Toads have inbuilt earthquake warning system

By Courtenay Rule March 31, 2010
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Toads are capable of detecting an impending earthquake several days before the first tremors strike.

TOADS ARE CAPABLE OF detecting an impending earthquake several days before the first tremors strike, and alter their behaviour accordingly, a new study suggests.

“Our study is one of the first to document animal behaviour before, during and after an earthquake,” says Rachel Grant, lead author of the study at the Open University in England. “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.”

Though anecdotal reports and previous studies of ants, rats and birds have shown animals altering behaviour in advance of an earthquake, this is usually just hours before the event and near to the epicentre. The toads in this study were shown to react, even though they were many tens of kilometres away. 

Toads dramatic behaviour change before earthquake

To make the discovery, Rachel led researchers who studied a population of common toads at a breeding site located 74 km from the epicentre of the major earthquake that struck L’Aquila, Italy, in April 2009.  Comparing data collected before, during and after the event, they found that the toads displayed a dramatic change in behaviour five days before the earthquake.

According to the study, published this week in the Journal of Zoology, the amphibians abandoned spawning and left breeding sites, not resuming normal behaviour until several days after the event.

The change in behaviour coincided with disruptions in the uppermost electromagnetic layer of the Earth’s atmosphere, say the authors – thought to be caused by the release of radon gas or gravity waves prior to the earthquake. The researchers speculate that the toads sensed and responded to these early warning signs of the coming quake.

Toads senses allow escape strategy

Rachel and her co-workers argue that since toads move slowly there is evolutionary pressure for them to develop an effective early escape response strategy.

Biologist and toad expert Rick Shine, at the University of Sydney, says that the finding has intriguing implications.

“I don’t doubt that many kinds of wild animals have ways of detecting things that science has yet to unravel,” he told Australian Geographic. “It certainly sounds as if the Italian toads are better at forecasting an earthquake than we are, and it would be fascinating to learn more about the subtle cues that apparently enable them to do so.”