Brimley, C. S. (1912). "Notes on the salamanders of the North Carolina mountains, with descriptions of two new forms." Proceedings of the Biological Society of Washington, 25, 135–140.

Description

Plethodon metcalfi is a medium salamander having an average total body length 14 cm. The tail length is about half its body length. There are 14 lateral costal grooves (Brimley 1912).

Plethodon metcalfi is distinguished from most other species in its genus by its lack of white, red, and yellow color markings (Highton and Peabody 2000). It can be distinguished from Plethodon jordani, its closest relative, by its gray cheeks and pale gray ventral side (Hairston 1950). Plethodon metcalfi does have variation between its northern and southern populations, with its northern populations look similar to Plethodon montanus and its southern populations look similar to Plethodon amplus and Plethodon meridianus (Highton and Peabody 2000).

In life, their dorsal side is a blueish gray color and their ventral side is a pale gray. The two colors form a lateral line where they meet (Brimley 1912). Generally, they have no colored markings, but in some populations there is lateral white spotting and dorsal brassy flecks. In these same populations, they also have darker ventral sides (Highton and Peabody 2000).

Southern populations of P. metcalfi are larger and have darker venters than the northern populations. Some isolated southern populations also have lateral white spotting and dorsal brassy flecking (Highton and Peabody 2000).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: Georgia, North Carolina, South Carolina

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (10 records).

Plethodon metcalfi occurs along the border between North and South Carolina near Georgia, United States of America. They mostly occur between Highlands, North Carolina in the west, Hendersonville, North Carolina in the north, and Greenville, South Carolina in the south (Ash 2020; Highton and Peabody 2000).

They tend to live in cool, wet, and temperate forests, and at elevations around 1000 meters above sea level. The forests are made up of oak trees and White Pine, and the leaf litter was often moist (Ash 2020).

Life History, Abundance, Activity, and Special Behaviors

Plethodon metcalfi has been observed to be nocturnal and territorial. The nocturnal activity, most likely foraging, changes depending on the season, being the most active from May to August, and by sex. Juveniles, females, and males have been observed later after sunset, respectively (Ash 2020).

Females mate every other year, in a biennial reproductive cycle, and oviposit deep underground (Arnold 1976; Petranka 1998). Hatching occurs 2 - 3 months after oviposition in late summer or early fall (Petranka 1998).

Larva

As of 2023, nests for this species have not been documented, however P. metcalfi is direct developing (Petranka 1998).

Trends and Threats

Plethodon metcalfi is able to adapt well to threats, such as logging, and is able to return to high population densities (IUCN 2022).

Possible reasons for amphibian decline

Habitat modification from deforestation, or logging related activities

Comments

Based on allozyme data, Plethodon metcalfi is part of the P. jordani species complex, which includes: P. jordani, P. metcalfi, P. montanus, P. amplus, P. meridianus and P. cheoah (Highton and Peabody 2000). This was reinforced with a Bayesian analysis on mtDNA and nDNA, which also showed that Plethodon metcalfi is sister to P. jordani (Fisher-Reid and Weins 2011).

The species was named after Dr. Zeno Payne Metcalf, who was the first to collect the species for science (Brimley 1912).

This species was featured as News of the Week on 16 November 2020:

To improve predictions for how species will respond to our changing climate, we should not neglect the behavioral consequences of climate change. Gade et al. (2020) set out to address this shortcoming: they wanted to project how the changing conditions of the next century will influence salamander surface activity. They conducted surveys of three species of the Plethodon jordani complex in the Appalachians of the US, identified predictors of salamander surface activity and abundance (temperature and water vapor pressure), then used this relationship to explore how the surface activity of P. jordani complex species will respond to stabilization and high emissions climate scenarios. They found that the probability of salamander surface activity during peak active season increased over time, though gladly temperatures were not predicted to surpass the species' thermal maxima. Surface activity is important to salamanders because it their opportunity to forage and mate, so this outcome may sound like good news. However, the authors qualify that there are physiological trade-offs at play, so modified behavioral patterns can have unpredictable consequences. For example, higher temperatures increase metabolism and may decrease the energy assimilation of salamanders, which can result in smaller body sizes and lower growth rates, and in turn, result in delayed sexual maturity and lower fecundity. The authors show how the examination of behavior like surface activity, critical to their fitness, can reshape our understanding of how species will fare with a changing climate (Written by Emma Steigerwald).

References

Arnold, S. J. (1976). Sexual behavior, sexual interference, and sexual defense in the salamanders Ambystoma maculatum, Ambystoma tigrinum, and Plethodon jordani. Zeitschrift für Tierpsychologie, 42, 247-300. [link]

Ash, A. N. (2020). Temporal Partitioning of Foraging in Plethodon metcalfi. Herpetological Conservation and Biology, 15(1), 61 - 68. [link]

Brimley, C. S. (1912). Notes on the salamanders of the North Carolina mountains, with descriptions of two new forms. Proceedings of the Biological Society of Washington, 25, 135–140. [link]

Fisher-Reid, M. C. and Weins, J. J. (2011). What are the consequences of combining nuclear and mitochondrial data for phylogenetic analysis? Lessons from Plethodon salamanders and 13 other vertebrate clades. BMC Evolutionary Biology, 11(1), 300. [link]

Hairston, N.G. (1950). Intergradation in appalachian salamander of genus Plethodon. Copeia, 1950(4), 262-273. [link]

Highton, R. (2000). "Detecting cryptic species using allozyme data." The Biology of Plethodontid Salamanders. R.C. Bruce, R.G. Jaeger, and L.D. Houck, eds., Kluwer Academic/Plenum Publishers, New York, New York, 215-241.

IUCN SSC Amphibian Specialist Group. (2022). Plethodon metcalfi. The IUCN Red List of Threatened Species 2022: e.T59348A196341003. https://dx.doi.org/10.2305/IUCN.UK.2022-1.RLTS.T59348A196341003.en. Accessed on 12 April 2023.

Petranka, J. W. (1998). Salamanders of the United States and Canada. Smithsonian Institution Press, Washington D.C. and London.

Species Account Citation: AmphibiaWeb 2023 Plethodon metcalfi: Southern Gray-cheeked Salamander <https://amphibiaweb.org/species/5842> University of California, Berkeley, CA, USA. Accessed Sep 24, 2023.

Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Sep 2023.

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