24/07/2026
Coleiras com GPS para contenção de pequenos ruminantes
WEEKLY RESEARCH SHARE
In a previous post, I showed a picture of a sheep wearing a GPS collar. Some people might consider these collars burdensome to the animal. Even if they're not, public perception may disagree, and there are other issues at play. Ear tags would be a better option for sheep and goats, especially when you consider wool growth and growth of young animals. A study comparing GPS collars and ear tags was recently published.
Title
The good, the bad, and the ugly: Comparison of GPS collar and solar-powered ear tag technologies for animal tracking
Highlights
• GPS performance was largely unaffected by canopy cover.
• Performance was generally consistent across manufacturers.
• Fix success was high for devices using LoRaWAN across levels of canopy cover.
• Accuracy and precision differed among devices using LoRaWAN.
• Efficacy of GPS ear tags can be comparable to GPS collars.
Abstract
Animal-borne global positioning system (GPS) technology is advancing rapidly, providing new opportunities to study animal ecology and improve livestock management. Evaluation of emerging GPS technologies is needed, particularly those incorporating autonomous solar charging and satellite, cellular, and Long-Range Wide-Area Network (LoRaWAN) data transmission. We quantified and compared the performance of GPS neck collars and solar-powered GPS ear tags using stationary trials conducted under varying canopy cover conditions. Using a crossover design, we evaluated fix acquisition probability (Pacq), horizontal error (HE), circular error probable (CEP), and, when applicable, battery longevity for 10 GPS devices (7 collars and 3 ear tags) produced by 9 manufacturers. GPS performance was generally consistent across manufacturers and device types and showed limited sensitivity to canopy cover. Devices using LoRaWAN maintained high Pacq (0.92–0.99) across canopy conditions, though HE (2.94–19.70 m) and 95% CEP (7.07–77.83 m) varied substantially among devices. Track Tag and 701x ear tags exhibited high Pacq, low HE and CEP, and sustained functionality throughout the study, indicating potential for wildlife and livestock monitoring. A minimum of 84 locations was sufficient for centroid variation to reliably represent HE. Horizontal error was centered on a device-specific centroid rather than the true location, resulting in systematic bias ranging from 0.96 to 3.50 m, except for one device (11.52 m). Overall, GPS ear tags achieved performance metrics comparable to traditional collars. These results can inform technology selection, though extrapolation beyond stationary conditions should be made cautiously, as GPS performance is often optimized under static deployments.
Source: Smart Agricultural Technology, March 2026
https://nri.tamu.edu/media/aqslfmny/the-good-the-bad-and-the-ugly-comparison-of-gps-collar-and-solar-powered-ear-tag-technologies-for-animal-tracking.pdf
