General Distribution
California giant salamander is known to occur on the Los Padres National Forest (Stephenson and
Calcarone 1999). Systematics
The genus Dicamptodon was previously considered to consist of a single species, but detailed
morphological and electrophoretic studies indicate that this group is polytypic (Good 1989). There is
evidence that coastal populations of Dicamptodon in the San Francisco Bay region are sufficiently
distinct to be recognized as a separate species (D. ensatus) from populations in the north (D. tenebrosus)
(Good 1989). No subspecies of D. ensatus are currently recognized (Petranka 1998). Habitat Requirements
California giant salamander is associated with semipermanent and permanent streams in mesic coastal
forests, particularly redwood forests (Petranka 1998, Stebbins 1951). Larvae are most abundant in
permanent, small- to medium-sized mountain streams. Adults can be found under rocks, logs, bark, and
other objects, usually in a damp location not far from a steam (Stebbins 1951). During the breeding
season, adults may be found under rocks in streams (Petranka 1998). Reproduction
Mating season and courtship behavior of this species is not currently known (Petranka 1998). Very few
nests have been discovered, but those that have been found were located in subterranean habitats in
flowing water. Eggs have been discovered in March and June (Stebbins 1951). This species appears to
have one of the longest incubation periods of all salamanders. Embryos in the early tail bud stage
require nearly 5 months to develop to the point where yolk supplies are nearly exhausted (Henry and
Twitty 1940). Dicamptodon larvae grow to approximately 4 inches (100 millimeters) within 1 year of
hatching; most metamorphose the following June–August when they reach 5–5.5 inches in length (130–
140 millimeters) (Petranka 1998). Daily/Seasonal Activity
Very little is known about the terrestrial ecology of California giant salamander (Petranka 1998).
Dicamptodon salamanders are nocturnal and sometimes diurnal (Stebbins 1951). Juveniles and adults
look for food on the forest floor on rainy nights and have been found as far as 39 feet (12 meters) from
nearby streams (Petranka 1998). Adult Dicamptodon salamanders have been observed in trees and
shrubs several feet above the ground, indicating that they are good climbers (Stebbins 1951). Diet and Foraging
Adult Dicamptodon salamanders feed on land snails and slugs, beetles, caddisfly larvae, moths, flies,
other amphibians, and small mammals such as shrews and white-footed mice. Larval salamanders eat a
variety of insects, including amphipods, sowbugs, caddisflies, beetles, wasps, flies, and moths (Stebbins
1951). Predator-Prey Relations
Shrews, birds, and other vertebrates are thought to prey on juvenile and adult California giant
salamanders (Petranka 1998). J.D. Anderson (1960) observed a larger California giant salamander
eating a smaller one and collected an adult that regurgitated a juvenile California giant salamander. On
two occasions, a Dicamptodon salamander has been observed with a 2-foot-long garter snake
(Thamnophis sp.) in its mouth (Stebbins 1951). Adult Dicamptodon salamanders are known to cannibalize smaller
salamanders and larvae (Anderson 1960, Zeiner and others 1988). Literature Cited
Anderson, J.D. 1960. Cannibalism in Dicamptodon ensatus. Herpetologica 16: 260.
Good, D.A. 1989. Hybridization and cryptic species in Dicamptodon (Caudata: Dicamptodontidae).
Evolution 43: 728–744.
Henry, W.V.; Twitty, V. C. 1940. Contributions to the life histories of Dicamptodon ensatus and
Ambystoma gracile. Copeia 1940: 247–250.
Nussbaum, R.A. 1976. Geographic variation and systematics of salamanders of the genus Dicamptodon
Strauch (Ambystomatidae). Miscellaneous Publications of the Museum of Zoology, University of
Michigan 149: 1–94.
Petranka, J. W. 1998. Salamanders of the United States and Canada. Washington, DC: Smithsonian
Institution and Press.
Stebbins, R.C. 1951. Amphibians of western North America. University of Berkeley, CA: California
Press.
Stephenson, J.R.; Calcarone, G.M. 1999. Southern California mountains and foothills assessment:
Habitat and species conservation issues. General Technical Report GTR-PSW-172. Albany, CA: Pacific
Southwest Research Station, Forest Service, U.S. Department of Agriculture.
Zeiner, D.C.; Laudenslayer, W.F., Jr.; Mayer, K.E., eds. 1988. California's Wildlife. Volume I:
Amphibians and reptiles. Sacramento, CA: California Statewide Wildlife Habitat Relationships System,
California Department of Fish and Game.
Information gathered from California DFG - California Interagency Wildlife Task Group
