Italian toads predicted L'Aquila earthquake
Legged it in advance of 2009 event
A UK biologist has presented evidence that common toads can predict imminent earthquakes after a colony she was studying hopped it before the major quake which hit L'Aquila, Italy on 6 April 2009.
Dr Rachel Grant of the Open University was routinely monitoring a Bufo bufo population at San Ruffino Lake, some 74km from the epicentre of the event. Five days before the 6.3-magnitude quake, "the number of male common toads in the breeding colony fell by 96 per cent", while "most breeding pairs and males fled" three days before the earth moved.
The BBC explains that the males' behaviour was "highly unusual", since "once they have bred, they normally remain active in large numbers at breeding sites until spawning has finished". In this case, "spawning had barely begun at the San Ruffino Lake site before the earthquake struck".
Grant also noted that spawning at the site ceased "from the first main shock to the last aftershock".
She believes the toads escaped to higher ground "possibly where they would be at less risk from rock falls, landslides and flooding", and their exodus coincided with "disruptions in the ionosphere, the uppermost electromagnetic layer of the earth's atmosphere", which scientists detected around 6 April using very low frequency (VLF) radio sounding.
The Beeb explains: "Such changes to the atmosphere have in turn been linked by some scientists to the release of radon gas, or gravity waves, prior to an earthquake."
Grant, whose research is published in the Journal of Zoology, said: "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."
Cows, however, don't appear to share the same talent. Back in 2008, Swedish scientists discovered that local ruminants were unmoved by a quake which shook southern Sweden, leading one disappointed boffin to conclude that "as a species, cows are not the world’s most earthquake-sensitive animals". ®
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