The acrobatic leaps of squirrels depend on complex calculations made in a fraction of a second and these rodents develop surprising strategies, sometimes resembling those used in the urban discipline of parkour, according to a new study published Thursday in the prestigious journal Science.
Scientists at UC Berkeley have built custom obstacle courses to better understand how squirrels adjust their movements in flight to avoid fatal falls.
They hope that this research can help one day develop more agile robots.
“Squirrels have a combination of characteristics that makes them very interesting: on the one hand, their acrobatic nature, their biological mechanics and their powerful muscles, which they can use for leaps that are several times the size of their body,” Nathan Hunt, lead author of the study, told AFP.
“On the other hand, their cognitive abilities. They have a very good memory, are very creative, and very good at finding solutions to problems,” he added.
The research team used peanuts to attract them. Perch were installed to simulate tree branches, forcing animals to jumps from various distances to receive their reward.
The scientists wanted to observe how squirrels make their decisions in the face of a difficult compromise: approaching the edge of the perch reduced the distance to jump but compromised their stability while reducing the propulsion force that could be used since the platform then became unstable.
As a result, squirrels preferred to run from the base of the perch, especially when the “branches” were the least rigid. The flexibility of the perches ultimately proved to be six times more important in their decision-making than the distance to be covered.
No squirrels fell during the experiment, thanks to different strategies — and their sharp claws.
The most surprising innovation: for the most difficult jumps, instead of aiming directly at the target, the squirrels used the sidewall as a step to “bounce”, thus seeming to use a parkour technique, this discipline was popularized by the Yamakasi in France in the 1990s.
When squirrels are chased by raptors, their escape can be played out in a few centimeters, which is probably the reason for their great agility, according to Nathan Hunt.
“It’s funny to publish this study because people very often watch squirrels in their gardens,” he says. And he himself can’t help but have other ideas of experiences by observing them, he confides.