Biomechanics at the University of California at Berkeley studied the behavior of fox squirrels (Sciurus niger), a widespread species of squirrels in North America. It turned out that they understand the elastic properties of branches and use this understanding when planning their jumps.
The researchers emphasize that in their experiment, the proteins, even if they fell down, were not in danger. In nature, a mistake in the place of repulsion or landing can easily cost an animal its life.
Californian biomechanics did not go far: the object of their research nests in abundance on the outskirts of the university campus. Squirrels are known to be susceptible to peanuts, and he served as the main motivating agent in the experiment.
Scientists suspended a steel sheet at a height of one and a half meters from the ground, attached a horizontally flexible rod to it, as well as something like a landing pad. The distance between them could be adjusted. The urge to gnaw peanuts made the squirrels jump from twig to playground – much as they do in nature, jumping from one flexible branch to another.
The rods were of the same length, but of different flexibility, and the researchers changed them periodically, making the task more difficult.
According to the first steps, the proteins determined the flexibility of the rod and drew appropriate conclusions for themselves, which was expressed in a change in the take-off point. The more flexible the rod, the earlier they started, despite the fact that the length of the jump increased significantly because of this. Before the experiments, scientists were convinced that squirrels are trying to minimize the length of the jump.
The second conclusion is more obvious: squirrels are great at learning. If the first landings on the site sometimes looked risky, squirrels even hung on their front or hind legs, then the next ones turned out to be much more accurate.
“It seems obvious that squirrels do not rely on instinct when they jump, but research by my colleagues has shown how much mental work they can do to ensure safe movement,” says Jesse Young of Ohio Northeastern Medical University. He did not take part in the work.