Ambystoma mavortium mavortium - Barred Tiger Salamander

Some adults are neotenic in permanent wetlands without fish. Terrestrial adults burrow into the soil using their forelimbs, or use mammal burrows.

During freezing conditions, terrestrial adults burrow below the frost line, while neotenic adults overwinter underwater.

Males tend to be slightly smaller than females. Captive neotenic adults live as long as 25 years while captive terrestrial adults have lived as long as 16 years.

Terrestrial adults assume a defensive pose when threatened, raising up on their hind legs, arching the tail and waving it, and releasing sticky noxious secretions from skin glands along the top of the tail.

Terrestrial adults feed on anything they can catch and overcome, mainly a variety of invertebrates, including insects and insect larvae and worms, along with some small vertebrates including lizards and mice and even small snakes.

Larvae feed on invertebrates including insects and insect larvae, mollusks, leeches, crayfish, tadpoles, small fishes, and salamander larvae.

Reproduction is aquatic. Fertilization is external with a male passing a spermatophore to a female. Breeding occurs in seasonal wetlands and permanent wetlands without fish, including lakes, slow streams, cattle tanks, quarry ponds, and flooded ditches.

Adults migrate from overwintering sites to wetlands used for breeding. Migration is usually triggered by warm spring rains a few weeks after ice melts in northern climates. In California, this would typically be in November or in the late winter and spring. Males migrate before females, sometimes several weeks before, and stay longer at the breeding site where they usually outnumber the females. Adults remain in the water for a short period - possibly up to a month.

An average of 38 - 59 eggs are laid. Depending on the subspecies, eggs are laid either singly, in clusters, or in strings, and are attached to submerged twigs and branches. Eggs of the barred subspecies hatch in 8 - 9 days.

Temperature, food supply, predation, and the persistence of water in the breeding wetlands all determine the length of the larval period, which is 10 weeks or more. Some larvae will overwinter and transform the next spring. Larvae feed on a wide range of invertebrates as well as tadpoles, small fish, and other salamander larvae. Prey size increases as larvae grow larger.

On rainy nights, newly-metamorphosed salamanders move overland from the breeding wetlands to upland sites which can be near the wetlands or some distance away.