OLFACTION AND HOMING IN PIGEONS

SUMMARY New experiments have been made on homing pigeons deprived of olfactory perception by occlusion of both nostrils with cotton tampons, or by resection of the olfactory nerve on one side and occlusion of the nostril on the other. They confirm the strong disturbance of orientation of the birds at the moment of release, which had already been observed in subjects with both olfactory nerves resected. Observations conducted on subjects with resected nerves have not shown other disturbances in general behaviour. The possibility is considered that, at the home site, pigeons associate odorous stimuli carried by winds from the surroundings with the direction from which they come. Recognizing a known odour at the release point, they should thereby be able to orient themselves toward home by flying in a direction opposite to the one with which the odour had been associated.