SSS 2008-08-26(在线收听) |
This is Scientific American's 60-Second Science. I'm Adam Hinterthuer. Got a minute?
Don't be fooled by those big bovine eyes and the mouth slowly chewing cud—cows have a magnetic personality. At least that’s the claim made by German researchers in the August 26th issue of the Proceedings of the National Academy of Sciences. Using Google Earth images, the scientists looked down on over 8,000 cattle around the world. And, when grazing or resting, cows tended to face either magnetic north or south.
The researchers combined field observations with the satellite data and discovered that herds of both deer and cattle tend to align themselves north-south. Factors like wind and the angle of the sun had little bearing on how the animals stood. More often than not, like needles of a compass, heads swiveled northward. While it’s been known that birds, bees and fish use the earth’s magnetic fields for orientation, this study is the first to point to a magnetic sense in large mammals. The scientists speculate that this behavior may allow the animals to stay spatially oriented. In case danger lurks and a cow needs to make any sudden…moos.
Thanks for the minute for Scientific American's 60-Second Science. I'm Adam Hinterthuer .
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原文地址:http://www.tingroom.com/lesson/sasss/2008/8/98875.html |