Pacific giant salamander (Dicamptodon tenebrosus )

Close up of a Pacific giant salamander on the ground
A Pacific giant salamander at Mt. Rainier National Park  (National Park Service - Mt. Rainier National Park)
Category: Amphibians
Family: Dicamptodontidae - Giant salamanders
Common names: Coastal giant salamander
Ecosystems: Riparian areas
If you see this species, please share your observation using the WDFW wildlife reporting form. Providing detailed information such as a photo and exact coordinates will improve the confidence and value of this observation to WDFW species conservation and management.

This salamander is common and occurs throughout western Washington. Main concerns for this species are land uses that contribute to stream sedimentation or elevated stream temperatures.

According to NatureServe, the state conservation status of the Pacific giant salamander population is considered “secure” in Washington. 

Description and Range

Physical description

The Pacific giant salamander is a large, stocky, marbled gold and brown salamander with a rounded snout, indistinct costal grooves, and a laterally compressed tail. The largest terrestrial salamander in North America; adults reach lengths of 6.7 inches snout-vent length and 13.4 inches total length. The marbling becomes less distinct as the salamander ages and may only be present on the head of very old individuals. The ventral surface (underside) is usually white to light gray (may also be dark in some individuals) without other markings or pattern. Twelve to thirteen costal grooves are present but indistinct.

Terrestrial forms

Metamorphosed (transformed) giant salamanders are easily distinguished from all other Washington salamanders by the marbled pattern on head and dorsal surfaces. Transformed Cope’s giant salamanders are rare; almost all individuals found are larval salamanders. The traits that distinguish the two species are subtle. The Pacific giant salamander is larger, has a wider head and longer legs. The first two traits require experience working with giant salamanders to learn how to discern these differences. To determine relative leg length, the forelegs are gently pressed backward against the body and the hind legs forward against the body (adpressed legs). The toes will touch or cross in the Pacific giant salamander but will not with a Cope’s giant salamander.

Larvae 

The larvae are stream-type with short gills and a low tail fin that ends on the body near the hind limbs. The short gills and low tail fin distinguish stream-type salamanders from pond-type.

The tips of the digits are black and hard (cornified). Small larvae (less than 2.2 inches snout to vent length) are light brown above and white below. Subtle tan to yellowish streaks of pigmentation is present on the dorsal and lateral surfaces in indistinct streaks. The tail is mottled with darker pigmentation and there is usually a dark blotch at the tip of the tail. Larger larvae (greater than 2.2 inches snout to vent length) are more mottled, have dark ventral surfaces and the mottling and spot on the tail are less conspicuous or may be absent.

Of the stream-type larvae, the torrent salamanders (Rhyacotriton species) can be easily distinguished by their orange ventral coloration and tiny gills that are barely visible when the salamander is out of water.

Differentiating Cope’s giant salamander larvae from Pacific giant salamander larvae is challenging, especially for smaller larvae (less than 2 inches snout to vent length). Range differences can be used;. only the Pacific giant salamander has been documented north of the Nisqually River in Pierce, King, Snohomish, Skagit and Whatcom counties.

For larvae 2 inches snout to vent length or greater, the following traits can be used to determine species. The head of Cope’s giant salamander is similar in width at the base and snout and the head width is less than 1/5 the snout to vent length. Toes do not touch or overlap when legs are adpressed against the body. The tan to yellowish pigmentation on the dorsal surface of the body is clustered into spots and blotches. Whereas the Pacific giant salamander has tan to yellowish pigmentation present in indistinct streaks as if someone painted it on the surface with a dry brush.

Eggs 

The eggs are laid under rocks or logs and are guarded by the females. The eggs are white without pigmentation, laid singly and attached to the nest wall by short pedicels (anchoring structures).For more details, see the Washington Herp Atlas.

Check out this short video of a Pacific giant salamander located in the Crabtree Valley in Oregon from Oregon Wild. 

Ecology and life history

Pacific giant salamanders are primarily associated with small to medium-sized mountain streams in moist coniferous forests. They may also enter larger flowing water bodies and still water habitats connected to the streams they inhabit. Breeding sites are limited to smaller flowing water bodies. Pacific giant salamanders are often the dominant vertebrate within streams. Most occurrences are found below 3,150 feet elevation but populations have been observed at higher elevations.

Metamorphosed forms spend most of their lives in the subterranean environment and are rarely seen. Most surface activity takes place at night, although diurnal activity is also reported. Larval forms are the life stage most likely to be observed.

Larvae can be observed year-round in flowing water bodies and may also be present in higher elevation ponds and lakes connected to flowing water bodies. Breeding takes place in the spring and fall.

Larvae and gilled adults can be observed day or night in streams. During the day, they are typically concealed under rocks or woody debris; at night, they are less likely to be sheltered and more likely to move about in streams.

The female lays her eggs in the spring and then guards the eggs until they hatch about 200 days later. The larval period is 18 to 24 months or may be permanent (gilled adults) depending on local conditions. Sexual maturity takes place in all forms that are around 4.5 inches snout-vent length.

When this salamander perceives a threat, their defensive behaviors include an audible growl, tail waving, emitting of noxious and toxic skin secretions, and biting.

Geographic range

In Washington, Pacific giant salamanders occur primarily west of the Cascade Crest in the Pacific Coast, Puget Trough and West Cascades ecoregions. They also occur east of the Cascade Crest in some areas of the East Cascades Ecoregion. They do not occur north of the Chehalis River on the Olympic Peninsula.

This map from the Washington Herp Atlas illustrates the known distribution of the long-toed salamander in Washington as of 2016. 

Pacific giant salamander distribution map of Washington: detections in 12 westside and 3 eastside counties as of 2016.
Washington Herp Atlas (2017)

For a map of range-wide distribution and conservation status of this species, check out NatureServe Explorer and the International Union for Conservation of Nature.

Regulations

Licenses and permits

Be advised that collection of this species is only permitted under a WDFW Scientific Collection Permit for research and educational activities.

Conservation

The state conservation status of the Pacific giant salamander is “secure” based on the assumption that it is common according to the most current records.

Activities that alter the integrity of small and medium-sized forested streams are of concern especially those actions that increase water temperature and sedimentation. Forestry practices that do not protect streams from sedimentation may be particularly problematic for salamander populations that occur in low-gradient streams where increased silt deposition may eliminate microhabitats crucial for the survival of the species. This happens when silt fills spaces between rocks and logs that would otherwise be used as sheltering, hiding, and nesting sites. Protecting riparian buffers around streams is important at sites occupied by these salamanders.

Resources

References

Bury, R.B. and P.S. Corn. 1988. Responses of aquatic and streamside amphibians to timber harvest: a review. In: Streamside management: riparian wildlife and forestry interactions. K.J. Raedeke, ed. Institute of Forestry Resources, University of Washington, Seattle, Washington, Contribution 59:165-181.

Corn PS, and R. B. Bury. 1989. Logging in western Oregon: responses of headwater habitats and stream amphibians. Forest Ecology and Management 29:39–57.

Leonard, W. P., H. A. Brown, L. L. C. Jones, K. R. McAllister and R. M. Storm. 1993. Amphibians of Washington and Oregon. Seattle Audubon Society The Trailside Series, Seattle, Washington. 169 pp.

Nussbaum, R. A., E. D. Brodie, Jr., and R.M. Storm. 1983. Amphibians and Reptiles of the Pacific Northwest. University of Idaho Press, Moscow, Idaho. 332 pp.

Petranka, J. W. 1998. Salamanders of the United States and Canada. Smithsonian Institution Press, Washington, D.C. 587 pp.

Personal communications

Aimee Macintyre, Washington Department of Fish and Wildlife, Olympia, Washington.

Larry Jones, Wildlife, Fish, and Rare Plants, Coronado National Forest, Tucson, Arizona.

WDFW publications

Hallock, L. A. and K. R. McAllister. 2009. Pacific Giant Salamander. Washington Herp Atlas. 2009. A cooperative effort of Washington Natural Heritage Program, Washington Department of Fish and Wildlife, U.S.D.I. Bureau of Land Management, and U.S. Forest Service. Map products updated March 2017. Provisional PDF version of the website (2005-2019) created July 2019. 250 pp.

WDFW educational resources

Other resources