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A Guide to the Amphibians
and Reptiles of California


Red-bellied Newt - Taricha rivularis

(Twitty, 1935)
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Red-bellied Newt Range Map
Range in California: Red

Dot-locality Range Map


Identifying Species of
Pacific Newts - genus Taricha




observation link





Red-bellied Newt Red-bellied Newt Red-bellied Newt
Aquatic phase adult, Mendocino County Aquatic phase adult, Mendocino County Aquatic phase adult, Mendocino County
Red-bellied Newt Red-bellied Newt Red-bellied Newt
Aquatic phase adult, Mendocino County Aquatic phase adult, Mendocino County Aquatic phase adult, Mendocino County
Red-bellied Newt Red-bellied Newt Red-bellied Newt
Aquatic phase adult, Mendocino County Aquatic phase adult, Mendocino County Terrestrial phase adult,
Mendocino County
Red-bellied Newt Red-bellied Newt Red-bellied Newt
Breeding adult male, Mendocino County Breeding adult male, Mendocino County Breeding adult male, Mendocino County
Red-bellied Newt Red-bellied Newt Red-bellied Newt
Adult underwater, Mendocino County Aquatic phase adult, Mendocino County Aquatic phase adult, Mendocino County
Red-bellied Newt Red-bellied Newt  
Adult, Mendocino County Underside of breeding adult male, Mendocino County  
Red-bellied Newt Red-bellied Newt  
Adult, Santa Clara County
© James Maughn
Juvenile, Santa Clara County
© James Maughn
 
Red-bellied Newt
Left: California Newt - Taricha torosa, Santa Clara County
Right: Red-bellied Newt - Taricha rivularis, Santa Clara County
© James Maughn
     
Breeding, Eggs, and Larvae
Red-bellied Newt Red-bellied Newt Red-bellied Newts
Breeding adult male in aquatic phase, Mendocino County Mass of breeding adults underwater, Mendocino County © Jessica Miller 
Red-bellied Newts Red-bellied Newts Red-bellied Newt
Red-bellied Newt Red-bellied Newts Red-bellied Newt
Aquatic male newts patrolling the shallow waters of a Mendocino County breeding creek before the females arrive.
Red-bellied Newts Red-bellied Newts Red-bellied Newts
Adults amplexing in shallow water Adults amplexing underwater in situ adults as found hiding under a log, Sonoma County. © Kate Britsch
Red-bellied Newt toes Red-bellied Newt Red-bellied Newt eggs
During the breeding season, adult males develop nuptial pads on the toes to improve their ability to hold onto females during amplexus. Adult newt and single egg,
Mendocino County © Jessica Miller 
Eggs, Mendocino County © Jessica Miller 
Red-bellied Newt eggs Red-bellied Newt eggs Red-bellied Newt larva
Eggs, Sonoma County. © 2008 Arnaud Jamin.
From the CalPhotos collection.
Larva in late August, Mendocino County
Red-bellied Newt larva Red-bellied Newt larva Red-bellied Newt larva
Red-bellied Newt larva Red-bellied Newt larva Red-bellied Newt larva
Larvae underwater in aquarium, late August, Mendocino County
Red-bellied Newt larva Red-bellied Newt larva Red-bellied Newt larva
Larvae underwater in creek, late August, Mendocino County
Red-bellied Newt larvae Red-bellied Newt larvae Red-bellied Newt larvae
Larvae underwater in creek, late August, Mendocino County
 
Habitat
Red-bellied Newt Habitat Red-bellied Newt Habitat Red-bellied Newt Habitat
Habitat, creek during early breeding season, March, Mendocino County Habitat, creek during early breeding season, March, Mendocino County Habitat, Sonoma County
Red-bellied Newt Habitat Red-bellied Newt Habitat Red-bellied Newt Habitat
Habitat, creek during breeding season, late February, Mendocino County
Habitat, creek during early breeding season, March, Mendocino County
Red-bellied Newt Habitat Red-bellied Newt Habitat Red-bellied Newt Habitat
Habitat, creek during breeding season, early March, Mendocino County
Habitat, creek during breeding season, early March, Mendocino County
Habitat, redwood forest,
Mendocino County
Red-bellied Newt Habitat Red-bellied Newt Habitat  
Breeding creek in late August,
Mendocino County

Habitat of the recently-described (2013) and possibly introduced population of Red-bellied Newts in Santa Clara County © Jon Hirt  
     
Short Videos
Red-bellied Newt Red-bellied Newt Red-bellied Newts
Red-bellied newts at their breeding creek in the redwood forest in Mendocino County. Male Red-bellied newts walking around a creek at the beginning of the breeding season, waiting for females to arrive. Two male Red-bellied newts try to steal a female away from a male in amplexus with her, but they do not succeed.
Red-bellied Newt larva Red-bellied Newt larva Red-bellied Newt
Red-bellied Newt Larvae only about an inch in length swim and crawl around in an aquarium. Red-bellied Newt Larvae only about an inch in length crawl around on the bottom of a rocky creek in Mendocino County in late August. Breeding male newts move around underwater in a small aquarium.
   
Description
 
Size
Adults are 2 3/4 - 3 1/2 inches long (7 - 8.9 cm) from snout to vent, and 5 1/2 - 7 1/2 inches (14 - 19.5 cm) in total length.

Appearance
A stocky, medium-sized, salamander with grainy skin, no costal grooves, and dark eyes.
(Other Taricha species have yellow in the eye.)
Breathes through lungs.

Larvae have numerous, fine black spots along the sides and back. The dorsal fin and balancers are not well-developed, compared to other Taricha species, but the hind limb development is more advanced at hatching.
Color and Pattern
Brownish black above, tomato red below.
There is dark coloring on the undersides of the limbs and a dark band across the vent.
Male / Female Differences
Breeding males develop smooth skin that looks wrinkled and baggy underwater, a flattened tail to aid with swimming, a swollen vent, and rough nuptial pads on the undersides of the feet to aid in holding onto females during amplexus.

Dark coloring across the vent is especially broad in males and often absent in females.

Comparison With Other Taricha Species
Identifying Species of Pacific Newts - Genus Taricha

Life History and Behavior
Rough-skinned when in the terrestrial phase.
Breathes through lungs.
Activity
Adults are terrestrial, becoming aquatic when breeding. 
Adults emerge after a few fall rains and move around feeding for a period before migrating to the breeding stream. (Adults that are not breeding that year, continue to forage on the forest floor.)
Acitivity typically occurs at night and in the late afternoon, but newts are also found active in streams and on the surface in daylight during the breeding season and during rains.
Often seen moving in large numbers to breeding sites during breeding season.
Terrestrial animals spend the dry summer in moist habitats under woody debris, rocks, in animal burrows.

Juveniles apparently spend most of their time underground and are not active on the surface until near sexual maturity. Coexists with T. granulosa but unlike that species, T. rivularis breeds in flowing, not still, water.
Sometimes hybridizes with T. granulosa.

At one time, Red-bellied Newts were very abundant at some locations. One estimate from the early 1960's was that there were 58,000 - 60,000 breeding newts in a 1.5 mile (2.5 km) long stretch of Pepperwood Creek.
Longevity
Longevity is estimated to be 20 - 30 years.
Defense
When threatened, this newt assumes a swaybacked defensive pose, closing its eyes, extending its limbs to the sides.
Unlike the other Taricha species, Red-bellied newts do not elevate or curl the tail. They sometimes lift the entire front of the body up off the ground, keeping the tail, pelvis, and hind limbs on the ground. This "unken reflex" exposes its bright red ventral surface coloring which is a warning to potential predators.

Poisonous skin secretions containing tetrodotoxin repel most predators. This potent neurotoxin is widespread throughout the skin, muscles, and blood, and can cause death in many animals, including humans, if eaten in sufficient quantity. (One study estimated that 25,000 mice could be killed from the skin of one Rough-skinned newt, the most toxic of the Taricha species.) This poison can also be ingested through a mucous membrane or a cut in the skin, so care should always be taken when handling newts.

In most locations the Common Gartersnake, Thamnophis sirtalis, is has a high resistance to this poison, and is known to prey on Red-bellied Newts.
Diet and Feeding
Eats a variety of invertebrates. Larvae most likely eat anything they can fit in their mouth.
Breeding
Reproduction is aquatic.
Breeding migration begins as early as late January, with adult males entering the water as early as early February.
Very heavy rainfall inhibits migration, as the newts need to wait until the streams recede from winter floods.
Breeding takes place from late February to May, peaking in March, in clean rocky streams and rocky rivers with moderate to fast flow.
Adults will leave the water during heavy rains when the flow is high.
Ponds, lakes, and other standing waters are avoided.

Newts typically return to the same part of the same creek throughout their life.
Experiments have shown that they have an excellent homing ability to find their native stream segment using their sense of smell.

There is no evidence that they are territorial and defend their stream segment from others.

Males breed more frequently than females - usually every year or every 2 years, while females breed every 2 or more years.

Males arrive at the streams 1-3 weeks before females.
In the water, they transform into their aquatic phase, with loose skin, swolen cloacal lips, and an enlarged and flattened tail that aids them in swimming. They patrol the edges of the stream waiting for females to arrive. When they arrive, the females are sometimes mobbed by a group of males until one has grabbed onto her back in amplexus and cannot be wrestled off by the other males.
Males develop nuptial pads on the fingers and toes to help their grip during amplexus.
The male hangs on to the female in amplexus until she is ready to fertilize her eggs. At that time, the male deposits a spermatophore and the female picks it up with her cloaca.
Eggs
The female lays and attaches a flattened egg mass usually only one egg layer thick under stones in the middle of the creek or rocks overhanging the creek, or onto submerged roots.
Clutch size is about 10 eggs.
Many egg masses are sometimes found under one stone.
Temperature determines how long the egss take to hatch.
In a laboratory, eggs hatched faster at a higher temperature (16 - 20 days) than at a lower temperature (30 - 34 days.)
Larvae
The larval stage lasts about 4 - 6 months.
In one population, the larvae hatched in late April, and transformed in late August. 
Metamorphosis typically occurs in late summer and early fall.
Transformed juveniles leave the stream and go into hiding in underground shelters where they spend most of their life until they are old enough to breed (4 - 6 years.)

Geographical Range
Endemic to California.
Occurs along the coast from near Bodega, Sonoma county, to near Honeydew, Humboldt county, and inland to Lower lake and Kelsey Creek, Lake County.
The most limited in distribution of the three species of Taricha.

An isolated population has been discovered in the Stevens Creek watershed in Santa Clara County, California, more than 80 miles (130 km) south of the former known range of the species. The population was not found to be genetically divergent from the main population, which has the lowest genetic diversity of any coastal California salamander species, so researchers were unable to determine if the popuation is natural or introduced.

Sean B. Reilly, Daniel M. Portik, Michelle S. Koo, and David B. Wake (2014) Discovery of a New, Disjunct Population of a Narrowly Distributed Salamander (Taricha rivularis) in California Presents Conservation Challenges. Journal of Herpetology: September 2014, Vol. 48, No. 3, pp. 371-379.

Habitat
A stream or river dweller.
Found in coastal woodlands and redwood forest along the coast of northern California.
Larvae retreat into vegetation and under stones during the day.

Notes on Taxonomy
None

Conservation Issues  (Conservation Status)
Development of forests and grassland habitats for agriculture and housing may pose a serious threat by drying out the land and degrading streams, and creating more vehicular traffic with corresponding road mortality of terrestrial newts, especially during breeding migrations.
Taxonomy
Family Salamandridae Newts Goldfuss, 1820
Genus Taricha Pacific Newts Gray, 1850
Species

rivularis Red-bellied Newt (Twitty, 1935)
Original Description
Twitty, 1935 - Copeia, p. 73

from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz

Meaning of the Scientific Name
Taricha: Greek - preserved mummy, possibly referring to the rough skinned appearance.
rivularis: Latin - of a brook or stream.

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Alternate Names
None

Related California Salamanders
Taricha torosa torosa - Coast Range Newt
Taricha torosa sierrae - Sierra Newt
Taricha granulosa - Rough-skinned Newt

More Information and References
California Department of Fish and Wildlife

AmphibiaWeb

Stebbins, Robert C., and McGinnis, Samuel M.  Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012.

Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972.

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.

Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Amphibians of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.

Bishop, Sherman C. Handbook of Salamanders. Cornell University Press, 1943.

Lannoo, Michael (Editor). Amphibian Declines: The Conservation Status of United States Species. University of California Press, June 2005.

Petranka, James W. Salamanders of the United States and Canada. Smithsonian Institution, 1998.

Jones, Lawrence L. C. , William P. Leonard, Deanna H. Olson, editors. Amphibians of the Pacific Northwest. Seattle Audubon Society, 2005.

Conservation Status

The following status listings come from the Special Animals List and the Endangered and Threatened Animals List which are published by the California Department of Fish and Wildlife.


Protected from take with a sport fishing license in 2013.


Organization
Status Listing
U.S. Endangered Species Act (ESA) None
California Endangered Species Act (CESA) None
California Department of Fish and Wildlife SSC California Species of Special Concern
Bureau of Land Management None
USDA Forest Service None
 

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