Rock‐Face Populations of the Mountain Salamander, Desmognathus Ochrophaeus, In North Carolina

Abstract

The ecology and life history of Desmognathus ochrophaeus inhabiting wet rock faces at high elevations near Highlands, North Carolina, were studied. Comparisons were made with rock—face populations in Great Smoky Mountains National Park and with woodland populations at Rabun Bald, Scaly Mountain, and Blue Valley in the Blue Ridge Mountains. The reproductive cycle in rock—face populations is annual; spawning occurs mostly in July and August, and females begin to emerge from brooding as early as late August. The new spermatogenic cycle begins in May and June. Animals on rock faces average 40—45 cm in movements between successive captures and appear to have a limited range. Animals displaced to the base of the rock face and higher on the rock face can return to their home range. Population density is high (up to 25 individuals/m2), diurnal activity is nearly as high as nocturnal activity (correlated with subdued body colors), and at least a moderate level of activity occurs during warm winter periods. Animals mature at 2 years of age as in woodland populations, but at a smaller size, and grow more slowly thereafter. Small body size is not due to paucity of food on the rock faces. The high population densities on the wet rock faces indicate that they are highly favorable habitats for D. ochrophaeus. Differences between rock—face and forest—floor populations are attributable to modified selective pressures in the two different ecological settings. Variation among rock—face populations is attributed to the intensity of selection for small body size and cryptic coloration, the size of the rock face, and variation among forest—floor populations from which they were derived. Since rock—face populations are linked genetically to surrounding forest—floor populations of D. ochrophaeus, they cannot be considered examples of taxonomic variation, but rather of ecotypic variation.

Reproductive Cycle, Growth, and Maturation of Northern Female Desmognathus ochrophaeus

“…3 by individuals between 30and 34 mm SVL with ovarian follicles greater than 1.00 mm diameter. The size and age at maturity observed during this study are similar to rockface populations reported byTilley (1974), although three of the four rockface populations studied byHuheey and Brandon (1973) matured at somewhat smaller size.Maturing ovarian follicles appeared to reach a maximum size between 2.50 and 3.00 mm diameter(Figs. 1 and 3); only 2 individuals had ovarian follicles exceeding 3 mm Martof and Rose (1963).…”

Effects of even-aged timber harvest on stream salamanders: Support for the evacuation hypothesis

“…Sampling locations of litter bags and origins of terrestrial transects were spatially separated P10 m. Removal sampling did not commence until litter bag and transect sampling was complete. With the exception Eurycea wilderae, focal salamanders of this study are known to be relatively philopatric (home ranges < 8.5 m 2 ), and move only short distances between observations (Huheey and Brandon, 1973;Kleeberger, 1984;Camp and Lee, 1996;Peterman et al, 2008). As such, salamanders observed using each method can be considered independent observations with little to no double counting.…”

“…Because time varied with each sampling period and nocturnal activity of salamanders varies throughout the night (Hairston, 1949;Keen, 1984), an individual covariate of sample time was incorporated into removal models. Due to the discrete sampling period (6 days) and relative philopatry of salamanders (Huheey and Brandon, 1973;Kleeberger, 1984;Camp and Lee, 1996;Peterman et al, 2008), we are confident that births and deaths are a nonissue, while immigration and emigration can be considered negligible. In another removal experiment, Hairston (1986) found no evidence for immigration into removal plots by either Desmognathus monticola or Desmognathus ochrophaeus (now recognized as D. ocoee).…”

Determinants of clinal variation in life history of dusky salamanders (Desmognathus ocoee): prey abundance and ecological limits on foraging time restrict opportunities for larval growth

“…Four of the 5 populations occur in wet rockface habitats, where seepage of the water table flows over road cuts or natural rock faces. These sites in the Southern Appalachians support dense populations of D. ocoee and other salamanders (Huheey & Brandon, 1973;Tilley, 1973Tilley, , 1980. All life stages including reproduction occur in the rockface habitats.…”