Amphibians of North Carolina

Scientific Name:	Common Name:		Family (Alpha):

NC Records
Plethodontidae Members:
Pseudotriton ruber - Red Salamander

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Taxonomy

Class: Amphibia

Order: Caudata

Family: Plethodontidae

Subfamily: Spelerpinae


Taxonomic Comments: The Red Salamander (Pseudotriton ruber) is a relatively large, stout, reddish salamander with a short tail and short legs. This species can be found throughout a large portion of the eastern US, and taxonomists have traditionally recognized four largely allopatric subspecies. These are the Northern Red Salamander (P. r. ruber) that is a large form with red or reddish orange above and prominent black spots, the Blue Ridge Red Salamander (P. r. nitidus) which is similar but smaller, and with little or no spotting on the top of the posterior half of the tail, the Black-chinned Red Salamander (P. r. schencki) that generally resembles P. r. ruber, but has heavy black flecking under the chin, and the Southern Red Salamander (P. r. vioscai) that is generally duller colored than the other subspecies and often has a herringbone pattern on the back. The latter occurs on the Coastal Plain, while the others occur in upland areas in and around the Appalachian Mountains and adjoining Piedmont. Folt et al. (2016) analyzed sequence data from two mtDNA and one nuclear gene and found five major clades using mtDNA. The analysis of the nuDNA resulted in discordant phylogenies. The authors concluded that none of the four currently recognized subspecies of P. ruber formed reciprocally monophyletic clades using either mitochondrial or nuclear DNA analyses and do not represent independently evolving lineages. The authors recommended continuing to recognize these subspecies for now, but many taxonomists would not do so since the morphologically defined subspecies do not closely parallel genetic patterns of variation across the range of this species. North Carolina has three of the four recognized subspecies. Here we provide range maps showing the approximate distributions of these in the state as suggested by Folt et al. (2016), but treat all in the species account below as P. ruber without recognizing subspecies.
Species Comments:

Identification

Description: The Red Salamander is a relatively large, stout salamander with a short tail and short legs. The tail of adults averages about 38% of the TL, and the eyes are yellow except in Coastal Plain forms in the southern portion of the range (Petranka 1998). The dorsum and sides of the body vary from purplish brown to bright crimson red and are heavily marked with irregularly rounded black spots. The belly varies from pinkish to red and contains scattered black spots in the adults. The ventral black spots are sometimes absent in juveniles and young adults. In most areas of the range small juveniles and young adults are bright crimson red and boldly marked with black spots. Individuals darken with age and old adults are often purplish brown with fused black spots that are less distinct (Petranka 1998). Coastal Plain populations from throughout the range are duller overall. Individuals from our Piedmont populations also tend to be less brightly colored than those from the mountains. In general, individuals cannot be readily sexed using external morphology. The adults vary from 9.5-18 cm TL and there are 16 or 17 costal grooves. Bruce (1978a) found that females averaged about 10% larger than males in southern Blue Ridge populations.

The hatchlings vary from 11-14 mm SVL and have stream-type morphology with the dorsal fin restricted to the tail region. Hatchlings and small larvae are rather uniformly light brown above and dull white below. The gills are prominent and are red to brownish red. As larvae mature, the dorsum often becomes weakly mottled or streaked. Dorsal spotting often develops in older larvae that are nearing metamorphosis. Populations in some local populations throughout the range, and in the upper Piedmont of North and South Carolina, are usually spotted and lack streaking. Older larvae retain the light brown dorsal color while those nearing transformation may acquire reddish coloration (Petranka 1998). The adult color pattern develops within a few months after the larvae metamorphose.

In North Carolina, dark individuals of P. ruber resemble the Mud Salamander (P. montanus), but the latter has brown eyes and fewer dorsal spots that are widely spaced, more rounded, and that rarely overlap. In contrast, all P. ruber in North Carolina have yellow eyes and much denser black spotting on the back. The spots tend to be more irregular in shaped and often overlap and partially fuse.

Online Photos: Google iNaturalist

Observation Methods: The larvae can be found by dip-netting or searching cover in small headwater streams and seepages. The adults are commonly encountered crossing roads during rainy nights during the fall and spring months as they disperse to and from overwintering and breeding sites. They can also be found beneath surface cover during warm weather.

AmphibiaWeb Account

Distribution in North Carolina

Distribution Comments: The Red Salamander occurs from southern New York southwestward to western Kentucky and western Tennessee and southward to the Florida Panhandle and the Gulf Coast of Alabama, Mississippi, and extreme eastern Louisiana. This species is found east of the Mississippi River and is absent from most of the Atlantic Coastal Plain from Virginia southward to eastern Florida. Populations occurs at elevations ranging from near sea level to greater than 1500 m (4921'), but are relatively uncommon above 1200 m (3937'). In North Carolina, P. ruber is common and widespread in the mountains, but less so in the Piedmont. It is known from only a few localities in the Coastal Plain (Beane et al. 2010).
Distribution Reference: Beane et al. (2010); Petranka (1998)
County Map: Clicking on a county returns the records for the species in that county.


GBIF Global Distribution

Key Habitat Requirements

Habitat: Populations are most commonly found in hardwood forests with a perennial source of running water. The larval period last for more than a year and breeding sites such as small headwater streams, seepages, springs, and spring-fed bogs that hold water year-round and lack predatory fish are ideal. In karst regions females sometimes breed underground in caves (Miller et al. 2008). Larvae have also occasionally been found in standing water habitats such as woodland pools and beaver ponds (Bruce 2003). This species is rarely associated with large, swift-flowing streams, but larvae have sometimes been found in higher-order streams in leaf mats or other cover along the edges of large pools. These likely reflect the downstream drift of small larvae from headwater streams and springs where breeding occurs. Adults and juveniles are often locally abundant in or near thick accumulations of leaf litter in streams, particularly during the cooler months of the year. Many individuals leave the immediate vicinity of breeding sites and moved into the surrounding forests during the warmer months of the year. Sites with plenty of surface cover such as slabs of bark, rotting logs, and rocks provide ideal microhabitats for the juveniles and adults. Individuals have occasionally been found in meadows and pastureland that adjoins breeding sites, but these do not appear to be the preferred habitats and likely reflect individuals that are migrating to and from streams.

Biotic Relationships: The natural predators are poorly documented but probably include crayfishes, fishes, woodland birds, snakes, shrews, raccoons, skunks, and the Spring Salamander (Petranka 1998). When pinched or prodded, the juveniles and adults usually assume a defensive posture which involves curling the body, elevating and extending the rear limbs, and placing the head in a protective position under the tail. While in this position, the tail is usually elevated and undulated slowly from side to side (Petranka 1998).

Pseudotriton ruber has been the subject of numerous evolutionary studies that have tried to explain geographic variation in coloration (see Petranka (1998) for a comprehensive review). The terrestrial red eft stage of the Eastern Newt (Notophthalmus viridescens) produces a powerful neurotoxin in the skin that is an effective chemical defense against predators. The bright crimson color of the efts serves as warning coloration and enhances a predator's ability to learn to avoid efts after an initial attack. Howard and Brodie (1971, 1973) hypothesized that P. ruber is a palatable Batesian mimic of Notophthalmus, and that avian predators are the primary agents selecting for the mimicry complex. A series of studies by these and other authors in the early 1970's provided strong support for the Batesian mimicry hypothesis. Both wild and domestic birds, for example, could be conditioned to avoid Red Salamanders after being exposed to red efts (Petranka 1998). The Mud Salamander (P. montanus) and Spring Salamander (Gyrinophilus porphyriticus) were also hypothesized to be a Batesian mimics of red efts for similar reasons.

Huheey and Brandon (1974) and Pough (1974) noted that geographic variation in skin coloration covaries among Notophthalmus and P. ruber. Both the red efts of Notophthalmus and P. ruber are brightly colored in montane areas where efts are abundant and diurnally active, but duller colored in non-mountainous areas where efts are rarely active during the day. These authors hypothesized that this pattern reflects selection for the mimicry complex in mountainous areas such as western North Carolina, and selection for cryptic coloration in regions where efts are uncommon and secretive during the day such as in Coastal Plain populations.

Several researchers challenged the Batesian mimicry hypothesis after discovering that both P. ruber and P. montanus produce highly toxic skin secretions that are concentrated on the back skin. These researchers concluded that P. ruber and P. montanus are not Batesian mimics of red efts since they have reduced palatabilities of their own that are reinforced by skin color and defensive posturing. Currently, both of our Pseudotriton species are considered to be part of a Mullerian mimicry complex in which all members are unpalatable and benefit by evolving similar warning coloration.

See also Habitat Account for Wet-Mesic Forests with Seepages/Headwater Streams

Life History and Autecology

Breeding and Courtship: The breeding season is geographically variable and -- depending on the location -- can occur at almost any time of the year except during the coldest months (Petranka 1998). Adults in Virginia and Maryland populations mate primarily during the autumn and spring months (Organ and Organ 1968), while those in southern Blue Ridge populations in North Carolina mate primarily during the summer. Males in this region have sperm-filled vasa deferentia from mid-June through September (Bruce 1978a). Most adults breed annually. The ratio of males to females in samples taken by Bruce (1978a) was 1.89 which suggests that males may potentially compete for mates. Organ and Organ (1968) observed courtship of individuals from southwestern Virginia in the lab in June. The following description from Petranka (1998) is a summary of the major elements of courtship.

A male initially approaches a female and rubs his snout across her snout, cheeks, and chin. He next moves his head and body beneath her chin and begins to undulate his tail. The female places her chin against the base of the male's tail and straddles his tail. The pair then engages in a tail-straddle walk that lasts for < 2 minutes and terminates with the male depositing a spermatophore. During the tail straddle walk the male places his tail laterally and undulates it while lifting and rotating the base upwards against the chin of the female. During spermatophore deposition the male presses his cloaca to the substrate and rhythmically contracts his cloacal region while violently undulating the tail. The male then arches his tail, flexes it strongly to one side, and leads the female forward over the spermatophore. The female picks up the sperm cap as she moves under it, and the couple separates soon thereafter. Rival males do not appear to be aggressive and a male normally deposits a maximum of two spermatophores per night. The spermatophore is about 3.5 mm high and has a base that tapers into a colorless, transparent stalk that supports white, adhesive sperm cap.

Males occasionally will court other males and mimic the female behavior to dupe them into depositing spermatophores (Organ and Organ 1968). This behavior presumably reflects sexual interference rather than an inability to recognize members of the opposite sex (Arnold 1977). They authors noted that courtship of P. ruber appears to be less complex than that of other plethodontids. In particular, the length of the tail-straddle walk appears to be much briefer in this species compared with other plethodontids. The authors' observations were made in small glass bowls which may have altered normal behavior such as the duration of the tail-straddle walk. Additional studies are needed to confirm their findings.

Reproductive Mode: The females appear to be capable of long-term sperm storage and often lay eggs several months after courting. Females in most populations oviposit from late-summer through early winter in springs, headwater streams, seepage-fed mountain bogs, caves, and other suitable breeding sites that hold water year-round (Bishop 1941, Bruce 1972a, 1978a, Semlitsch 1983a). The nests have rarely been found which implies that most females oviposit in cryptic sites deep within seepages, springs or streambanks (Petranka 1998). Miller et al. (2008) found six egg clutches with attending females deep within in a cave in eastern Tennessee. They documented several other records of populations being associated with caves, which suggests that females often use caves with perennial underground water flow as breeding sites.

Females normally attach their eggs singly by gelatinous stalks to the undersides of rocks or other support structures that are often submerged in water, although Miller et al. (2008) found some laid either in small rimstone pools or attached directly to gravel beneath rocks in a Tennessee cave. Each embryo is surrounded by a vitelline membrane and two jelly envelopes, and freshly laid ova are white and about 4 mm in diameter (Bishop 1925, 1941, Petranka 1998). Clutches at different developmental stages have been found from October through February in New York, in November in Virginia, and from mid-September through early December in Tennessee (Miller et al. 2008, Petranka 1998).

Estimates of clutch sizes are mostly based on counts of mature ovarian eggs. The number of mature ova in 29 gravid females from several sites in the southern Appalachians that were examined by Bruce (1978a) varied from 29-130, averaged 70, and was positively correlated with female SVL. Females presumably brood their eggs until hatching since females disappear from surface sites in the autumn and do not reappear until shortly after hatching begins in late autumn or winter (Petranka 1998). All six nests that were found by Miller et al. (2008) in a Tennessee cave were accompanied by a single adult. The incubation period in southern Blue Ridge populations last about 3 months, with hatching occurring from about mid-December through mid-February (Bruce 1978a). Hatchlings or very late-term embryos have been found in November in New York and Virginia, in January in Coastal Plain streams in South Carolina, in March in Ohio, and in March in the South Carolina Piedmont (Bruce 1974, Petranka 1998).

Aquatic Life History: The hatchlings and older larvae reside in slow-moving sections of springs, seepages, and stream pools where decaying leaves, bottom debris, and aquatic plants provide cover and foraging sites (Petranka 1998). Cecala et al. (2007) documented the prey of larvae in three streams in the western Piedmont of North Carolina. The larvae consumed a wide variety of prey, particularly midges and fingernail clams. Numerous other prey were taken in small numbers, including insects such as mayflies, stoneflies, caddisflies, craneflies and beetles. Other prey included crayfishes, earthworms, leeches, isopods, copepods, amphipods and other invertebrates. On rare occasion, other salamander larvae were taken. In general, larvae consumed a greater diversity of prey items as they aged, and the consumption of prey decreased during the warmer summer months. Miller (2020) observed larvae feeding on the eggs of a Southern Two-lined Salamander (Eurycea cirrigera) in Tennessee.

The larval period is prolonged and annual growth rates vary depending on water temperature and the length of the growing season (Petranka 1998). Larvae in Coastal Plain populations that were studied by Semlitsch (1983a) grew 1.2-2.0 mm/month during the first 6 months after hatching, while those in a Piedmont population studied by Bruce (1972a) grew 1.2 mm/month during the first 5-6 months after hatching. The larval period last from 1.5-3.5 years depending on the locale and local site conditions.

Transformation occurs from April-November, but most larvae transform in late spring through mid-summer. In general, northern populations tend to have longer larval periods than southern or Coastal Plain populations that experience warmer water temperatures and longer growing seasons (Petranka 1998).

In western North Carolina most larvae metamorphose between May and July after a larval period of 27-31 months (Bruce 1972a, Gordon 1966). Size at metamorphosis in two studies varied from 34-46 mm SVL (Bruce 1972a) and 62-86 mm TL (Gordon 1966). In two Coastal Plain populations in South Carolina the larval period lasted only 18-23 months and the larvae metamorphosed from June-November when they averaged 47 mm SVL (Semlitsch 1983a). The mean size at metamorphosis was 43 and 39 mm SVL in Piedmont and Blue Ridge populations that were studied by Bruce (1972a, 1974) in the Carolinas. Bruce (1972a) estimated annual survivorship at one site to be about 50% per year. The larvae tended towards having Type II survivorship in which mortality rates were independent of larval age and size.

Terrestrial Life History: Because the larvae transform at a relatively large size the juvenile stage is brief. Most males studied by Bruce (1978a) in the southern Appalachians sexually matured within 1 year after metamorphosing and bred during their fourth summer when nearly 4 years old. A few males required an additional year before mating for the first time. The males matured sexually when 53-63 mm SVL and the females when 55-68 mm SVL. Most females laid eggs for the first time when about 5-years old or older, then reproduced annually thereafter. Bruce (1978a) found that the sex ratio of juveniles was near 1:1, but that the number of mature males greatly outnumbered the number of mature females.

The juveniles and adults overwinter in aquatic sites and often concentrate in springs or streams during the late fall (Petranka 1998). Bruce (1978b) found that juveniles and adults in the southern Blue Ridge disperse from springs and streams into surrounding habitats in early spring. They remain on land until early summer, then gradually return to aquatic sites over the summer and autumn. Individuals in a local population in New York rarely dispersed more than 30 m from their overwintering site, but in other areas of the range they are often found far from aquatic sites and sometimes in relatively dry habitats (Petranka 1998). Red Salamanders are commonly seen crossing roads on rainy nights as they migrate to and from aquatic sites.

The adults have been found in burrows in soft sediments in streamside habitats, and beneath logs and other cover on the forest floor. They occasionally show up in pastures or other non-forested habitats. The juveniles and adults appear to be generalist, opportunistic feeders. They reside beneath cover during the day and are generally more active on the ground surface at night where they feed on invertebrates and take small amphibians, including Plethodon cinereus (Petranka 1998). Documented dietary items include a variety of insects, as well as earthworms, snails, slugs, spiders and millipedes.

General Ecology

Community Ecology: Red Salamander larvae often share aquatic habitats with Spring Salamander larvae. Gustafson (1993) conducted experiments in artificial streams to test for the impacts of intraguild predation among three species of larval plethodontid salamanders (Gyrinophilus porphyriticus, Pseudotriton ruber, and Eurycea cirrigera). Large G. porphyriticus and large P. ruber larvae significantly decreased the survival of small P. ruber larvae, presumably through direct predation and cannibalism. There was a trend toward reduced growth of Pseudotriton and Eurycea in the presence of these intraguild predators. The presence of large Gyrinophilus also significantly reduced the growth rate of large Pseudotriton, both in the absence and presence of intraguild prey. These results suggest that intraguild predation may be an important force shaping salamander communities in headwater streams. The extent to which these results apply to natural systems needs to be investigated further.

Adverse Environmental Impacts

Habitat Loss: Countless local populations of the Red Salamander have undoubtedly been lost historically due to urbanization, deforestation, and the conversion of lands to agricultural fields following European colonization. Mountaintop removal has severely impacted salamander communities in coal-mining areas of Appalachia since this often results in the complete or partial burial of low-order streams by valley filling. Price et al. (2015) noted that ~1900 km of headwater streams in Central Appalachia were likely destroyed by valley filling that was allowed via permits. In addition to breeding sites being outright destroyed by burial, downstream areas in these and other surface coal-mining operations are also degraded from siltation, acidification, and the leaching of toxic chemicals. Stream-breeding salamanders that inhabit impacted areas have been adversely affected, along with stream invertebrates that serve as their food resources (e.g., Hutton et al. 2020, Price et al. 2015, Schorr et al. 2013).

Habitat Fragmentation: Stream channelization, stream pollution, and excessive siltation have impacted many populations in fragmented landscapes with a matrix of urban areas, farmland, and bottomland forest remnants.

Status in North Carolina

NHP State Rank: S5

Global Rank: G5

Environmental Threats: In North Carolina, local populations of P. ruber and other stream-breeding salamanders in the lower valleys of the mountains and in many areas of the Piedmont have been eliminated or greatly reduced in numbers due to factors such as deforestation, urbanization, row-cropping, stream channelization and stream pollution and siltation. Surasinghe and Baldwin (2014) found that both current and historical land uses -- particularly timbering and row-crop agriculture -- have had lasting impacts on the local diversity of salamander species that occur in the Piedmont and Blue Ridge. In the Piedmont, lands that were intensely row-cropped many decades ago and have since become reforested still have low salamander diversity. Willson and Dorcas (2003) found that current land use is also affecting salamander abundance in Piedmont streams, and that the relative abundance of salamanders was strongly inversely proportional to the percentage of disturbed habitat in watersheds. They noted that the practice of establishing forested buffer zones along streams is not effective in conserving stream salamander populations in small riparian ecosystems that are embedded within landscapes with high human use.

Photo Gallery for Pseudotriton ruber - Red Salamander		15 photos are shown.
	Recorded by: Andrew W. Jones Surry Co.	Recorded by: Andrew W. Jones Surry Co.
	Recorded by: Andrew W. Jones Polk Co.	Recorded by: Andrew W. Jones Polk Co.
	Recorded by: tom ward Buncombe Co. Comment: Note the yellow eyes that are helpful in distinguishing this species from the Mud Salamander.	Recorded by: tom ward Buncombe Co. Comment: These were observed approximately 250 feet from the creek (and nearest breeding site) as determined using Buncombe property appraiser GIS. I have observed P. ruber at this spot 4 times with 2 being the same individual on separate nights. The other specimen was about 120 feet from the creek.
	Recorded by: tom ward Buncombe Co. Comment: These were observed approximately 250 feet from the creek (and nearest breeding site) as determined using Buncombe property appraiser GIS. I have observed P. ruber at this spot 4 times with 2 being the same individual on separate nights. The other specimen was about 120 feet from the creek.	Recorded by: B. Bockhahn Transylvania Co.
	Recorded by: A. Lasley, E. Fite Burke Co.	Recorded by: K. Bischof Burke Co.
	Recorded by: Steve Hall Hoke Co.	Recorded by: Owen McConnell & Jacob Perry Graham Co.
	Recorded by: Joe Mickey Wilkes Co.	Recorded by: Jim Petranka Buncombe Co.
	Recorded by: Steve Hall and Dawson Sather Orange Co. Comment: Older adults like this one are often much duller than the juveniles.

Pseudotriton ruber - Red Salamander

Photo Gallery for Pseudotriton ruber - Red Salamander

15 photos are shown.