California tiger salamander (Ambystoma californiense)
|Synonyms:||Ambystoma tigrinum californiense|
|Size||Male length: 20 cm (2)|
Female length: 18 cm (2)
Classified as Vulnerable (VU) on the IUCN Red List (1).
Due to the low numbers of this species in the wild and its nocturnal habits, the California tiger salamander is a rarely seen amphibian (3). The aquatic larvae are yellowy-grey in colour and have feathery external gills and an elongated dorsal-caudal fin. Terrestrial adult salamanders are lustrous black with scattered white or yellow spots on the back and sides, and have pink-tipped toes (3). The head is depressed with a broad rounded snout, and it has small brown protruding eyes and a large tongue (4). As well as its slightly longer length, the male California tiger salamander can be distinguished by a swollen cloaca (3).
This salamander occurs in the San Joanquin-Sacromento river valleys, bordering foothills and coastal valleys of central California (3).
The California tiger salamander inhabits a region characterised by cool rainy winters and hot dry summers (3). It frequents oak savanna, grassland and the edges of mixed woodland, and requires shallow ponds for breeding in the winter (4).
In winter, adult California tiger salamanders congregate at suitable breeding sites, typically shallow ponds and pools that have formed during the heavy winter rains (3). A few days after arriving at the breeding pool, the adults spawn and leave the pond soon after (5). The eggs in the pond take two to four weeks to hatch, with the hatchlings initially feeding on zooplankton. Older larvae feed on tadpoles and aquatic invertebrates until undergoing metamorphosis as pond levels recede in late spring (6). Adult California tiger salamanders are presumed to feed predominantly on a wide variety of invertebrate and small vertebrate prey (7). It is thought that most individuals take four to five years to reach sexual maturity (8), and can live for over ten years (7).
Following metamorphosis the California tiger salamander is nocturnal, and prefers to spend most of its time underground. It aestivates (a form of summer hibernation) in the burrows of California ground squirrels (Spermophilus beecheyi) arising during rainy periods in November (5). Surprisingly, the California ground squirrel is a predator of adult salamanders, as is the striped skunk (Mephitis mephitis), while the California red-legged frog (Rana draytonii) and the garter snake (Thamnophis species) preys on California tiger salamander larvae (7).
The main threats to the California tiger salamander are habitat loss and fragmentation. Its habitat originally comprised seven million hectares of grasslands intermixed with grasses and open oak woodland (5). Today, it has been reduced to remnant grasslands with much of the land now being used for crops and grazing animals or has been fragmented by roads. Factors such as mosquito fishing, rodent poisoning and environmental pollution are also killing large numbers (9). Hybridisation with non-native tiger salamanders is also thought to be threatening the continuity of the species (9)
With the California tiger salamander’s range now reduced to less than 50 percent of its original historical extent, conservation action is necessary to ensure the future of this vulnerable species (1). While this species does occur in several protected areas, most populations are found on private land that is currently unprotected (1). Since 2005 this salamander has been protected by law in California (1).
To find out more about wildlife conservation in California see:
The Conservation Fund:
The Nature Conservancy:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Aestivates: becomes dormant during the summer or dry season, analogous to hibernation in winter.
- Caudal fin: the tail fin.
- Cloaca: a common cavity into which the reproductive, alimentary and urinary systems open.
- Dorsal: the dorsal fin is the unpaired fin found on the back of the body.
- Hybridisation: cross-breeding between two different species or subspecies.
- Invertebrates: animals with no backbone.
- Larvae: stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
- Metamorphosis: an abrupt physical change from the larval to the adult form.
- Nocturnal: active at night.
- Spawn: produce and deposit large quantities of eggs in water.
- Zooplankton: tiny aquatic animals that drift with currents or swim weakly in water.
IUCN Red List (March, 2010)
U.S. Fish and Wildlife Service. (2009) California Tiger Salamander Species Account. Sacramento Fish and Wildlife Office, U.S. Fish and Wildlife Service. Available at:
- Barry, S. and Shaffer, H. (1994) The status of the California tiger salamander (Ambystoma californiense) at Lagunita: A 50-year update. Journal of Herpetology, 28: 159-164.
- Bishop, S. (1967) Handbook of Salamanders. Cornell University Press, New York.
- Storer, T. (1925) A synopsis of the amphibia of California. University of California Publications of Zoology, 27: 1-342.
- Anderson, J. (1968) A comparison of food habits of Ambystoma macrodactlylum sigillatum. Herpetologica, 24: 273-284.
- Lanoo, M.J. (2005) Amphibian Declines: The Conservation Status of United States Species. University of California Press, Berkley and Los Angeles, California.
- Trenham, P.C., Shaffer, H.B., Koenig, W.D. and Stromberg, M.R. (2000) Life history and demographic variation in the California tiger salamander (Ambystoma californiense). Copeia, 2000(2): 365-377.
- Stebbins, R. and Cohen, N. (1997) A Natural History of Amphibians. Princeton Academic Press, New Jersey.