Abstract

The growing diversity of animal-borne sensor types is revolutionizing our understanding of wildlife biology. For example, researcher-developed sensors, such as audio and video loggers, are being increasingly attached to wildlife tracking collars to provide insights into a range of topics from species interactions to physiology. However, such devices are often prohibitively power-intensive, relative to conventional wildlife collar sensors, and their retrieval without compromising long-term data collection and animal welfare remains a challenge. We present an open-source system (SensorDrop) for remotely detaching individual sensors from wildlife collars. SensorDrop facilitates the retrieval of power-intensive sensors while leaving non-resource-intensive sensors intact on animals. SensorDrop systems can be made using commercially available components and are a fraction of the cost of other timed drop-off devices that detach full wildlife tracking collars. From 2021 to 2022, eight SensorDrop units were successfully deployed on free-ranging African wild dog packs in the Okavango Delta as part of audio-accelerometer sensor bundles attached to wildlife collars. All SensorDrop units detached after 2-3 weeks and facilitated the collection of audio and accelerometer data while leaving wildlife GPS collars intact to continue collecting locational data (>1 year), critical for long-term conservation population monitoring in the region. SensorDrop offers a low-cost method to remotely detach and retrieve individual sensors from wildlife collars. By selectively detaching battery-depleted sensors, SensorDrop maximizes the amount of data collected per wildlife collar deployment and mitigates ethical concerns on animal rehandling. SensorDrop adds to the growing body of open-source animal-borne technologies being utilized by wildlife researchers to innovate and expand upon data collection practices and supports the continued ethical use of novel technologies within wildlife studies.

Keywords: animal‐borne sensors; bio‐logging; conservation technology; drop‐off; open‐source hardware; radiocollar.