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

amphibia Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbor ...

n native to

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. It is a

mole salamander The mole salamanders ( genus ''Ambystoma'') are a group of advanced salamanders endemic to North America. The group has become famous due to the presence of the axolotl (''A. mexicanum''), widely used in research due to its paedomorphosis, an ...

. Previously considered to be a subspecies of the

tiger salamander The tiger salamander (''Ambystoma tigrinum'') is a species of mole salamander and one of the largest terrestrial salamanders in North America. Description These salamanders usually grow to a length of with a lifespan of around 12–15 years. ...

(''A. tigrinum)'', the California tiger salamander was recently designated a separate species again. The California tiger salamander

distinct population segment {{no footnotes, date=February 2018 A distinct population segment (DPS) is the smallest division of a taxonomic species permitted to be protected under the U.S. Endangered Species Act. ''Species'', as defined in the Act for listing purposes, is a ...

(DPS) in

Sonoma County Sonoma County () is a county located in the U.S. state of California. As of the 2020 United States Census, its population was 488,863. Its county seat and largest city is Santa Rosa. It is to the north of Marin County and the south of Mendocino ...

and the

Santa Barbara County Santa Barbara County, California, officially the County of Santa Barbara, is located in Southern California. As of the 2020 census, the population was 448,229. The county seat is Santa Barbara, and the largest city is Santa Maria. Santa Barba ...

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 The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

and they may warrant status as separate species.

Description

The California tiger salamander is a relatively large, secretive amphibian

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

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 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

, especially in the

Laguna de Santa Rosa The Laguna de Santa Rosa is a wetland complex that drains a watershed encompassing most of the Santa Rosa Plain in Sonoma County, California, United States. The California Office of Environmental Health Hazard Assessment has issued a safe e ...

(outside the

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

), south to

, in vernal pool complexes and isolated ponds along the Central Valley from

Colusa County Colusa County () is a county located in the U.S. state of California. As of the 2020 census, the population was 21,839. The county seat is Colusa. It is in the North Valley of California, northwest of the state capital, Sacramento. History C ...

Kern County Kern County is a county located in the U.S. state of California. As of the 2020 census, the population was 909,235. Its county seat is Bakersfield. Kern County comprises the Bakersfield, California, Metropolitan statistical area. The county sp ...

, and in the coastal range. Both the Sonoma and Santa Barbara populations are listed as

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

since 2000 and 2003, respectively. On August 4, 2004, the

US Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...

listed the California tiger salamander as

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...

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 and predators, such as American bullfrogs and access to breeding habitats. There is also a hybrid between the California tiger salamander and the introduced

Barred Tiger Salamander The barred tiger salamander or western tiger salamander (''Ambystoma mavortium'') is a species of mole salamander that lives in lower western Canada, the western United States and northern Mexico. Description The barred tiger salamander typica ...

s (''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; these salamanders are poorly equipped for burrowing. Little is known about their underground life. This underground phase has often been referred to as

estivation Aestivation ( la, aestas (summer); also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and a ...

(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 Overwintering is the process by which some organisms pass through or wait out the winter season, or pass through that period of the year when "winter" conditions (cold or sub-zero temperatures, ice, snow, limited food supplies) make normal acti ...

". 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

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found ...

s. When their pond dries, they resorb their

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s, develop lungs, and then the

metamorph In mythology, folklore and speculative fiction, shape-shifting is the ability to physically transform oneself through an inherently superhuman ability, divine intervention, demonic manipulation, sorcery, spells or having inherited ...

s 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

Santa Rosa Plain Conservation Strategy

from the California Department of Fish and Game.

{{Taxonbar, from=Q2030667 Mole salamanders

Salamanders Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...