Homing Pigeon - Navigation

Navigation

Research has been performed with the intention of discovering how pigeons, after being transported, can find their way back from distant places they have never visited before. Most researchers believe that homing ability is based on a "map and compass" model, with the compass feature allowing birds to orient and the map feature allowing birds to determine their location relative to a goal site (home loft). While the compass mechanism appears to rely on the sun, the map mechanism has been highly debated. Some researchers believe that the map mechanism relies on the ability of birds to detect the Earth's magnetic field. It is true that birds can detect a magnetic field, to help them find their way home. Scientists have found that on top of pigeon's beak large number of particles of iron are found which remain aligned to north like man made compass, thus it acts as compass which helps pigeon in determining its home. A light-mediated mechanism that involves the eyes and is lateralized has been examined somewhat, but recent developments have implicated the trigeminal nerve in magnetoception. Research by Floriano Papi (Italy, early 1970s) and more recent work, largely by Hans Wallraff, suggests that instead pigeons orient themselves using the spatial distribution of atmospheric odors, known as olfactory navigation. Near their home lofts, in areas they have previously visited, pigeons probably are guided by visual landmarks.

Various experiments suggest that different breeds of homing pigeons rely on different cues to different extents. Charles Walcott at Cornell was able to demonstrate that while pigeons from one loft were confused by a magnetic anomaly in the Earth it had no effect on birds from another loft a mile away. Other experiments have shown that altering the perceived time of day with artificial lighting or using air conditioning to eliminate odors in the pigeons' home roost affected the pigeons' ability to return home.

Some research also indicates that homing pigeons navigate by following roads and other man-made features, making 90 degree turns and following habitual routes, much the same way that humans navigate.