A fragrant map of the surrounding environment allows pigeons to find their way again according to new Italian research.
The European pigeon (Columba
palumbus) is part of the family of
pigeons and is a decent migrant.
Carrier pigeons have satellite navigation. Or rather, olfactory. An Italian research, conducted by Anna Gagliardo of the University of Pisa, explained how pigeons - known to be able to travel hundreds of kilometers across unknown territories - find the way home easily. From an early age these birds are exposed to the smells of their territory of origin and their fellows. Once they become adults, these smells allow them to build themselves a real "smelling map" of the environment that surrounds them, indispensable to guide them on their long journeys.
Olfactory navigators and magnetic navigators
The research of the University of Pisa follows a similar study two years ago that hypothesized a different orientation ability, based on the identification of variations in terrestrial electromagnetic fields. To test the two theories in parallel, Gagliardo freed 48 pigeons at 50 kilometers from their "home". Half of the birds the olfactory nerve had been cut off from the other half the trigeminal nerve, the nerve involved in identifying "magnetic maps". The next day, only one pigeon with a cut-throat had not returned home, while only four of the non-functioning olfactory pigeons had found their way back. A proof, therefore, in favor of the hypothesis of the maps.
To each his own method
The orientation of migratory birds has always fascinated science, which however has never been able to explain with absolute certainty how this happens. Some birds seem to find their way home recognizing the constellations, others instead rely on terrestrial magnetism, others still identify the known territories by recognizing the berries and insects they habitually eat or follow, like the pigeons themselves, the roads of men.
In short, it seems that in the end the methods used are more than one. It is true that the ability of pigeons to recognize odors in the distance remains among the most particular ever identified.
(News updated August 9, 2006)