Animals and Earthquakes

Unusual Animal Behavior Prior to Earthquakes: A Survey in North-West California

by: David Jay Brown & Rupert Sheldrake

Abstract

During November of 1996 a telephone survey of 200 Santa Cruz County households was carried out in North-West California to find out how many people have observed unusual animal behavior prior to an earthquake. 15%
(N=30) of those surveyed reported that they have witnessed at least one occurrence of an animal acting unusual before an earthquake. Common observations included reports that the animals appeared frightened, agitated, excited, disoriented, or were missing. 66% (N=132) of households surveyed had pets. 57% (N=17) of those people who observed this phenomenon were pet owners, while 43% (N=13) were non-pet owners.
This phenomenon was observed 53% (N=1!9) of the time in dogs, 19% (N=7) of the time in cats, 6% (N=2) of the time in chickens, 6% (N=2) of the time in other birds, 6% (N=2) of the time in horses, 6% (N=20) of the time in cows, and 3% (N=I) of the time with possums. The lead times prior to the earthquake ranged from several seconds to a week, with the most frequent observations occurring between several minutes and several days prior to the earthquake. The implications of these results are discussed with regard to the possibility that some animals may possess a sensitivity to certain earthquake precursors, which could serve to help warn people of an approaching earthquake.

Introduction

Observations of unusual animal behavior prior to earthquakes have been reported around the world since the beginning of recorded history (Tributsch, 1982). In particular, the Chinese and Japanese have recorded these observations for many hundreds of years (Lee, Ando, and Kautz, 1976), and have made attempts to incorporate these reports into an earthquake warning system with some success (Allen, 1976). For example, on February 4, 1975 the Chinese evacuated the city of Haicheng several hours before a 7.3 magnitude earthquake largely on the basis of unusual animal behavior observations (Allen, 1976).

The anomalous behaviors most frequently reported include restlessness or excitability, a heightened sensitivity to mild stimulation, vocal responses, a tendency for borrowing, premature termination of hibernation, and leaving their normal habitats. The precursory lead times vary from just a few seconds to more than several months. (Lee, Ando, and Kautz, 1976). These unusual behaviors have been reported in a wide diversity of animal species, including many varieties of mammals, birds, reptiles, fish, and insects (Tributsch, 1982).

However, only a limited number of scientifically credible accounts of this phenomenon are available. The vast majority of observations are anecdotal, and are usually classified as folklore. One well-researched book on the subject-- When the Snakes Awake-- details much of what is known historically and scientifically about earthquakes and unusual animal behavior (Tributsch, 1982). Scientific accounts of this phenomenon through the mid seventies have been summarized in the "Proceedings of the 1976 USGS Conference on Abnormal Animal Behavior Prior to Earthquakes" (Evernden, 1976).

Some compelling evidence comes from Japan, where it has been reported that certain fish develop a heightened sensitivity to stimulation due to electrical changes prior to some earthquakes (Hatai and Abe, 1932; Suyehiro, 1968; Suyehiro, 1972.).

However, perhaps the most important evidence comes from a five year study conducted by the Stanford Research Institute-- Project Earthquake
Watch-- which obtained statistically significant results indicating that reports of unusual animal behavior increase prior to some earthquakes.
(Otis and Kautz, 1985).

The study reported upon in this paper was carried out as part of an international investigation into the unexplored abilities of animals, which began with the publication of Seven Experiments that Could Change the World (a book by one of this paper's authors). One primary thesis of the book is that there are many valuable research opportunities available which are relatively simple and inexpensive to carry out (Sheldrake, 1995).

This survey was done in order to find out how common these observations of unusual animal behavior are among the population of an earthquake-prone region. The survey was conducted by telephone in Santa Cruz County, California during November of 1996, and it involved 200 randomly-selected households.

Method

Data were collected by means of telephone interviews conducted by David Brown (D.B.), following a standard questionnaire format.

The households surveyed were in Santa Cruz County. Most were in and around the university-beach town of Santa Cruz, population 52,700, between Boulder Creek and Watsonville, in north-central California.
Santa Cruz was chosen because of its proximity to the epicenter of the
1989 Loma Prieta earthquake, and the San Andreas Fault. Santa Cruz is also within D.B.'s local proximity, and calling within the area helped to minimize the cost of the study.

Households were selected from the Pacific Bell Santa Cruz County 1996 telephone directory (area code 408) using an electronic random number generator to determine the page and column number, as well as its position on the page.

D.B. introduced himself as follows: "My name is David Brown. I'm conducting a survey on pets and animals. I was wondering if I could ask you a few questions?" Approximately 20% of the people reached by phone agreed to partake in the survey. When a cooperative subject was found, D.B. then asked a series of questions and recorded the answers on a standard form as follows.

Name---------

Address

Tel:

1) Do you or does anyone in your household own a pet? Yes No

If yes, then: 2) What type of animal?

Species:

2a) If dog, then: What breed of dog?

3) Have you ever noticed your pet or any other animal exhibiting any type

of unusual behavior prior to an earthquake?
Yes No

If yes, then:

4) What type of behavior did you notice?

5) How long prior to the earthquake did you notice this behavior?

6) When and where was the earthquake

7) Where were you when this occurred?

location:

Statistical analysis was carried out... [Rupert]

Results

Pet Ownership

Out of 200 households surveyed, 132 had pets. Cats were the most common pet followed by dogs. The figures were as follows:

Cats 83
Dogs 69
Birds 7 (excluding chickens)
Rabbits 6
Fish 6
Lizards 3
Horses 2
Chickens 2
Rats 2
Hamster 1
Snakes 1

Most of these households had one kind of pet: 49 had cats only, and 38 had dogs only; 23 had both dogs and cats; 6 had cats and other pets (excluding dogs); 2 had dogs and other pets; 5 had cats, dogs, and other pets; 9 had only other pets.

The percentages of households with pets in Santa Cruz County was 66%, which is higher than the U.S. national averages of 57.9%. [Rupert-- I'm in the process of obtaining California state averages for pet owners.] There were also more cats represented in the survey than the national and state. The U.S. national averages are as follows: 37% own dogs, 31% own cats, 6% own birds, 3% own fish, and 1.5% own rabbits (Jaegerman, 1992).

Observations of unusual animal behavior prior to an earthquake were noticed in the following species:

Dogs 19
Cats 7
Wild Birds 2
Cows 2
Horses 2
Chickens 2
Pet Birds I (Canaries)
Possum 1

57% (N=17) of those people who observed this phenomenon were currently pet owners, while 43% (N=13) were non-pet owners. Non-pet owners were referring to previously owned pets or farm animals, other people's pets, and wild animals.

Types of Behaviors Noticed

The following descriptions and adjectives were used to describe the animal's unusual pre-earthquake behavior:

barking repeatedly : (won't stop, and for no apparent reason): 7 times with dogs.
appeared frightened or scared : 4 times with dogs. 2 times with cats.
was running around : 4 times with dogs. 1 time with a cat. 1 time with cows.
hiding or trying to hide : 3 times with dogs. 2 times with cats.
nervous ' : 1 time with wild birds. 1 time with pet bird. I time with dog.
missing or disappeared : 1 time with a dog. I time with a cat.
ran away_: 1 time with a dog. 1 time with a cat.
excited : I time with pet bird. 1 time with wild birds.
disoriented : I time with a dog. 1 time with a cat.
retreating into self : 1 time with a dog. 1 time with a cat.
restless : 2 times with dogs.
antsy and roaming more : 1 time for general farm animals-- horses, cows, chickens, dogs, and cats.
acting schizy : I time with a cat.
freaking out : I time with a cat.
seemed agitated : 1 time with chickens.
acting crazy: I time with a dog.
whining : 1 time with a dog. 1 time with a cat.
running up and down trees _: I time with a cat.
appeared tense : 1 time with a dog.
looking and listening-: I time with a dog.
pecking one another aggressively : I time with wild birds.
closer to people : 1 time with a dog.
jumpy: 1 time with a dog.
skittish : 1 time with a dog.
flighty: 1 time with a dog.
acting uneasy : 1 time with cows.
act up: 1 time with cows.
wouldn't eat : I time with cows.
shaking : I time in with a dog.
squirrelly : I time with a cat.
pacing : I time with a cat.
howling : 1 time with a cat.
stillness or silence : 1 time with wild birds.
in unusual place : 1 time with a cat.
in a usual place at an unusual time 1 time with a possum.
looking around inquisitively : 1 time with a dog.
wild animal out of habitat : 1 time with a possum.
unsettled : 1 time with a dog.
leaving as a flock just moments before an earthquake : 1 time with wild birds.

Lead Time Prior to the Earthquake that the Animal's Unusual Behavior was Observed

The amount of lead time that the unusual behavior was observed prior to the earthquake ranged from several seconds to approximately a week, with the most frequent observations falling into the range of several minutes to several days. Lead time data for each type of animal are summarized in Table 1.

Table 1

Total 0-5 min 5 + min Hours Days Not Sure

Dogs 19 6 (32%) 3 (16%) 2 (10%) 5 (26%) 3 (16%)

Cats 7 2 (29%) 1 (14%) 3 (43%) 1 (14%)
Wild Birds 2 1 (50%) 1 (50%)
Cows 2 1 (50%) 1 (50%)
Chickens 2 1 (50%) 1(50%)

Pet Birds 1 1
Possums 1 1
Horses 1 1

People were often unsure of the amount of time, and had to estimate an approximation in retrospect. According to the reports, 32% (N=6) of the dogs behaved unusually less than 5 minutes prior to the earthquake. 16%
(N=3) did so over five minutes prior to the earthquake, but under an hour (approximately a 1/2 hour for one, ten minutes for the other two).
10% (N=2) appeared to react more than an hour to a day in advance (approximately "a day" for each of the two dogs). 26% (N=5) did so for more than a day in advance to several days in advance, ranging from a day and a half to three or four days. One week was the longest approximate lead time reported for a dog. 16% (N=3) of the dog observers were unable to estimate the amount of time.

29% (N=2) of cat observers report to have witnessed the unusual behavior less than 5 minutes prior to the earthquake. 14% (N=I) acted unusual slightly longer in advance (3 to 6 minutes was the estimate). 43% (N=3) were longer than an hour, but under a day (1 to 1 1/2 hours was the estimate for one, and "a day" for the other two) in advance. 14% (N=I) of cat observations occurred between a day and week in advance of the earthquake (between several days and a week was the estimate).

In the two instances with wild birds the first report was between an hour to an hour and a half in advance, while the other was estimated to be a day to a day and a half in advance. With regard to the cows, one estimate was several hours, the other was two to three days. The chickens were reported to act about a minute or so in advance in one instance, and several hours in advance in another. In the one instance of someone's pet birds (canaries) the lead time was estimated to be one or two days. The possum was reported to be out several hours before the earthquake in the middle of the afternoon. The horses were reported to be acting unusual several hours in advance of the earthquake.

Times and Locations of Earthquakes and Unusual Behavior

The majority of respondents were located in Santa Cruz County at the time that they observed the anomalous behavior.

In Santa Cruz County:

Santa Cruz 10
Watsonville 6
Aptos 3
Rio Del Mar 1
Capitola 1
Live Oak 1
Boulder Creek 1

Outside Santa Cruz County, but in California:

Salinas 1
San Jose 1
Sherman Oaks 1
Aromas 1
Correlates 1
Not Sure 1

Outside California:

Tacoma, WA 1

The majority of respondents were referring to the October 17, 1989 Loma Prieta earthquake, which was centered several miles north of the city of Santa Cruz. One person referred to the January 17, 1994 Northridge earthquake, which was centered several miles from her location in Sherman Oaks. The other respondents were unsure.

1989 Loma Prieta 18
1994 Northridge 1
Not Sure 1 1

Discussion

Report Reliability

The subjective nature of survey responses inherently raises questions of reliability. A possible source of bias in this study may stem from a tendency for people to exaggerate an animal's abilities due to their emotional attachment with the animal. Conversely, people who pay relatively little attention to animals may not observe them closely enough to be aware of these, perhaps, more subtle responses.

Bias could also result from either a belief in, or a 'denial of the possibility that animals have the ability to predict earthquakes. Also, because these observations are all reported in retrospect, and are associated with a powerful and often upsetting event, bias may result from the accompanying shock or trauma which could alter one's perception or memory of the experience.

It is beyond our current ability to know with any certainty how much these and other forms of bias influenced our data. What is evident, however, is that a substantial number of people believe that they have witnessed abnormal animal behavior prior to an earthquake.

Comparison of Animals and Behaviors

Dogs were the animal most frequently sited as behaving unusually prior to an earthquake. This is an especially interesting finding considering that there were more cat than dog owners in the study, and a previous survey of this same population found a correlation between this higher number of cat owners and a greater number of believers in "psychic" cats than dogs (Brown and Sheldrake, 1997). This finding of more "psychic"
cats had been somewhat counterintuitive as, in general, dog owners tend to have closer relationships with their pets than cat owners, and cats tend to be less sociable and more independent than dogs (Hart, 1995).

Unusual behavior is difficult to define, and determining if there is a characteristic behavior is not clear-cut, although there are some distinct patterns. For example, an intense fear that appears to make some animals cry and bark for hours, and others flee in panic has been reported often. Equally characteristic is the apparent opposite effect of wild animals appearing confused, disoriented, and losing their fear of people (Tributsch, 1982). Since there is experimental evidence that charged ionic particles can effect neurotransmitter ratios in animal brains, and that charged ions may be released prior to some earthquakes, it has been suggested that this may explain these two seemingly-contradictory behavior patterns (Tributsch, 1982).

In addition to the stories collected from the respondents in this survey, the authors of this paper have been collecting dozens of detailed accounts of unusual animal behavior prior to earthquakes through requests in newspapers and magazines, as well as on radio stations and internet sites.

Many people reported dogs vanishing or barking uncontrollably. A number of pet owners found their ordinarily calm cats suddenly darted off and hid, or paced around crying for a few minutes before the earthquake.
There were reports of goats and horses leaping around wildly, noisy birds suddenly becoming silent, or a whole flock of seagulls taking off all at once just before an earthquake. A few people noticed the number of roadkill increasing for several days before an earthquake. Although it's primarily accounts of dogs and cats that have been reported, many other types of animals in the wild, on farms, and in zoos; including horses, cows, goats, possums, rats, chickens, and other birds have been observed acting in unusual ways.

Possible Explanations for the Unusual Behavior, and Why More Research into the Extraordinary Abilities of Animals is Necessary

The anecdotal evidence presented in this paper does not necessarily imply the existence of earthquake prediction abilities in animals. Some of the mysterious behavior discussed in this paper may ultimately be explainable in terms of reactions to ordinary stimuli. People may sometimes misperceive or exaggerate an animal's abilities, and the anticipatory behavior may be projected upon them in retrospect. However, some of the unusual behavior discussed in this paper may be due to a genuine sensitivity to precursory earthquake signals, and when these results are combined with the results of previous studies and observations, a very strong case can be made for the existence of this phenomenon.

In the case that animals are actually reacting to precursory earthquake signals, the following explanations have been proposed:

1. Because many animals possess auditory capacities beyond the human range, it has been suggested that some animals may be reacting to ultrasound emitted as microseisms from fracturing rock (Armstrong, 1969).

2. Fish have a high degree of sensitivity to variations in electric fields, and because telluric current variations have been noted before some earthquakes, it has been suggested that this is what the fish may be reacting to (Ulomov and Malashev, 1971).

3. Because some animals have a sensitivity to variations in the earth's magnetic field (usually as a means of orientation), and since variations in the magnetic field occur near the epicenters of earthquakes (Chapman and Bartels, 1940), it has been suggested that this is what the animals are picking up on (Otis and Kautz, 1985). Marsha Adams, an independent earthquake researcher in San Francisco, claims to have developed sensors that measure low-frequency electromagnetic signals which allow her to predict earthquakes with over 90% accuracy, although this remains to be substantiated. Adams suspects that low-frequency electromagnetic
signals-- created by the fracturing of crystalline rock deep in the earth along fault lines-- are "biologically active", and that her instruments are picking up the same signals that sensitive animals do (Brown, 1997).

4. Some organisms respond to changes in the polarity and concentration of atmospheric ions, and it has been suggested that this sensitivity enables some animals to detect the air-ionizing effects of radon released from the ground in advance of certain earthquakes. (Ulomov and Mavashev, 1967). Tributsch has suggested that a piezoelectric effect may be at work here. On the average, the earth's crust consists of 15% quartz, and in certain areas it can be as high as 55%. According to Tributsch, the piezoelectric effect of the quartz is capable of generating enough electrical energy to account for the creation of airborne ions before and during an earthquake. This electrostatic charging of aerosol particles may be what the animals are reacting to.
Animals, also observed acting unusual in similar ways prior to thunderstorms, may have evolved a sensitivity to electrical changes in their environment (Tributsch, 1982).

5. The effects of radon gas on the level of air ionization explained above, can also be expected to change the field gradient, and dozens of animals have been shown to be sensitive to changes in the electric field gradient of the atmosphere (Chalmers, 1967).

6. The animals may be perceiving and responding to stimuli that currently science has no way to measure.

Experiments that can help us decide between these explanations are not easily performed, as studying earthquakes has inherent difficulties, because they are infrequent and unpredictable by their very nature.
However, further investigation in this area could help us discover what the animals are reacting to, and to allow us to build sensors to detect the earthquake precursory signals. We suspect that these types of investigations hold enormous potential for understanding animals better, and predicting earthquakes more reliably. If an understanding of what animals are reacting to were to be obtained, it's value would be tremendous.

However, even without understanding what the animals are reacting to, it is conceivable that an earthquake warning system could be created by networking people who observe animal behavior on a routine basis-- as Kautz and Otis did with Project Earthquake Watch, and the Chinese and Japanese have practiced for hundreds of years. Even something as simple as tracking the number of missing animals may prove to have some predictive value with regard to earthquakes. Retired USGS geologist James Berkland claims to be able to predict earthquakes with over 75% accuracy, in part through calculating the number of lost pet ads in the newspaper each day. (Brown, 1996).

The pool of untapped resources potentially residing right under our noses may be vast. There are between 51 and 58 million households in the U.S. with dogs, and 49 and 60 million households with cats (American Demographics, 1991). [Rupert-- I am in the process of obtaining statistics for California.] This huge untapped and easily accessible population of potentially geophysically-sensitive animals may be holding an enormous wealth of information.

Animal experiments in this area hold great promise. Although studying the possible relationship between earthquake precursors and animal behavior may prove challenging, utilizing the animals' apparent sensitivity to precursory signals may not be difficult, and the benefits could be enormous. When one considers the annual and historical devastation wrought by earthquakes in the form of lives, property, and valuable resources, it becomes increasingly clear why studying this apparent sensitivity in animals is so vital.

Acknowledgments

We would like to thank all the people who took part in this survey, as well as Pamela Smart, Nina Graboi and Ralph Abraham for their valuable contributions.

David Jay Brown
P.O. Box 1082
Ben Lomond, California
95005 USA

Rupert Sheldrake
20 Willow Road
Hampstead, London
NW3 1TJ England

References

American Demographics, vol. 13, May, 1991, p. 40.

Allen, C. "The Role of Animal Behavior in the Chinese Earthquake Prediction Program." In Abnormal Animal Behavior Prior to Earthquakes.
J.F. Evernden (ed.), National Earthquake Hazards Reduction Program, USGS, Menlo Park, CA, 23-24, September 1976, pp. 5-13.

Armstrong, B.H. "Acoustic Emission Prior to Rockburst and Earthquakes."
Bull. Seismol. Soc. Am.59, 1259-1279, 1969.

Brown, D.J. "Interview with James Berkland", unpublished, October, 1996.

Brown, D. J. "Interview with Marsha Adams", unpublished, October, 1996.

Brown, D.J., and Sheldrake, R. "Psychic Pets Part Two: A Survey in North-West California."

Chalmers, J.A. Atmospheric Electricity. Pergamon Press Inc., New York, 1967.

Chapman, S. and Bartels, J. Geomagnetism, Vol. 1. Clarendon Press, Oxford, 1940, p. 194ff.

Evernden, J.F. (ed.) Abnormal Animal Behavior Prior to Earthquakes. U.S.
Dept. of Interior Geological Survey, Conference 1. Convened under the auspices of the National Earthquake Hazards Reduction Program, USGS, Menlo Park, CA, 23-24, September 1976.

Hart, L.A. "Dogs as Human Companions: A Review of the Relationship." In:
The Domestic Dog: Its Evolution, Behaviour and Interactions with People, (ed. Serpell, J.). Cambridge: Cambridge University Press, 1995.

Hatai, S. and Abe, N. "The Responses of the Catfish, Parasilurus ascotus, to Earthquakes." Proc. Imperial Acad. Japan, 8, 1932, pp. 374-378.

Jaegerman, M. New York Times (National Edition) "Price Tag: The Top Ten Pets", November 12, 1992, p B-5.

W.H.K. Lee, M. Ando, and W.H. Kautz. "A Summary of the Literature on Unusual Animal Behavior Before Earthquakes." In Abnormal Animal Behavior Prior to Earthquakes. J.F. Evernden (ed.), National Earthquake Hazards Reduction Program, USGS, Menlo Park, CA, 23-24, September 1976, pp. 15-54.

Sheldrake, R. and Smart, P. "Psychic Pets: A Survey in North-West England."

Sheldrake, R., Seven Experiments that Could Change the World, Riverhead Books, 1995.

Suyehiro, Y. "Unusual Behavior of Fishes to Earthquakes." In Scientific Report, Keikyu Aburatsubo Marine Park Aquarium, Vol. 1, 1968, pp. 4-11.

Suyehiro, Y. "Unusual Behavior of Fish to Earthquakes, Il." In Scientific Report, Keikyu Aburatsubo Marine Park Aquarium, Vol. 4, 1972, pp. 1314.

Tributsch, H., When the Snakes Awake, MIT Press, 1982.

Ulomov, V.I. and Malashev, B.Z. "The Tashkent Earthquake of 26 April, 1966." Acad. Nauk. Uzbek, FAN, Tashkent, 1971.

Table 1. Replies to Questions

3. How long prior to the earthquake did you notice this behavior?

Numbers (and percentages) of animals reacting

Total 0-5 min 5 + min Hours Days Not Sure

Dogs 19 6 (32%) 3 (16%) 2 (10%) 5 (26%) 3 (16%) Cats 7 2 (29%) 1 (14%) 3 (43%) 1 (14%) Wild Birds 2 1 (50%) 1 (50%) Cows 2 1 (50%) 1 (50%) Chickens 2 1 (50%) 1(50%)

Pet Birds 1 1
Possum 1 1
Horses 1 1

(Note: Some people responded for more than one animal.)
 

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