EFFECTS OF ABLATION OF THE PRESUMED EQUIVALENT OF THE MAMMALIAN PREFRONTAL CORTEX ON PIGEON HOMING

Pigeons (Columba livia) with bilateral ablation of the posterodorsolateral neostriatum and the overlying corticoid were compared with unoperated control subjects in homing from both familiar and unfamilar sites. Before the operation all the pigeons were subjected to 8 training flights from a site destined to be the familar one. Postoperatively, the groups did not differ in orientation from the familiar site. In their releases from unfamiliar sites, however, the operated birds oriented in the training flight direction, whereas the control subjects were oriented homeward. In all the releases the homing performance, including both the homing speed and the number of returned birds, was significantly higher in the control group. Thus, the ablated tissue plays a role in homing behavior possibly through mediation of spatial orientation, of olfactory navigation, or of both.