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