The wandering salamander ( Aneides vagrans ) lives in the canopy of California redwoods, considered the tallest trees on our planet. As a consequence, not much is known about these amphibians. When disturbed, the salamander is known to jump from tree branches. A study published in the journal Current Biology literally teaches, as it attaches a video, how the animal’s jump is very similar to that of a parachutist. The salamander falls into the void with its limbs and tail extended and its body flat as a board.
“The fact that A. vagrans jumps from the tallest trees on Earth suggests an adaptation for controlled descent in these highly arboreal salamanders, especially given the potential dangers of uncontrolled falls from the canopy,” the authors write, referring to the danger of falling from the top of the tree.
It is curious that salamanders “parachute” since their anatomy, although ideal for climbing, is not exactly aerodynamic . “The cylindrical body of salamanders does not favor stability, and the absence of elaborate aerodynamic control surfaces suggests the need for postural and appendicular movements to maintain a stable body posture in the air. Here we demonstrate that arboreal salamanders are capable of parachuting and gliding, and we examine how they control descent without conspicuous aerodynamic features (eg, fins on the skin),” the authors say in the publication.
The researchers then set out to understand what the salamander might do to glide like a parachutist. To do this, they built a vertical wind tunnel that simulated falling from a tree, instead of launching them naturally. What they discovered was that the animals had a whole repertoire of movements and postures that they used to control their falls. By twisting their tails and changing the position of their toes and legs, the salamanders were able to keep their bodies nearly parallel to the ground as they fell. They could also rotate horizontally.
By adopting a paratrooper-like stance, the salamanders reduced their vertical speed by up to 10% , according to the study.
“The selection pressures imposed on falling from heights can be substantial, and have led to the evolution of diverse aerial behaviors among arboreal taxa; however, the aerial behavior that occurs in arboreal salamanders is surprising, and calls for further work on the natural occurrence of drooping, gliding, and directed aerial descent in treetop-dwelling tetrapods,” say the researchers. researchers.
Now, Christian Brown, one of the authors, is investigating whether the animals are capable of directing their flight to avoid falling directly to the ground. In his opinion, if they can do so, they are more likely to land on the trunk to grab onto lower tree branches or even ferns growing on the bark.
The researcher believes that if these salamanders fell to the ground they would not die since they weigh very little (no more than 6 grams) and the fluff that surrounds the base of the sequoia would serve as a cushioning mattress. The dangerous thing would be rather the return to the cup and it is that a 2021 study revealed that it could take hours or days to reach the area. In all that time, salamanders can dry out, be eaten by another animal, or even run out of steam before they can find any food.
Brown claims that other animals might have unexpected skydiving and gliding abilities that people haven’t yet noticed. He hopes the study will draw attention to the complex but poorly understood biodiversity of the redwood canopy.
“Scientists have barely studied the redwood canopy ecosystem and the unique fauna it has formed through evolution,” he said in a news release.
Reference:
Brown, Christian E. et al. Gliding and parachuting by arboreal salamanders. 2022. Current Biology. DOI: https://doi.org/10.1016/j.cub.2022.04.033
