Did the endangered animal--pandas in China's Wolong Reserve   know that Monday's earthquake was coming before it hit? A British tourist, who was watching the pandas as the earthquake hit, offered a deep observation.   He said, "They had been very lazy, just eating a little bit of bamboo then, and all of a sudden they were moving rapidly around their pen   and looking back. They must have sensed something was wrong."   Some scientists say animals can sense danger by discovering subtle or sudden changes in the environment. When the tsunami   hit in 2004, there were reports that elephants in Sri Lanka fled to higher ground well before the waves crashed into the coastline. Panda researcher Marc Brody says some animal species, such as elephants who are known to hear low frequency sound waves, hear things very quickly and may get an early warning.   Some animal species have a greater awareness of shaking in the ground than humans, so they may sense smaller  _ before a big earthquake.   The tourist said, "We were looking forward to seeing the pandas, but we were not sure whether the pandas were going to come out of the pen or not, So we were waiting for that to happen when we heard this huge noise which is just what you can't describe. What was it like? It was just a huge noise and the land was shaking underneath you. Certainly it was a terrible experience to be standing there going through the earthquake." Form the passage we can conclude that the author   _  .
experienced the tsunami in 2004 is a panda researcher from Britain knew why the pandas moved rapidly before the earthquake was frightened by the earthquake