Fig. 1. Experimental arrangements. (A–D) The positions of food sources (F1, F2), the start and local landmarks are shown for the different experimental configurations. Landmarks were black cylinders approximately 45 cm in height. (A,B) The direct paths to F1 and F2 from the start are 45° apart. The configuration in B was used for two experiments: restricted and unrestricted training. The grey line and circle represent the barrier and metal ring used to prevent access to F1 during `restricted training' to F2. (C,D) The direct paths to F1 and F2 from the start are 90° apart.