November 30, 2010
Have you ever been drenched because you were standing too near a dog shaking water from her coat? It turns out that dogs (and other mammals including mice, tigers, and bears) really know how to shake.
Science News reports that researchers at the Georgia Institute of Technology recorded video of 40 different animals, representing 15 different species. They wanted to learn about how wet, hairy mammals shake off water after they get drenched.
They learned that these animals are not only expert shakers, but they each do it at exactly the right speed to eliminate all those pesky water drops.
The bigger the animal, the slower it shakes. A mouse moves its body back and forth 27 times per second, but a grizzly bear shakes only four times per second. Why is it important for mammals to quickly shed excess water? Dr. David Hu, who led the study, told Science News: "If a dog couldn’t dry itself, we calculated that it would have to use 25 percent of its daily calories to heat its body to get rid of the water. Every time they got wet they would get hypothermia and die."
No wonder your dog is such an expert shaker!
Dog Photo: Alamy/guardian.co.uk
Bear Photo: Mike Dunn/NaturalSciences.org
Posted by: Seymour Simon
