[3] Taricha torosa was divided into two subspecies until 2007, when it was determined that the Sierra and coastal populations represent distinct evolutionary lineages.

[9] California newts are primarily nocturnal and find cover under rocks, logs, or leaf litter throughout the day.

During this wet season, they travel to ponds, streams, and slow-moving water bodies to breed, often returning to the same locations annually.

Shortly after breeding season, the California newt tends to revert back to more solitary behavior in both the aquatic and terrestrial phases of its life cycle.

[11] In addition to its bright coloration, the California newt has developed the ability to secrete a foamy substance when exposed to high temperatures.

The foam acts as a barrier as it forms a protective layer that helps the newt retain moisture and shield itself from burns during wildfire events.

Increases in newt toxicity then apply a selective pressure favoring snakes with mutations conferring even greater resistance.

This evolutionary arms race has resulted in the newts producing levels of toxin far in excess of what is needed to kill any other conceivable predator.

In this posture the California Newt stretches out flexes the dorsal side of their body shooting their head and tail into the air, and exposing their brightly colored underbelly.

[18][19] This variation of the unken reflex seems to be species-specific and differs from Taricha granulosa due to the tail remaining straight instead of curling.

Earthworms, snails, slugs, woodlice, bloodworms, mosquito larvae, crickets, and other invertebrates are among the California newt's prey.

Some populations have been greatly reduced in southern California coastal streams due to the introduction of non-native, invasive species and human habitation.

The mosquitofish (Gambusia affinis) and red swamp crayfish (Procambarus clarkii) have caused the greatest reduction in newt populations.

The crayfish will also disrupt newt breeding via competition for space during the summer mating season and physically antagonizing adults.