Red-backed salamander

Description

The red-backed salamander (Plethodon cinereus) is a small, hardy woodland salamander species in the family Plethodontidae. The species inhabits wooded slopes in eastern North America, west to Missouri, south to North Carolina, and north from southern Quebec and the Maritime provinces in Canada to Minnesota. It is also known as the redback salamander, eastern red-backed salamander, or the northern red-backed salamander to distinguish it from the southern red-backed salamander (Plethodon serratus). It is one of 56 species in the genus Plethodon. Red-backed salamanders are notable for their color polymorphism and primarily display two color morph varieties ("red-backed" and "lead-backed"), which differ in physiology and anti-predator behavior. The red-backed salamander is a small terrestrial salamander, 5.7–10.0 cm (2.2–3.9 in) in total length (including tail), which usually lives in forested areas under rocks, logs, bark, and other debris. It is one of the most numerous salamanders throughout its range. Red-backed salamanders are mostly insectivorous, but prey on a wide assortment of other small invertebrates including isopods, millipedes, centipedes, pseudoscorpions, harvestmen, spiders, and gastropods. On one occasion an individual was found to have cannibalized a P. cinereus embryo. Predators of the red-backed salamander are many and varied, and include small mammals, snakes, ground-foraging birds, and larger salamanders. The red-backed salamander exhibits color polymorphism and two color variations are common: the "red-backed" or "red-stripe" variety has a red dorsal stripe that tapers towards the tail, and the darker variety, known as the "lead-backed" (or simply "lead") phase, lacks most or all of the red pigmentation. The red-backed phase is not always red, but may actually be various other colors (e.g., yellow-backed, orange-backed, white-backed, or a rare erythristic morph in which the body is completely red). Both morphs have speckled black and white bellies. Additional color anomalies of this species also exist, including iridistic, albino, leucistic, amelanistic, and melanistic anomalies. These color morphs are rarer than the red-backed, lead-backed, and erythristic morphs, but still have been reported with consistency among varying populations of this species.