WALCOTT, C: Multimodal Orientation and Navigation in Homing Pigeons

How homing pigeons displaced into unfamiliar territory find their way home has been the subject of extensive experimentation and debate. One reason for the controversy is that pigeons seem to use multiple cues. Clock-shifting experiments show that experienced pigeons use the sun as a preferred compass; only when it is not available do they switch to magnetic cues. Homing pigeons wearing frosted lenses as they fly often have trouble locating the exact position of their loft. This suggests that landmarks around the home loft are probably important in the final stages of the process. The sensory basis of the “map” or position finding system is probably equally or even more complicated. When conditions around the loft are suitable, pigeons may use olfactory cues to find their way but under other circumstances I believe that they may use some feature of the earth’s magnetic field for their navigation. The Wiltschkos showed that pigeons raised without free access to ambient odors are not disoriented when anosmic while their siblings raised with free access to the prevailing wind were disoriented. Similarly, sibling pigeons from two lofts only 1.5 miles apart in Lincoln, Mass. were either well oriented or totally disoriented when released under sunny skies at magnetic anomalies. Their orientation or disorientation depended upon which of the two lofts they had been reared in. All of these experiments and many more suggest that pigeons use multiple and redundant cues to find their way home. Further, there is the possibility that which cues they adopt may well be influenced by the characteristics of the home loft and the environment that they were reared in.