When a natural disaster approaches, animals are one step ahead of not only ordinary people, but also scientists. Developed sensory ability allows them to receive a signal of danger in advance and take measures to save lives. Researchers still don’t know why, but some animals can detect an earthquake several hours or even days before it occurs, as evidenced by noticeable changes in their typical behavior.
Mammals live in a world of smells that humans cannot perceive. Reptiles respond to ground vibrations and sound waves, while birds and insects are sensitive to changes in the electromagnetic field. The sensory apparatus of animals is complex and much more efficient than the human one, as it is well adapted to the environment and is a survival factor.
Behavior of domestic animals
Scientists who monitored the behavior of livestock on the Italian farm Fratelli Angeli in the municipality of Caprile confirmed that farm animals are able to sense earthquakes. Cows, sheep, and shepherd dogs have been equipped with sensors that record changes in their movement speed. The researchers monitored the activity of animals before and during the 6.6 magnitude earthquake that occurred in Norcia on October 30, 2016. As a result, all animals showed unusually high levels of arousal before the shocks. At the same time, the waiting time for an earthquake (from one to twenty hours) is inversely proportional to their distance from the epicenter (from 5 to 28 km). Scientists recommend continuing research on the behavior of domestic animals before natural disasters and integrating the data obtained into earthquake detection and early warning systems.
Behavior of mammals in the wild
In 2004, shortly before the earthquake and tsunami in Sri Lanka, elephants mass broke their chains and headed towards the mountains. The local people noticed the strange behavior of the animals and decided to follow them. This helped them save lives when an earthquake of magnitude 9.3 occurred in the Indian Ocean, and then a tsunami wave more than 15 meters high reached the coast. At the same time, according to eyewitnesses on the island of Phuket in Thailand, elephants massively climbed the mountain and reached its top a few minutes before the tsunami hit the shore.
It is worth noting that elephants are known for their unique ability to perceive infrasound (frequency up to 10 Hz) and communicate in this range with their relatives. As is known, infrasound is generated in the Earth’s crust during earthquakes, hurricanes and lightning strikes. Therefore, scientists advise taking the predictions of elephants about the impending danger very seriously. In Indonesia, elephants have been equipped with GPS beacons to track their movements and thus determine whether sudden animal migration outside their natural habitat could indicate an impending earthquake or volcano eruption.
How birds detect an earthquake
Eyewitnesses of the magnitude 7.8 earthquake in Turkey and Syria, which occurred on February 6, 2023, claim that a few hours before the disaster, the birds behaved strangely, namely, they began to gather in large flocks, fly chaotically over houses and emit loud cries. They tried to sit on the tallest trees and looked for safe shelters until the first powerful tremors. Scientists suggest that the sensory system of birds, especially species that migrate seasonally, may detect earthquake precursor signals due to:
- developed sensitivity to electromagnetic signals in the Earth’s crust and atmosphere;
- the ability to sense changes in the Earth’s electric field;
- high sensitivity to vibrations.
However, researchers cannot definitively assert the abilities of birds to predict earthquakes. Their sensitivity to changes in the electric and magnetic fields of the planet can be activated already during tectonic shifts, but not hours before.
Behavior of reptiles
It is known that snakes, lizards and other reptiles leave their burrows and seek safer shelter before earthquakes. Until recently, researchers did not consider the behavior of reptiles as a way to study precursor signals of disasters.
In 1975, in Haicheng, China, many snakes left the city before a powerful earthquake, despite the fact that the animals were supposed to be in hibernation. Local scientists concluded about the impending disaster, declared the evacuation of residents, which helped prevent numerous casualties among the population during the strong tremors. Since then, China has developed an earthquake prediction system based on the behavior of snakes.
Behavior of insects before an earthquake
In 2012, German scientists from the University of Duisburg-Essen published a report on long-term observations of the behavior of European ant colonies, which deliberately chose habitats near faults and potential earthquake zones.
Insects left anthills and spent the night in open space several hours or days before the main tremors. Such changes in behavior were observed only during earthquakes with a magnitude greater than 2.0. Scientists believe that changes in the behavior of ants before an earthquake can be explained by two abilities that insects have:
- ability to sense changes in gas composition due to sensitive chemical receptors;
- sensitivity to fluctuations in the Earth’s magnetic field.
Supplementing seismological data with information on changes in animal behavior improves the quality of monitoring, the ability to more accurately predict earthquakes and develop an early warning system for the population about impending tectonic catastrophes in the region.