Like dogs, which an earlier study showed orient themselves to Earth's magnetic lines when pooping, dolphins are affected by magnets - initial proof the aquatic mammals are magnetosensitive, or magnetoreceptive.

Marine biologists from the Universite de Rennes and Institut Universitaire de France exposed dolphins at the Planete Sauvage, or Wild Planet, dolphinarium, in Port-Saint-Pere, France, to a series of magnetized objects and the researchers observed the dolphins swam more aggressively towards semi-submerged barrels emitting a magnetic field, as opposed to Identical demagnetized barrels, which served as the experiment's controls, according to a report by United Press International.

Then again, though clearly affect by the magnetic signals, the six observed bottlenose dolphins ended up interacting in equal amounts with the magnetized as well as magnetized barrels -- which suggested the dolphins might not have been so much attracted to the magnetic signals as they were intrigued by them.

It long been understood dolphins rely mainly on echolocation to navigate the seas and locate other animals, whether those others happen to be friends, enemies or prey.

Scientists have also suspected for a while that dolphins also possess the ability to perceive magnetic fields, but the hard evidence the scientific community needed as proof had been hard to find.

But now, say the French scientists, their discovery has made it much easier for such research conclusions to stick.

"Dolphins are able to discriminate between objects based on their magnetic properties, which is a prerequisite for magnetoreception-based navigation," Dorothee Kremers, who along with her colleagues at the Ethos unit of the Université de Rennes authored the recent study, said in the UPI stroy. "Our results provide new, experimentally obtained evidence that cetaceans have a magnetic sense, and should therefore be added to the list of magnetosensitive species."

The study was published earlier this week in the journal Naturwissenschaften, The Science of Nature.