Amphibians
Red Salamander
Pseudotriton ruber · also called red salamander, northern red salamander
The red salamander is a splash of coral against the dark leaf litter of an Appalachian spring — bright orange-red, dusted with black spots, with startling yellow eyes. It is a bluff. It is mostly harmless, but it has borrowed the warning colours of a genuinely toxic neighbour.
Overview
Red salamanders live in and around cold, clean springs, seeps, and spring-fed streams in the eastern United States, especially the Appalachians and Piedmont. They are 10–18 cm, stout, and bright red to salmon (purplish with age), and hunt worms, insects, snails, and smaller salamanders at night.
Lungless
Like most of its family, the red salamander has no lungs and breathes entirely through its skin and mouth lining — which only works while it stays cool and wet, tying it to unpolluted spring habitats.
Borrowed warning colours
The red salamander closely resembles the red eft — the toxic land stage of the eastern newt. Predators that have been sickened by an eft avoid anything that looks like one, so the far less toxic red salamander gains protection for free. This is Batesian mimicry.
Defence
Threatened, it curls up, hides its head under its tail, and lashes the raised tail at the attacker — offering the least valuable part of its body.
Status
The red salamander is Least Concern and locally common, but tied to cold, clean, unsilted springs and declining where those are polluted, drained, or warmed.
Red Salamander: common questions
Why is the red salamander bright red?
The leading explanation is mimicry. The red salamander shares its range with the red eft, which is the brightly coloured juvenile land stage of the eastern newt, and the eft has genuinely toxic skin containing tetrodotoxin-related compounds that make predators sick. Birds and other predators that have tried to eat a red eft learn to avoid the distinctive orange-red, black-flecked look. The red salamander, which is far less toxic, has evolved a very similar appearance and so benefits from that learned avoidance without having to invest in strong defences of its own. This is Batesian mimicry, a harmless species copying a dangerous model. Experiments in which model efts and mimic salamanders were offered to wild birds support the idea, though the red salamander does also have mildly noxious skin secretions.
How does the red salamander breathe without lungs?
It belongs to the lungless salamanders, the largest salamander family, which lost their lungs early in their evolution. Instead of lungs, the red salamander takes in oxygen and releases carbon dioxide directly across its thin, moist, blood-vessel-rich skin, and across the lining of its mouth and throat. This works only as long as the skin stays wet and the animal stays cool, because warm or dry conditions slow gas exchange and can suffocate the salamander. It is why red salamanders are restricted to cold, clean, well-oxygenated spring water and the permanently damp ground around it, and why they are so sensitive to pollution, sedimentation, and warming of those springs.
Is the red salamander poisonous or dangerous to handle?
It is not dangerous. The red salamander produces only mild skin secretions that taste unpleasant to a predator and are nothing like the potent toxin of the red eft it mimics, and it cannot bite hard enough to hurt a person. As with any amphibian, though, its skin is highly permeable and easily damaged, and it can absorb salts, oils, sunscreen, and insect repellent from human hands, so it should be handled as little as possible and only with clean, wet, chemical-free hands, and never kept in a warm or dry container. Salamanders can also carry Salmonella, so hands should be washed afterwards.
What is the difference between a red salamander and a red eft?
They look alike on purpose, but they are different animals at different life stages. The red eft is the terrestrial juvenile phase of the eastern newt (Notophthalmus viridescens); after a few years on land it returns to water, turns olive-green, and lives as an aquatic adult newt. It has rough, dry-looking skin and genuinely toxic secretions. The red salamander is a separate species that stays reddish for life, has smooth, slimy skin, larger size, bright yellow eyes, and only weak defences. If you find a small, bright orange, rough-skinned salamander walking through the woods on a damp day, it is almost certainly a red eft; a larger, glossy, spotted red one near a spring is a red salamander.