Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/13/2004
Publication Date: N/A
Technical Abstract: One challenge of animal behavior studies employing global positioning system (GPS) collars is determining data resolution needed for specific goals of a project. It is generally desirable to collect the highest resolution data possible, however factors such as battery life and memory constraints must be considered. Our objective was to evaluate compromises between a finite battery life and maximizing the amount of behavioral information garnered. This was accomplished by fitting cattle with GPS collars and monitoring travels at a resolution of 5 minutes for 15 days in three 800 ha pastures. Upon retrieval of collars, data were uploaded, differentially corrected, and UTM coordinates were derived to allow estimation of distance traversed between positions. Subsequently, positions were iteratively omitted from datasets to reflect increasingly longer sampling intervals and regression models were fit describing estimated mean total distance cows traveled at various sampling intervals (5-1440 minutes). Increasing sampling intervals from 5 to 10 minutes decreased estimated mean total distance by 20.1% from 136 to 109 km (p < 0.0001). This relationship was constant over successive doublings of the sampling interval. As intervals were reduced to < 160 minutes, estimates of mean distance traveled increased at approximately 614 m/minute. As intervals were reduced from once daily to 160 minutes, estimates of mean distance traveled increased at a more gradual rate of 32.5 m/minute. A one minute reduction in sampling interval equates to a 5.6 day reduction in battery life indicating tradeoffs associated with obtaining high resolution data.