Dark nigrescens variation,
Pierce County, Washington
Dark nigrescens variation,
Pierce County, Washington
Intergrade of T.e.elegans and
T. e. vagrans.
Found in northern Siskiyou and Modoc counties and in south central Oregon, this intergrade was once considered a unique subspecies: Thamnophis elegans biscutatus - Klamath Gartersnake.
More pictures of this intergrade snake can be viewed here.
A medium-sized slender snake with a head barely wider than the neck and keeled dorsal scales.
Some averag scale counts:
Average of 8 upper labial scales, occasionally 7, scales 6 and 7 are enlarged, higher than wide.
Average of 10 lower labial scales.
The front and rear pair of chin shields are equal in length.
The internasals are wider than long and not pointed in front.
Average scale count at mid-body is 21, rarely 19.
Color and Pattern
Ground color is gray, brown, or geenish and there are typically light dorsal and lateral stripes.
The dorsal stripe is yellow, brown, or orangish, but black markings on the edges may make it appear irregular or a series of dark and light dots.
The dorsal stripe also fades on the tail.
The sides are checkered with black markings.
Occasionally these markings will fill in most of the sides between stripes.
The underside is light with scattered black markings, often concentrated in the center.
The underside may also be black except on the throat and tail.
There is a melanistic phase of this snake in the Puget Sound area and in British Columbia.
Look here to see a brick red phase from the Sedona area of Arizona.
Active in daylight. Chiefly terrestrial - not as dependant on water as other gartersnake species, but more likely to be found near water. When frightened, this species will sometimes seek refuge in vegetation or ground cover, but it will also crawl quickly into water and swim away from trouble. If frightened when picked up, this snake will often strike repeatedly and release cloacal contents and musk.
Diet and Feeding
Western Terrestrial Gartersnakes - Thamnophis elegans - eat a wide range of prey (among the widest of any snake species - Rossmann, et al. 1996.) The prey depends on the size of the snake (large snakes tend to eat larger prey, small snakes can only eat smaller prey) and what prey is available. Populations found on the humid North Coast where slugs are abundant are genetically predisposed to eat slugs, while populations in dryer areas where slugs are less common refuse to eat slugs when they are offered. (Rossmann, et al. 1996.)
Diet includes: invertebrates such as slugs, leeches, snails, and earthworms; fish; amphibians - tadpoles, frogs, (and probably salamanders); snakes and lizards; birds; and small mammals such as mice and voles.
Thamnophis elegans terrestris has been found in San Luis Obispo County eating Taricha torosa, which are deadly poisonous to most predators.
(Feldman, Hansen, & Sikola. Herpetological Review 51 2020.)
It's possible that T. e. vagrans is also able to develop a resistance to newt toxins.
There is evidence * that when Common Gartersnakes (Thamnophis sirtalis) eat Rough-skinned Newts (Taricha granulosa) they retain the deadly neurotoxin found in the skin of the newts called tetrodotoxin for several weeks, making the snakes poisonous (not venomous) to predators (such as birds or mammals) that eat the snakes. Since California Newts (Taricha torosa) also contain tetrodotoxin in their skin, and since gartersnake species other than T. sirtalis also eat newts, it is not unreasonable to conclude that any gartersnake that eats either species of newt is poisonous to predators.
T. elegans mates primarily in spring, with young born live July - Sepember.
High altitude populations of this subspecies in California might breed later.
Occurs in a wide variety of habitats. In California, this snake occurs in coniferous forest, sagebrush, grassy meadows, often in the vicinity of water.
In California, the subspecies Thamnophis elegans vagrans - Wandering Gartersnake, is found east of the southern Sierra Nevada Mountains. Intergrades occur in the far northeast corner of the state in Modoc and estern Siskiyou counties, and running the length of the Sierra Nevada mountains, (although I am not certain exactly where or how wide it is.)
Overall, this subspecies has a very large range, occurring from Canada south into New Mexico, including Oregon, Washington, Nevada, Idaho, Montana, Wyoming, South Dakota, Nebraska, Colorado, Utah, and Arizona.
The species Thamnophis elegans - Western Terrestrial Gartersnake, ranges widely from the California coast north through most of northern California, Oregon, Washington, Idaho and Montana, into Canada, including Vancouver Island, British Columbia, Alberta and Saskatchewan, and east into the states of Wyoming, Colorado, Utah, Arizona and New Mexico and just barely making it into South Dakota, Nebraska, and Oklahoma. Many isolated populations exist, including those in the San Bernardino Mountains and one in Baja California Norte, Mexico (the San Pedro Martir Gartersnake.)
The species Thamnophis elegans - Western Terrestrial Gartersnake, occurs from sea level to 13,100 ft. (3,990 m) in elevation in Colorado. (Stebbins, 2003)
Notes on Taxonomy
T. e. vagrans intergrades withT. e. elegans in northeast California in Modoc and eastern Siskiyou counties and in south central Oregon (this snake was formerly classified as the subspecies Thamnophis elegans biscutatus - Klamath Gartersnake. Intergrades with T. e. elegans also occur along the southern and southeastern edge of the Sierras.
Rossman, Ford, and Seigel (1996) emphasize that a detailed study of geographic variation throughout the range of Thamnophis elegans is badly needed.
Bronikowski and Arnold (2001, Copeia 2001:508-513) found several clades within T. elegans that do not always follow the subspecies boundaries.
Hammerson (1999, Amphibians and Reptiles of Colorado. 2nd ed. Univ. of Colorado Press) synonymized T. e. arizonae and T. e. vascotanneri but retained three subspecies, T. e. vagrans, T. e. elegans, and T. e. terrestris.
Thamnophis - Greek - thamnos - shrub or bush, and ophis - snake, serpent
elegans - Latin - fine or elegant -- "delicately carinated" vagrans - Latin - wandering - Yarrow, 1875: "rightly called from its wide range"
Rossman, Douglas A., Neil B, Ford, & Richard A. Siegel. The Garter Snakes - Evolution and Ecology. University of Oklahoma press, 1996.
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.
Samuel M. McGinnis and Robert C. Stebbins. Peterson Field Guide to Western Reptiles & Amphibians. 4th Edition. Houghton Mifflin Harcourt Publishing Company, 2018.
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 Snakes of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.
Bartlett, R. D. & Alan Tennant. Snakes of North America - Western Region. Gulf Publishing Co., 2000.
Brown, Philip R. A Field Guide to Snakes of California. Gulf Publishing Co., 1997.
Ernst, Carl H., Evelyn M. Ernst, & Robert M. Corker. Snakes of the United States and Canada. Smithsonian Institution Press, 2003.
Wright, Albert Hazen & Anna Allen Wright. Handbook of Snakes of the United States and Canada. Cornell University Press, 1957.
Brown et. al. Reptiles of Washington and Oregon. Seattle Audubon Society,1995.
Nussbaum, R. A., E. D. Brodie Jr., and R. M. Storm. Amphibians and Reptiles of the Pacific Northwest. Moscow,
Idaho: University Press of Idaho, 1983.
St. John, Alan D. Reptiles of the Northwest: Alaska to California; Rockies to the Coast. Lone Pine Publishing, 2002.
The following conservation status listings for this animal are taken from the November 2020 California "Special Animals List" and the November 2020 "State and Federally Listed Endangered and Threatened Animals of California" list, both of which are produced by multiple agencies and available here: https://www.wildlife.ca.gov/Data/CNDDB/Plants-and-Animals. You can check the link to see if there are more recent lists.
If no status is listed here, the animal is not included on either list. This most likely indicates that there are no serious conservation concerns for the animal. To find out more about an animal's status you can go to the NatureServe and IUCN websites to check their rankings.
This snake is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.