Anecdotal evidence from breeders of racing pigeons as well as initial aerial tracking studies together suggested that pigeons may follow roadways and use highway landmarks as turning points in their flight. However, the challenge of accurately tracking the birds stood in the way of solid quantitative analysis. In the new work, miniaturized GPS "flight-loggers," which pigeons carried on their backs, allowed researchers a clear and reliable picture of the birds' flight paths.
Over three years, the researchers analyzed more than 200 flight paths of 20-80 km in length made by pigeons travelling toward their home loft from numerous release sites located in the general vicinity of Rome, Italy. They found that, when released from familiar sites, pigeons with homing experience were significantly attracted to highways and a railway track running in the approximate directions home. When these structures began to veer significantly from the beeline to the loft, some birds tended to break away and head in a more homeward direction, but others took a detour by following the highway until a main junction, at which point they followed a valley road in the direction of the loft.
Overall, the degree to which the birds appeared to follow roadways was strongest in the early and middle sections of their homeward journeys, when, the researchers suspect, roads serve to stabilize the birds' innate compass course. As they approached the loft, the birds appeared to switch strategies and rely more on topographical points as bona fide "road map" components. The birds may use these features in a cognitiv
Contact: Heidi Hardman