Red kangaroos are formidable jumpers (they can travel almost 30 feet in a single jump), but when they stand on all fours, which is the posture they take most of the time, they use their tail as if it were a fifth limb.
What’s more, according to a team of researchers from different institutions in the US, Canada and Australia, in that position it provides them with a greater propulsion force than their four legs together.
“It actually does as much mechanical work as its tail as we do with one of our legs,” says Professor Maxwell Donelan, an expert in biomedical physiology at Simon Fraser University, British Columbia, and one of the study’s signatories. .
“At first we thought they used the tail as a kind of support or as if it were a pole to swing on,” says Rodger Kram of the Department of Integrative Physiology at the University of Boulder in Colorado, also a co-author of the essay.
In human locomotion, the foot we place backwards works as if it were the accelerator in a vehicle, while the one we place in front acts as a brake, a system that, according to these scientists in the journal Biology Letters , is not particularly efficient.
On the contrary, they compare the movement of the red kangaroos, the largest of all these marsupials, characteristic of Australia, with those of a skateboarder who kept one foot on the skateboard and pushed with the other. “ Their tails have more than 20 vertebrae ; we could equate them to the bones of one of our feet, the thigh and the calf, ”says Donelan.
