Comparison of models' predictions with experimental data.

Comparison of the mean experimental (empty circle) and expected values (cross) obtained under (A–C) model 1 (sheep decision to follow is independent of other sheep), (D–F) model 2 (following is prompted by the number of already departed sheep) and (G–I) model 3 (sheep decision depends on the number of departed and non-departed sheep). Left column represent the individual stimulus / response function as a function of the number of already departed sheep D in each group size (N = 2, 4, 6 and 8). Note that the corresponding number of non-departed sheep is N−D. Mid and right columns represent the corresponding results at the collective scale: mean latency of the first follower and mean duration of the move (i.e. mean duration from the trained' departure and the last follower's departure). Dashed lines represent the standard deviation.