Fig. 1. Series 1. Pooled data relative to the initial orientation recorded at Bolgheri, Agliana and Marinella. Circular diagrams showing the initial orientation of the pigeons; each symbol on the periphery of each circle identifies the vanishing bearing of one bird. C, intact control pigeons; V1, pigeons subjected to the section of the ophthalmic branch of the trigeminal nerve; ON, pigeons subjected to the section of the olfactory nerves. The home direction is set at 360°. Arrows inside each circle represent the mean vector of each group, the length and direction of which are reported. The inner lines delimitate the 95% confidence limits.