When a chipmunk teases a rattlesnake

Science News, August 27, 2005

Several of the Northeast's least ferocious forest creatures taunt rattlesnakes. In woodland-surveillance videos, scientists have watched chipmunks, gray squirrels, and a thrush lunge at and hop over the vipers.

Harassing of North American snakes had previously been reported along the West Coast (SN: 6/26/04,p. 403; 10/9/99, p. 237). California ground squirrels can survive snakebites as adults, but the pups can't. If adults find a snake lurking near a burrow, they snap their tails and rush, nip, and kick sand at it. The harassed snake often leaves the scene.

Now, Rulon Clark of Cornell University has documented similar snake taunting in East Coast critters. He had set out to study how timber rattlesnakes hunt. It was slow work since a foraging rattler generally sits still for a day or so until something strays into striking range. To collect data efficiently, Clark set up surveillance cameras to monitor the snakes.

Out of 88 snake-hunting bouts caught by his 2,000 hours of video, 6 featured dramatic episodes of harassment: 3 starred a gray squirrel; 2, a chipmunk, and 1, a pair of wood thrushes.

As far as he knows, Clark says, these animals don't have built-in resistance to snake venom. However, they can move fast and dodge out of harm's way. And their antics work: A snake treated to such a commotion was four times as likely as an undisturbed snake to abandon its hunting spot, Clark notes.--S.M.