Le rôle de l’odorat dans l’orientation de certains oiseaux

In Italy (notably in the University of Pisa) and Germany, a long series of experiments has provided evidence that olfactory cues are important to pigeon homing. Birds with their olfactory nerves sectioned neither orient nor home from unfamiliar sites. Pigeons whose exposure to natural air flow has been manipulated by deflector lofts or by tunnels show the predicted deflection of their vanishing directions. Birds transported long distances do not orient unless they are allowed to sample the natural air on the outward journey; filtering the air through charcoal eliminates the pigeons ability to orient. These and many other observations make a convincing case that pigeons make some use of olfactory information in their orientation.
Replications of the experiments in different regions, however, yielded widely differing results. These discrepancies led to the well-known controversy among scientists about the role of olfactory input and its general importance for orientation.