Dicamptodon tenebrosus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Dicamptodon tenebrosus
Species Authority: (Baird and Girard, 1852)
Common Name(s):
English Pacific Giant Salamander
Amblystoma tenebrosum Baird and Girard, 1852

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2004
Date Assessed: 2004-04-30
Needs updating
Assessor(s): Geoffrey Hammerson
Reviewer(s): Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)
Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.

Geographic Range [top]

Range Description: This species occurs from Western North America from southern British Columbia (Chilliwack River drainage) south through western Washington and western Oregon to northwestern California (Good 1989; Farr, 1989 COSEWIC report; Petranka 1998).
Canada; United States
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Total adult population size is unknown but probably exceeds 10,000. Larvae are often abundant and are far more common than the adults.
Population Trend: Stable

Habitat and Ecology [top]

Habitat and Ecology: Larvae and paedomorphic adults usually inhabit clear, cool or cold, well-oxygenated streams and often take cover under stones (Parker 1991); aquatic stages also occur in some mountain lakes and ponds. Metamorphosed adults are found in humid forests under rocks and logs, etc., near mountain streams or rocky shores of mountain lakes (Stebbins 1985). Eggs are attached to logs or rocks in creeks (Nussbaum and Clothier 1973, Jones et al. 1990).
Systems: Terrestrial; Freshwater

Threats [top]

Major Threat(s): Logging and associated water temperature increases and siltation are a potential threat. Abundance is much greater in old growth and mature forests than in young forests (see Petranka 1998). However, overall, this species is not significantly threatened at present.

Conservation Actions [top]

Conservation Actions: Habitat protection is needed.

Bibliography [top]

Anderson, J.D. 1968. Dicamptodon , D. ensatus. Catalogue of American Amphibians and Reptiles: 1-2.

Behler, J.L. and King, F.W. 1979. The Audubon Society Field Guide to North American Reptiles and Amphibians. New York.

Blackburn, L., Nanjappa, P. and Lannoo, M.J. 2001. An Atlas of the Distribution of U.S. Amphibians. Ball State University, Muncie, IN, USA.

Collins, J.T. 1990. Standard common and current scientific names for North American amphibians and reptiles, 3rd edition. Society for the Study of Amphibians and Reptiles: Herpetological Circular: 1-41.

Daugherty, C.H., Allendorf, F.W., Dunlap, W.W. and Knudsen, K.L. 1983. Systematic implications of geographic patterns of genetic variation in the genus Dicamptodon. Copeia: 679-691.

Ferguson, H.M. 1998. Demography, dispersal and colonisation of larvae of Pacific giant salamanders (Dicamptodon tenebrosus) at the northern extent of their range. M.Sc. Thesis., University of British Columbia, Vancouver.

Ferguson, H.M. 2000. Larval colonisation and recruitment in the Pacific giant salamander (Dicamptodon tenebrosus) in British Columbia. Canadian Journal of Zoology: 1238-1242.

Good, D.A. 1989. Hybridization and cryptic species in Dicamptodon (Caudata: Dicamptodontidae). Evolution: 728-744.

IUCN. 2004. 2004 IUCN Red List of Threatened Species. Downloaded on 23 November 2004.

Johnston, B. 1998. Terrestrial Pacific giant salamanders (Dicamptodon tenebrosus): natural history and their response to forest practices. M.Sc. Thesis., University of British Columbia, Vancouver.

Jones, L.L.C., Bury, R.B. and Corn, P.S. 1990. Field observation of the development of a clutch of Pacific giant salamander (Dicamptodon tenebrosus) eggs. Northwestern Naturalist: 93-94.

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 Society, Seattle, Washington.

McComb, W.C., McGarigal, K. and Anthony, R.G. 1993. Small mammal and amphibian abundance in streamside and upslope habitats of mature Douglas-fir stands, western Oregon. Northwest Science: 7-15.

Nussbaum, R.A. 1969. Nests and eggs of the Pacific giant salamander, Dicamptodon ensatus (Escholtz). Herpetologica: 257-262.

Nussbaum, R.A. 1976. Geographic variation and systematics of salamanders of the genus Dicamptodon Strauch (Ambystomatidae). University of Michigan, Museum of Zoology, Miscellaneous Publication: 1-94.

Nussbaum, R.A. and Clothier, G.R. 1973. Population structure, growth, and size of larval Dicamptodon ensatus (Erscholtz). Northwest Science: 218-227.

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

Parker, M.S. 1991. Relationship between cover availability and larval Pacific giant salamander density. Journal of Herpetology: 355-357.

Parker, M.S. 1994. Feeding ecology of stream-dwelling Pacific giant salamander larvae (Dicamptodon tenebrosus). Copeia: 705-718.

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

Species at Risk Branch. 2002. Species at Risk Range Maps. Canadian Wildlife Service, Environment Canada. (, Ottawa.

Stebbins, R.C. 1985. A Field Guide to Western Reptiles and Amphibians. Second Edition. Houghton Mifflin Company, Boston, Massachusetts.

Welsh, H.H., Jr., Hodgson, G.R. and Lind, A.J. 2005. Ecogeography of the herpetofauna of a northern Californian watershed: linking species patterns to landscape processes. Ecography: 521-536.

Citation: Geoffrey Hammerson 2004. Dicamptodon tenebrosus. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 03 September 2015.
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