Enter the robots. Joshi's engineering lab built a squirrel with a heatable tail and a tail flagging mechanism, each controlled separately.
Using the robosquirrel, Aaron Rundus, then a graduate student in Owings' lab and now an assistant professor at West Chester University in Pennsylvania, showed that the snakes responded to the heat signal from the squirrel.
"It was the first example of infrared communication in the animal world," Joshi said. That work was published in 2008: an article published in IEEE Robotics & Automation Magazine in December, 2011, summarized much of the work to date.
Fieldwork is more challenging, he said. Ryan Johnson-Masters, a graduate student in Joshi's lab and now at the Sandia National Laboratory in Livermore, built a new robot with smaller and more robust controls that was easier to transport into the field.
The field season is fairly short, a few weeks in late spring and early summer when squirrel pups are born and rattlesnakes come hunting for them.
Then you need to find rattlesnakes in rough country.
"It's definitely an adventure," Joshi said.
Clark began collaborating with Owings and Joshi in 2007. Together, they wrote a grant proposal to the National Science Foundation to take the robosquirrel into the field. The grant was funded with $390,000 in 2010.
Once the researchers have located a foraging snake, they put down some track, set up the robosquirrel and a video camera to record the scene and retreat behind a blind. The snakes seem to accept the robosquirrel as real, Clark said. One of their videos shows a snake biting the robot's head.
Snakes will rarely strike at a flagging adult squirrel -- and if they do they almost always miss, Clark said.
"Squirrels have a remarkable ability to
|Contact: Andy Fell|
University of California - Davis