Toads ‘have earthquake early warning system’
If you live in an earthquake zone and one day you notice the local amphibians behaving oddly then it might be time to hop it.
A British biologist believes that common toads may be able to sense impending seismic activity days before it occurs following a chance study of the creatures’ behaviour ahead of last year’s quake in the Italian town of L’Aquila.
Rachel Grant of the UK’s Open University was studying breeding patterns in a toad colony in San Ruffino Lake about 50 miles from L’Aquila. Five days before the quake struck she recorded a 96 percent fall in the numbers of male toads. Three days ahead of the quake the number of breeding toads had dropped to zero.
Within six days of the quake the toads were once again laying spawn at the lake — but none was laid between the first and last tremors.
Grant believes that the toads fled to higher ground during the quake, perhaps alerted by electromagnetic disruptions in the atmosphere caused by the release of radon gas possibly caused by a buildup of seismic pressure. Alternatively they may be able to feel tremors in the earth imperceptible to humans or sensitive to electrical signals emitted by rocks under stress.
“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,” she says.
The trait could have evolved over millions of years, she added.
“An earthquake could wipe out a population in that area,” she said. “A landslide or flood could wipe out virtually 100 percent of the males, and quite a lot of the females.”
Seismologists have long struggled in vain to find ways of predicting imminent earthquakes.
But Roger Musson, a seismologist with the British Geological Survey, cast doubt on the theory and said a causal link would be hard to prove.
“What happens is somebody observes some strange animal behavior then there is an earthquake, so they link the two,” said Musson. “There are probably plenty of cases in which there is strange animal behavior and no earthquake.