Image of the Day: Swish Swish

Animals’ tails swat away insects using both wind and whack.

Oct 16, 2018
Kerry Grens
An elephant at Zoo Atlanta
Marguerite Matherne

The tails of elephants, giraffes, and some other mammals swing like a pendulum with a second, shorter pendulum attached to the bottom, according to a study of their swishing motion published yesterday (October 15) in the Journal of Experimental Biology. Video analysis, modeling, and simulations show that the animals’ tails generate winds sufficient to shoo away mosquitoes and can move at speeds fast enough to hit the insects.

“Most people assume that horses and other mammals swing their tails as some kind of deterrent for bugs; we wanted to provide scientific evidence for this claim,” Marguerite Matherne, a grad student in David Hu’s lab Georgia Tech and lead author of the study, says in a press release.

M.E. Matherne et al., “Mammals repel mosquitoes with their tails,” J Exp Biol, 221:jeb178905, 2018. 

The double-pendulum swing measured from an actual elephant tail (left) and a computer model (right)
Marguerite Matherne