How are distances between individuals of grazing cows explained by a statistical model?

A statistical model to describe how distances between individuals of grazing cows are explained is discussed in this paper. This model was constructed by the following five effects: (1) behavior of the entire crowd (measured by troop length in this study), (2) repulsive and attractive forces operating directly between two individuals (direct effect), (3) effect of third individual on distance between two given individuals (half-indirect effect), (4) effects of unconnected pairs on the distance between two given individuals (indirect effect), and (5) residual effect which cannot be explained by the above four effects to determine distances between individuals (random/involuntary movement effect). These effects were analyzed using simple and multiple regression equations. Whole data taken every 5 min were divided into two phases: a grazing phase and a resting phase. stances between two individuals in the grazing phase were much greater than the distances in the resting phase. The temporal variation of distances between two individuals in the grazing phase was much larger than the variation of distances in the resting phase. The order of the contributions of the five effects to the total variation of temporal changes in distances between individuals were: random movement effect>troop length effect∼direct effect>half-indirect effect>indirect effect.