SUITABILITY OF A GPS COLLAR FOR GRAZING STUDIES

Abstract

The traditional means of tracking animal location in a field is by visual observation. Not only is this method laborintensive, it is also prone to error as the observer can alter cattle movement, observation periods are often too short to obtainconfidence in general daily behavior patterns, and observer fatigue becomes an issue. In the 1990s, the University of Kentuckybegan using GPS collars on cattle to track their position with the goal of incorporating this information into cattle managementpractices. One of the key unanswered questions regarding the GPS collars is the accuracy of the position data recordedby the collar. The objective of this work was to assess the capabilities and limitations of using GPS collars to track animalmovement in grazed watersheds. Static tests were conducted in an open field, under trees, and near fence lines to ascertainthe impacts of various field features on collar performance. Dynamic tests were carried out to examine the errors associatedwith the collars while operated under real-world conditions. Results from these tests indicate that the collars generally providedata with horizontal accuracies of 4 to 5 m. This information will assist researchers in the development of experimentsbased on collar capabilities and limitations.