Amphibians of North Carolina
Scientific Name:
Common Name:
Family (Alpha):
« »
Plethodontidae Members:
NC Records

Plethodon welleri - Weller's Salamander


Taxonomy
Class: Amphibia Order: Caudata Family: Plethodontidae Subfamily: Plethodontinae
Taxonomic Comments: Plethodon welleri consists of several geographically isolated groups that are largely confined to higher-elevation peaks in the Blue Ridge Mountains. Populations on Grandfather Mountain have less brassy pigmentation on the dorsum and a less spotted belly than those from elsewhere in the range. They were treated by Thurow (1956) as a separate subspecies (P. w. welleri) from the remaining populations (P. w. ventromaculatus). Larson and Highton (1978) sampled three populations from throughout the range and found that the recognized subspecies did not form genetically cohesive groups. As such, they are no longer recognized as valid taxa. The currently isolated groups of P. welleri very likely expanded their ranges during glacial advances and may have come into geographic contact and exchanged genes. Detailed studies of genetic variation are needed to better document patterns of geographic variation within this species.
Species Comments: Plethodon welleri was named after Worth Hamilton Weller who discovered this species. Mr. Weller died shortly after graduating from high school while collecting this species on Grandfather Mountain during a summer thunderstorm. His body was found between boulders, along with an attached collection bag that contained several specimens of P. welleri. Charles Walker soon named the species in his honor.
Identification
Description: Plethodon welleri is a small eastern Plethodon with a modal number of 16 costal grooves. The adults vary from around 64-92 mm TL and have a blackish dorsum that is heavily flecked or blotched with golden or brassy pigmentation. The coloration on the sides is often similar to that on the dorsum, but some individuals may have silvery white spotting or a silvery-white wash that is most concentrated along the lower sides. The belly is dark and finely spotted with white except for populations on Grandfather Mountain, which tend to have uniformly dark bellies (Thurow 1956). Some individuals may have a few reddish spots or reddish flecking on the legs. The tail is rounded and comprises about 30-40% of the total length. Males develop small mental glands during the breeding season and have papillose vent linings (smooth in females).

The hatchlings vary from 12.5-15.0 mm SVL and 18.5-23.5 mm TL (Organ 1960a). They lack the heavy brassy patterning of the adults, but develop pairs of brassy spots along the anterior portion of the back within a few days after hatching (Petranka 1998). These expand and merge with age so that older juveniles resemble the adults with respect to color patterning.
Online Photos:    Google
Observation Methods: Individuals can be found beneath surface cover during the day and foraging on the surface on warm, moist nights during the summer months.
AmphibiaWeb Account
Distribution in North Carolina
Distribution Comments: Weller's Salamander is a southern Appalachian endemic that is found from southwestern Virginia southwestward through extreme eastern Tennessee and western North Carolina to northern Madison County, North Carolina. Populations are mostly confined to the higher mountaintops such as Whitetop Mountain, Mount Rogers, Grandfather Mountain, and Unaka Mountain, but a few have been found at lower elevation sites at elevations as low as 700 m (2300') or so (Beane et al. 2010, Niemiller and Reynolds 2011, Petranka 1998).
Distribution Reference: Beane et al. 2010, Hammerson 2004, Niemiller and Reynolds 2011
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: Populations have been found in both mesic hardwood forests and spruce-fir forests. Most populations appear to be isolated mountaintop relicts of an ancestral form that was more widespread. These are strongly associated with high elevation forests, particularly spruce-fir forests that occur above 1500 m in elevation (Petranka 1998, Thurow 1963). Populations also occur in northern hardwood forests where they adjoin spruce-fir forests. A few populations have been found in rich hardwood forests at lower elevation sites, particularly in or near talus. Thurow (1963) found them at a low-elevation site that was dominated by Eastern Hemlock and Yellow Birch. At higher elevations, individuals are commonly found in or beneath rotting logs, and beneath slabs of bark and rocks.
See also Habitat Account for Spruce-Fir Forests
Life History and Autecology
Breeding and Courtship: Much of our understanding of the breeding season and courtship behavior is based on Organ's (1960a) detailed studies of populations in Virginia. The adults in this region appear to mate only during the fall, with a peak in activity in October. Thurow (1963) found males in a series from Grandfather Mountain with their vasa deferentia swollen with sperm in both April and September. This suggests that a secondary breeding bout may occur during April or early May in more southern populations. The only published description of courtship is that of Organ (1960a) based on laboratory observtions. The following is a summary that was provided by Petranka (1998).

When a male encounters a female he immediately begins to undulate his tail back and forth about 1.5 times per second. The male then places his nasolabial grooves and mental gland on the female and slowly advances towards the female's head while maintaining contact with her skin. The males lack enlarged premaxillary teeth (Thurow 1963), so the skin is presumably not abraded during this time. After reaching her head, the male breaks contact and circles under the female's chin. As he passes under her, he holds his back and undulating tail in contact with her chin. As his tail passes under her chin, the male arches the base of his tail and begins a series of vertical undulations that alternate with horizontal undulations. The female then straddles the male's tail and presses her chin against the base of his undulating tail. An abbreviated tail-straddle walk occurs that rarely covers a distance of more than 8 cm.

Just prior to spermatophore deposition the male begins a series of lateral sacral rocking movements, and the female responds by moving her head counter to the direction of the male's movement. The male then lowers his vent to the substrate and deposits a spermatophore. He raises his vent, arches the base of his tail upward, and flexes the tail sharply to one side of the female. The female keeps her chin pressed against the bent tail of the male, and the two move forward rapidly until the vent of the female in positioned over the spermatophore. The female then picks up the sperm cap with her cloacal lips, leaving the spermatophore stalk behind. The spermatophore is mushroom-shaped and consists of a pale yellow sperm cap and a colorless, jelly-like stalk.

Organ (1963a) noted that males will attempt to court both sexes, and that males that are approached by courting males will often turn and viciously bit them on the legs or tail.
Reproductive Mode: Only a few nests have been found in the wild. These were all at higher elevation sites where females oviposit from May through early July following the spring warm-up (Hamed et al. 2012, Hoffman and Kleinpeter 1948, Petranka 1998). Organ (1960a) found three nests on 16 August in southwestern Virginia with late-term embryos, and five additional nests between 18 August and 5 September with hatchlings and empty egg capsules. Hoffman and Kleinpeter (1948) found two nests with freshly laid eggs in early July. The nests at all of these sites were located in well-rotted conifer logs, either between the upper surface of the log and moss mats, or in rotting wood a few centimeters below a moss mat. Hamed et al. (2012) found a nest with two eggs several cm below the leaf litter near the base of a decaying Yellow Birch log. This is the only known record of a female nesting in leaf litter, and the low egg count suggests that the eggs may have been heavily preyed upon. The overall scarcity of nesting records implies that many females nest in subsurface retreats, including talus slopes.

Females deposit their eggs in a tight, grape-like cluster and usually suspended them by a tough, whitish stalk. The individual eggs are either attached directly to the stalk or to other eggs. The outer capsule of individual eggs are 3.5-6.5 mm in diameter and the embryos are surrounded by the vitelline membrane and two jelly capsules (Hoffman and Kleinpeter 1948, Organ 1960a). Late-term embryos have three pairs of antler-like gills that are lost at or near hatching. The females coil about their eggs through hatching and many apparently remain with their young until they disperse from the nests. Organ (1960a) found from 5-10 eggs in three nests and 4-11 hatchlings in five other nests in Virginia, while Hoffman and Kleinpeter (1948) found two nests with seven and nine eggs.
Aquatic Life History: This species is fully terrestrial and lacks an aquatic larval stage.
Terrestrial Life History: Many aspects of the natural history of the juvenile and adults are poorly documented (Petranka 1998). Individuals remain in or beneath logs, under pieces of bark, or beneath rocks during the day. They become active on the ground surface with the onset of darkness, particularly on rainy or humid nights, where they search for small invertebrates and seek mates. The known dietary items include pseudoscorpions, mites, spiders, beetles, lepidopteran larvae, hemipterans, flies and shed skin (Thurow 1963).

Individuals are active on the ground surface except during the coldest months of the year, typically from April through October. The adults do not appear to be very aggressive outside of the breeding season (Organ 1960a, Thurow 1976) and there is little evidence of this species being strongly territorial. The males reach sexual maturity when > 31 mm SVL and females when > 35 mm SVL (Highton 1962a, Thurow 1963). Most individuals appear to mature when about 3-years old, and females probably produce their first clutch a year later (Petranka 1998).
General Ecology
Adverse Environmental Impacts
Status in North Carolina
NHP State Rank: S2
Global Rank: G3
Status in North Carolina: SC
Environmental Threats: Although most of the known populations of P. welleri occur on land that receives some level of protection, long-term climate change will likely adversely affect this species, particularly if spruce-fir forests are eliminated or greatly reduced in size as the climate on mountaintops warms (Sutton et al. 2014). Highton (2005) sampled Weller's salamanders along the North Carolina-Tennessee border (Mitchell and Unicoi counties, respectively) during 1971-1987 and 1993-1995 and in Grayson and Smyth counties, Virginia, during 1957-1984 and 1999 and found dramatic declines in both areas based on surface catches. Additional monitoring is needed throughout the range to determine if long-term declines are occurring.

Photo Gallery for Plethodon welleri - Weller's Salamander

2 photos are shown.

Recorded by: Max Ramey
Avery Co.
Recorded by: Max Ramey
Avery Co.