Toads may help predict quakes

Toads deserted a lake 74km away five days before the 6.6 quake struck L'Aquila in Italy last year. Photo / AP

The common toad may be ugly, warty and squat, but it is blessed with an extraordinary gift. It has an uncanny ability to predict earthquakes several days before they occur, according to a remarkable study that documents for the first time an extraordinary "supersense" in wild animals.

Scientists studying a colony of breeding toads living in an Italian lake found they suddenly disappeared en masse five days before a magnitude 6.3 earthquake struck the town of L'Aquila in central Italy in the early hours of April 6, 2009. Most remarkably, L'Aquila is 74km from the lake.

The researchers behind the observations believe there is no explanation other than the toads must have been able to detect some changes in their environment which led them to believe that violent tremors were imminent.

Within days of the earthquake, the toads had returned to their breeding pool to continue spawning.

Anecdotal reports of animals behaving strangely before an earthquake are not unusual, but most cannot be properly assessed scientifically because they rely on eyewitness accounts after the event.

In this case, however, the scientists were monitoring the toads long before the earthquake happened.

"Our study is one of the first to document animal behaviour before, during and after an earthquake. Our findings suggest that toads are able to detect pre-seismic cues such as the release of gases and charged particles, and use these as a form of earthquake early warning system," said Dr Rachel Grant of the Open University in Milton Keynes.

"We looked at the weather and other possible causes of the sudden disappearance of the toads, but nothing seemed to fit. There didn't seem to be any other reason for it except that they had somehow managed to sense that an earthquake was going to happen."

The lake where the toads were breeding was being monitored nightly by Grant and her Italian colleagues, who were studying the effect of moonlight on amphibian behaviour. Russian scientists suggested the toads may have been able to detect the release of radioactive radon gas from the ground, or charged particles in the ionosphere of the night sky, Grant said. It may be an evolved ability to protect the slow-moving animals from mudslides caused by earthquakes, she said.

ANIMAL MAGIC

* Kestrels can see ultraviolet light which helps them detect voles, their favourite prey.

* Homing pigeons can detect the Earth's magnetic field to allow them to navigate over long distances.

* Lions often hunt at night, because their eyes can see about seven times better in the dark than humans.

* Fish use their skin to detect movement and vibrations in water, in the same way people can feel breezes.

* Sharks can smell a single drop of blood diluted in 100 litres of water.

- INDEPENDENT