Here’s a riddle for you: What lives in a tree, chirps when surprised, and eats worms ? Sure... birds fit the bill... And so do arboreal salamanders !
These amphibians may not be as showy as their winged roommates but they do have something that all birds lack: a prehensile tail, which they use for anchoring themselves as they climb through the branches of live oaks and sycamores along the coast of California. They’re also missing a few things that any self-respecting bird possesses. Like feathers. And lungs.
The feathers aren’t a surprise, but at first glance it’s hard to see how any terrestrial animal can do without lungs. These slender amphibians don’t have gills either, even as babies. They go strait from the egg stage to looking like miniature adults. So how do they breath? It turns out that oxygen is absorbed strait into their bloodstream through their skin and through the lining of their mouths. This means that, even though they don’t need to live near water, they do need damp conditions to survive. Dry air just doesn’t absorb as easily. It also means that they can survive underwater longer than most animals, although they won’t be happy about it.
How they manage to produce sound without lungs or vocal chords is a more difficult question, but they’ve hit on a unique solution. When surprised (grabbed by a predator or a human’s hand, for instance) they retract their eyeballs into the roof of their mouth to compress the air there which results in a sharp squeak or chirp. The predator is often so shocked by the noise that they drop the salamander. If they don’t they run the risk of being bitten. Unlike many amphibians, arboreals have sharp teeth to go along with their feisty personalities.
If foregoing lungs and living in trees isn’t enough to put these herps into the odd animal category, how about adding parental care to the mix? Female arboreal salamanders are often found curled around their egg clutches, sometimes accompanied by a male. And while they don’t actively teach their young anything they do share their trees with them for a season or longer despite their territorial nature.
Birds are interesting to watch. Sometimes it’s actually hard not to notice them. But the next time you look up at a tree, spare a thought for what else might be hiding in its branches. The answer might surprise you.