Answer by Rory Young:
There are numerous such stories from all over the world and throughout history about animals warning of impending natural cataclysm. The Roman writer Claudius Aelianus wrote that for five days prior to the destruction of the Greek city of Helike by earthquake and tsunami "all the mice and martens and snakes and centipedes and beetles and every other creature of that kind in the city left in a body" and on the night prior to the earthquake none were left.
Which heightened senses in animals could account for these stories and what could they be detecting?
Sight and smell can only detect certain dangers that are close by. Hearing is a different story however.
There are two types of hearing. The first is acoustic hearing.
Beyond our range of hearing there is ultrasound, which is above our range of hearing and there is infrasound which is below our range of hearing.
Canids are well known for their ability to hear ultrasound and to be able to hear much softer sounds than us.Bats use it for radar navigation Some apes too have this ability.
uses its incredible hearing to detect its termite prey.
Guerrilla fighters from ZANLA based in Mozambique during the Rhodesian Bush War used baboons as air raid warnings. Once it had survived one attack by the Rhodesian Airforce, a baboon would be able to tell well in advance that a group of planes was on its way.
I have been unable to find out if any of this animals in the Japan Earthquake and Tsunami had previously experienced earthquakes or tremors. However, there is the possibility that the reaction could have evolved as an innate instinct.
Infrasound travels further. Elephants routinely communicate at 12 km from each other. Snakes detect infrasound through their bellies.
The other type of hearing used by some animals is seismic hearing.
Seismic hearing involves listening to vibrations through the substrate. This can be the ground itself or simply a leaf.is widespread in the animal kingdom and its users include moles, many species of rodents, skunks, deer, elephant shrews, marsupials, rabbits and elephants.
The use of seismic hearing in animals ranges from elephants hearing a heard charging in panick from up to 32 kms away to a beetle tapping the ground to attract a mate.
There is no need to go into the details of what reasons animals might use seismic communication for. What is important in relation to the question is that these animals can pick up seismic sound incredibly well.
What is completely unknown and unstudied however is what exactly they are detecting.
When an earthquake occurs 'thetravel through the earth's crust about twice as fast as the , so they arrive first. The greater the distance, the greater the delay between them. For an earthquake strong enough to be felt over several hundred kilometers (approximately M > 5) this can amount to some tens of seconds difference. The P waves are also weaker, and often unnoticed by people. Thus the signs of alarm reported in the animals at the , some five to ten seconds prior to the shaking from the M 5.8 , was undoubtedly prompted by the p-waves. This was not so much a prediction as a warning of shaking from an earthquake that has already happened.*
So this could account for reactions shortly prior to earthquakes and especially for tsunamis caused by earthquakes that have occurred very far away. It cannot
however account for the records of animals reacting hours or even days before.
There is the possibility that they react to changes in seismic or other activity prior to the earthquake happening. This could very likely be possible if they have previously been exposed to an earthquake and this is why.
There is something as I use routinely in my work. An American tracker named Tom Brown Jnr. coined a term for it; "The Baseline Symphony".
When I have been away from the bush for a while I will, on returning, first spend anything from hours to days walking on my own. By doing so I "tune in" to this "baseline symphony".
The best way of explaining it is that it is all normal sounds, pressures, temperatures, light and other activity that is routine all combining to create a feeling of harmony.
If I am walking along and suddenly notice a change to this baseline symphony I stop and really pay attention as it means something is afoot. It can be the approach of a predator which has led to a change in bird calls or it can be a change in wind direction meaning a change in weather or a myriad of other things. Sometimes there is a really dramatic change to the baseline symphony where several dramatic changes occur at once. My strongest memory of this was when firearms have been used by poachers nearby to where I have been but to far to hear directly.
I believe all animals, especially wild animals use this "sixth sense" routinely. It is not a "stand alone" sense but sort of a "right-brain" usage combination of all the other senses to produce a "gut feeling".
In the case of an imminent earthquake is it not possible that prior to its occurrence there is a dramatic change to the baseline symphony? Perhaps a combination of seismic sound, sound from the ocean and air, air pressure?
There is no evidence for this little theory. I would not be surprised though to find that despite not knowing how animals can detect an imminent earthquake, that practical people don't start using animals for earthquake warning like the ZANLA guerrillas used baboons for air-raid warning..