Birds calibrate the compass every night

2004/06/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Zoologia

We are aware of the ability of birds to orient themselves on long journeys, using for this purpose the magnetic field of the Earth. But the field varies from place to place and yet they do not lose the north. It seems that they calibrate the compass in the evening depending on the orientation of the light rays, thus following the right path.

It is the result of an experiment conducted in Illinois, USA. Several birds from the Thrush family were captured and separated by a small transmitter. At dusk they were released, but some made them pass through a magnetic field to disorient themselves. Consequently, these birds headed west rather than north. At dusk the next day, all the birds flew north. It is a sign that the disoriented find the north again.