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For the first time, scientists have filmed the behaviour of wild animals in Peru prior to a quake and believe their study could help improve short-term seismic forecasting. This still shows a Razor-billed curassow
For centuries there have been accounts of animals behaving bizarrely before earthquakes.

Now, for the first time, scientists have filmed the behaviour of wild animals prior to a quake and believe their study could help improve short-term seismic forecasting.

They found that animals in Peru - such as pumas and razor-billed curassow birds - ran for cover days before the event.

Researchers believe that the changes in behaviour may be linked to airborne ions.



Led by Dr Rachel Grant of Anglia Ruskin University, experts used data gathered from a series of motion-triggered cameras located in the Yanachaga National Park in Peru.

The research found that significant changes in animal behaviour began 23 days before the magnitude 7.0 Contamana earthquake that struck the region in 2011.

On a typical day, the cameras would record between five and 15 animal sightings.

However, within the 2-day period in the run-up to the earthquake, they recorded five or fewer sightings.


For five of the seven days immediately before the earthquake, no animal movements were recorded at all, which was incredibly unusual for the mountainous rainforest region.

Dr Grant, a lecturer in animal and environmental biology, told MailOnline that rodents seemed to be particularly sensitive and disappeared completely eight days before the quake.

'Usually they're quite ubiquitous in the forest. They're very common and were everywhere in the control period, but then completely disappeared.'

The study which was co-authored by Professor Friedemann Freund of the SETI Institute and Professor Jean-Pierre Raulin of the Centre of Radio Astronomy and Astrophysics Mackenzie (CRAAM) in Brazil, and is published by the journal Physics and Chemistry of the Earth, looked at reasons for this disappearance.

They recorded the reflection of very low frequency (VLF) radio waves above the area surrounding the epicentre.

The scientists detected disturbances in the ionosphere - the layer of the earth's atmosphere which contains a high concentration of ions and free electrons and is able to reflect radio waves - which started two weeks before the earthquake.

A particularly large fluctuation was recorded eight days prior to the quake, coinciding with the second significant decrease in animal activity observed in the pre-earthquake period.


Prominent among the most likely causes for the unusual animal response are positive airborne ions, which are known to be generated in large numbers at the Earth's surface when rocks deep below are subjected to increasing stresses during the build-up to an earthquake.

Positive ions in the air lead to unpleasant side effects in animals and humans, such as 'serotonin syndrome'.


This is caused by an increase in the serotonin levels in the bloodstream, and can lead to symptoms such as restlessness, agitation, hyperactivity and confusion.

They expected the injection of positive airborne ions into the Earth's atmosphere before seismic activity to have a profound effect on mammals and birds - in particular those living on the ground and in burrows, and the study seems to prove this.

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Dr Grant, a lecturer in animal and environmental biology, told MailOnline that rodents seemed to be particularly sensitive and disappeared completely eight days before the quake. This still from an in-situ camera shows a Paca rodent during the control period of the experiment
'As far as we know, this is the first time that motion triggered cameras have documented this phenomenon prior to an earthquake,' Dr Grant said.

'The results are particularly interesting as we also found evidence of disturbances in the ionosphere in the area where the earthquake struck.

'We believe that both of these anomalies arise from a single cause: seismic activity causing stress build-up in the earth's crust, leading, among other things, to massive air ionisation.

Professor Friedemann Freund of the Seti Institute, who works at Nasa's Ames Research Centre in California, added: 'The camera traps were located on a ridge at an altitude of 900 metres.

'If air ionisation occurred, it is likely that it was particularly strong along such a ridge.

'Hence, the animals would have escaped to the valley below, where they were exposed to fewer positive airborne ions.

'With their acute ability to sense their environment, animals can help us understand subtle changes that occur before major earthquakes.

'These changes, that we are now able to measure, express themselves in many different ways at the earth's surface and above.'

Dr Grant said that that next step in the research is to find a reproducible way of monitoring behavioural changes before an earthquake, because 'we don't want a false alarm'.

She intends to investigate wither zooplankton - tiny animals that live in water - could be used as a biological indicator for seismic activity.

'We hope our work will stimulate further research into this area, which has the potential to help with short-term seismic risk forecasting,' she added.
THE IONOSPHERE AND QUAKES

Scientists recorded the reflection of very low frequency radio waves above the area surrounding the epicentre of the Peruvian earthquake.

In particular they monitored the ionosphere, the layer of the Earth's atmosphere which contains a high concentration of ions and free electrons and is able to reflect radio waves.

It is thought that positive airborne ions, which are known to be generated in large numbers at the Earth's surface when rocks deep below are subjected to increasing stresses during the build-up to an earthquake, trigger unusual animal behaviour.

Positive ions in the air lead to unpleasant side effects in animals and humans, such as 'serotonin syndrome'.

This is caused by an increase in the serotonin levels in the bloodstream, and can lead to symptoms such as restlessness, agitation, hyperactivity and confusion.