Dicamptodon ensatus

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

View Printer Friendly

Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AMPHIBIA	CAUDATA	AMBYSTOMATIDAE

Scientific Name:

Dicamptodon ensatus

Species Authority:

(Eschscholtz, 1833)

Common Name/s:

English

–

California Giant Salamander, Pacific Giant Salamander

Synonym/s:

Triton ensatus Eschscholtz, 1833

Assessment Information [top]

Red List Category & Criteria:	Near Threatened ver 3.1
Year Published:	2004
Assessor/s:	Geoffrey Hammerson, Bruce Bury
Reviewer/s:	Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)
Justification: Listed as Near Threatened because although the species might not to be in decline, its Extent of Occurrence is much less than 20,000 km2, thus making the species close to qualifying for Vulnerable.

Geographic Range [top]

Range Description:	This species can be found in west-central California, USA (Good 1989). It also occurs from Sonoma and Napa Counties south to Santa Cruz County and to Monterey County (Petranka 1998). It is found from 0-900m asl.
Countries:	Native: United States
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	The total adult population size is unknown but is likely to be at least several thousand. It is locally abundant (J.W. Petranka pers. comm.), but terrestrial adults are far less abundant than the aquatic larvae (Petranka 1998). No population data are available to determine trends in its population status (D.B. Wake pers. comm.).
Population Trend:	Unknown

Habitat and Ecology [top]

Habitat and Ecology:	Larvae of this species usually inhabit clear, cold streams, but are also found in mountain lakes and ponds. Adults are found in humid forests under rocks and logs, for example, near mountain streams or rocky shores of mountain lakes (Stebbins 1985b). Eggs are usually laid in the headwaters of mountain streams. Breeding typically occurs in water-filled nest chambers under logs and rocks or in rock crevices.
Systems:	Terrestrial; Freshwater

Habitat and Ecology:

Larvae of this species usually inhabit clear, cold streams, but are also found in mountain lakes and ponds. Adults are found in humid forests under rocks and logs, for example, near mountain streams or rocky shores of mountain lakes (Stebbins 1985b). Eggs are usually laid in the headwaters of mountain streams. Breeding typically occurs in water-filled nest chambers under logs and rocks or in rock crevices.

Systems:

Terrestrial; Freshwater

Threats [top]

Major Threat(s):	The greatest threats to this species are stream siltation and urban development (Petranka 1998; D.B. Wake pers. comm.), and it is also threatened by habitat fragmentation due to land use changes, including urbanization, agricultural development, and logging (H.H. Welsh pers. comm.). In the related Pacific giant salamander (D. tenebrosus), larvae may be reduced in numbers where there has been clear-cut logging (Corn and Bury 1989) or siltation from roads (Welsh and Ollivier 1998). However, opening of forest canopies over streams might lead temporarily to higher primary productivity that in turn increases the body sizes of larval D. tenebrosus (Murphy and Hall 1981).

Major Threat(s):

The greatest threats to this species are stream siltation and urban development (Petranka 1998; D.B. Wake pers. comm.), and it is also threatened by habitat fragmentation due to land use changes, including urbanization, agricultural development, and logging (H.H. Welsh pers. comm.). In the related Pacific giant salamander (D. tenebrosus), larvae may be reduced in numbers where there has been clear-cut logging (Corn and Bury 1989) or siltation from roads (Welsh and Ollivier 1998). However, opening of forest canopies over streams might lead temporarily to higher primary productivity that in turn increases the body sizes of larval D. tenebrosus (Murphy and Hall 1981).

Conservation Actions [top]

Conservation Actions:	Dicamptodon ensatus occurs in numerous protected areas, and is therefore probably only moderately threatened, even though its range is small and close to urban areas.

Conservation Actions:

Dicamptodon ensatus occurs in numerous protected areas, and is therefore probably only moderately threatened, even though its range is small and close to urban areas.

Citation:	Geoffrey Hammerson, Bruce Bury 2004. Dicamptodon ensatus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 25 May 2012.
Disclaimer:	To make use of this information, please check the <Terms of Use>.
Feedback:	If you see any errors or have any questions or suggestions on what is shown on this page, please fill in the feedback form so that we can correct or extend the information provided