7. March 2024
Earthquakes are devastating – and difficult to predict. It is hard to forecast exactly when and where an earthquake will occur, despite advances in seismology and data processing. But time and again, people report that animals behave unusually before such natural disasters. Do animals really have a “sixth sense” for earthquakes, and can they warn us about them?
Tales of nervous water buffalo, ants or birds that get restless before an earthquake are commonplace. The latter were the subject of a report by Roman naturalist Pliny the Elder way back during the eruption of Mount Vesuvius in 79 AD. But even in modern times, anecdotes of animals behaving oddly before natural disasters continue to do the rounds. In 1975, the Chinese metropolis of Haicheng is said to have been evacuated in time ahead of a severe earthquake because the authorities drew the right conclusions from the strange behaviour of the indigenous snakes. For a long time it was virtually impossible to verify such observations scientifically because the animals would have had to have been continuously monitored both before and after a disaster. However, today’s sensors and current methods of data evaluation are now opening up new possibilities in this field.
Researchers from the Max Planck Institute of Animal Behavior in Radolfzell have used this method to investigate the behaviour of animals in an earthquake region in the Italian region of Abruzzo. The animals participating in the experiment were six cows, five sheep and two dogs, all of which are said to have behaved strangely during earthquakes in the past. The researchers equipped the four-legged subjects with motion sensors and recorded their activities over several months. During this time, the authorities reported numerous earthquakes in the region.
Collective state of emergency
Evaluations of the animal tracking revealed that the animals showed odd behavioural patterns up to 20 hours before an earthquake. “The closer they were to the epicentre of the impending quake, the earlier they changed their behaviour,” says project leader Martin Wikelski. These behavioural anomalies became particularly evident when the behaviour of the entire group was considered. “As a collective, the animals seem to show capabilities that are not so easy to discern on an individual level,” explains Wikelski.
So far, the researchers can only speculate as to what enables dogs, sheep and cows to “sense” an approaching earthquake: They may be able to smell the gases that are released in increasingly high volumes before an earthquake. Another possible explanation is that when the rock comes under severe pressure before an earthquake, it releases positively charged oxygen ions which then rise to the top and change the chemistry of the air. It is conceivable that the animals might perceive this ionisation through their fur.
First early warning animals in use
However, the researchers have already shown what an animal early warning system could look like: Chips on the collars worn by the animals send measurement data to a computer every three minutes. If the computer detects increased activity in the animals for at least 45 minutes, an alarm is triggered. This has already happened once, the researchers say. “And three hours later, a small earthquake did indeed shake the region, the epicentre of which was directly under the animals’ stable,” reports Wikelski.
The researchers have also equipped goats and sheep on Mount Etna in Sicily with GPS tracking transmitters and motion sensors. And the data evaluations would have shown that, in all seven major eruptions during this time, the animals had fled to the nearest shelter ahead of the event, Wikelski says.
The glass cat
These are quite promising results, but they are of course not nearly enough to draw well-founded conclusions. To broaden their research and transform the method into a systematic earthquake early warning system, the researchers now want to observe more animals over longer periods of time in different earthquake zones around the world.
To this end, they have been cooperating since 2023 with an Austrian start-up that produces GPS trackers for dogs and cats. The start-up will integrate suitable algorithms into its own software to allow it to record the unusual behaviour of the four-legged housemates. This will allow the researchers to access data from more than 600,000 animals worldwide. And since animals are exempt from the GDPR, they don’t have to ask them for permission in advance to collect and process their data.
Animal monitoring from orbit
But the researchers led by Martin Wikelski also want to record animal activities from space – based on the global animal observation system known as Icarus. This originally used a transmitting and receiving system on the ISS space station to operate. But with the outbreak of the Ukraine war, the partnership between the German and Russian space agencies was suspended and data transmission ended.
To fill this gap, the Icarus team therefore launched a mini-satellite into space in the summer of 2023. And they made a virtue out of necessity: According to the researchers, is not only is the small satellite more powerful than the installation on the ISS, but unlike the latter it can also collect data from birds, bats, sea turtles and land mammals equipped with transmitters in every corner of the world.
If all goes according to plan, the Icarus project will resume operations in October 2024. In the coming years, more mini-satellites are to be launched into orbit to allow data transmission in virtually real time: a key prerequisite for an animal early warning system. Until it can be said with certainty whether animals can systematically warn us of earthquakes, a lot of data still needs to be collected and evaluated – and we will all have to be patient for a little longer.
