In the crowns of the tallest trees in the world, an amphibian has carved out an unlikely niche.
The wandering salamander, more closely related to a frog than the lizards it resembles, feeds on small invertebrates in the canopies of California's giant redwoods, nearly 100 metres above the forest floor.
But living so high off the ground comes with a unique set of challenges, not least of which is falling.
Rather than clinging on for dear life, scientists have observed the wandering salamander — Aneides vagrans — leaping from the canopies when disturbed.
Now they've figured out how the salamander avoids going splat when it reaches the ground.
Finding the answer involved taking a bunch of salamanders from five different species, and a mini wind tunnel — a shrunken version of the type you might see skydivers practising in.
The experiment from there, as you can probably imagine, was pretty straightforward — toss the salamanders into the wind tunnel and observe.
The wandering salamander, which measures about 10 centimetres from snout to tail, and one other canopy-dwelling species "parachuted" in much the same way a skydiver would — spreading their limbs and slowing and controlling their descent.
The researchers published their results in Current Biology this week.
'Parachuting' salamanders
Although the trick has been observed in some frogs, this is a surprising first for salamanders, according to amphibian expert Jodi Rowley from the Australian Museum and UNSW, who wasn't involved in the research.
"It did surprise me that there was a species of salamander that actually did this," Dr Rowley said.
In 2012, Dr Rowley and her colleagues discovered a new species of flying frog in Vietnam — Helen's Tree Frog — which is named after Dr Rowley's mother.
"My colleagues and I discovered Helen's Tree Frog, which is in this small group of crazy flying frogs," she said.
"[The frogs have] taken it to another level, they've got these huge parachute feet, they're webbed and they're impressive — they drop out of the trees."
But unlike some frogs, salamanders have no particularly obvious physical adaptations that might help them glide, aside from slightly larger footpads, according to study lead author Christian Brown from the University of South Florida.
"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," he said.
"This level of aerial control was unexpected because these salamanders do not seem to possess conspicuous features for aerial control."
Not only were they able to control their fall, but through subtle movements of their tails and limbs, were able to glide directionally, Mr Brown said.
"Most surprising to us was the exquisite level of control that the more arboreal salamanders had in the vertical wind tunnel," the PhD candidate said.
"Wandering salamanders were especially adept and seemed to instinctively deploy skydiving postures upon first contact with the airstream."
The researchers think the salamanders probably use this skill to glide back to their tree trunk, rather than falling all the way to the forest floor below.
The salamanders were able to slow their descent by up to 10 per cent.
In all 45 trials, the wandering salamander was observed to "parachute", followed closely by the arboreal salamander, which slowed its descent on 40 of 45 occasions.
The arboreal salamander inhabits smaller oak trees.
But the ground-dwelling Ensatina salamander showed little propensity for flight, managing to slow its fall on just three occasions.
On most occasions, it seemed to "flail" its limbs and demonstrated very little control when falling.
Given that there are over 7,000 species of amphibian, Dr Rowley said it's a fairly rare trait to have evolved in just a few species. And it's likely the skill was developed the hard way.
"It would be survival pressure," Dr Rowley said.
