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Auckland University researchers believe they are close to proving that bats use the magnetic north and south poles as a navigation tool, unlike birds which use the angle of the magnetic field.
Dr Stuart Parsons and Professor Michael Walker, who teach biological sciences, are confident they will establish that bats, which are mammals, use magnetic polarity whereas birds, which aren't mammals, use magnetic inclination.
Dr Parsons said it was of particular interest given bats and birds are the only vertebrates which fly.
They have proven that when bats are kept in a contained dark habitat and the magnetic field is reversed around them they will then reverse the position they sleep in the roost.
That suggests the bats, which exclusively fly at night, are relying on the information from the polarity of the magnetic field as a location guide.
Dr Parsons said most research into the detection of magnetic fields by animals had been conducted using non-mammals, such as birds which used the inclination or angle of the magnetic field as a navigation guide.
It had been long suspected that mammals differed by using polarity although few had been tested.
Mammal navigation by magnetic fields was a possible explanation as to how cats and dogs could in instances travel long distances to get back to their homes, especially when they had not seen where they had been taken.
Dr Parsons said the university research team would continue its work on bats in China where they would install them with global positioning devices to assess their flight behaviour.
That would be compared to the behaviour of pigeons. Dr Parsons said pigeons flew parallel and perpendicular to the magnetic field as a way of trying to figure out where they were.
Already in New Zealand a student had taken nine long-tailed bats to locations they did not know, away from their home base in a King Country cave.
It was found they were able to find their way back within 24 hours even at distances of up to 20km away.
