Weasels Dance for Food?

Q: I have read that weasels sometimes perform a "hypnotic dance" to mesmerize their prey before attacking them. Any truth to this notion?
J., Kansas City, Missouri

A: A brown weasel pokes his head out of a burrow, white throat gleaming in the sun, turns his head this way and that, and spies gray voles nibbling on grass in the meadow. He knows the voles will scatter when he comes out. So he goes unpredictable.

He leaps straight up, humps his flexible back, bending like a jack-knife diver, then straightening, dives back in the hole — in one swift movement almost too fast to follow. He leaps back out, high into the air, hisses and bounds away from the voles. The voles watch, fascinated. The weasel doesn't disappoint. He dances back to the hole, frizzes his tail and dives in, only to leap out, and prance with sideways leaps towards the voles, making a chuckling noise.

Still the mouse-like creatures watch. The weasel stops and flips his back legs straight out, like a bucking bull, and comes down, a little closer. He flips up again, but lands on his back, twists around, closer. Leaps and leaps and lands — among them! Pouncing on a fat vole with his forelegs, he bites the back of the head and kills.

Predators "can exploit unpredictability to confuse prey, as when weasels do 'crazy dances' to baffle the voles that they stalk," says evolutionary psychologist Geoffrey F. Miller, professor at the University of New Mexico.

"The normal method of hunting is to stalk or trail the prey, and then to kill swiftly with a bite on the back of the victim's head," says the International Wildlife Encyclopedia. But occasionally their strategy is to take "leave of their senses, bounding about, bucking, somersaulting, and so on."

Weasels, burning energy at a fearsome rate, need food, desperately, all the time. They eat 40% or more of their body mass daily," says biologist Jim Lieb of the Alaska Department of Fish & Game.

Further Reading:

Protean primates: The evolution of adaptive unpredictability in competition and courtship, by G. F. Miller (1997). In A. Whiten & R. W. Byrne (Eds.), Machiavellian Intelligence II: Extensions and evaluations, pp. 312-340. Cambridge, UK: Cambridge U. Press.

International Wildlife encyclopedia, edited by Maurice Burton and Robert Burton

Weasel war dance video, (loud) by Spatata and YouTube.com

Weasels, Alaska Department of Fish & Game

Voles, Alaska Department of Fish & Game

(Answered May 14, 2007)