occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (20,000-200,000 square km (about 8000-80,000 square miles)) The range includes the Sierra Nevada, California, north to the Pit River, south to the Tehachapi Mountains, and extends east along major rivers to the Owens Valley and west-central Nevada, at elevations of about 90-2,440 meters (300-8,000 feet) (Rossman et al. 1996, Ernst and Ernst 2003, Stebbins 2003).
Distribution: USA (Oregon, California),
Catalog Number: USNM 866
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Locality: Pitt River, bank of, Locality In Multiple Counties, California, United States, North America
- Holotype: Kennicott, R. 1859. U.S. and Pacific Railroad Expedition and Survey of California and Oregon. 10 (Part 4, No. 4): 10.
Sierra Nevada Forests
The Limestone salamander is a highly localized endemic of the Sierra Nevada forests foothills conifned to a limited reach of the Merced River. The Sierra Nevada forests are the forested areas of the Sierra Nevada Mountains, which run northwest to southwest and are approximately 650 kilometers long and 80 km wide. The range achieves its greatest height towards the south, with a number of peaks reaching heights of over 4000 meters. Several large river valleys dissect the western slope with dramatic canyons. The eastern escarpment is much steeper than the western slope, in general.
The Sierra Nevada forests ecoregion harbors one of the most diverse temperate conifer forests on Earth displaying an extraordinary range of habitat types and supporting many unusual species. Fifty percent of California's estimated 7000 species of vascular plants occur in the Sierra Nevada, with 400 Sierra endemics and 200 rare species. The southern section has the highest concentration of species and rare and endemic species, but pockets of rare plants occur throughout the range.
Sierra Nevada amphibian endemics are the Yosemite toad, Mount Lyell salamander (Hydromantes platycephalus), the Vulnerable Limestone salamander (Hydromantes brunus), Kern salamander and the Endangered Inyo Mountains salamander (Batrachoseps campi). The non endemic amphibians are: the Endangered Southern mountain yellow-legged frog (Rana muscosa); the Near Threatened Cascades frog (Rana cascadae); Northern red-legged frog (Rana aurora); Pacific chorus frog (Pseudacris regilia); Foothill Yellow-legged frog (Rana boylii); Long-toed salamander (Ambystoma macrodactylum); and the Monterey ensatina (Ensatina eschscholtzii).
A considerable number of mammalian taxa are found in the ecoregion, including the Long-eared chipmunk, Alpine chipmunk, Western heather vole, Walker Pass pocket mouse, and the Yellow-eared pocket-mouse. A diverse vertebrate predator assemblage once occurred in the ecoregion including Grizzly bear (Ursus arctos), Black bear (Ursus americanus), Coyote (Canis latrans), Mountain lion (Puma concolor), Ringtail (Bassariscus astutus), Fisher (Martes pennanti), Pine marten (Martes americana) and Wolverine (Gulo gulo).
There are a small number of reptilian taxa present in the Sierra Nevada forests: sagebrush lizard (Sceloporus graciosus); Northern alligator lizard (Elgaria coerulea); Southern alligator lizard (Elgaria multicarinata); Sharp-tailed snake (Contia tenuis); California mountain kingsnake (Molothrus ater); Common garter snake (Thamnophis sirtalis); Couch's garter snake (Thamnophis couchii); Western gopher snake (Pituophis catenifer); Longnose snake (Rhinocheilus lecontei); and the Common kingsnake (Lampropeltis getula).
A number of bird species are found in the ecoreion including high level predators that include several large owls, hawks and eagles. Other representative avifauna species present are the Blue-headed vireo (Vireo solitarius); Brown-headed cowbird (Molothrus ater); and the Near Threatened Cassin's finch (Carpodacus cassinii).
- C.MIchael Hogan & World Wildlife Fund. 2014. Sierra Nevada forests. Encyclopedia of Earth. National Council for Science and Environment. Washington DC
- Michael G. Barbour, Todd Keeler-Wolf, Allan A. Schoenherr. 2007. Terrestrial vegetation of California. University of California Press. 712 pages
Great Basin Shrub Steppe Habitat
The Great Basin shrub steppe is one of the ecoregions inhabited by the Utah prairie dog. The Great Basin shrub steppe ecoregion is situated in the most northerly of the four American deserts. Unlike the other three, which have almost exclusive ties to warm-temperate and tropical/subtropical vegetation types, the Great Basin has affinities with cold-temperate vegetation.
Dominant plant species in the region include such distinctly cold-temperate species as sagebrushes (Artemisia), saltbrushes (Atriplex), and Winter-fat (Ceratoides lanata). These scrub species are much-branched, non-sprouting, aromatic semi-shrubs with soft wood and evergreen leaves. The Great Basin also contains species with evolutionary ties to warmer climates, such as rabbitbrush (Chrysothamnus), blackbrush (Coleogyne), hopsage (grayia) and horsebrush (Tetradymia). The region, however, contains few cacti species, either in numbers of individuals or species, and also lacks most characteristic desert plants in minor drainages.
Some other notable mammals found in the Great Basin ecoregion are: Belding's ground squirrel (Spermophilus beldingi); Yellow-bellied marmot (Marmota flaviventris); Bighorn sheep (Ovis canadensis); Bushy-tailed woodrat (Neotoma cinerea); Canada lynx (Lynx canadensis); Canyon mouse (Peromyscus crinitus); Cliff chipmunk (Tamias dorsalis); Coyote (Canis latrans); Desert cottontail (Crotaphytus insularis); North American porcupine (Erethizon dorsatum).
Anuran taxa found in the Great Basin scrub steppe are eight in number: the Black toad (Anaxyrus exsul VU); Great Basin spadefoot toad (Spea intermontana); Northern leopard frog (Lithobates pipiens); Pacific treefrog (Pseudacris regilla); Northern red-legged frog (Rana aurora); Columbia spotted frog (Rana luteiventris); Southwestern toad (Anaxyrus microscaphus); and Woodhouse's toad (Anaxyrus woodhousii). The Tiger salamander (Ambystoma tigrinis) is the sole salamander found in this ecoregion.
The Great Basin holds numerous reptilian taxa: Bluntnose leopard lizard (Gambelia sila EN); Common kingsnake (Lampropeltis getula); Sierra gartersnake (Thamnophis couchii); Black-collared lizard (Crotaphytus insularis); Desert horned lizard (Phrynosoma platyrhinos); Desert spiny lizard (Sceloporus magister); Western gopher snake (Pituophis catenifer); Ground snake (Sonora semiannulata); Long-nosed leopard lizard (Gambelia wislizenii); Long-nosed snake (Rhinocheilus lecontei); Milk snake (Lampropeltis triangulum); Panamint alligator lizard (Elgaria panamintina), a California endemic found only in the following desert mountains: Panamint, Inyo, Nelson, White, Cosos and Argus; Yellow-bellied racer (Coluber constrictor); Ringneck snake (Diadophis punctatus); Sagebrush lizard (Sceloporus graciosus); Pygmy short-horned lizard (Phrynosoma douglasii); Side-blotched lizard (Uta stansburiana); Striped whipsnake (Masticophis taeniatus); Western banded gecko (Coleonyx variegatus); Western patch-nosed snake (Salvadora hexalepis); Western pond turtle (Emys marmorata); Western terrestrial garter snake (Thamnophis elegans); Tiger whiptail (Cnemidophorus tigris); Zebra-tailed lizard (Callisaurus draconoides); Rubber boa (Charina bottae); and Night snake (Hypsiglena torquata).
A large number of bird species occur within the Great Basin, either as resident or migratory taxa. Example avian species found here are: Lewis's woodpecker (Melanerpes lewis); Phainopepla (Phainopepla nitans); Pinyon jay (Phainopepla nitans VU), a specialist found in pinyon-juniper woodlands; Greater sage grouse (Centrocercus urophasianus NT); Sandhill crane (Grus canadensis).
- C.Michael Hogan & World Wildlife Fund. 2015. Great Basin shrub steppe. Great Basin shrub steppe. Encyclopedia of Earth, National Council for Science and the Environment. Washington DC. Ed. M. McGinley
- J.M. Hoekstra, J. L.; Jennings, M.; Revenga, C.; Spalding, M. D.; Boucher, T. M.; Robertson, J. C.; Heibel, T. J.; Ellison, K. (2010). Molnar, J. L., ed. The Atlas of Global Conservation: Changes, Challenges, and Opportunities to Make a Difference. University of California Press. ISBN 978-0-520-26256-0.
California Central Valley Grasslands Habitat
This taxon is found in the California Central Valley grasslands, which extend approximately 430 miles in central California, paralleling the Sierra Nevada Range to the east and the coastal ranges to the west (averaging 75 miles in longitudinal extent), and stopping abruptly at the Tehachapi Range in the south. Two rivers flow from opposite ends and join around the middle of the valley to form the extensive Sacramento-San Joaquin Delta that flows into San Francisco Bay.
Perennial grasses that were adapted to cool-season growth once dominated the ecoregion. The deep-rooted Purple Needle Grass (Nassella pulchra) was particularly important, although Nodding Needle Grass (Stipa cernua), Wild Ryes (Elymus spp.), Lassen County Bluegrass (Poa limosa), Aristida spp., Crested Hair-grass (Koeleria pyramidata), Deergrass (Muhlenbergia rigens,), and Coast Range Melicgrass (Melica imperfecta) occurred in varying proportions. Most grass growth occurred in the late spring after winter rains and the onset of warmer and sunnier days. Interspersed among the bunchgrasses were a rich array of annual and perennial grasses and forbs, the latter creating extraordinary flowering displays during certain years. Some extensive mass flowerings of the California Poppy (Eschscholzia californica), Lupines (Lupinus spp.), and Exserted Indian Paintbrush (Castilleja exserta) are found in this grassland ecoregion.
Prehistoric grasslands here supported several herbivores including Pronghorn Antelope (Antilocapra americana), elk (including a valley subspecies, the Tule Elk, (Cervus elaphus nannodes), Mule Deer (Odocoileus hemionus), California ground squirrels, gophers, mice, hare, rabbits, and kangaroo rats. Several rodents are endemics or near-endemics to southern valley habitats including the Fresno Kangaroo Rat (Dipodomys nitratoides exilis), Tipton Kangaroo Rat (Dipodomys nitratoides nitratoides), San Joaquin Pocket Mouse (Perognathus inornatus), and Giant Kangaroo Rat (Dipodomys ingens). Predators originally included grizzly bear, gray wolf, coyote, mountain lion, ringtail, bobcat, and the San Joaquin Valley Kit Fox (Vulpes velox), a near-endemic.
The valley and associated delta once supported enormous populations of wintering waterfowl in extensive freshwater marshes. Riparian woodlands acted as important migratory pathways and breeding areas for many neotropical migratory birds. Three species of bird are largely endemic to the Central Valley, surrounding foothills, and portions of the southern coast ranges, namely, the Yellow-billed Magpie (Pica nuttalli), the Tri-colored Blackbird (Agelaius tricolor EN), and Nuttall’s Woodpecker (Picoides nuttallii).
The valley contains a number of reptile species including several endemic or near-endemic species or subspecies such as the San Joaquin Coachwhip (Masticophis flagellum ruddocki), the Blunt-nosed Leopard Lizard (Gambelia sila EN), Gilbert’s Skink (Plestiodon gilberti) and the Sierra Garter Snake (Thamnophis couchii). Lizards present in the ecoregion include: Coast Horned Lizard (Phrynosoma coronatum NT); Western Fence Lizard (Sceloporus occidentalis); Southern Alligator Lizard (Elgaria multicarinata); and the Northern Alligator Lizard (Elgaria coerulea).
There are only a few amphibian species present in the California Central Valley grasslands ecoregion. Special status anuran taxa found here are: Foothill Yellow-legged Frog (Rana boylii NT); Pacific Chorus Frog (Pseudacris regilla); and Western Spadefoot Toad (Pelobates cultripes). The Tiger Salamander (Ambystoma tigrinum) occurs within this ecoregion.
Although many endemic plant species are recognized, especially those associated with vernal pools, e.g. Prickly Spiralgrass (Tuctoria mucronata). A number of invertebrates are known to be restricted to California Central Valley habitats. These include the Delta Green Ground Beetle (Elaphrus viridis CR) known only from a single vernal pool site, and the Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus) found only in riparian woodlands of three California counties.
Vernal pool communities occur throughout the Central Valley in seasonally flooded depressions. Several types are recognized including valley pools in basin areas which are typically alkaline or saline, terrace pools on ancient flood terraces of higher ground, and pools on volcanic soils. Vernal pool vegetation is ancient and unique with many habitat and local endemic species. During wet springs, the rims of the pools are encircled by flowers that change in composition as the water recedes. Several aquatic invertebrates are restricted to these unique habitats including a species of fairy shrimp and tadpole shrimp.
- Michael G.Barbour, Todd Keeler-Wolf and Allan A. Schoenherr. 2007. Terrestrial vegetation of California. 712 pages
- World Wildlife Fund & C. Michael Hogan. 2013."California Central Valley grasslands". Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed.Mark McGinley.
Habitat and Ecology
Comments: Habitats of this highly aquatic snake include pools of permanent or seasonal streams (often rocky), meadow ponds, lakes, reservoirs, and associated riparian zones (e.g., cottonwood, willow, sycamore, alder), in areas with oak woodland, grassy valleys, chaparral, montane coniferous forest, or (east of the Sierra crest) pine-juniper-sagebrush (Rossman et al. 1996, Ernst and Ernst 2003, Stebbins 2003).
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Comments: Preys on invertebrates (e.g., earthworms and leeches), amphibians and their larvae, fishes and their eggs.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 - 300
Comments: This species is represented by a large number of occurrences (subpopulations).
10,000 - 1,000,000 individuals
Comments: Adult population size is unknown but presumably exceeds 10,000. This snake is locally common in various parts of its range.
Life History and Behavior
Comments: Primarily diurnal, but also active in the early evening on warm days. Inactive in cold temperatures or extreme heat.
Lifespan, longevity, and ageing
Viviparous. See Hansen (2002, Herpetol. Rev. 33:142).
Molecular Biology and Genetics
Statistics of barcoding coverage: Thamnophis couchii
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Global Short Term Trend: Relatively stable (=10% change)
Comments: Extent of occurrence, area of occupancy, number of subpopulations, and population size probably are relatively stable or declining at a rate of less than 10 percent over 10 years or three generations.
Global Long Term Trend: Increase of 10-25% to decline of 30%
Degree of Threat: Unknown
Comments: No major threats are known. Anecdotal evidence suggests that some populations may be declining as a result of predation by introduced non-native fishes (Rossmand et al. 1996).
Names and Taxonomy
Comments: Thamnophis hammondii, T. gigas, and T. atratus (including subspecies hydrophilus and aquaticus) formerly were included in Thamnophis couchii but now are recognized as distinct species (Rossman et al. 1996, Crother et al. 2000, 2003, 2008; Ernst and Ernst 2003).