Salamandre cendrée— Quebec wildlife

The red-backed salamander (Plethodon cinereus) is a small, hardy woodland salamander species in the family Plethodontidae. 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). 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 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.

Habitat and range

Distribution of P. cinereus are in close contact with the soil on the forest floor. As deciduous forests mature, acid deposition can accelerate the acidification of soils. Acidic conditions can limit the distribution of amphibians and the numbers of sibling species, while the pH value of soil has a strong effect on the density and distribution of P. cinereus. When choosing between acidic and neutral soils, P. cinereus prefers to occupy more neutral soils. P. cinereus is rarely found in soils with a pH value of 3.7, and relatively more to be found in soils with a pH value of about 3.8 or higher. Juvenile P. cinereus have never been found in soils with a pH value lower than 3.7. Similar conclusions have also been supported in the laboratory. P. cinereus prefers to occupy substrates near neutral pH. A pH value between 2.5 and 3 results in acute mortality, while a pH value between 3 and 4 results in chronic mortality. Low pH will reduce their growth and respiration. Slowed growth and delayed metamorphosis make juvenile P. cinereus more vulnerable to predators and has serious consequences for population survival. Several other factors, such as moisture and temperature, can affect the population density or dispersion of Botrytis as well. During prolonged dry periods, individuals move down into the soil, while during short dry periods they retreat under logs or rocks. They will avoid very warm areas, and when the temperature drops to 4–5 Celsius degrees, they will retreat to the ground as well. The optimum temperature is 10 to 15 Celsius degrees. Moreover, intraspecific and interspecific competition also affected the distribution of P. cinerea. Individuals confine themselves to moist microhabitats (beneath rocks, woody debris, etc. as well as beneath the soil) for long periods of time in order to maintain hydration when surface conditions are inhospitably dry or hot, and are only active on the surface to travel, forage, or reproduce for short periods. The duration of surface activity is directly limited by the rate of cutaneous water loss to the environment, which is influenced by environmental variables such as altitude, forest canopy cover, and the amount of recent precipitation.