Can Animals Sense Earthquakes?
Maryann Mott
for National Geographic News

The belief that animals can predict earthquakes has been around for centuries.

In 373 B.C., historians recorded that animals, including rats, snakes and weasels, deserted the Greek city of Helice in droves just days before a quake devastated the place.

Accounts of similar animal anticipation of earthquakes have surfaced across the centuries since. Catfish moving violently, chickens that stop laying eggs and bees leaving their hive in a panic have been reported. Countless pet owners claimed to have witnessed their cats and dogs acting strangely before the ground shook—barking or whining for no apparent reason, or showing signs of nervousness and restlessness.

But precisely what animals sense, if they feel anything at all, is a mystery. One theory is that wild and domestic creatures feel the Earth vibrate before humans. Other ideas suggest they detect electrical changes in the air or gas released from the Earth.

Earthquakes are a sudden phenomenon. Seismologists have no way of knowing exactly when or where the next one will hit. An estimated 500,000 detectable quakes occur in the world each year. Of those, 100,000 can be felt by humans, and 100 cause damage.

One of the world's most earthquake-prone countries is Japan, where devastation has taken countless lives and caused enormous damage to property. Researchers there have long studied animals in hopes of discovering what they hear or feel before the Earth shakes in order to use that sense as a prediction tool.

American seismologists, on the other hand, are skeptical. Even though there have been documented cases of strange animal behavior prior to earthquakes, the United States Geological Survey, a government agency that provides scientific information about the Earth, says a reproducible connection between a specific behavior and the occurrence of a quake has never been made.

"What we're faced with is a lot of anecdotes," said Andy Michael, a geophysicist at USGS. "Animals react to so many things—being hungry, defending their territories, mating, predators—so it's hard to have a controlled study to get that advanced warning signal."

In the 1970s, a few studies on animal prediction were done by the USGS "but nothing concrete came out of it," said Michael. Since that time the agency has made no further investigations into the theory.

Erratic Behavior in Dogs

Researchers around the world continue to pursue the idea, however. In September 2003 a medical doctor in Japan made headlines with a study that indicated erratic behavior in dogs, such as excessive barking or biting, could be used to forecast quakes.

There have also been examples where authorities have forecast successfully a major earthquake, based in part on the observation of the strange antics of animals. For example, in 1975 Chinese officials ordered the evacuation of Haicheng, a city with one million people, just days before a 7.3-magnitude quake. Only a small portion of the population was hurt or killed. If the city had not been evacuated, it is estimated that the number of fatalities and injuries could have exceeded 150,000.

The Haicheng incident is what gave people hope that earthquakes might be predictable, says Michael, and what prompted the animal behavior studies by the USGS.

It was later discovered, though, that a rare series of small tremors, called foreshocks, occurred before the large quake hit the city.

"It was the foreshock sequence that gave (Chinese officials) the solid prediction," Michael said.

Still, the Chinese have continued to look at animal behavior as an aid to earthquake prediction. They have had several notable successes and also a few false alarms, said Rupert Sheldrake, a biologist and author of the books, Dogs that Know When Their Owners Are Coming Home and The Sense of Being Stared At.

A reproducible connection between animal behavior and earthquakes could be made, he said, but "as the Chinese have discovered, not all earthquakes cause unusual animal behavior while others do. Only through research could we find out why there might be such differences."

Sheldrake did his own study looking at animal reactions before major tremors, including the Northridge, California, quake in 1994, and the Greek and Turkish quakes in 1999.

In all cases, he said, there were reports of peculiar behavior beforehand, including dogs howling in the night mysteriously, caged birds becoming restless, and nervous cats hiding.

Geologists, however, dismiss these kinds of reports, saying it's "the psychological focusing effect," where people remember strange behaviors only after an earthquake or other catastrophe has taken place. If nothing had happened, they contend, people would not have remembered the strange behavior.

Reporting Strange Behavior

Sheldrake disagrees. Comparable patterns of animal behavior prior to earthquakes have been reported independently by people all over the world, he said. "I cannot believe that they could all have made up such similar stories or that they all suffered from tricks of memory."

More research is needed and is long overdue, said Sheldrake, who proposes a special hotline or Web site where people could call or write in if they saw strange behavior in their animals. A computer would then analyze the incoming messages to determine where they originated. A sudden surge of calls or e-mails from a particular region might indicate that a quake was imminent.

The information would be checked to make sure the observations were not caused by other circumstances known to affect the behavior of animals, such as fireworks, or changes in weather. And to avoid issuing false warnings, Sheldrake said, the data would be used in conjunction with other monitoring devices such as seismological measurements.

"Such a project would capture the imagination of millions of people, encourage large-scale public participation and research—and would be fun," he said. "What is holding this research back is not money but dogmatism and narrow-mindedness."

Animal Expert Comments on Tsunami Animal Impact

Tsunamis, triggered by a massive 9.0 earthquake in the Indian Ocean, have created mass destruction impacting humans and nature. As the human death toll numbers continue to escalate, Sri Lanka wildlife officials report that they have not found any animal carcasses. Did they have a sixth sense?

Animal behavior expert Diana L. Guerrero said, "Anecdotal accounts seem to indicate that many do have that sixth sense. In fact, references can be found back through time (even around 373 BC) indicating that people believe that animals can predicate seismic activity."

The author found works from the Massachusetts Institute of Technology and Stanford University exploring the possibility that animal's anticipate disaster--and that they may even exhibit behavioral clues that might be used as predications.

She said, "It is not uncommon for animals to exhibit behavioral changes before an impending disaster. I've seen changes in normal patterns of behavior in both wild and domestic animals prior to seismic activity. Wild animals often vacate areas, gather in strange groupings, and sometimes will even enter into human habitats they normally avoid."

Guerrero is the author of the booklet, "Animal Disaster Preparedness for Pet Owners & Pet Professionals" and is one of the contributing editors to "Resources for Crisis Management in Zoos and Other Animal Care Facilities." In addition to her written works, she holds numerous certifications in the animal disaster field from groups such as the Federal Emergency Management Agency (FEMA) and the Humane Society of the United States (HSUS). The author has also worked with many of the nation's animal disaster rescue groups.

She continued, "Disasters in other countries pose a variety of challenges. The wide scope impact and magnitude of the events will have long-term affects. However, the lack of reports of animal casualties does not mean there are not animal victims."

In the wave of this week's destruction, human and animal survival stories
are beacons of light against the backdrop of intense tragedy. Outside of Sri Lanka, other hard hit regions report thousands of decaying human bodies mixed with those of dead dogs, fish, cats and goats. Clean up operations have begun and a number of emergency rescues agencies are involved from all over the world.

"Although animal relief has been around a while, animal disaster relief efforts have strongly evolved in the United States over the past twelve years. On the global scene, most activities are spearheaded by the World Society for the Protection of Animals, but every group relies on the networks formed by local agencies--if they exist." Guerrero said.In India many such organizations have mobilized to assist animal victims of the latest disaster. Groups such as the Animal Help Foundation, Blue Cross Society, and International Animal Rescue have begun to assess the area and assist animals. Reports from other groups are expected but communications are often compromised due disaster damage and power outages.

Preliminary reports from those areas indicate large numbers of dead animals and populations of stray of dogs deluge the streets. The Point Calimere Wildlife Sanctuary was reported to be under five feet of water with two elephants entrenched in the mud. "Unless you have experienced a disaster you can't really imagine what it is like--and this disaster is so great, and the tragedy so wide scope, it is unprecedented."

The woman speaks not only from professional experience--she has personally experienced the ravages of a large magnitude earthquake and the havoc of the recent California wildfires.

Guerrero continued, "Tragedy during disasters is inevitable but if you can prepare and mitigate the circumstances you can minimize the impact on your household, neighbors, and community."

Guerrero's animal disaster preparedness booklet, now in the seventh dition, offers assistance to Americans to do just that. It contains guidelines about how to prepare prior to a disaster, how to form or get involved in a animal disaster preparedness network, and what items to include in kits for dogs, cats, horses, and birds. The work also includes tip sheets for behavior, identification, health, diet, and sanitation for multiple species during a disaster.

The added bonuses are the sections on post disaster animal behavior and resources for the pet owner including animal disaster agencies, where to get training, and suppliers of kits and equipment (focusing on the United States).She concluded, "If you want to assist humans or animals there are agencies you can support and I hope you will take action to help."

"Magnetic Map" Found to Guide Animal Migration

Bijal P. Trivedi
for National Geographic Today

Do you ever wonder why migrating animals such as birds, salmon, and whales, to name a few, never seem to meander off course and get lost? The answer, according to a couple of new studies, may be that those migration routes and navigation skills are hard-wired into the animals' brains.

Studies of loggerhead turtles revealed that hatchlings have the ability to sense the direction and strength of Earth's magnetic field, which they use for navigating along the turtles' regular migration route.
The migration begins and ends on the shores of eastern Florida. It takes the turtles on a circuit around the Sargasso Sea, an elliptical region in the North Atlantic Ocean that's strewn with seaweed known as sargasso. The entire journey takes five to ten years to complete.

"These tiny, defenseless sea turtles embark on this 8,000-mile (12,900-kilometer) migration route around the Atlantic, and they do it alone without following other turtles," said biologist Kenneth Lohmann of the University of North Carolina in Chapel Hill, North Carolina, who led the study.

Long Journey

The loggerhead turtles are less than two inches (five centimeters) long when they emerge from underground nests on the eastern Florida coasts. They crawl straight from their shells and plunge into the Gulf Stream, then into the North Atlantic gyre, a circular current that wraps clockwise around the Sargasso Sea.

The North Atlantic gyre takes the turtles from their Florida nests and east across the Atlantic, past the Azores, south past the Canary and Cape Verde Islands, and finally back toward their birthplace on North American shores.

To determine whether the turtles inherited a migratory map, Lohmann and his colleagues collected baby loggerheads straight from their nests and studied their behavior while exposing them to different magnetic fields.

Each of the 79 loggerheads in the study was outfitted with a blue nylon-Lycra "bathing suit" that was tethered to a tracking system. The turtles were then placed in a shallow circular water tank. Surrounding the tank was a huge electric coil that generated magnetic fields.

Lohmann's team exposed the turtles to magnetic fields that simulated three key locations along the migratory route—northern Florida, the northeastern gyre near Portugal, and the southern gyre—and recorded the direction in which each animal swam.

"We found that turtles followed their migratory route," said Lohmann.

When the turtles were exposed to a magnetic field that mimics the one that occurs near Portugal, for example, the turtles paddled south. In the ocean, the movement in that direction would keep the turtles in warm, nutrient-rich circuit and away from cold waters.

"These turtles have never been exposed to water, yet they were able to process magnetic information and change their swimming direction accordingly," said Lohmann. "It seems they inherited some sort of magnetic map." The report appears in the current issue of the journal Science.

The researchers do not know how the turtles sense the magnetic field or what part of the brain is involved.

The results of the study have broad implications for conservation efforts. If populations of turtles from different locations inherit different instructions that guide their migration, then these populations are clearly unique, said Lohmann. This means that a void created when a certain population at one location becomes extinct cannot be filled by introducing turtles that are endemic to another part of the world.

"This suggests that we need to pay more attention to conserving specific populations rather than simply focusing on the species in general," said Lohmann.

If fish carry a similar "magnetic map," this could explain why low fish populations in one region do not benefit from a spillover of the same species from another location.

Wired for Navigation

In a second report published in Science, scientists have discovered a ollection of nerve cells in the brains of subterranean Zambian mole rats that enable the animal to process magnetic information used in navigation.

The mole rats dig tunnels up to 200 meters (220 yards) long and build their nests in the southernmost tip of their burrows. As the direction of the magnetic field changes, so does the location of the moles' nests.

As in the loggerhead turtle study, the German and Czech researchers who conducted the mole rat study have not yet determined how the mole rats detect the magnetic fields.

Lohmann described the mole rat study as "an excellent step forward," tying a specific region of the brain with navigational ability.

The Use Of Animals In
Earthquake Prediction

Research being carried out in China has indicated that recognition of unusual animal behavior in a systematic way can lead and be used, in conjunction with other methods, as a means of predicting large and potentially destructive earthquakes. The following are examples of observed unusual animal behavior before major earthquakes occurred.

Unusual Animal Behavior

In 1920, the largest earthquake to hit China with a magnitude of 8.5 occurred in Haiyuan County, Ninghsia Province. According to reports of eyewitnesses, prior to this earthquake, wolves were seen running around in packs, dogs were barking unusually, and sparrows were flying around wildly. It is reported that prior to the 6.8 magnitude earthquake in 1966 in Hsingtai County, Hopei Province, in Northern China, all the dogs at a village near the epicenter had deserted their kennels and thus survived the disaster.

Prior to the earthquake of July 18, 1969, (magnitude 7.4) in the Pohai Sea, unusual behavior was observed in seagulls, sharks, and five different species of fish. Based on observations of unusual behavior of giant pandas, deer, yaks, loaches, tigers and other animals, a warning was issued at the Tientsin People's Park Zoo, two hours before the earthquake struck.

The Chinese began to study systematically the unusual animal behavior, and the Haicheng earthquake of February 1975 was predicted successfully as early as in mid-December of 1974. The most unusual circumstance of animal behavior was that of snakes that came out of hibernation and froze on the surface of the earth. Also a group of rats appeared. These events were succeeded by a swarm of earthquakes at the end of December 1974. During the following month, in January 1975, thousands of reports of unusual animal behavior were received from the general area. Local people saw hibernating snakes coming out from their holes and into the snow. In the first three days in February the activity intensified even more and unusual behavior of the larger animals such as cows, horses, dogs and pigs was reported. On February 4, 1975, an earthquake of magnitude 7.3 struck the Haicheng County, Liaoning Province.

More instances of unusual animal behavior were reported. A stock breeder in northern China, feeding his animals before dawn on July 28, 1976, in the area of the Kaokechuang People's Commune, approximately 40 kilometers away from the city of Tangshan, reported that his horses and mules instead of eating were jumping and kicking until they finally broke loose and ran outside. A few seconds later, a dazzling white flash illuminated the sky. Tremendous rumbling noises were heard as a 7.8 magnitude earthquake struck the Tangshan area.

Other reports of unusual animal behavior prior to the occurrence of earthquakes have been reported in the literature and in books. Such unusual animal behavior included goats refusing to go into pens; cats and dogs picking up their offspring and carrying them outdoors; pigs squealing strangely; chickens dashing out of the coops in the middle of the night; fish dashing about aimlessly; and birds leaving their nests. It has also been reported that zoo animals refused to go back into their shelters at night; snakes, lizards and other small mammals evacuated their underground nests; insects congregated in huge swarms near the seashores; cattle sought higher ground; domestic animals became agitated; and wild birds left their usual habitats.

Surveys done in China show that the largest number of cases of unusual animal behavior precede the earthquake, particularly in the 24 hours before it strikes. In other parts of China where major earthquakes have been preceded by foreshocks, unusual behavior in rats, fish, and snakes were observed as early as three days prior to the earthquake, but continuing to several hours, or even a few minutes before.


Studies of Animal Behavior


Throughout China's long history, unusual behavior has been observed in every kind of common animal. Most of the behavior falls into the category of unusual restlessness and disorientation.

Since animals have the capability of acting as predictors of earthquakes, the Chinese scientists have carried out surveys of animal behavior variations prior to earthquakes. A team of scientists including biologists, geophysicists, chemists, meteorologists, and biophysicists conducted a survey in the Tangshan area and in 400 communes in 48 counties around it after the 1976 earthquake. The scientists visited a number of places that were hit by other destructive earthquakes and, through interviews and discussions with local people, collected information on over 2,000 cases of unusual animal behavior occurring prior to an earthquake. The majority of the reports involved domestic animals. Based on this survey a preliminary report was prepared by the Chinese identifying 58 kinds of domestic and wild animals that had demonstrated unusual behavior.

The principal focus of research work in China has been on the behavior of pigeons. Biological studies on pigeons determined that a hundred tiny units exist between the tibia and fibula on a pigeon's leg. These nerve units are connected to the nerve center, and are very sensitive to vibrations. Scientists determined that prior to an earthquake of magnitude 4.0, which occurred in the area of the study, fifty pigeons that had severed connections between the tibia, fibula, and the nerve centers, remained calm before the earthquake, while those with normal connections became startled and flew away.

Because of the success in monitoring unusual animal behavior for the prediction of certain earthquakes, the Chinese, who have pioneered this work, have looked into ways to construct instruments that would duplicate the sensory organs of animals which were able to monitor, and sense, stimuli preceding an earthquake. Researchers found it very difficult to understand the mechanism of response stimuli. Physical or chemical stimuli come out of the earth prior to an earthquake and these must be the stimuli that animals can sense. For example, dogs may be able to hear the microfacturing of rocks a few milliseconds before a quake shock reaches the surface. Electromagnetic changes in the earth prior to an earthquake may be sensed by such animals as sharks and catfish which have low or high frequency receptors and sense such changes actively or passively. Also such electromagnetic field changes could be affecting migrating birds and the navigational ability of fish.


Mechanisms of Animal Responses


What is the sensory mechanism of animals that controls their responses to changes related to an impending earthquake? As mentioned earlier, the behavior of an animal might be subject to changes in the magnetic field preceding a major earthquake and such changes may be sensed by energy transfer at the electron level which, in turn, cause changes in the cellular behavior, or response. The living cell is essentially an electrical device and a micromolecular structure, and the sensory organs are all interconnected. Electromechanic changes occurring prior to the occurrence of a large earthquake may be sensed by certain animals and filtered, then instinctively interpreted. Thus animals may have the means and sensitivity to sort out and discriminate the threatening precursory signals of an impending earthquake, thus activating a behavior pattern for survival.

These precursory electromagnetic or electromechanic changes which precede an earthquake, although mixed with background noise, must be filtered by animals and coordinated through their sensory response to the total environment. Thus, behavior is determined by the sensitivity of the different component parts of the living system to the surrounding medium. Experiments with new instruments and electronic solid state sensors are being used now to determine animal response to impending catastrophic occurrences.

The benefit from such research would be in duplicating the sensory responses of animals to construct equally responsive instruments that can record or monitor these precursory changes. Thus, observing and studying animal behavior could lead to better earthquake prediction instrumentation.


Operational Network

Since China considers such information on animal behavior vital to prediction, it established in 1968 its first experimental station for earthquake predictions making use of biological observations. This experimental station was established in Hsingtai Province. Other similar stations were set up in 1971 in Aksu, Sinkiang Province, where earthquakes were expected to occur. Since 1971, the Chinese have established an operational network in different communes or counties. Whenever unusual events occur and are reported by numerous observers, these are evaluated as a way of predicting earthquakes. So far, by this means, two major earthquakes have been predicted. This is easy for the Chinese since 80 percent of the population live in farming areas that are in close association with animals which can be observed readily. It is a little more difficult for people living in urban areas to observe similar animal behavior.


Tsunami Page of Dr. George P.C.