Evaluation of Solar-Powered GPS Ear Tags and Long-Range Data Transmission for Use in Wildlife Research: Case Study of Collared Peccary (Pecari tajacu)

Abstract Background Global Positioning System (GPS) technology has become a widely adopted tool in wildlife monitoring and research. Spatial location data can provide unique insights into animal behavior, resource selection, movement patterns, and species interactions. However, GPS data are often flawed by data loss (missing fixes due to failed GPS attempts) and horizontal error (discrepancy between recorded and true locations), which, if not accounted for, can lead to biased estimates of space use, movement, and resource selection. We evaluated solar-powered GPS ear tags (mOOvement, Brisbane, Queensland, Australia) that transmit location data using a Long Range Wide Area Network (LoRaWAN) during stationary tests at two sites in southern Texas and during deployment on collared peccaries ( Pecari tajacu ). Results Overall fix success during stationary testing was 58.2% at La Copita Demonstration Area and Research Ranch and 51.2% at Chaparral Wildlife Management Area (CWMA). At La Copita, fix success decreased as woody cover and distance from the LoRaWAN antenna increased in combination, whereas neither covariate influenced fix success at CWMA. Woody cover and antenna distance did not influence horizontal error at either site; average horizontal error was 21.7 m at La Copita and 26.9 m at CWMA. Battery performance also differed between sites and across woody-cover conditions, with reduced solar recharge and greater battery decline occurring under some densely vegetated conditions. Of 10 tags deployed on collared peccaries, one failed to transmit data. The remaining nine transmitted locations for 3–7 days and averaged 41.0% fix success before battery voltage declined and transmissions ceased. Peccaries frequently occupied dense woody cover, particularly during midday, likely limiting solar exposure during periods of greatest recharge potential. Conclusions Performance of solar-powered, LoRaWAN-enabled GPS ear tags depended on local environmental conditions and the ecology of the species carrying the device. Although these tags may provide a relatively low-cost option for wildlife telemetry, moderate fix success, positional error, and dependence on solar recharge may limit their application in densely vegetated environments or for species that regularly seek cover. Researchers should evaluate habitat conditions, species behavior, spatial-resolution requirements, and opportunities for solar recharge through pilot testing before large-scale deployment.