General – The Red-backed Salamander is the most commonly encountered salamander throughout most of its range. The Red-backed Salamander is characterized by the red stripe which begins immediately behind the head and extends nearly to the tip of the tail. The red stripe is usually very straight throughout its entire length along the body and generally covers the entire back of the salamander. In some populations the red color of the stripe is replaced by dark gray (above right). This is called the lead-backed phase. The belly is finely mottled with equal amounts of white and black creating a “salt and pepper” effect. Red-backed salamanders have 16 to 19 grooves on their sides. They have no circular constriction at the base of their tails, and they have five toes on their hind feet and four toes on their front feet. Males and females look the same.
The Red-backed Salamander along with all salamanders within the family Plethodontidae are lungless. Nearly all of their respiration takes place through cutaneous gas exchange. This means that they breathe through their skin. The remaining gas exchange takes place through buccopharyngeal (within the mouth) respiration. Unlike most salamanders, Red-backs do not spend any part of their lives in the water. They are completely terrestrial (though dependent upon moisture). (Note that these salamanders sometimes lose portions of their tails during encounters with predators).
Average Size – Red-backed normally reach a length between 2 1/2″ to 5 ”
Life Span – Red-backed salamanders can live for several years, in some cases up to 10 years.
Diet – Red-backed salamanders feed on a large variety of invertebrates. These include mites, spiders, insects, centipedes, millipedes, beetles, snails, ants, earthworms, flies, and larvae. They forage by thrusting out their tongue in a quick, forward motion to capture their prey.
Normal Behavior and Interaction – They are relatively solitary and defend small territories in which they feed. Red-backed Salamanders protect their limited food supply by marking out territories. This behavior occurs most often when moisture levels are low and the salamanders have to hide under logs or rocks. Both males and females leave scent marks on the ground as well as leaving their droppings. Other salamanders can learn a lot from these clues. They learn each others territorial boundaries, the size and importance of the salamanders that live in the area, and their identity, including whether or not they are related. When finding food is very hard due to dry conditions, adults who have their own territories will sometimes allow young salamanders that are related to them to use their territories. Intruders are also warned away by seeing the size of the salamander and watching it give threatening displays.
Red-backed salamanders come out from their hiding places at night after a rain. This is when they do most of their hunting. Red-backed salamanders can survive these times with little food because they are pulse feeders, which means they eat large amounts when conditions are good and store the extra nourishment as fat to live off of when conditions are bad.
Range – Red-backed salamanders are native to the Nearctic (temperate) region only. They live in Eastern North America. Their range extends west to Missouri; south to North Carolina; and north from southern Quebec and the Maritime Provinces in Canada to Minnesota. They are most common in areas of appropriate habitat throughout the midwestern United States. Red-backed salamanders are found in deciduous forests throughout their range. They live in fallen leaves as well as under rocks, logs, or in small burrows. When disturbed, they will crawl into tunnels or under leaves.
Like many other amphibians, salamanders can be hurt by high levels of acidity. Red-backed salamanders respond the same way to acidic surroundings as amphibian larvae do when exposed to acidic water, their sodium balance is disrupted. They are rarely found on soils with a pH of 3.7 or lower.
Breeding – Red-backed salamanders mate in the fall but the female does not lay her 3 to 14 eggs until the following spring. The eggs are laid in a cluster in naturally occurring cracks and crevices. Eggs can also be laid in or under rotting wood. The mother wraps her body around the egg cluster until they hatch. The baby salamanders come out of the eggs looking like small adults. Upon emerging from the egg, young salamanders are independent. Salamanders recognize their relatives through smell and although they are solitary, mothers will allow their young to stay in her foraging area. Female salamanders mate every other year.
Red-backed salamanders make up an important food source for a wide variety of snakes, birds, and mammals. They have the ability to drop all or part of their tail if under attack from a predator and can grow a new one afterwards. The tail that grows back is often lighter in color than the original tail.
Red-backed salamanders play an important biological role in both providing food for their predators as well as consuming large numbers of invertebrates.