About Taricha rivularis (Twitty, 1935)
Taricha rivularis, commonly called the red-bellied newt, was first described by Twitty in 1935. When fully grown, this species measures 2.75 to 3.5 inches (70 to 89 mm) from snout to vent, and 5.5 to 7.5 inches (140 to 190 mm) from snout to the end of the tail. It has grainy skin, with a brownish-black dorsal side and a bright tomato-red underbelly. Males often have a broad dark color patch across the vent that females lack. Breeding males develop smooth skin and a flattened tail. This newt can be told apart from other coastal newts by its red belly and the absence of yellow in its eyes. The red-bellied newt is native to coastal California. Its main range extends along the coast from Bodega in Sonoma County, inland to Lower Lake, and north to Honeydew in Humboldt County. It inhabits coastal woodlands, particularly redwood forests. A separate disjunct population exists 130 kilometres (81 mi) south of Sonoma County in the upper Stevens Creek watershed in the Santa Cruz Mountains, and this population is genetically identical to the main Sonoma County population. Red-bellied newts start life as aquatic larvae, which resemble tadpoles but are more elongated and have external gills. After larvae mature into adult form, a process that takes around four to six months, they leave the water to live underground until they reach breeding age, which typically takes four to six years. Adults can live between 20 and 30 years. Once sexually mature, males begin gathering at stream banks as early as January or February. Females join the aggregation one to three weeks later to mate. Red-bellied newts lay their eggs in fast-flowing streams or rocky rivers. Females deposit eggs in roughly 12 streamlined clusters, each holding six to 16 eggs. Eggs are most often attached to the undersides of rocks, or to branches and roots that extend into the water. After breeding, adults leave the stream moving at an angle upstream rather than directly uphill. Unlike males, females do not breed every year.
