Amphibians
Wandering Salamander
Aneides vagrans · also called clouded salamander (former name)
High in the crown of a California redwood, in a mat of soil and ferns balanced on a limb 60 metres up, lives a small lungless salamander. If it comes off that branch, it does not simply fall. It spreads its legs, slows down, and flies itself back to the tree.
Overview
Aneides vagrans lives along the northern California coast in coast redwood forest, both on the ground under logs and bark and high in the canopy of old redwoods, in the deep mats of soil and fern that build up on their massive limbs. It is lungless, breathing through its skin, and it has gripping toe tips and a prehensile tail for climbing.
The skydive
A 2022 study filmed wandering salamanders in a wind tunnel. Instead of falling limply they immediately splayed all four legs and the tail into a skydiver’s posture, slowing the descent by about 10 percent and steering back toward a trunk — an ability strong in these tree-dwellers and absent in their ground-living relatives.
No tadpole
The female lays eggs in a moist canopy fern mat or rotting log and guards them until they hatch directly into tiny salamanders.
Status
Least Concern and locally common, though the canopy populations depend on the small remaining fraction of old-growth redwood with centuries-old limb soil.
Wandering Salamander: common questions
Does the wandering salamander actually glide?
Not glide in the way a flying squirrel does, but it does far more than fall. When researchers released wandering salamanders into a vertical wind tunnel that simulated a fall, the salamanders reacted within a fraction of a second by throwing out all four limbs and the tail into a splayed, belly-down posture, the same shape a human skydiver holds. This markedly slowed their descent and gave them enough control to turn, pitch forward and back, and move horizontally through the air toward a target such as a tree trunk. It is best described as a controlled parachuting descent with steering, and among salamanders tested it was strongest in the tree-living wandering salamander and weakest or absent in ground-dwelling species.
How does a salamander end up living 60 metres in the air?
The coast redwood is one of the tallest trees on Earth, and on the huge horizontal limbs of an old redwood, debris, needles, and dust collect over centuries into deep mats of true soil, which grow their own gardens of ferns, huckleberry, and even other small trees, and hold moisture like a sponge. These canopy soil mats are a cool, damp, invertebrate-rich habitat suspended in the treetops, and the wandering salamander, being a skin-breathing climber that needs no open water, is one of several animals that live in them full-time, potentially for their whole lives without ever touching the ground.
Is it the same as the clouded salamander?
They were considered the same species until 1998. The clouded salamander, Aneides ferreus, lives in Oregon, and the wandering salamander, Aneides vagrans, lives along the northern California coast and just over the Oregon line, and the two are separated by a gap in the range. Genetic studies showed the California and northern populations were distinct enough to be their own species, and it was given the name vagrans because the pattern suggests the California animals dispersed northward, probably by riding drift logs along the coast, sometime after the last glaciation.
Are wandering salamanders endangered?
The species is listed as Least Concern and remains fairly common in suitable coastal forest. The concern is more subtle. The canopy populations depend specifically on very large, very old redwoods that have had centuries to accumulate limb soil, and most such trees were logged in the nineteenth and twentieth centuries. Second-growth redwood forest supports ground-dwelling wandering salamanders but not, for a long time, the elaborate canopy habitat. So while the animal is not at risk of extinction, one of the most remarkable ways it lives is confined to the small fraction of old-growth redwood that survives.