From robo-squirrel to researcher

AMHERST, Mass. — One gray squirrel, its bushy tail twitching, barked a warning as another scrounged for food nearby.

It was an ordinary spring day at Hampshire College, except that the rodent issuing the warning was powered by amps, not acorns.

Dubbed "Rocky" after the cartoon character, the robo-squirrel is working its way into Hampshire's live-squirrel clique, controlled by researchers several yards away with a laptop and binoculars.

Sarah Partan, an assistant professor in animal behavior at Hampshire, hopes that by capturing a close-up view of squirrels in nature, Rocky will help her team decode squirrels' communication techniques, social cues and survival instincts.

Rocky is among many robotic critters worldwide helping researchers observe animals in their natural environments rather than in labs. The research could let scientists better understand how animals work in groups, court and intimidate rivals.

In Indiana, for instance, a fake lizard shows off its machismo as researchers assess which actions intimidate and which attract real lizards. Pheromone-soaked cockroach counterfeits in Brussels, meanwhile, exert peer pressure on real roaches to move out of protective darkness. In California, a tiny video camera inside a fake female sage grouse records close-up details as it's wooed — and more — by unusually promiscuous males.

The research may even help explain similar behaviors in humans, researchers say.

"Animals and humans are all affected by behaviors, body postures and signals from each other that we may not be aware of," Partan said.

The use of fake critters to infiltrate real groups of animals is so new that few companies build or sell such tools to researchers.

Many of the scientists using animal doppelgängers have modified toy animals or, like Partan and her students, cobbled together their own with fake fur, small motors, circuits and other material. Rocky's movement is controlled by basic computer programs, and it has tiny speakers inside that play recordings Partan purchased from an animal-sounds library at Cornell University.

Although animal behavior has been studied for years, much remains unknown about instinctive responses, and robot critters can help researchers discover how far a species can be pushed beyond its survival instincts.