Adult Northern Ravine Salamanders are small and short-legged, similar in both body shape and size to red-backed and Zigzag Salamanders. Unlike both of the aforementioned species, this salamander always lacks a dorsal stripe and is gray-black or dark brown in coloration. The legs are generally very short and the body is very elongate giving this salamander a more wormlike appearance than other similar species. The underbelly and chin are uniformly dark. Most individuals grow to a length of around 4 in.
The egg-laying habits of this species are not well known, but are likely similar to those of other species in the genus. Juveniles are similar to adults.
The Northern Zigzag Salamander (Plethodon dorsalis) and Eastern Red-Backed Salamander (Plethodon cinereus) are both very similar but often have an orange or yellow dorsal stripe and have lighter, "salt-and-peppered" chins. The Zigzag Salamander also has orange coloration around the axila ("armpits"). The Red-Backed Salamander is sympatric (occurs side by side) throughout the range of this species and the Zigzag Salamander occurs alongside this species in eastern Jefferson and western Switzerland Counties. The Northern Dusky Salamander (Desmognathus fuscus) is much more robust and generally brownish in coloration with a light line running from its eyes to its jaw. Though this salamander is sympatric with the Northern Ravine Salamander, the Dusky Salamander tends to be found in much wetter microhabitats.
Ecology and Conservation
Northern Ravine Salamanders are a species of the deeply dissected, well drained hills of southeastern Indiana and appear to be common both in moist shaded forest, and on more exposed slopes. They are often found along stream corridors and on ridgetops, though rocky slopes seem to be their preferred habitat. Northern Ravine Salamanders are surface active mainly during cooler weather and may be found under cover throughout the winter when the ground is not frozen. They are most active during the late winter and spring, but may be found reliably from September to May when the weather is mild. During the summer, they presumably retreat underground. These salamanders feed on a variety of small invertebrates.
Northern Ravine Salamanders, like all other species in the genus, have no larval stage and simply lay their eggs underground or under cover during spring. The young hatch out between late fall and the next spring. Little is known about the breeding of this salamander, but breeding and egg deposition likely takes place sometime during the late winter and early spring.
Although this species has a fairly restricted range in Indiana, they are apparently abundant where they occur and appear to adapt well to human-altered ecosystems; as is evident from their presence in and around old bridges and structures in the Whitewater Gorge of Richmond (Wayne County).
Northern Ravine Salamanders have a relatively small range, occurring from southeastern Indiana and Ohio into West Virginia and southwestern Pennsylvania. They are found almost exclusively within the Switzerland Hills natural region in southeastern Indiana. They inhabit well-drained, hilly terrain as far north as Wayne and Henry Counties and as far south as western Jefferson County.
There are no recognized subspecies of the Northern Ravine Salamander (Plethodon electromorphus). It belongs to the family Plethodontidae, which is the world's most diverse family of salamanders.
Conant, R. and J. T . Collins. 1998. Reptiles and Amphibians of Eastern and Central North America. Third Edition, Expanded. Houghton Mifflin, New York, NY.
Minton, S. A. Jr. 2001. Amphibians and Reptiles of Indiana. Indiana Academy of Science, Indianapolis, IN .
Petranka, J. W. 1998. Salamanders of the United States and Canada. Smithsonian Institute Press, Washington D.C.