CALIFORNIA TIGER SALAMANDER } Ambystoma californiense
Ambystoma is derived from either the Latin anabystoma, meaning “to cram into the mouth,” or from amblystoma, the Greek for “blunt mouth.”
DESCRIPTION: Large for a modern amphibian, the male California tiger salamander can reach up to 8.5 inches in length, the female up to seven. Adults have protruding eyes and long tails, and their slick bodies are mostly black with brilliant yellow spots and stripes on their back, sides, and tail. Larvae are greenish gray in color.
HABITAT: California tiger salamanders can be found in annual grasslands and oak woodlands with hot, dry summers and cool, rainy winters. For most of the year, they reside in underground burrows created and abandoned by small mammals. They need ephemeral pools for breeding.
RANGE: Historically these salamanders ranged throughout California’s Sacramento and San Joaquin River valleys, the surrounding foothills, and the lower elevations of the state’s central coast. Now their distribution is limited to disjunct vernal pool complexes in the northern part of their historical range. The northernmost and southernmost populations, residing in Sonoma and Santa Barbara counties respectively, are genetically distinct and geographically isolated from others.
MIGRATION: Once fall and winter rains begin, adult tiger salamanders emerge from underground hibernation habitat in mammal burrows and migrate to breeding ponds. After breeding, adults disperse back to uplands habitat to retreat underground. Adults may migrate long distances between summering and breeding sites: salamanders have been found along roads more than 1.2 miles from any known breeding ponds. Juvenile salamanders dispersing from ponds have been trapped more than 1,200 feet from their natal ponds.
BREEDING: Following early-winter rains, California tiger salamanders nocturnally emerge from their burrows and lay their eggs in newly formed vernal pools. After the eggs are fertilized internally, a female can lay up to 1,300, which she deposits individually or in small batches. Adults move back to their terrestrial burrows after breeding.
LIFE CYCLE: Within two weeks of egg fertilization, salamander larvae hatch, remaining in their natal pools for two to three months. By late spring or summer, once they reach metamorphosis, juveniles roam up to two miles away to hibernate in terrestrial habitat. Salamanders are thought to have lifespans of 10 years or more.
FEEDING: For the first six weeks of life, juveniles eat small crustaceans, algae, and mosquito larvae. Adult salamanders prey on aquatic insects, invertebrates, and tadpoles of Pacific tree frogs, California red-legged frogs, western toads, and spadefoot toads.
THREATS: The California tiger salamander is threatened by habitat destruction due to urban and agricultural development, habitat fragmentation, pesticides, hybridization with nonnative tiger salamanders, introduced diseases, and predation by nonnative species.
POPULATION TREND: Surveys showed that by 1993, the California tiger salamander had been extirpated from at least half of its historic localities. By 2004, only six tiger salamander meta-populations within 48 breeding ponds remained in Santa Barbara County, and by 2005, only seven viable tiger salamander breeding sites remained in Sonoma County.