Amphibians
Arboreal Salamander
Aneides lugubris · also called climbing salamander
The arboreal salamander breaks two rules people assume about salamanders: that they stay near the ground and near water, and that they are silent and harmless. This one climbs trees, squeaks when you pick it up, and can draw blood.
Overview
Aneides lugubris is a lungless salamander of California’s oak woodland and coast redwood forest. It is 10–18 cm long, dark and pale-flecked, with a prehensile tail and squared, gripping toe tips. It hunts insects and smaller salamanders at night, on the ground and high in the canopy.
A climber that bites
It regularly goes ten metres or more up into oaks and redwoods, sheltering in wet tree cavities. Its broad, muscular head and enlarged teeth let a big one bite through human skin — rare for a salamander — and it also gives a squeak or bark when handled.
No water needed
Eggs are laid in tree hollows or under logs, guarded by the female, and hatch into miniature salamanders with no aquatic stage. Through California’s long dry summers the salamander hides deep in moist cavities and emerges only on humid nights.
Status
Least Concern and stable, common in oak woodland, reduced only where that habitat is cleared.
Arboreal Salamander: common questions
Does the arboreal salamander really live in trees?
Yes, and it is one of the few salamanders that does so habitually. It is regularly found ten metres or more up in the canopy of oaks and, in the redwood belt, has been recorded in the crowns of some of the tallest trees on Earth, living in the pockets of moist debris that collect in cavities and forks and under sheets of loose bark. It also spends time on the ground, under logs and rocks, and it is not fully committed to an arboreal life the way some tropical salamanders are, but the prehensile tail and the grippy, squared toe tips are clear adaptations for getting up into and around the trees.
Can an arboreal salamander hurt you?
A large one can give a surprisingly sharp bite. Most salamanders have small, weak jaws and simply cannot bite through human skin, but the arboreal salamander has a heavy, wedge-shaped head packed with jaw muscle and a set of enlarged teeth, and an adult clamping onto a finger can puncture the skin and leave a bruise. It is not venomous and the wound is minor, more startling than harmful, but it is a reason to handle the species gently and briefly, if at all. The bite is a genuine defence, backed up by the squeaking and by mild skin secretions.
Why does it make noise when almost no other salamander does?
Salamanders as a group have no voice box and are among the quietest of all vertebrates, communicating instead by scent and touch. A handful of species, including the arboreal salamander and some of its close relatives in the genus Aneides, can force air out through the throat to produce a squeak, a click, or a low bark, usually when they are seized. The sound is thought to be a startle defence, a sudden unexpected noise that may make a predator hesitate or drop the salamander, similar in effect to the way some frogs and beetles squeal or hiss when grabbed.
How does a lungless salamander survive California's dry summers?
By staying hidden and inactive. The arboreal salamander belongs to the lungless family, breathing entirely through its skin and the lining of its mouth, which only works while those surfaces are damp. Through the long rainless summer it retreats into the most humid microhabitats it can find, deep tree cavities that hold moisture, cracks in rock, and the interior of rotting logs, and it drops its activity right down, feeding little and moving only if conditions allow. When the autumn rains return it comes back to the surface and resumes normal life, and this on-and-off pattern is typical of California's terrestrial salamanders.