This column is by Esther Lutz, University of Illinois Extension, Coles County Master Naturalist.
Animal Sensitivity to Earthquakes
The bed shook strangely in the pre-dawn moments, and there was an eerie, wind-like noise outside. I remember being jostled awake by the strange vibrations and drowsily wondering why the old cat would be romping across the bed like that so early in the morning. But actually, she was nowhere to be found. I was barely aware of my husband's voice in the darkness, saying, "Did you feel that?" The dog was barking uncontrollably in the backyard as we slowly came to our senses and realized that something really unusual had occurred – an earthquake!
Throughout the day everyone was talking about it and relating individual accounts of their own freaky experiences when they first realized what had happened that early April morning. News reports of the strange event dominated the air waves, and newspapers reported on the aftershocks for days afterward. I remember reading numerous articles about where the seismic activity originated and just how far away the shocks were felt. But the accounts that I found to be most curious were those of people who had observed strange and unusual behaviors in their animal friends just before the onset of the actual quake itself. Were the animals somehow aware that something was about to happen?
Anecdotal stories have been reported commonly through the years concerning animals that behave strangely before major earthquakes. It's no secret that animals hear things before we hear them, smell things before we smell them, sense things of which we are not even remotely aware. But can they truly sense an impending earthquake? Therein lies the mystery.
Can animals predict the onset of earthquake activity before humans experience it?
Some researchers believe that animals are aware of an oncoming seismic event because they are naturally more susceptible to subtle changes in the environment. Others counter that there are many reasons behind strange animal behavior and that a human psychological aspect may play a part – people want to believe that their animals experience a premonition of what is to come. Whether or not animals can detect earthquakes before humans is still debated. What is known is that earthquake prediction in any form is not an exact science.
Outside the United States, seismologists in several earthquake regions continue to engage in studies that attempt to examine the level of animal sensitivity as a part of a larger study to learn how to better predict earthquakes. Since 1971, the Chinese have established an operational network of experimental stations in various regions of high seismic activity in order to evaluate unusual events that are reported by observers, including uncharacteristic behavior in animals. Because a large percentage of the population in China live in farming areas, the Chinese are in close association with animals and can more readily observe them. They began to systematically study unusual animal behavior, and the Haicheng earthquake of February 1975 was predicted successfully as early as mid December of 1974. Most unusual was the circumstance in which snakes came out of hibernation in the dead of winter and froze on the earth's surface. Strangely, groups of rats suddenly appeared. These odd events were followed by a series of earthquakes at the end of December 1974. The following month, thousands of reports of unusual animal behavior were received in which snakes were seen coming out of their dens into the snow, and larger animals such as cows, horses, pigs, and dogs exhibited restless behaviors. On February 4, 1975, an earthquake of magnitude 7.3 struck the Haicheng County, Liaoning Province in northeast China. Because of the widespread animal observations, people were alerted in advance, and casualties were believed to be far less than would be expected had there been no prior warning. The Haicheng quake is believed to be one of the only major earthquakes successfully predicted in history by the observation of animals.
How do the animals know that an earthquake is imminent?
It is known that there are physical and chemical cues that come from the earth prior to an earthquake. It is postulated that it must be these that animals can sense. For example, dogs may hear the microfracturing of rocks a few milliseconds before the shock reaches the surface. It has also been theorized that animal behavior may be subject to changes in the magnetic field preceding a major quake. These changes may be sensed by a transfer of energy at the electron level in living cells; such electric cellular changes occurring before the onset of a large quake may be sensed and filtered by animals, then interpreted instinctively. Animals may therefore have the sensitivity to sort out the precursory signs and signals of the coming vibrations and enact a behavioral response that helps them to survive.
What kinds of unusual behaviors have been reported?
Odd behaviors reported in literature and in books include goats refusing to go into pens, cats and dogs picking up their offspring and carrying them outdoors, chickens dashing out of coops in the middle of the night, pigs squealing strangely, fish darting about aimlessly in the waters, birds leaving nests and natural areas, cattle seeking higher ground, insects congregating in huge swarms near seashores, horses and mules refusing to go into pens, and domestic animals becoming restless and agitated. Surveys in China and elsewhere have shown that the largest number of unusual behaviors precede the quake, particularly in the 24 hours before it strikes. Where major quakes were preceded by foreshocks, odd behavior in rats, fish, and snakes were observed as early as three days prior and continuing to several hours or even a few minutes before.
So what can we conclude from our recent seismic experience? Are there physical, chemical, and electromagnetic events that are detectable at the earth's surface which might signal an impending earthquake? Have animals evolved the sensory abilities to detect them and engage in some type of seismic-escape response? There are more questions than answers, it seems. I prefer to place my trust in the ability of living creatures to instinctively react to nature's mysterious forces. And the next time my dog barks frantically, I plan to listen.