Description
A small terrestrial salamander. Stocky with relatively long legs, adults range in size from 4.5 to 5.8 cm snout to vent length (9.5-10.5 cm total length). Modal number of costal grooves is 14. Males are slightly smaller than females and have a mental gland, a raised area on the chin used in courthip. There are indistinct paratoid glands on the back of the head, and the feet are broad and slightly webbed (Brodie and Storm 1970; Petranka 1998). Hatchlings are 15-18 mm snout to vent length (Nussbaum et al. 1983). Three color morphs occur and populations often have 2 or, rarely, all 3. The dark phase is dark brown to black dorsally with a yellow, orange, green, or red stripe that extends to the tip of the tail. The venter is dark and the throat is yellow. The yellow morph has a tan or yellowish ground color dorsally and ventrally, and the rose morph is similar with a pinkish to salmon coloration over the body (Brodie 1970; Nussbaum et al. 1983).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: Washington

View distribution map in BerkeleyMapper.

This species has a patchy distribution in western Washington with populations in the Willapa Hills, the Olympic peninsula and Mt. St. Helens/Mt. Rainier in the Cascade range. Preferred habitats are conifer forests with average annual rainfall >150 cm. The most aquatic species of Plethodon, animals are frequently found in seepages and splash zones of waterfalls and in rocky areas along streams (Brodie 1970). Populations may also be associated with talus, and away from streams individuals can be found under an assortment of cover objects (Nussbaum et al. 1983; Petranka 1998).

Life History, Abundance, Activity, and Special Behaviors
Like other members of the genus Plethodon, P. vandykei 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 behavior has not been described in detail for this species, but is probably similar to the closely related species P. idahoensis. Fertilization occurs by means of a spermatophore deposited on the substrate by the male and picked up in the cloaca by the female (Lynch and Wallace 1987). Courtship occurs in spring and perhaps fall. Oviposition takes place in the spring. Females attend the eggs until hatching in the fall (Nussbaum et al. 1983; Jones 1989). Clutch size ranges from 7-14 (Stebbins 1951; Jones 1989). Eggs are cream-colored and measure about 4-5 mm in diameter (Blessing et al. 1999). Each clutch is suspended by one or two gelatinous threads attached to the walls of the cavity (Blessing et al. 1999).

Only six nests of Van Dyke's salamanders have been discovered. The first was described as a "grape-like cluster" attached by a common pedicel to a moss-covered stone in a damp location (Noble 1925) and the second was located inside a partially rotted log (85 cm in diameter and 5 m in length) in an old-growth forest on a north-northeast facing slope, near a small headwater stream (Jones 1989). Four additional nests were found in logs near undisturbed or protected streams during the summer of 1997, in the Olympic Peninsula (Blessing et al. 1999). Three of those four nests were located in old-growth forest (western hemlock and Pacific silver fir), while one was located inside a buffer of old trees in a clear-cut area. The four clutches were all found in cavities in sapwood, 6.5-7.0 cm below the surface of large decaying moss-covered conifer logs, and were each attended by an adult salamander (likely female). Clutches were left in the logs and took 144 days of observation to hatch, a much longer period than reported for other species of Plethodon (generally about 45-90 days, according to Petranka 1998).

Not much is known about the natural history of this species. Adults are most active in the spring and fall months, but individuals are not commonly encountered (Petranka 1998).

Trends and Threats
Patchy distribution and apparently low population densities suggest that this species should receive conservation attention. Populations are at risk from logging and intense management of forests (Welsh 1990; Petranka 1998). This species has limited ability to survive in disturbed habitat (Hammerson 2004). It occurs in two protected areas, Mt. St. Helens National Monument and Olympic National Park (Hammerson 2004).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Subtle changes to necessary specialized habitat

Comments
Plethodon idahoensis was formerly included within P. vandykei, sometimes treated as a subspecies, but mitochondrial data reveal deep divergence between the two (Carstens et al. 2004). Genetic work throughout the range of these forms has supported suggestions that populations in the Rocky Mountains be regarded as a separate species from populations in western Washington (Highton and Larson 1979; Collins 1991; Howard et al. 1993).

References

Blessing, B.J., Phenix, E.P., Jones, L. and Raphael, M.G. (1999). ''Nests of the Van Dyke's salamander (Plethodon vandykei) from the Olympic Peninsula, Washington.'' Northwestern Naturalist, 80, 77-81.

Brodie, E. D., Jr. (1970). "Western salamanders of the genus Plethodon: Systematics and geographic variation." Herpetologica, 26(4), 468-516.

Brodie, E. D., Jr., and Storm, R. M. (1970). ''Plethodon vandykei Van Denburgh. Van Dyke's Salamander.'' Catalogue of American Amphibians and Reptiles. American Society of Ichthyologists and Herpetologists, 91.1-91.2.

Carstens, B. C., Stevenson, A. L., Degenhardt, J. D., and Sullivan, J. (2004). ''Testing nested phylogenetic and phylogeographic hypotheses in the Plethodon vandykei species group.'' Systematic Biology, 53, 781-792.

Collins, J. T. (1991). "A new taxonomic arrangement for some North American amphibians and reptiles." Herpetological Review, 22, 42-43.

Hammerson, G. 2004. Plethodon vandykei. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. www.iucnredlist.org. Downloaded on 13 March 2011.

Highton, R., and Larson, A. (1979). "The genetic relationships of the salamanders of the genus Plethodon." Systematic Zoology, 28, 579-599.

Howard, J. H., Seeb, L. W., and R. L. Wallace (1993). "Genetic variation and population divergence in the Plethodon vandykei group (Caudata: Plethodondidae)." Herpetologica, 49, 238-247.

Jones, L. L. C. (1989). ''Plethodon vandykei (Van Dyke's Salamander). Reproduction.'' Herpetological Review, 20, 48.

Lynch, J. E., Jr., and Wallace, R. L. (1987). ''Field observations of courtship behavior in Rocky Mountain populations of Van Dyke's Salamander, Plethodon vandykei, with a description of its spermatophore.'' Journal of Herpetology, 21, 337-340.

McIntyre, A. P., Schmitz, R.A., and Crisafulli, C.M. (2006). ''Associations of the Van Dyke’s Salamander (Plethodon vandykei) with geomorphic conditions in Headwall Seeps of the Cascade Range, Washington State.'' Journal of Herpetology, 40, 309-322.

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.

Welch, H. H., Jr. (1990). "Relictual amphibians and old-growth forests." Conservation Biology, 4, 309-319.

Species Account Citation: AmphibiaWeb 2011 Plethodon vandykei: Van Dyke's Salamander <https://amphibiaweb.org/species/4156> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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