RoboSquirrel helps learn about rattlesnakes

  • Fri Jul 20th, 2012 5:36pm
  • Life

It isn’t R2-D2, the small droid in “Star Wars,” but RoboSquirrel may help answer questions for rattlesnake researchers.

A curious thing happens when an adult squirrel, at least in California, meets a rattlesnake. It waves its tail like a construction flagger, from side to side. It also heats up the tail’s temperature.

Biologists at University of California at Davis, and San Diego State University wanted to find out why these presumed survival skills worked, and whether one was most important.

University engineers developed a robotic squirrel ( because there were too many variables using live squirrels and snakes, and squirrels would only do both signals at the same time.

RoboSquirrel’s ability to do one signal at a time was the key.

This spring and early summer, researchers took their robots into the field to arrange squirrel-rattlesnake interactions that they would record on video.

Their research suggests that a rattlesnake responded to the heat signal seen in the infrared wavelength.

If rattlers struck, they missed (squirrels are very quick), perhaps distracted by the moving heat signal; others slithered away. And tail-shaking could be a predator warning for other squirrels.

Until RoboSquirrels are mass-produced to scout for rattlesnakes, hikers will have to fend for themselves, looking for rattlesnake tracks, snakes sitting on a warm rock in the sun or coiled on the trail, rattles shaking.

Fortunately, a rattlesnake is not mindlessly aggressive, usually striking only when threatened by an unobservant human or one who stupidly tries to pick it up.

Since there are no RoboSquirrels in Washington to scout ahead and wave their tails to warn hikers east of the Cascades, hikers will just have to fend for themselves.

And since human tail-wagging won’t send a danger signal to a rattlesnake, knowledge will have to do. Here are some tips about the western rattlesnake from the Burke Museum at the University of Washington and the state Department of Fish and Wildlife.

•A rattlesnake is brown or slightly greenish-brown with large blotches along the back and white crosscuts on the tail. The triangular head is larger than the neck. The rattles are conspicuous.

They live in warm, dry, often rocky habitats.

The cold-blood snake controls its temperature by moving in and out of sunlight, or changing its orientation to the sun.

At maturity, they can be 4 feet long.

Western rattlesnakes are calm and rarely rattle, preferring stillness and avoidance. Rattling is done with fast-moving twitches of 20 to 100 times per second.

A new rattle segment is added each time the skin is shed, which can be several times a year.

Rattlesnake fangs are hollow and are used to inject venom.

Researchers in Eastern Washington are attaching radio transmitters on rattlesnakes to discover how and where rattlesnakes hibernate, as little is known about their behavior.

Being bit by a rattlesnake can by an expensive proposition, costing $2,500 to $5,000 for anti-venom medicine. Call 911 or get to a hospital as soon as possible, since that is where the anti-venom medicine is most likely to be found.

Field “remedies” can do more harm than good. Moving slowly keeps the heart rate low and slows the spread of the venom.

You won’t need R2-D2 or RoboSquirrel if you use common sense.

Columnist Sharon Wootton can be reached at 360-468-3964 or