access to breeding habitats. 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. Life cycle Adults spend the majority of their lives underground, in burrows created by other animals, such as ground squirrels 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 (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 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. See also Vernal pools or ponds References California Natural Diversity Database California Natural Diversity Database External links Santa Rosa Plain Conservation Strategy Santa Rosa Plain Conservation Strategy Description from the California Department of Fish and Game. USGS Field Guide Mole salamanders Salamanders Amphibians of the United States Fauna of the California chaparral and woodlands Natural history of the California Coast Ranges Natural history of the Central Valley (California) Taxa named by John Edward Gray Endangered fauna of California Amphibians described in 1853