Can toads predict earthquakes?

jrholliday's picture

Using animals as a possible early warning for earthquakes is nothing new: Chinese researchers began a systematic study of unusual animal behavior and in December 1974 predicted a major earthquake that did, in fact, occur in February 1975.  Skeptics, however, are quick to debunk nearly all such observations. For the 1975 prediction, it was pointed out that most of the information came from a series of strong foreshocks.

In folklore, some animals are described as being better able to predict earthquakes than others--especially dogs, cats, chickens, horses, and other smaller animals.  Goats, cows, and most larger animals are generally described as being less able to predict earthquakes.  Animal behavior reports, however, are often ambiguous.  More troubling, they are not consistently observed.  Most recent studies classify animal-based warning as "anecdotal" and conclude they are unreliable at best.

That said, a recent study published in the Journal of Zoology found that a colony of toads deserted their mating site three days before an earthquake struck in L’Aquila, Italy last year.  They reacted despite the colony being 46 miles from the quake’s epicenter, and no toads returned to the site until ten days later, well after the last of the significant aftershocks had finished.

From ABC news:

The discovery was made by accident by biologist Dr. Rachel Grant of The Open University in England while she was studying the effects of lunar cycles on the toads’ behavior and reproduction.

Male toads usually stay at the breeding sites until spawning is complete, but 96% of them abandoned the pool five days before the quake and Grant said numbers remained low until 10 days afterwards. The number of pairs declined to zero just three days before the earthquake and stayed low until after the last aftershock.

How the toads sensed the earthquake is unclear, but Grant found scientists noticed disruptions in the ionosphere, the uppermost electromagnetic layer of the earth’s atmosphere, at the time of the L’Aquila earthquake, which Grants says the toads may have detected. “Suddenly the toads were all gone, disappeared, not a single toad, and that carried on for days, which was very unusual. And after the earthquake struck the toads came back, and that was very convincing evidence.”

Grant said there is also data that found radio signals were disturbed in the area give days before the earthquake, so there may also be a link between toad behavior and radio signals.

You can find the full article here.

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