Figure 2.

Experiment 1. (a) Schematic of the rectangular arena and the square-shaped array of distinctively coloured cylinders used during the training. The inner arrows represent the arrangement of the accessible openings on cylinders (empty arrows represent correct cylinder; grey arrows represent incorrect cylinders; black arrows represent unrewarded cylinders at test). For convenience, the rewarded position is represented at one position only. (b) Mean percentage of the correct choices (±s.e.m.) made by the chicks during the training. (c) Mean percentage of the choices (±s.e.m.) made by the chicks to the geometrically correct (C) and the incorrect cylinders (E) at the experimental test.