Western Red-backed Salamander (Plethodon vehiculum)

KINGDOM Animalia
PHYLUM Chordata
CLASS Amphibia
ORDER Caudata
FAMILY Plethodontidae


This small salamander (total length 7-11.5 cm) is very slender and, if the legs weren’t seen, could be mistaken for a blunt-headed, pointy-tailed worm. Most individuals have a distinct dorsal stripe of red or yellow or tan, extending all the way to the tail tip. The limb bases are usually the same color. Some individuals, however, are unstriped and evenly dark above.

Red-backed salamanders are locally common in wet forests and on talus slopes throughout the lowlands of western Washington and more widely in the Pacific Northwest, west of the Cascades. They are often associated with decaying logs on the forest floor, where they spend the day hidden. Individuals are often discovered by looking beneath cover such as leaf litter, logs, bark, and rocks. Foraging and other behavior takes place at night; presumably safety from avian predators and higher humidity are both factors promoting nocturnality.

Like all salamanders, this is a creature that needs moisture. Like all amphibians, it respires through its skin, and the skin must be moist for this to be possible. Members of the large family Plethodontidae, to which this species belongs, are called lungless salamanders because they have no lungs. Thus dermal respiration is essential to survival. During dry periods, as for example through midsummer, most Western Red-backed Salamanders move underground.

Small salamanders are insectivores, although they also eat many invertebrates other than insects. Springtails, mites, and other very tiny prey are common in their diet, but earthworms, isopods, spiders, harvestmen, beetles, ants, and many other types of insects are also taken. They hunt in a surprisingly small area, with home ranges of just a few square meters.

Mating takes place when temperatures are sufficiently high during the fall and winter. Females in some populations breed only every other year, laying their 10-12 eggs in spring in sheltered areas, often underground. Few clutches have been found, but when found, the female is usually guarding them, presumably against invertebrate egg-eaters.