Toads can predict earthquakes

Scientists are about to publish a study of the special ability of toad - they can predict earthquakes.

A species of toad was very popular before the earthquake in Italy's city of L'Aquila occurred on April 6, 2009, killing more than 300 people.

Biologist Rachel Grant of the Open University in the UK is working on a project to study Bufo Bufo toad in Lake San Ruffino - about 74 km north of L'Aquila - the 6.3-magnitude earthquake out, AFP leads an upcoming research study.

For 29 days, Grant and a colleague counted the number of toads, measuring the temperature, wind speed, humidity and many other environmental parameters around the lake. On March 28, 2009, the team found more than 90 male toads gathered at a location to prepare for the breeding season. But two days later their number suddenly dropped sharply. On April 1 - that is, 5 days before the earthquake - 96% of the male toads have disappeared.

When the full moon was on the evening of 9 April, a few dozen male toads returned to mate with the female frog. After that night the number of male toads suddenly decreased and an aftershock with an intensity of 4.5 on the Richter scale appeared on April 13. Two days after the aftershock the number of male toads increased.

Toad Bufo Bufo often mates on the full moon nights. Photos: wikimedia.org.

In addition, the two researchers found that there were no toads at the mating site for three days before the earthquake. Nor did any pairs of toads appear at the mating site from the earthquake to the last aftershock.

Grant says, under normal conditions, if the male toads have arrived at the mating site, they will never leave until the breeding season ends. To decipher the mystery, she and her colleagues use ultra-low frequency radio receivers to measure electrical activity on the ionosphere - the upper layer of the atmosphere and contain many free ions and electrons.

The results show that toads always disappear at times when the number of low-frequency radio radiation is high.

A previous study demonstrated that disturbances in the ionosphere before earthquakes often release radon - a chemical element in the inert gas group.

"Our research shows that toads have the ability to detect earthquake signals, such as the release of radon and charged particles, " Grant said.