Every other Friday, the Outside/In team here at NHPR answers listener questions about science and the natural world. This week's question comes from Mande in northern Illinois.
"Can animals really sense earthquakes before they’re about to strike?"
Producer Justine Paradis reports.
This transcript has been lightly edited for clarity.
Justine Paradis: Earthquakes are famously unpredictable. But humans have long observed warning signs in the natural world. The Chinese noticed rats and snakes fleeing their burrows. The ancient Greeks knew to watch out when a strange fog rolled in unexpectedly. In Venezuela, people said...
Martin Wikelski: ...just look to the chickens and the donkeys and the pigs. You know when they go crazy that [an] earthquake is coming.
Justine Paradis: This is Martin Wikelski, director of the Department of Migration at the Max Planck Institute in Germany. He explained that animal perception of earthquakes is a hard thing to study, because to understand what animals do during an earthquake, researchers also need to understand what they were doing before and after.
But that’s the problem, isn’t it? No one knows when and where an earthquake will strike next. But, a few years ago, Martin got lucky — at least in a research sense.
Martin Wikelski: There was an opportunity in Italy where there was an earthquake. It was devastating, but it hadn't really killed people.
Justine Paradis: Martin and his team got to work. They set up at a local farm, and started recording the behavior of the animals there, planning to study their response to the aftershocks. But then a new earthquake happened to strike very close to the farm. And so they finally got there before, during, and after.
The cows were the first to react.
Martin Wikelski: But they were not getting hyperactive. They were freezing… so, total quiet in a cow stable... that made the dogs go crazy because this is something that never happens.
Justine Paradis: Then, it was a domino effect through the barnyard. All that barking made the sheep go wild. Then the chickens freaked out.
Martin Wikelski: And then finally the cows went mad. And then everybody was completely, outrageously crazy for 45 minutes.
Justine Paradis: Martin says this mayhem was definitely earthquake-specific. Normal disruptions, like thunderstorms or a visit from the vet, might cause outbursts, but nothing close to this level of chaos. But what started that chaos in the first place? What were the animals actually sensing? Here’s the hypothesis.
Martin Wikelski: We think it comes from the static, basically from the ions that are going into the air from the future hypocenter. There are these enormous pressures on rocks, and that means that rock material is going into the air. It's sort of subliming.
Justine Paradis: Basically, the theory is that before a quake starts, the air around the hypocenter (the place deep in the earth where an earthquake originates) becomes charged with ions.
Martin says animals didn’t evolve to detect earthquakes. But they did evolve to be hypertuned to the unknown. When something just feels off, like when the hairs on your arm stand up from static. This is theoretically what the cows were experiencing.
Martin Wikelski: A body of an animal that is completely full with hair. If you have a static going around that, it must feel completely weird. I mean, even we feel that in front of thunderstorms.
Justine Paradis: There’s other research out there, too. In the lead-up to an earthquake in the Peruvian Andes, scientists tracking animal activity with wildlife cameras observed a significant drop in animal activity, notably rodents.
As for Martin's research, it's not yet ready to support official advance warning systems, but he thinks it'll get there.
Martin Wikelski: It is at an early stage, but that is the future. Absolutely.
If you’d like to submit a question to the Outside/In team, you can record it as a voice memo on your smartphone and send it to outsidein@nhpr.org. You can also leave a message on our hotline, 1-844-GO-OTTER.
