Advanced acrobatics are essential for the survival of squirrels. The slightest mistake could result in death when jumping between curved branches that wobble in the wind. New videos show squirrels effectively juggling between branches.
These rodents plot jumps in nanosecond increments. These choices take into account the stiffness of the branch as well as the separation of the tree limbs. Squirrels create maneuvers in midair for extremely difficult jumps. These discoveries are discussed in the Science issue from August 6 by researchers. They discover that the squirrels’ stunts are comparable to those performed by parkour practitioners, who scale walls, flip over railings, and jump between structures.
According to Michelle Graham, this is “a terrific illustration of how cool ‘regular’ creatures can be.” She wasn’t a part of the study. However, she attends Virginia Tech in Blacksburg to study biomechanics. Graham claims that “we’ve all seen squirrels do strange things in nature.” But nobody ever gives it much thought.
Unless you’re Nathaniel Hunt, that is. For years, he has marveled at how quickly squirrels move through the treetops. Tree canopies are extremely difficult settings to maneuver through, according to Hunt. At the University of Nebraska at Omaha, he studies integrative biology. A squirrel has to determine how far it has to go and when to jump in order to navigate between curved branches. Jumping from a branch’s base provides a secure base. The distance to the next branch, however, might be too great for the squirrel to cross. That distance gets less as you get closer to the branch’s tip. But it might not be a strong enough point to launch from. How sensitive are they to that trade-off, questioned Hunt.
He created an obstacle course set in an artificial forest with his coworkers to find out. The researchers then encouraged fox squirrels (Sciurus niger) that were allowed to roam freely to run and jump through the course. The researchers gave peanuts to the furry test animals as an incentive.
The squirrels first mastered the ability to jump across a gap from made-up branches. The branches varied in stiffness. A prize—a basket of peanuts fastened to a landing peg—was waiting on the other side of the opening. In the high-speed video, the leaps from launch to landing were documented. Twelve squirrels in all finished the 96 leaping tests.
Earlier, the squirrels jumped from branches with more bend. They might have been aiming to increase the force of their jumps. However, using that tactic made the animals travel a greater distance. The researchers used computer models of squirrel jumps to investigate this behavior. One model iteration closely resembled squirrel behavior. In this instance, the ability of the branch to bend was six times more crucial than the size of the gap in predicting when a squirrel would jump. We were shocked to find that the two objects were weighed differently by squirrels, according to Hunt.
For five squirrels, the researchers upgraded their obstacle course. In this location, the branches were more malleable and the space between them grew. The first leaps of the squirrels weren’t particularly graceful. None fell, although most landed awkwardly. They swung around to grab the landing peg with their front paws and pulled themselves up. The squirrels should have landed cleanly on all fours, but Hunt claims that it only took them five times for them to get the hang of it. All they had to do was change their beginning pace.
If squirrels frequently traverse the same tree limbs, their rapid learning could be useful. According to Hunt, this “may explain how they move so smoothly and quickly” over particular branches. They already know everything they require to know about that branch.
The researchers were also taken aback by the squirrels in other ways. Squirrels developed elaborate jumps for longer jumps or those that needed landing higher or lower than the starting point. Many turned in midair and “jumped” off a neighboring wall with their legs. They were able to land challenging jumps thanks to this parkour-style move. In cases where they were approaching a landing too quickly, squirrels would also utilize parkour to slow down. It’s another point of control, according to Hunt.
According to Graham, “jumping across limbs is such a frequent behavior” for many creatures that live in trees. “Yet we so often simply analyze it in sections,” says the researcher. For instance, they might focus on the takeoff but ignore the landing. This study offers a more thorough perspective, she claims. She finds it “very interesting” because when planning jumps, squirrels choose branch stiffness over gap size. “I don’t think I would have predicted that,”
