Dolphins sensitive to magnets

Dolphins behave differently when swimming near magnetised objects, indicating that they are indeed sensitive to magnetic stimuli, says a study.

"Dolphins are able to discriminate between objects based on their magnetic properties, which is a prerequisite for magnetoreception-based navigation," said co-researcher Dorothee Kremers from Universite de Rennes in France.

"Our results provide new, experimentally obtained evidence that cetaceans have a magenetic sense and should, therefore, be added to the list of magnetosensitive species," Kremers added.

The study conducted in the delphinarium of Planete Sauvage, an animal park in France provides experimental behavioural proof that these marine animals have the ability to perceive a magnetic field.

The researchers watched the spontaneous reaction of dolphins to a barrel containing a strongly magnetised block or a demagnetised one.

The analyses revealed that the dolphins approached the barrel much faster when it contained a strongly magnetised block than when it contained a similar, not magnetised one.

However, the dolphins did not interact with both types of barrels differently.

They may, therefore, have been more intrigued than physically drawn to the barrel with the magnetised block, the study noted.

Some observations of the migration routes of free-ranging cetaceans, such as whales, dolphins and porpoises, and their stranding sites suggested that they may also be sensitive to geomagnetic fields.

The study appeared in the journal Naturwissenschaften - The Science of Nature.