Accelerometer‐informed GPS telemetry: Reducing the trade‐off between resolution and longevity

Danielle Brown, Scott LaPoint, Roland Kays, Wolfgang Heidrich, Franz Kümmeth, Martin Wikelski

Wildlife Society Bulletin · 2012 · 127 citations · 34 references

Concepts

TL;DR

GPS tracking is widely used to study animal ecology, but fixed‑interval schedules can either miss fine‑scale movement or waste battery power, especially for medium‑sized forest dwellers that rely on cavities and burrows. The study develops a dynamic GPS schedule driven by onboard accelerometer activity to balance resolution and battery life. The authors compared traditional GPS tags with accelerometer‑informed tags on tamanduas and fishers, linking location attempts to real‑time activity data. Accelerometer‑informed tags achieved 73.6 % more daily locations, 61.7 % higher success rates, 28.2 % less satellite search time, and 67.4 % fewer redundant attempts, yielding higher‑resolution tracks that revealed behaviors missed by traditional tags and effectively reduced the resolution–battery trade‑off. © 2012 The Wildlife Society.

Abstract

Abstract Tracking animal movement using Global Positioning System (GPS) technology is an increasingly popular method for studying animal ecology, behavior, and conservation. To date, most GPS location schedules have been set at regular intervals. If intervals are too long, they undersample the details of movement paths, and if too short, they oversample resting sites and deplete the unit's battery without providing new information. We address this problem by creating a dynamic GPS schedule that is linked to the activity level of the animal via an accelerometer onboard the tracking tag. We deployed traditional and accelerometer‐informed GPS tags on northern tamanduas anteater ( Tamandua mexicana ) in tropical forest in the Republic of Panama (2009–2010), and on fisher ( Martes pennanti ) in temperate forest in New York, USA (2009–2011). These species are medium‐sized forest‐dwellers that frequently use tree cavities, ground burrows, and thick vegetation for resting and foraging, all traits that make them particularly challenging for GPS tracking. The accelerometer‐informed tags performed better than the traditional GPS tags: they attempted 73.6% more locations per day, achieved 61.7% higher location success rates, spent 28.2% less time searching for satellites, made 67.4% fewer redundant location attempts in places where animals were inactive, and ultimately provided more data for a given battery size. The resulting tracks of animal movement had high temporal resolution, revealing aspects of their behavior and ecology that would have been missed by traditional tags, especially for the fast‐moving fisher. By dynamically linking the location schedule to animal movement rate, accelerometer‐informed GPS tags reduce the trade‐off between collecting detailed movement data and recording movement data for a longer period of time. © 2012 The Wildlife Society.

References

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