Scientists have a new ally in their battle to understand animal behaviour – a robotically animated dead squirrel. Designed by Aaron Rundus of the University of California, Davis, it is helping to show how California ground squirrels protect their pups from rattlesnakes.
Rundus previously discovered that ground squirrels heat their tails and swish them around, presumably to let an approaching rattlesnake know that they are not to be tangled with. Rattlesnakes are adept at sensing infrared radiation, so would be expected to spot the warning sign. But it was unclear if this supposed signal had any effect on the snakes.
Enter Robosquirrel, a stuffed squirrel featuring a heating element in its tail and a realistic remote-controlled swishing action. When Rundus presented this to rattlensnakes in the lab, they were more likely to coil up or poise to strike in fear. But with the heater turned off the rattlers remained unrattled, showing that the squirrels’ heat-based signalling is a genuine mode of communication. Robosquirrel Mk II is reportedly in development, promising yet more life-like snake-scaring features.