Unusual Animal Behavior Prior to Earthquakes: A Survey in North-West
by: David Jay Brown & Rupert Sheldrake
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
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,
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,
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
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.
1) Do you or does anyone in your household own a pet? Yes No
If yes, then: 2) What type of animal?
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?
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?
Statistical analysis was carried out... [Rupert]
Out of 200 households surveyed, 132 had pets. Cats were the most common
pet followed by dogs. The figures were as follows:
Birds 7 (excluding chickens)
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:
Wild Birds 2
Pet Birds I (Canaries)
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
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
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
Lead Time Prior to the Earthquake that the Animal's Unusual Behavior was
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
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
Rio Del Mar 1
Live Oak 1
Boulder Creek 1
Outside Santa Cruz County, but in California:
San Jose 1
Sherman Oaks 1
Not Sure 1
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
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,
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
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.
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.
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
David Jay Brown
P.O. Box 1082
Ben Lomond, California
20 Willow Road
NW3 1TJ England
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Armstrong, B.H. "Acoustic Emission Prior to Rockburst and Earthquakes."
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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
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1940, p. 194ff.
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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.)