Fig. 1. Pooled distributions representing the initial orientation of the three experimental groups: SS, sham operated control pigeons; V1, pigeons subjected to the resection of the ophthalmic branch of the trigeminal nerve; ON, pigeons subjected to the resection of the olfactory nerve. The pooled distributions (mean vector direction, , and mean vector length, r) were obtained by setting the home direction (H) to 360°. Each symbol represents the vanishing bearing of a single bird. The open and the filled dots represent the birds released from Bolgheri and Marinella, respectively. The outer arrow indicates the home direction, the inner arrow represents the distribution's mean vector. The inner lines delimitate the 95% confidence interval of the distribution.