Northern Redback Salamander
Plethodon cinereus
Summary: This eastern forest species is extremely abundant in the beech-maple forests of Porter and LaPorte Counties, and presently occurs at least as far west as the West Creek drainage of Lake County Indiana. A few Cook County records are known, but except for a well documented Calumet City historical locality, these are of questionable validity.
Description: A small and slender salamander, 2.2 to 5.0 inches (5.7-12.7cm) total length. There are two color phases; the "redback" has a broad, straight-edged red dorsal stripe from the back of the head to nearly the tip of the tail, bordered on either side by the black to dark gray ground color. The "leadback" is uniformly dark above, with no evidence of a stripe. Both color phases may have faint light speckling on the lower sides, and the underside is speckled with both black and white. Most populations include individual salamanders of both color phases, although often one or the other will be more common.
The redback phase is easily identifiable on color pattern alone. The leadback differs from the four-toed salamander in having five toes on the rear feet, an unconstricted tail, and a darker underside. Juvenile Ambystoma are heavier-bodied relative to their size than leadbacks, with which they are occasionally confused.
Distribution and Status: Redback salamanders are abundant in forested parts of Porter and LaPorte Counties, and especially in the dunes area, but absent from most of the rest of the region. There are valid 1950s specimens from the Calumet City area, and Dave Beamer recently discovered moderately large populations in the West Creek drainage of Lake County Indiana. There have been several reports of redbacks in southwest and northwest Cook County; however, I tend to discount these. Two of the reports are by experienced herpetologists, and the identification is not in doubt. But because all of the reports are based on only one or two specimens, and because they are consistently in densely populated suburban regions, I suspect the animals were intentionally released there.
The redback salamander is widespread in the northeastern United States. Chicago region populations are near the western limit of the range.
Habitat: Redback salamanders are completely independent of standing water, although they often utilize moist areas near wetlands. They are considered characteristic of mesic beech-maple forest, and they tend to reach great abundance in good quality examples of that community type. During a November 1, 1998 visit to an old-growth site in Berrien County, Michigan, Satie Airame and I found 43 redbacks in three-and-a-half hours of searching under less than ideal weather conditions. I have seen similar densities at Porter and LaPorte County sites.
Other wooded habitats are also utilized. In LaPorte County flatwoods, floodplain forest, and red maple swamps are used. Many of the dunes sites in Porter County are wet-to-mesic microhabitats within drier oak woodland or sand savanna.
Phenology: Redback salamanders are most active on the surface in spring and fall. Courtship may occur in either of those seasons (Blanchard, 1928), with egg deposition in mid-June (Pfingsten and Downs, 1989). Eggs are deposited on land, either underground or within decayed logs (Test and Heatwole, 1962). Females guard the eggs until hatching in late summer. The hatchlings are fully terrestrial at birth.
Field Notes
October 19, 1984. Indiana Dunes State Park. 60s and clear. Plethodon cinereus easy to find along the north edge of the great marsh.
May 6, 1989. Porter County. To the dunes with Alan Resetar. Cold, 5 degrees C mid-afternoon, snow flurries. Chorus frogs and peepers calling, only a few, near West Beach. Near Dune Acres found a few Plethodon cinereus. Later south of Chesterton, in a beech-maple hollow with trillium in bloom, found a few more P. cinereus and a large polyploid Ambystoma.
October 14, 1998. LaPorte County. Steep to moderate forested slopes with large ravines, considerable seepage feeding adjacent wetlands. Plethodon cinereus common in beech-maple forest.
October 28, 1998. LaPorte County. Large buttonbush swamp with some open sedge hummock areas, surrounded by mixed forest, some beech-maple, some oak, a few yellow birch near wetland margin. Found eight Plethodon cinereus and one juvenile Ambystoma maculatum in a brief search.
Literature Cited
Blanchard, F. N. 1928. Topics from the life history and habits of the red-backed salamander in southern Michigan. American Naturalist 62:156-164.
Pfingsten, R. A., and F. L. Downs. 1989. Salamanders of Ohio. Ohio State University Bulletin 7(2). xx+315p.
Test, F. H., and H. Heatwole. 1962. Nesting sites of the red-backed salamander, Plethodon cinereus, in Michigan. Copeia 1962:206-207.
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| Updated: October 9, 2007
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