Sierra newts diverged from California newts (Taricha torosa) 7 to 13 million years ago due to geological constraints within the Sierra Nevada. These constraints include the height of the mountains, the water available in the valleys, and food resources. Sierra newts have a geographic range that includes the Sierra Nevada and the southern Cascades. They are primarily found in the northern and central parts of the Sierra Nevada from Shasta County to Kern County at elevations under 609.6 m, while California newts (Taricha torosa) occupies areas south of Tulare County. (Kuchta and An-Ming, 2006; Kuchta, 2007; Livezey, 1963)
Sierra newts occupy both terrestrial and aquatic environments. They spend most of their lives on land, but return to water for breeding. They mainly use forests, shrublands, grasslands, savannas, and foothills with conifers. During the dry season, they stay in moist parts of these habitats, under woody debris or in animal burrows. While breeding, they use temporary pools, ditches, ponds, slow-moving streams, lakes, and reservoirs. ("Biology of Decision Species", 2010; "California Wildlife Habitat Relationships System", 2013; Chen, 2015)
Adult Sierra newts measure 7 to 9 cm from snout to vent. They are reddish to brown on their dorsal side, orange to yellow on their ventral side, and have no costal grooves. There is light coloring around their yellow eyes and on their snout that is different from other Taricha species. They also have warty skin, which contains tarichatoxin (tetrodotoxin). The best distinguishing characteristic of Sierra newts is the Y-shaped vomerine teeth pattern on their upper jaw, which is different than the V-shaped pattern in other newts. During the breeding season, the skin of the male becomes smooth and lighter in color, the tail develops a blade, nuptial pads develop on their toes for grasping the female, and their vents enlarge. The skin of females during the breeding season becomes more vascular, their tail may develop a small blade, and their vents become more prominent. Sierra newt larvae are aquatic and can get up to 13 to 14 mm. They are yellow on their dorsal side, with two broad black bands on their back. Older larvae have dark spots that look like blotches on their bodies. ("Biology of Decision Species", 2010; "California Wildlife Habitat Relationships System", 2013; Chen, 2015)
Sierra newts have an aquatic larval stage. Eggs hatch 14 to 52 days after they are laid. Depending on the resources available, the larval stage can last 3 to 4 months before metamorphosis results in a terrestrial juvenile. This stage last for 5 to 8 years. An adult will then migrate back to their original breeding grounds, develop sexual features, and reproduce. ("Biology of Decision Species", 2010; "California Wildlife Habitat Relationships System", 2013; Chen, 2015)
Courtship and mating is similar in all Taricha species, with slight variation on the duration and angle of the body in certain steps of amplexus. Males migrate to the breeding ground a few days before females arrive, and begin to develop features that allow them to become aquatic and sexual. Among these features is the enlargement of their cloacal lips, the vascularization of their skin, and the development of a broad blade on the tail. When the females arrive, her skin also vascularizes but retains some of the terrestrial roughness. It’s also possible for the female to develop a small blade on her tail, but this does not always occur. Once in the water, the skin of the female releases a pheromone that the males respond to quickly. The male will then clasp the female’s torso with his forelimbs and rubs his chin on her nose. The male begins to press his cloaca against her dorsum, while rubbing her nose in lateral movements with his chin for about an hour. Once this ritual is done, he will then move diagonally across her shoulder to lay his spermatophore about 3 centimeters from her head. He then uses lateral movements of his hips to move his dorsum away from her, which causes his spine to bend at a right angle from her, a position termed sacral curvature. Sierra newt males form a sacral curvature shallower than red-bellied newts, but more prominent than California newts. If the female accepts his gift, she will move into a position where her cloaca is in position to collect the spermatophore. If she denies it, she will act like she is coming into position but will then continue past. (Davis and Twitty, 1964)
Sierra newts start to migrate to the breeding ground 6 to 8 weeks before the breeding season begins. Males arrive first and start their sexual transformation. There are more males than females generally, so the sooner the male has completed his metamorphosis, the more likely he is to find a mate. Females arrive closer to the end of the migration period and transform. Mating can occur multiple times for both sexes. Females oviposit multiple clutches of 11 to 22 eggs (2.8 to 3.5 mm in diameter) on submerged objects, though the total number of clutches produced by one female in a season is not known. Once deposited, the eggs take 14 to 52 days to incubate. The larval stage then then lasts a few months, depending on water temperature, food availability, and other environmental factors. ("California Wildlife Habitat Relationships System", 2013; Chen, 2015)
Females deposit clutches of fertilized eggs under submerged objects (rocks, vegetation, twigs) to protect their offspring from predation. The clutches of eggs are surrounded by a jelly-like membrane that's toxic. ("California Wildlife Habitat Relationships System", 2013; Chen, 2015; Kuchta and An-Ming, 2006)
Data are lacking for the lifespan of Sierra newts. Due to their close phylogenetic relationship to California newts (Taricha torosa), its lifespan can be approximated to 21.8 years.
Sierra newts have multiple anti-predatory mechanisms, depending on how threatened they feel. When a predator nears, they will stand with their legs out to the side, their head raised back to expose the orange on the ventral surface and their tail will then go straight. This is known as the “unken” reflex. If the predator ignores this warning and attacks, they will be in for a dose of tarichatoxin (tetrodoxin), a neurotoxin that can paralyze, cause seizures, and even kill. This toxin is also present in the eggs of the newt to protect from predators. The presence of the toxin in the embryo suggests that it was transferred from the mother, since tetrodoxin has been shown to come from eating foods that contain it. Low levels are also present in the membrane that surrounds the embryo, but are not related to the embryo toxicity. It is not known how the toxin is present in the membrane at this time. Sierra newts are also known to yelp when picked up. When encountering other newts, they may click and rise up on their legs while wagging their tail. During breeding season, males spend more time in the water looking for a mate. During this time, both male and female adults have been known to eat the eggs of fellow newts and other aquatic vertebrates. Females cannibalize eggs more often than males. Sierra newts are diurnal outside of the mating season but will become nocturnal when migrating to the breeding ground. Adults are both diurnal and nocturnal during the breeding season, and larvae also show this behavior. ("California Wildlife Habitat Relationships System", 2013; Brame, Jr., 1968; Chen, 2015; Gall, et al., 2014)
Most movement of Sierra newts occurs during breeding season, when they have been known to travel up to 1000 m to breed. During the dry season, Sierra newts move very little. ("California Wildlife Habitat Relationships System", 2013; Chen, 2015)
Female Sierra newts communicate with future mates by releasing a pheromone. When in danger, they have an “unken” reflex. To communicate with other Sierra newts, a clicking sound is made. (Chen, 2015; Davis and Twitty, 1964; Hanifin, et al., 2008; Mosher, et al., 1966; Sallhe and Mecham, 2012)
Invertebrates are the main food source for adults. These include worms, eggs, crustaceans, insects, and slugs. They are also known to eat opportunistically if a small vertebrate is present, such as a hatchling bird. Larvae eat decomposing organic matter and small aquatic invertebrates. ("California Wildlife Habitat Relationships System", 2013; Chen, 2015)
Garter snakes are common predators of Sierra newts, along with bullfrogs. Garter snakes are resistant to the effects of the tetrodotoxin present throughout the adult newt. When threatened, Sierra newts take a defensive stance, with the limbs to the side, tail straight back, and eyes closed. They also expose the orange on the ventral side as a warning of its toxicity. Both the orange coloring and the toxicity of the newt are anti-predatory mechanisms. Larval newts are preyed on by adult newts and other carnivorous predators because, unlike the egg and adult stages, larval newts are not poisonous. ("Biology of Decision Species", 2010; "California Wildlife Habitat Relationships System", 2013; Chen, 2015; Hanifin, et al., 2008; Kuchta, 2007)
Sierra newts occupy an intermediate position in their food web. They are consumers of invertebrates and some small vertebrates but are prey to snakes and other larger vertebrates. Larvae play an important role as detritivores and consumers within the aquatic habitats that they occupy. Finally, because they use both terrestrial and aquatic habitats, they connect these systems from an ecosystem perspective. ("California Wildlife Habitat Relationships System", 2013; Chen, 2015; Mosher, et al., 1966; Sallhe and Mecham, 2012)
There are no known positive effects of Sierra newts on humans. (Chen, 2015)
Sierra newts have a neurotoxin called tarichatoxin (tetrodotoxin). It can be found in the eggs and embryos of female newts. This toxin is also present in the skin, glands, blood, muscles, and viscera of both sexes of adult newts, with the skin being most toxic. If ingested in a high enough dose, the neurotoxin found in these newts can kill a human. It has been shown that the tarichatoxin present in one adult newt can kill approximately 2,500 mice. (Mosher, et al., 1966; Sallhe and Mecham, 2012)
Sierra newts are not currently listed as an endangered species on any of the conservation sites. Potential threats that could change this status include: stocking of trout that may eat eggs and larvae, introduced bullfrogs, collection for experimentation, and degradation of habitat. ("Biology of Decision Species", 2010; "California Wildlife Habitat Relationships System", 2013)
Sierra newts diverged from California newts (Taricha torosa) 7 to 13 million years ago. The northern and central clades of Sierra newts diverged from each other 2.6 to 3.4 mya. (Davis and Twitty, 1964; Kuchta, 2007)
Chelsea Zahner (author), Indiana University - Purdue University Fort Wayne, Mark Jordan (editor), Indiana University-Purdue University Fort Wayne, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
uses sound to communicate
having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.
uses smells or other chemicals to communicate
particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
parental care is carried out by females
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
mainly lives in water that is not salty.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
An animal that eats mainly insects or spiders.
fertilization takes place within the female's body
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
marshes are wetland areas often dominated by grasses and reeds.
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
eats mollusks, members of Phylum Mollusca
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
specialized for swimming
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
chemicals released into air or water that are detected by and responded to by other animals of the same species
an animal which has a substance capable of killing, injuring, or impairing other animals through its chemical action (for example, the skin of poison dart frogs).
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
uses sight to communicate
California Department of Fish and Game. Biology of Decision Species. ICF J&S 00264.08. California: U.S. Fish and Wildlife Service. 2010.
California Department of Fish and Wildlife. California Wildlife Habitat Relationships System. A075. Sacramento, California: California Interagency Wildlife Task Group. 2013.
Brame, Jr., A. 1968. The Number of Egg Masses and Eggs Laid by the California Newt, Taricha torosa. Journal of Herpetology, 2/3: 169-170.
Chen, A. 2015. "Amphibia Web: Information on Amphibian Biology and Conservation" (On-line). AmphibiaWeb. Accessed April 01, 2015 at http://www.amphibiaweb.org/cgi/amphib_query?rel-common_name=like&rel-family=equals&rel-ordr=equals&rel-intro_isocc=like&rel-description=like&rel-distribution=like&rel-life_history=like&rel-trends_and_threats=like&rel-relation_to_humans=like&rel-comments=like&rel-submittedby=like&max=200&orderbyaw=Family&include_synonymies=Yes&show_photos=Yes&rel-scientific_name=contains&where-scientific_name=Taricha+sierrae&rel-genus=equals&where-genus=&rel-species=equals&where-species=&where-common_name=&where-subfamily=&where-family=any&where-ordr=any&rel-isocc=occurs+in&where-isocc=&rel-species_account=matchboolean&where-species_account=&rel-declinecauses=equals&where-declinecauses=&rel-iucn=begins+with&where-iucn=&rel-cites=equals&where-cites=&where-submittedby=.
Davis, W., V. Twitty. 1964. Courtship Behavior and Reproductive Isolation in the Species of Taricha (Amphibia, Caudata). Copeia, 1964/4: 601-610.
Gall, B., A. Stokes, J. Pett, K. Spivey, S. French, E. Brodie III, E. Brodie Jr.. 2014. Tetrodotoxin concentrations within a clutch and across embryonic development in eggs of the rough-skinned newts (Taricha granulosa). Toxicon, 90: 249-254.
Hanifin, C., E. Brodie, Jr, E. Brodie III. 2008. Phenotypic Mismatches Reveal Escape From Arms-Race Coevolution. PLoS Biology, 6/3: e60.
Knapp, R. 2005. Effects of Nonnative Fish and Habitat Characteristics on Lentic Herpetofauna in Yosemite National Park, USA. Biological Conversation, 121/2: 265-279.
Kuchta, S. 2007. Contact Zones and Species Limits: Hybridization Between Lineages of the California Newt, Taricha torosa, in the Southern Sierra Nevada. Herpetologica, 63/3: 332-350.
Kuchta, S., T. An-Ming. 2006. Lineage Diversification on an Evolving Landscape: Phylogeography of the California Newt, Taricha torosa (Caudata: Salamandridae). Biological Journal of Linnean Society, 89: 213-239.
Livezey, R. 1963. Distribution of Some California Amphibians and Reptiles. Herpetologica, 18/4: 279-281.
Mosher, H., J. Wakely, G. Fuhrman, F. Fuhrman, H. Fischer. 1966. The Occurrence of Tetrodotoxin (Tarichatoxin) in Amphibia and the Distribution of the Toxin in the Organs of Newts (Taricha). Toxicon, 3/3: 195-203.
Sallhe, S., J. Mecham. 2012. Physiology of the Amphibia 2. New York: Academic Press, INC.