Amphibians of North Carolina

Scientific Name:	Common Name:		Family (Alpha):

NC Records
Plethodontidae Members:
Plethodon teyahalee - Southern Appalachian Salamander

Taxonomy

Class: Amphibia

Order: Caudata

Family: Plethodontidae

Subfamily: Plethodontinae


Taxonomic Comments: A group of wide-ranging large Plethodon species in the eastern US with a blackish ground color and varying levels of whitish or golden flecking, blotching, and spotting have traditionally been known as 'slimy salamanders' due to glutinous secretions that are produced from the tail. These were originally thought to represent a single wide-ranging species (the Slimy Salamander, Plethodon glutinosus), but were split into 16 species by Highton (Highton 1984, 1989; Highton and MacGregor 1983) and constitute the 'Plethodon glutinosus complex'. One (P. aureolus) was described in 1984 and the other (P. kentucki) was resurrected in 1983. The remainder were described by Highton (1989) and constitute a complex of geographically and genetically variable groups that are difficult to distinguishable from one another based on external phenotypic traits. Highton (1989) analyzed geographic variation in protein patterns and split these into numerous species using an arbitrary genetic distance to define species. This resulted in a series of parapatric forms that show varying levels of gene exchange in contact zones. Frost and Hillis (1990) objected to splitting P. glutinosus into multiple species based solely on arbitrarily selected genetic distances and cited a variety of perceived problems, including several biases in estimating genetic distances. Data from studies using mitochondrial and nuclear sequence data (Fisher-Reid and Wiens 2011, Wiens et al. 2006) was used to justify keeping Highton's original taxonomy for the group. These studies sometimes relied on sequence data from a single representative individual of each species and did not carefully examine contact zones or examine levels of gene exchange between form, which Hillis (2019) argued is essential for making taxonomic decisions. Joyce et al. (2019) analyzed multiple specimens from Alabama that represented three members of the P. glutinosus complex (P. glutinosus, P. grobmani, and P. mississippi) and concluded that these represent a single species of slimy salamander (P. glutinosus) rather than three as proposed by Highton (1989). They further argue that similar issues arise when multiple individuals have been used in studies: paraphyly is common place and the validity of several species is questionable (e.g., Smith et al. 2018, Wiens et al. 2006). To complicate matters further, members of the P. glutinosus complex show widespread evidence of historical or present gene exchange with members of the P. jordani complex (Weisrock et al. 2005). Joyce et al. (2019) recommended only recognizing three species within the P. glutinosus complex: P. aureolus, P. kentucki, and P. glutinosus. The latter would be treated as a geographically variable species that contains all of the remaining species that Highton recognized. The taxonomic status of many members of the Plethodon glutinosus complex is clearly unresolved, and there may never be a complete resolution of the problem given that experts often embrace different taxonomic philosophies when interpreting geographic variation within a group. In addition, there is often widespread discordance in the lines of evidence used to delineate species. North Carolina may have as many as 6 members of the 16 species recognized by Highton, although two are of questionable status. These include P. aureolus, P. chattahoochee, P. chlorobryonis, P. cylindraceus, P. glutinosus and P. teyahalee. Here we continue to include all six of these forms in the North Carolina fauna, with the understanding that the taxonomic status of some may change in the future.
Species Comments:

Identification

Description: This is a relatively large, light-chinned member of the P. glutinosus complex with a grayish black dorsum, very small white dorsal spots, and reduced lateral white spotting. Specimens often have small red spots on the legs. The belly is uniformly gray and the throat is lighter than the belly (Petranka 1998). The tail is rounded in cross-section, slightly longer than the body, and produces sticky secretions that function in defense against predators. Sexually active males have conspicuous, rounded mental glands. The adults vary from around 12-21 cm TL and there are usually 16 costal grooves. The juveniles resemble the adults in coloration and spotting patterns.

Plethodon teyahalee hybridizes to varying degrees with several other large Plethodon, and the hybrids often deviate in coloration from pure P. teyahalee. This species hybridizes extensively with all four geographic isolates of P. shermani. The hybrids typically have less white spotting on the back and sides than pure P. teyahalee and less red coloration on the legs than pure P. shermani. It also hybridizes with P. jordani in the northeastern portion of the latter's range. The hybrids have varying amounts of both red coloration on the cheeks and white spotting. Plethodon teyahalee contacts P. glutinosus on the western side of the Blue Ridge Mountains in eastern Tennessee. At one site in Polk Co. the two do not appear to hybridize, but in Monroe and Sevier counties there are hybrid zones (Highton and Peabody, 2000). Highton and Peabody (2000) reported that P. teyahalee hybridizes with P. chattahoochee in Clay County, North Carolina near Hayesville, and with P. chlorobryonis in northwestern South Carolina where there is a hybrid zone where the two meet (Highton and Peabody 2000). This species is best identified using a combination of geographic range and dorsal and lateral spotting. Hybrids are common in many areas and can be readily identified where they involve P. shermani and P. jordani. In other cases genetic analyses may be required.

Online Photos: Google iNaturalist

Observation Methods: The adult are active on the ground surface at night except during very dry conditions. They can be found beneath surface cover during the day.

AmphibiaWeb Account

Distribution in North Carolina

Distribution Comments: Highton (1983) reported that P. teyahalee is found from west of the French Broad River in Madison Co. southward to Oconee, Pickens, Anderson, and Abbeville counties, South Carolina and Rabun County, Georgia. The range extends westward through southwestern North Carolina to extreme southeastern Tennessee. This species is typically found at lower elevations than P. shermani and P. jordani and generally below 1,550 m in elevation. Certain populations in Buncombe Co. east of the French Broad River more closely resemble P. teyahalee than P. cylindraceus. it is uncertain if they are true P. teyahalee or perhaps hybrids between P. teyahalee and P. cylindraceus. We are currently treating these as the former.
Distribution Reference: Highton (1983)
County Map: Clicking on a county returns the records for the species in that county.


GBIF Global Distribution

Key Habitat Requirements

Habitat: The Southern Appalachian Salamander is found in mesic deciduous forests. Optimal habitats are mature stands with a deep leaf litter layer, deep, moist soils, and ample amounts of bark, rotting logs, and other surface cover.

See also Habitat Account for General Montane Mesic Forests

Life History and Autecology

Breeding and Courtship: Although poorly documented, breeding presumably occurs from July through October given that this species frequently hybridizes with other large Plethodon species that mate at this time (Petranka 1998). Courtship has not been described in detail but is undoubtedly very similar to that of P. jordani and P. shermani since these species frequently hybridize (see the detailed description of courtship for P. jordani).

Dawley (1984b, 1987) conducted a series of laboratory trials which indicate that ethological barriers mediated through olfactory cues contribute to reproductive isolation between Plethodon teyahalee and certain other cogeners. In one study male P. teyahalee showed strong preferences for odors of female conspecifics over those of sympatric P. aureolus. In another, male P. teyahalee and P. jordani from an area in the Smoky Mountains where these two species do not hybridize preferred chemical cues from conspecific females compared to heterospecific females.

The partial or complete breakdown of barriers occurs in or near hybrid zones. Dawley (1987) found that male P. teyahalee that were collected next to a hybrid zone in the Nantahala Mountains preferred females of their own species. However, male P. shermani did not prefer conspecifics over heterospecifics. Female P. teyahalee collected next to the hybrid zone preferred male heterospecific odors, while none of the other females show preferences when tested in matchups analogous to those used to test males. When hybrids from the Nantahala Mountains are used in courtship trials, P. shermani does not discriminate between conspecifics and hybrid mates (Petranka 1998).

Reproductive Mode: The nests of P. teyahalee have never been found, but nesting is presumed to occur underground in late spring or early summer in underground cavities, with hatching occurring 2-3 months after the eggs are deposited.

Aquatic Life History: This is a fully terrestrial species that lacks an aquatic stage.

Terrestrial Life History: The juveniles and adults live in mesic forests and are nocturnally active. They stay in moist leaf litter, in underground burrows, or beneath cover objects during the day and emerge with the onset of darkness to feed on insects and other small invertebrates. Servidio et al. (2013) found that ants in the genus Aphaenogaster were important prey items of P. teyahalee and P. teyahalee x shermani hybrids in the Nantahala Mountains. These are one of the primary seed dispersers of many of the woodland wildflowers in the region, which suggests that P. teyahalee could potentially play an important ecological role in indirectly altering seed dispersal and seedling establishment in southern Appalachian forests.

General Ecology

Community Ecology: Hairston (1980a, 1983b) conducted field experiments to examine competitive interactions between members of the P. jordani complex and P. teyahalee, and documented the responses of each species to the experimental removal of the other. Experiments were conducted in the Great Smoky Mountains with P. jordani where the elevational overlap is slight and in the Balsam Mountains with P. metcalfi where the overlap is much more extensive. In both cases the removal of either P. jordani or P. metcalfi increased the surface densities of P. teyahalee. Removal of P. teyahalee did not affect the densities of P. jordani, but did increase the proportion of juveniles in the population. Hairston concluded that competition occurs between the two species, but was unable to pinpoint the resources that were in short supply. Later studies (see Hairston 1987, Nishikawa 1985, Petranka 1998) suggest that aggressive interaction related to interference competition for space is the primary factor mediating interactions between these species.

Drummond (2015) conducted laboratory trials to determine how P. shermani, P. teyahalee, and their hybrids interact and found that P. shermani was the most aggressive, with more than six times the number of aggressive behaviors as P. teyahalee, and with more than two times the number of aggressive actions as hybrids. His data suggest that P. teyahalee is restricted to lower elevations due to competitive exclusion by P. shermani.

In the Great Smoky Mountains P. teyahalee and P. jordani tend to segregate elevationally, with P. jordani occupying the higher elevation sites. Gifford and Kozak (2011) examined interactions between the two and concluded that P. jordani is restricted to higher elevations because of physiological constraints, while competition with P. jordani prevents P. teyahalee from expanding its range to include higher-elevation habitats.

Adverse Environmental Impacts

Status in North Carolina

NHP State Rank: S4

Global Rank: G4

Environmental Threats: This and other eastern salamanders are sensitive to intensive timbering such as clear-cutting (Ash 1988, Petranka et al. 1993, 1994) and less intensive harvesting practices that leave the basic structure of the forest intact would benefit this and other salamander species in southern Appalachian forests. Raybuck et al. (2015) examined the short-term response of P. teyahalee and P. metcalfi to prescribed fire, midstory herbicide application and shelterwood harvest in western North Carolina and found in the short-term run (<3 years), P. metcalfi and P. teyahalee populations did not appear to be affected negatively by the these three experimental treatments.

Photo Gallery for Plethodon teyahalee - Southern Appalachian Salamander		7 photos are shown.
	Recorded by: B. Bockhahn, J. Thomson Buncombe Co.	Recorded by: K. Bischof Transylvania Co.
	Recorded by: Owen McConnell Graham Co.	Recorded by: K. Bischof Transylvania Co.
	Recorded by: K. Bischof Transylvania Co.	Recorded by: Owen McConnell Graham Co.
	Recorded by: Steve Hall, Nelson Hairston, Haven Wiley, UNC Vertebrate Ecology Class Swain Co.

Plethodon teyahalee - Southern Appalachian Salamander

Photo Gallery for Plethodon teyahalee - Southern Appalachian Salamander

7 photos are shown.