SCIENCE / MEDICINE : WHAT SCIENTISTS KNOW ABOUT ANIMAL BEHAVIOR : Fish and amphibians

Fish have highly sensitive otolithic organs of the ear that can detect extremely weak seismic activity-up to three magnitude levels smaller than those detected by humans. This includes tiny foreshocks that frequently precede sizable earthquakes. Many fish and amphibians also possess the ability to sense exceptionally small gradients of water displacement that can be caused by the foreshocks. Catfish, sharks and rays may also be able to sense light electromagnetic variations created by early seismic activity.

Pocket mice

One of the attempts to assess animal behavior was conducted by UCLA researchers, who built a simulated outdoor habitat for about 50 pocket mice in the Morongo Valley. Pocket mice were used because they do not drink water and were therefore easy to isolate. On March 15, 1979, a swarm of earthquakes struck the area, the three largest measuring magnitudes of 5.2,4.9 and 4.8. More than 35 smaller quakes were also recorded.

“To our obvious delight, significant, and in some cases dramatic, activity anomalies were recorded from most animals in both the indoor and outdoor activities,” the UCLA researchers reported. However, the report concluded that the increased activity could have been attributed to other factors.