Wandering salamanders (Aneides vagrans) reside in the crowns of the world’s tallest trees, California’s coast redwoods, and have been observed to readily jump from the canopy when disturbed. In a new paper published today in the journal Current Biology, University of South Florida doctoral candidate Christian Brown and colleagues described the aerial performance of falling wandering salamanders, which maintain stable gliding postures via adjustments of the limbs and tail in lieu of specialized control surfaces.
That wandering salamanders jump from the tallest trees on Earth suggests adaptation for controlled descent in these creatures, especially considering the potential dangers of uncontrolled falls from the canopy.
“Although hundreds of species of lungless salamanders are known to climb, aerial behavior had not been described,” Brown said.
“Our investigation of aerial behavior revealed that highly arboreal species of salamanders, especially the wandering salamander, reliably engage in parachuting and gliding to slow and direct their descent.”
In the study, Brown and his colleagues studied the salamanders’ aerial performance in which they maintain stable gliding postures by adjusting their legs and tail.
In wind-tunnel experiments, the salamanders parachuted consistently, slowing their vertical speed by up to 10% while falling.
They also coupled parachuting with undulations of their tail and torso to effect gliding at non-vertical angles about half of the time.
“To observe salamanders, which are generally associated with ponds and streams, in the air is a bit unexpected in and of itself,” Brown said.
“Most surprising to us was the exquisite level of control that the more arboreal salamanders had in the vertical wind tunnel.”
“Wandering salamanders were especially adept and seemed to instinctively deploy skydiving postures upon first contact with the airstream.”
“These salamanders were not only able to slow themselves down, but also used fine-scale control in pitch, roll, and yaw to maintain upright body postures, execute banking turns, and glide horizontally.”
“This level of aerial control was unexpected because these salamanders do not seem to possess conspicuous features for aerial control.”
“It is a novelty, something unexpected in an otherwise well-studied group of animals, but it illustrates the urgency with which animals that are living in trees must evolve aerial capacity, even if they don’t have wings,” said University of California, Berkeley’s Professor Robert Dudley.
“Flight, in the sense of controlled aerial behavior, is very common. They’re controlling their body posture, and they’re moving laterally.”
“This predisposes many, many things that are living in trees to ultimately evolve flapping flight, which is probably hard to evolve and why it has only turned up three times on the planet today.”
Christian E. Brown et al. 2022. Gliding and parachuting by arboreal salamanders. Current Biology 32 (10): 453-454; doi: 10.1016/j.cub.2022.04.033