Description
Plethodon elongatus is a medium-sized terrestrial salamander. Compared to other species of Plethodon in the Pacific Northwest they are long and slender, with a modal number of 18 costal grooves (Brodie and Storm 1971; Petranka 1998). Adults are 6 - 7.5 cm snout to vent length (11 - 15 cm total length) (Stebbins 1985; Petranka 1998). The limbs are relatively short and the toes are short and slightly webbed (Brodie and Storm 1971; Stebbins 1985). Dorsal coloration is dark brown or black, with a reddish or reddish-brown straight-edged mid-dorsal stripe. The stripe may extend from head to tip of tail, but may be less pronounced in older animals. The venter is dark gray, with throat light gray and mottled (Petranka 1998). White or yellow flecks are concentrated on the sides, dorsal surface of the limbs, and gular (throat) region. These flecks are sparser on the head and venter, and rarely on the dorsal surface (Brodie and Storm 1971). Males are slightly larger than females and have a mental gland, a raised region on the chin used in courtship (Petranka 1998). With age, the jaw closing muscles become more pronounced and the region behind the eyes has a distinct bulge (D. B. Wake, pers. comm.). Hatchlings are about 18 mm snout to vent length and they have a more distinct dorsal stripe than adults (Brodie and Storm 1971; Petranka 1998).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: California, Oregon

View distribution map in BerkeleyMapper.

This species is limited to moist coastal forests in northwestern California and southwestern Oregon (Brodie and Storm 1971; Petranka 1998). Individuals are usually found in damp areas of stabilized talus slopes, especially on north-facing slopes; may also be found under logs, bark, or other forest floor refugia (Brodie and Storm 1971; Diller and Wallace 1994). Occurance of salamanders is significantly correlated with older forests with closed, multi-storied canopy and the presence of rocky substrates dominated by cobble-sized pieces (Welsh and Lind 1995). The absence of a range overlap with the ecologicaly similar P. vehiculum suggests that interactions between the two species may affect their respective distributions (Stebbins 1951).

Life History, Abundance, Activity, and Special Behaviors
Like other members of the genus Plethodon, P. elongatus is completely terrestrial through all stages of its life history; courtship, mating, and egg deposition occur on land. There is no free living larval stage, and juveniles hatch completely metamorphosed (Stebbins 1985; Petranka 1998). Courtship has never been observed, although mating probably occurs in fall and winter (Welsh and Lind 1992; Petranka 1998). Fertilization occurs by means of a spermatophore deposited on the substrate by the male and picked up in the cloaca by the female (Duellman and Trueb 1986). Females lay eggs in spring or early summer, and attend the eggs until hatching in the late summer or early fall (Leonard et al. 1993; Jockusch and Mahoney 1997; Petranka 1998). Clutch size, ranges from 3 - 11, average 8 (Stebbins 1951; Nussbaum et al. 1983; Welsh and Lind 1992).

The diet consists of small invertebrates including isopods, mites, spiders, hemipterans, beetles, hymenopterans, lepidopterans, and centipedes. Predators have not been documented, but probably include small snakes and mammals, and woodland birds (Petranka 1998). When uncovered or attacked individuals of P. elongatus remain immobile (Brodie 1977).

Trends and Threats
In sufficiently wet areas, populations of P. elongatus do not appear to be negatively affected by logging (Diller and Wallace 1992). In these regions Del Norte salamanders inhabit various successional stages. However, in areas with less fog and annual precipitation, salamander numbers decline sharply following logging (Welsh and Lind 1988; 1991). Old growth forests may represent an optimal habitat (Welsh and Lind 1995). Due to continuing logging activities, populations of P. elongatus are becoming increasingly fragmented and isolated (Welsh and Lind 1992).

Comments
Some authors recognize the Siskiyou Mountains salamander, P. stormi, as a subspecies of the Del Norte salamander (e.g. Stebbins 1985). Currently these are recognized as two separate species (e.g. Petranka 1998), but a detailed examination of geographic variation in morphology and genetics for both species is necessary to resolve this issue.

See another account at californiaherps.com.

References

Brodie, E. D., Jr. (1977). "Salamander antipredator postures." Copeia, 1977, 523-535.

Brodie, E. D., Jr., and Storm, R. M. (1971). ''Plethodon elongatus Van Denburgh. Del Norte Salamander.'' Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles, 102.1-102.2.

Diller, L. V., and Wallace, R. L. (1994). ''Distribution and habitat of Plethodon elongatus on managed, young growth forests in Northern Coastal California.'' Journal of Herpetology, 28(3), 310-318.

Duellman, W. E., and Trueb, L. (1986). Biology of Amphibians. McGraw-Hill, New York.

Jockusch, E. L., and Mahoney, M. J. (1997). ''Communal oviposition and lack of parental care in Batrachoseps nigriventris (Caudata: Plethodontidae) with a discussion of the evolution of breeding behavior in plethodontid salamanders.'' Copeia, 1997, 1966-1982.

Leonard, W.P., Brown, H.A., Jones, L.L.C., McAllister, K.R., and Storm, R.M. (1993). Amphibians of Washington and Oregon. Seattle Audubon, Seattle.

Nussbaum, R. A., Brodie, E. D., Jr., and Storm, R. M. (1983). Amphibians and Reptiles of the Pacific Northwest. University of Idaho Press, Moscow, Idaho.

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

Stebbins, R. C. (1985). A Field Guide to Western Reptiles and Amphibians. Houghton Mifflin, Boston.

Stebbins, R.C. (1951). Amphibians of Western North America. University of California Press, Berkeley.

Welsh, H. H., Jr. and Lind, A. J. (1988). ''Old growth forests and the distribution of the terrestrial herpetofauna.'' Management of amphibians, reptiles, and mammals in North America, General Technical Report RM-166. R. C. Szaro, K. E. Severson, and D. R. Patton, eds., USDA Forest Service, Rocky Mountain Forest and Range Experimental Station, Fort Collins, Colorado, 439-455.

Welsh, H. H., Jr. and Lind, A. J. (1991). ''The structure of the herpetofaunal assemblage in the Douglas-fir/hardwood forests of northwestern California and southwestern Oregon.'' Wildlife and Vegetation of Unmanaged Douglas-fir Forests, USDA Forest Service, General Technical Report PNW-GTR-285. L. F. Ruggiero, K. B. Aubry, A. B. Carey, and M. H. Huff, eds., USDA Forest Service, 394-413.

Welsh, H. H., Jr., and Lind, A. J. (1992). ''Population ecology of two relictual salamanders from the Klamath Mountains of northwestern California.'' Wildlife 2001: Populations. McCullough, D.R., and R.H. Barrett, eds., Elsevier Applied Science, New York., 419-437.

Welsh, H.H., Jr., and Lind, A. J. (1995). ''Habitat correlates of the Del Norte Salamander (Plethodon elongatus) (Caudata: Plethodontidae), in northwestern California.'' Journal of Herpetology, 29(2), 198-210.

Species Account Citation: AmphibiaWeb 2021 Plethodon elongatus: Del Norte Salamander <https://amphibiaweb.org/species/4130> University of California, Berkeley, CA, USA. Accessed Dec 25, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 25 Dec 2024.

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