Navigation of the Racing Pigeon

Research has been performed with the intention of discovering how racing pigeons 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).[5] While the compass mechanism appears to be use of the sun, the map mechanism has been highly debated.[6] Some researchers believe that the map mechanism relies on the ability of birds to detect the Earth's magnetic field. Much of this work has been conducted by Rosthina and Wolfgang Witschko and has shown that alteration of magnetic fields around the home loft result in disrupted homing ability. Recently, researchers have attempted to determine how pigeons can detect magnetic fields, and two different mechanisms have been proposed. A light-mediated mechanism that involves the eyes and is lateralized has been examined somewhat, but recent developments have implicated the trigeminal nerve in magnetoreception.[7][8] 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[6] (See the August 20, 2005 issue of Science News.). 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 one strain of pigeons was confused by a magnetic anomaly in the Earth that had no effect on another strain of birds. 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.

My personal theory is, racing pigeons navigate through an invisible grid system surrounding the earth, which is undetected by optical vision of humans. There are many old texts about this invisible grid system around the earth, which has not been taken into consideration.