Robins can see Earth's magnetic field
Robins can see Earth's magnetic field
Robins can 'see' the Earth's magnetic field which allows them to navigate, scientists
believe.
German scientists studied 36 European robins and concluded that the birds can
'see' the Earth's magnetic field, allowing them to navigate
The information, relayed to a specialised light-processing region of the brain called
''cluster N'', helps the robin find its way on migration flights.
Experts know birds possess an internal magnetic compass, but there is
disagreement about what form it takes.
One idea is that tiny magnets in the beak wired to the nervous system detect lines of
magnetic force.
Another is that magnetic fields are ''seen'' via the eyes using a complex
light-sensitive mechanism.
The new research suggests that, for robins at least, the second theory is probably
correct.
German scientists studied 36 European robins and found birds with damage to
''cluster N'' were unable to orientate themselves using the Earth's magnetic field.
But damage to another nerve channel necessary for a beak-sensing system had no
effect.
The researchers, led by Dr Henrik Mouritsen from the University of Oldenburg,
wrote in the journal Nature: ''The results of the present study ... specifically suggest
that cluster N of European robins is an essential part of a circuit processing
light-dependent magnetic compass information for night-time orientation.
''The exact role of cluster N within this circuit has not been determined, but the
present results raise the distinct possibility that this part of the visual system
enables birds to 'see' magnetic compass information.''
Other types of magnetic sensor may also exist in birds, said the scientists. There was
strong evidence that upper beak magnetosensors were used by pigeons.
Robins can 'see' the Earth's magnetic field which allows them to navigate, scientists
believe.
German scientists studied 36 European robins and concluded that the birds can
'see' the Earth's magnetic field, allowing them to navigate
The information, relayed to a specialised light-processing region of the brain called
''cluster N'', helps the robin find its way on migration flights.
Experts know birds possess an internal magnetic compass, but there is
disagreement about what form it takes.
One idea is that tiny magnets in the beak wired to the nervous system detect lines of
magnetic force.
Another is that magnetic fields are ''seen'' via the eyes using a complex
light-sensitive mechanism.
The new research suggests that, for robins at least, the second theory is probably
correct.
German scientists studied 36 European robins and found birds with damage to
''cluster N'' were unable to orientate themselves using the Earth's magnetic field.
But damage to another nerve channel necessary for a beak-sensing system had no
effect.
The researchers, led by Dr Henrik Mouritsen from the University of Oldenburg,
wrote in the journal Nature: ''The results of the present study ... specifically suggest
that cluster N of European robins is an essential part of a circuit processing
light-dependent magnetic compass information for night-time orientation.
''The exact role of cluster N within this circuit has not been determined, but the
present results raise the distinct possibility that this part of the visual system
enables birds to 'see' magnetic compass information.''
Other types of magnetic sensor may also exist in birds, said the scientists. There was
strong evidence that upper beak magnetosensors were used by pigeons.
