Furry mammals can shake themselves 70 percent dry in just a fraction of a second, according to new research. The study, which looked at the shaking speeds of 16 species of mammals, from mice to lions to bears, found that the smaller the animal, the faster it must shake to dry its fur.
"We think this has been evolving over millions of years of time to become so good," said study researcher David Hu, who studies biolocomotion at Georgia Tech. "Imagine if you could come out of the shower and, instead of using a towel, you could just press a button and in one-thirtieth of a second you're 70 percent dry."
Why do mammals shake when wet? The simple answer, as you may guess, is to dry. Perhaps a better question is why an animal wants to be dry. According to our calculations, a wet animal could spend 20% or more of it’s daily food energy to evaporate water in its fur, if it cannot shake.
In our study we found the largest mammals such as bears, tigers, and large dogs shake about 4 times per second while small mice shake at more than 30 times per second!
Shaking mammals generate high centrifugal accelerations when spinning. A drop residing in a mammals fur will experience an acceleration many times gravity when ejected. We found that mammals can generate accelerations 10-70 times gravity in their fur when shaking.
how animals shake themselves dry could help scientists to develop ways
to rapidly shed water from man-made equipment. Hu hopes that devices can
be engineered to incorporate elasticity similar to the all-important
loose skin, and suggests that even the humble washing machine could
learn a trick or two from the animal world about shedding water.