GPS tracking for monitoring animal, plant and soil interactions in livestock systems

GPS tracking is becoming increasingly common as a research tool for monitoring livestock activity. This paper reports on the development of UNEtracker, a low-cost GPS collar that can be deployed in large numbers for monitoring stock movement. An assessment of positional accuracy of UNEtracker showed a mean error from actual receiver position of 4.14 metres with a standard deviation of 3.04 metres. Results demonstrated 99.9% of points fell within 20 and 97.3% within 10 meters of the known point. The UNEtracker was used to track the movement of four steers over a 14 day period. The tracked steers were shown to have distinct preferences for certain areas within the trial site. A Livestock Hour Index (LHI) is used as a means of quantifying and mapping the impact of livestock activity on the landscape. Integration of LHI data with maps of photosynthetically-active biomass (as derived from satellite imagery), elevation, and even information concerning neighbouring herds, has been demonstrated to provide significant interpretation power to the collected data.