Does pigeon homing depend on stimuli perceived during displacement?

Summary In order to test whether stimuli perceived during passive displacement are important for the subsequent homing, pigeons were transported in an apparatus designed to prevent them from receiving relevant information: The experimental birds were continuously rotated quite rapidly (1.5 cps, radial acceleration about 4 g); in addition, they were exposed to an artificial magnetic field and supplied with bottled air. Control birds were transported in open-air cages on top of the van with free view to all sides.Five pairs of releases from equal distances in opposite directions were conducted. Experienced birds were released at distances of about 15, 90, and 300 km from the loft, inexperienced birds at distances of about 180km. In each pair of releases both groups of pigeons were significantly homeward oriented. Neither in initial orientation nor in homing performance nor in the distribution of recoveries were the experimental birds inferior to the controls or in any perceptable way different from them.It is concluded that homing of passively displaced pigeons is not primarily based on information gathered during the outward journey.Abbreviations EP experimental pigeon(s) - CP control pigeon(s)The possibility to maintain our pigeon loft in a building that belongs to the Zoological Institute (Prof. M. Lindauer) of the University of Würzburg is gratefully acknowledged.