Eastern Newt (Notophthalmus viridescens)
Its primary threat is habitat loss and alteration, but diseases may also affect this species.
Appearance. Eastern newts are highly adaptable little salamanders that are roughly 2½ to 5 inches long as adults. Like other salamanders, their appearance changes during life stages that can include larva, juvenile, terrestrial adult, and aquatic adult, depending on environmental conditions. Aquatic adults are typically olive green, yellowish green, or brown, with raised crests or lines on their head and a peppering of black dots on their back and their yellow or orange belly. Some individuals have red spots on their back. Eastern newts lack indented vertical lines, or costal grooves, on their sides. The peppered belly and lack of costal grooves distinguishes this species from other Minnesota salamanders. During the juvenile period, the eft stage, this newt is rust brown or orangish, sometimes with red spots. The terrestrial adult is dark brown above, often with no markings, rarely with red spots. In all of its stages, the eastern newt’s skin is rough and its belly is yellow or orange with black spots.
Habitat and Range. The eastern newt is found throughout the eastern United States north into Canada and west to the eastern edge of the Great Plains. In Minnesota, it occurs primarily in forested areas in the eastern half of the state, where aquatic habitats such as lakes, vernal ponds, and streams connect to healthy forested uplands. Suitable forested habitats include healthy deciduous and mixed forests with abundant leaf litter and downed, decaying logs.
Natural History. Eastern newts have a complex and variable natural history. After hatching from an aquatic egg, the aquatic larvae breathe with gills for two to four months. At this point they may transform into efts, which are typically terrestrial, a stage that may last only a few months to seven years or more. Some skip the eft stage, and some populations have aquatic efts. Following the eft stage (if present) they change into either an aquatic adult or a terrestrial adult and can shift between these two forms. The terrestrial forms are active April into October, living in the forest, where they take shelter under logs, leaves, rocks, and other objects and overwinter below the frostline. By night, especially during rainy weather, they move about on the surface. Their rough, dry skin reduces water loss, so unlike Minnesota’s other salamanders, which prefer moist environments, eastern newts are often found under dry logs and leaves. Mating occurs in the water in the fall, winter, and spring. Courtship includes an undulating “hula” display by the male. In the spring, females may lay more than 100 eggs singly or in clusters attached to vegetation in the water. The eggs hatch in two to four weeks. All stages of eastern newts feed on small invertebrates. Aquatic specimens consume crustaceans, snails, clams, fairy shrimp, amphibian and fish eggs, and insect larvae, while terrestrial stages eat invertebrates such as insects, insect larvae, and snails.
Status. Notophthalmus viridescens louisianensis, often called the central newt, is the subspecies of eastern newt found in Minnesota. It is a species in greatest conservation need in the state. The primary threat is habitat loss and alteration, but diseases may also affect this species. Although rather broadly distributed across the state, its known range has many gaps. Targeted surveys are needed to better understand the range of this species. If you see an eastern newt, please report it to the DNR’s Minnesota Biological Survey at [email protected] or 1-888-345-1730.