The California tiger salamander (''Ambystoma californiense'') is a

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amphibian native to California. It is a mole salamander. Previously considered to be a subspecies of the tiger salamander (''A. tigrinum)'', the California tiger salamander was recently designated a separate species again. The California tiger salamander distinct population segment (DPS) in Sonoma County and the Santa Barbara County DPS are listed as federally endangered, while the Central California DPS is listed as federally threatened. The Sonoma County, south San Joaquin, and the Santa Barbara County DPS have diverged from the rest of the California tiger salamander populations for over one million years, since the Pleistocene and they may warrant status as separate species.

Description

The California tiger salamander is a relatively large, secretive amphibian endemic to California. Adults can grow to a total length of about 7–8 inches. It has a stocky body and a broad, rounded snout. Adults are black with yellow or cream spots; larvae are greenish-grey in color. The California tiger salamander has brown protruding eyes with black irises.

Habitat and range

The California tiger salamander depends on

vernal pools Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...

and other seasonal ponds and stock ponds for reproduction; its habitat is limited to the vicinity of large, fishless vernal pools or similar water bodies. It occurs at elevations up to 1000 m (3200 ft). Adults migrate at night from upland habitats to aquatic breeding sites beginning with the first major rainfall of fall and winter, and return to upland habitats after breeding. Historically, the California tiger salamander probably occurred in grassland habitats throughout much of the state. It occurs from Sonoma County, especially in the Laguna de Santa Rosa (outside the floodplain), south to Santa Barbara County, in vernal pool complexes and isolated ponds along the Central Valley from Colusa County to Kern County, and in the coastal range. Both the Sonoma and Santa Barbara populations are listed as endangered since 2000 and 2003, respectively. On August 4, 2004, the US Fish and Wildlife Service listed the California tiger salamander as threatened within the Central DPS. The six populations are found in Sonoma County, the Bay Area (Stanislaus County, western Merced County, and most of San Benito County), the Central Valley, the southern San Joaquin Valley, the Central Coast Range, and Santa Barbara County. The loss of California tiger salamander populations has been due primarily to the

loss of habitat Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

and predators, such as

American bullfrog The American bullfrog (''Lithobates catesbeianus''), often simply known as the bullfrog in Canada and the United States, is a large true frog native to eastern North America. It typically inhabits large permanent water bodies such as swamps, po ...

s and access to breeding habitats. There is also a hybrid between the California tiger salamander and the introduced Barred Tiger Salamanders (''Ambystoma tigrinum mavortium'') which has been hybridizing for 50–60 years.

Life cycle

Adults spend the majority of their lives underground, in burrows created by other animals, such as

ground squirrels Ground squirrels are members of the squirrel family of rodents (Sciuridae), which generally live on or in the ground, rather than trees. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known ...

and

gophers Pocket gophers, commonly referred to simply as gophers, are burrowing rodents of the family Geomyidae. The roughly 41 speciesSearch results for "Geomyidae" on thASM Mammal Diversity Database are all endemic to North and Central America. They are ...

; these salamanders are poorly equipped for burrowing. Little is known about their underground life. This underground phase has often been referred to as estivation (the summertime equivalent of hibernation), but true estivation has never been observed, and fiber optic cameras in burrows have allowed researchers to witness salamanders actively foraging. Adults are known to eat earthworms, snails, insects, fish, and even small mammals but adult California tiger salamanders eat very little.

Reproduction

California Tiger Salamander (CTS) (21065297770)

Breeding takes place after the first rains in late fall and early winter, when the wet season allows the salamanders to migrate to the nearest pond, a journey that may be as far as a 1.3 miles and take several days. The eggs, which the female lays in small clusters or singly, hatch after 10 to 14 days. The larval period lasts for three to six months. However, California tiger salamander larvae may also " overwinter". Transformation for overwintering larvae may take 13 months or more. Recent discoveries, such as overwintering, have management implications for this threatened species, particularly when aquatic habitats undergo modification. The larvae feed on other small invertebrates, including tadpoles. When their pond dries, they resorb their gills, develop lungs, and then the metamorphs leave the pond in search of a burrow. "... the average female bred 1.4 times and produced 8.5 young that survived to metamorphosis per reproductive event, resulting in roughly 12 lifetime metamorphic offspring per female." California tiger salamanders can live up to 15 years.

References

California Natural Diversity Database
California Natural Diversity Database

External links