Toads 'sense imminent earthquakes'
Published 31/03/2010 | 09:51
Many animals are believed to have a "sixth sense" about natural disasters, but new research suggests common toads really can sense a coming earthquake.
Researchers at the Open University studying toads in Italy, found 96% of males abandoned a breeding site 46 miles (74km) from the epicentre of the earthquake that hit L'Aquila in 2009, five days before it struck.
The number of pairs at the site dropped to zero three days before the quake, according to the study published in the Zoological Society of London's Journal of Zoology.
And there was no fresh toadspawn laid at the spot from the date the earthquake struck to the last significant aftershock of more than 4.5 on the Richter scale.
According to the researchers, male toads would normally remain in the breeding sites from the point mating activities get under way until spawning is complete.
The scientists believe the toads could be able to detect environmental changes, such as the release of gases or charged particles from the ground, before seismic events.
The coming earthquake appears to have prompted them to break off from breeding and evacuate the site.
Their exodus coincided with disruptions in the ionosphere, the uppermost electromagnetic layer of the Earth's atmosphere, which could be the result of the release of radon gas and gravity waves prior to an earthquake.
Dr Rachel Grant, who was studying the impact of the lunar cycle on the toads when the earthquake struck, said: "Our study is 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."