The Four-toed Salamander (Hemidactylium scutatum) lives an enigmatic and secretive life among North Americas bogs and vernal pools. Four-toed salamanders are small, tend to be coppery or grayish in color, have a notable constriction at the base of the tail, and sport bright white bellies with black spots. And of course, they have four toes on each foot. They predate small invertebrates along their sloped and/or mossy homes. Like other small salamanders in the Plethodontid family, they are not easy to detect without some basic knowledge of their life history. A patchy distribution of the Four-toed Salamander in the southern portion of its range makes this amphibian even more difficult to detect, and human development of wetlands exacerbate this fact.
H. scutatum is a small, terrestrial salamander in the family Plethodontidae. The species likely originated in the Blue Ridge of the Appalachians around 8 million years ago, where it eventually dispersed into its current distribution (Herman and Bouzat 2016). In Mississippi, the first documented specimen was found in 1930 in Jefferson Davis County. Dundee (1968) also noted apparent differences in habitat preference compared to their typical mossy mainstays in the Appalachians and further north. Four-toed Salamanders in Mississippi (and other southern states) were often found in “rolling terrain covered with hardwoods and conifers” with nearest wetlands completely lacking the usual moss association: Sphagnum (Dundee 1968).
Nevertheless, we know much of the reproductive behavior of H. scutatum from habitats featuring Sphagnum and other mosses. Nests are created in clumps or mats of moss adjacent to bogs and fishless ponds, often on steep inclines (Harris and Gill 1980, Harris and Ludwig 2004, Banning et al. 2008). Nests are also frequently communal; multiple females may lay eggs in one grouping, weaving through the embryos which inoculates the young with skin bacteria to protect them from fungal infection (Banning et al. 2008). Most often, only one female will remain on the nest no matter how many clutches are present (Harris and Gill 1980).
Without as clear a habitat character to indicate potential presence of Four-toed Salamanders in Mississippi (or Louisiana, Alabama, Florida), detecting them is relatively uncommon. Citizen science observations on sites like iNaturalist and HerpMapper occur every couple of years at best in Mississippi. They have been seen in the plateau habitats of northeast Mississippi as well as the loess hills south of the Mississippi River Delta. A systematic survey of habitats they were previously known from during ideal conditions may be a useful step in determining their current status in the state.
References
Banning, J. L., A. L. Weddle, G. W. Wahl Iii, M. A. Simon, A. Lauer, R. L. Walters, and R. N. Harris. 2008. Antifungal skin bacteria, embryonic survival, and communal nesting in four-toed salamanders, Hemidactylium scutatum. Oecologia 156:423–429.
Dundee, H. A. 1968. First Record of the Four-Toed Salamander, Hemidactylium scutatum, in Mississippi, with Comments on Its Disjunct Distribution in Arkansas and Louisiana. Journal of Herpetology 1:101–103.
Harris, R. N., and D. E. Gill. 1980. Communal nesting, brooding behavior, and embryonic survival of the four-toed salamander Hemidactylium scutatum. Herpetologica 141–144.
Harris, R. N., and P. M. Ludwig. 2004. Resource level and reproductive frequency in female four‐toed salamanders, Hemidactylium scutatum. Ecology 85:1585–1590.
Herman, T. A., and J. L. Bouzat. 2016. Range‐wide phylogeography of the four‐toed salamander: out of Appalachia and into the glacial aftermath. Journal of Biogeography 43:666–678.