PIGEON HOMING - DEPRIVATION OF OLFACTORY INFORMATION DOES NOT AFFECT THE DEFLECTOR EFFECT

1. Pigeons reared in deflector cages show on release a very pronounced bias of their mean vanishing bearings in the predicted direction, confirming the results of Baldaccini et al. (1975a). The angle of deviation though is only about half the angle of actual wind deflection in the cages. The concentration of bearings about the mean direction is significantly smaller than those of controls reared in cages without defectors. 2. The homing speed of the pigeons reared in deflector cages is significantly lower than that of pigeons reared in control cages. 3. Application of an anesthetic (Xylocaine spray, effective during transport and at the release site) onto the olfactory and respiratory epithelia of the nose does not in any significant way influence this 'deflector effect.' 4. Plugging the nose with silicone rubber does not affect the 'deflector effect.' Homing speed and homing success in pigeons with plugged nares are drastically reduced, in naive as well as in experienced pigeons. 5. It is suggested that the factors involved may not be olfactory ones but of some other physical or chemical nature, mediated or caused by the wind and picked up by some sensory mechanism other than olfaction. © 1979 Springer-Verlag.