Habitat loss is a big problem for Ambystoma californiense. Urban development and agriculture is eliminating its natural habitat. It is preyed upon by introduced species of fish and bullfrogs (Loredo et al. 1996). Ambystoma californiense has toxic skin secretions (Loredo et al. 1996), probably as a defense mechanism against the rodents it shares burrows with. The ground squirrel populations are controlled throughout much of California (Petranka 1998). This is another way in which Ambystoma californiense individuals are losing thier homes. Due to this, the ways in which ground squirrels are controlled and where they are controlled should be taken into consideration.
Special Concern species in California (Holland et al. 1990)
Category I species on Federal Endangered Species List (Loredo et al. 1996)
IUCN Red List of Threatened Species: vulnerable
Development - Life Cycle: metamorphosis
Ambystoma californiense larvae eat aquatic invertebrates (Petranka 1998, Barry and Shaffer 1994). Adults are known to eat earthworms. They feed with a three part gape cycle, tongue extension cycle, and anterior head body movement common to ambystomatids (Beneski et al. 1995).
Ambystoma californiense is isolated from Ambystoma tigrinum, with which it was once considered conspecific. It is endemic to California, and are found in the Central Valley and adjacent foothills and coastal grassland (Petranka 1998, Loredo et al. 1996).
Biogeographic Regions: nearctic (Native )
Ambystoma californiense likes a Mediterranean climate of cool wet winters and hot dry summers. They inhabit annual grasslands and open woodlands of foothills and valleys. Ground squirrel burrows are necessary for the survival af A. californiense (Petranka 1998, Loredo et al 1996).
Terrestrial Biomes: savanna or grassland ; chaparral
male SVL 80-108 mm
female SVL 79-118 mm
Ambystoma californiense has broad rounded snouts with small eyes. It is a lustrous black and marked with rounded or irregular yellow spots. Bellies are a grayish color and may contain a few small dull yellow spots. These salamanders have 12 costal grooves on their sides (Petranka 1998).
Other Physical Features: ectothermic ; bilateral symmetry
Ambystoma californiense breeds from late winter into early spring in large temporary ponds. They are explosive breeders, meaning they emerge, breed quickly, and then return to their burrows. They may breed two or three times a year this way. Juveniles migrate from these ponds to underground burrows in the spring during the rains. They are especially vulnerable to dehydration and heat stress during their overland movement (Petranka 1998, Loredo et al. 1996, Holland et al. 1990). They are rarely seen, due to nocturnal breeding migrations, and living in burrows underground (Loredo et al. 1996). Females attach one egg at a time to twigs, grass stems, vegetation, or detrious. These eggs are covered by a vitelline membrane and three jelly coats. They are distinguished by a pale yellow brown coloring and are about 2 mm in diameter (Petranka 1998). Eggs hatch 2-4 weeks after deposition (Petranka 1998, Barry and Shaffer 1994). Larvae coloring is yellowish gray. They are similiar to adults, except for large dorsal fins extending onto the back, and large feathery gills (Petranka 1998).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate)
The California tiger salamander (Ambystoma californiense) is a vulnerable 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.[4] 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.[5][6] 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[7] and they may warrant status as separate species.
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.
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 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.[7][8][9]
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.[10][11] There is also a viable hybrid between the California tiger salamander and the introduced barred tiger salamander (Ambystoma tigrinum mavortium), which genetic evidence suggests have been hybridizing for 50–60 years.[12]
Adults spend the majority of their lives underground, in burrows created by other animals, such as ground squirrels and gophers;[13][14] 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,[15] snails, insects, fish, and even small mammals[16][17] but adult California tiger salamanders eat very little.[18]
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[19] 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."[20]
California tiger salamanders can live up to 15 years.
_(21065297770).jpg)
{{cite journal}}: Cite journal requires |journal= (help) The California tiger salamander (Ambystoma californiense) is a vulnerable 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.
