For centuries, people have described unusual animal behavior just ahead of seismic (地震的) events: dogs barking endlessly, cows halting their milk, toads leaping from ponds. A few researchers have tried to prove a link, but most such attempts have relied largely on anecdotes and single     1    .

Now researchers at the University of Konstanz, along with a multinational team of colleagues, say they have managed to     2     measure increased activity in a group of farm animals prior to seismic activity. During separate periods     3     about four months in 2016 and 2017, the researchers     4     these highly sensitive biologgers and GPS sensors, which can record accelerated movements in any direction, to six cows, five sheep and two dogs living on a farm in an earthquake-prone area of northern Italy to keep track of the activities and the nervousness of animals. “Only now can we do continuous biologging,” says study co-author Martin Wikelski. “Because the     5     possibilities are finally there.”

The paper’s statistical analysis showed animals’ activity significantly increased before magnitude 3.8 or greater earthquakes when they were housed together in a stable — but not when they were out to pasture (吃草). Wikelski says this difference could be linked to the increased stress some animals feel in     6     spaces. Analyzing the increased movements as a whole, the researchers claim, showed a clear signal of     7     behavior hours ahead of tremors.

Besides, it showed that the farm animals appeared to anticipate quakes anywhere from one to 20 hours ahead, reacting earlier when they were closer to the origin and later when they were farther away. This finding is     8     with a hypothesis that animals somehow sense a signal that spreads outward. It holds that in the days before an earthquake, shifting tectonic plates (地壳板块) squeeze rocks along a fault line, causing the rocks to release minerals that force ions into the air, and then the animals react to this novel     9    .

Not involved with the new study, Wendy Bohon, a geologist from Washington, D.C., is     10     of the air ionization idea. Heiko Woith, a geologist at GFZ German Research Center for Geosciences, says the time frame was still too short and points out that limited data collection in many studies makes it impossible to determine whether a measured signal was related to a quake or was simply noise.

A powerful typhoon hit East China in July 2016. The     1     and landslides caused a great number of     2     ,left 61 missing and forced the evacuation of hundreds of thousands of people. The typhoon brought huge loss to the     3     areas along theYangtze River. In the months that have passed since then, tireless     4     have been made to offer help to all the people in need.