A Northern Desert Nightsnake crawls across an old cement highway into the desert.
Not Dangerous (Non-poisonous) - Mildly venomous, but not considered harmful to most humans or large animals.
Adults can be 12 - 26 inches long (30-66 cm.) Most seen are 8 - 12 inches long, rarely over 16 inches.
Hatchlings are about 7 inches in length.
A small slender snake with a narrow flat head, smooth scales in 21 rows, and vertical pupils.
Color and Pattern
Color varies, often matching the substrate, from light gray, light brown, beige, to tan or cream, with dark brown or gray blotches on the back and sides.
Usually a pair of large dark markings on the neck and a dark bar through or behind the eyes.
Whitish or yellowish and unmarked underneath.
The vertical pupils on a night snake can help you tell them apart from
gophersnakes and other similar species which have circular pupils.
Life History and Behavior
Nocturnal, and also active at dusk and dawn.
Can be found under rocks, boards, dead Joshua tree branches, and other surface objects.
Often seen crossing desert roads on warm nights.
Diet and Feeding
Eats a wide range of terrestrial vertebrates, mostly lizards and their eggs, sometimes small snakes, frogs, and salamanders.
Nightsnakes, genus Hypsiglena, have mildly venomous saliva that is introduced into prey by the repeated chewing action of two enlarged teeth found at the rear of the mouth. The venom is not injected by fangs, it is introduced into the prey through small puncture wounds made by the enlarged teeth. The venom helps to incapacitate the small prey, but it is not considered harmful to humans. The small size of the snake's head, the location of the fangs, and the chewing action necessary to administer the venom, make it difficult for a nightsnake to envenomate anything but small animals. (Werler & Dixon, 2000)
Oviparous. After mating, females lay a clutch of 2-9 eggs from April to September. (Stebbins, 2003)
Eggs hatch in 50-65 days. Hatchlings are about 7 inches in length. (Bartlett & Tennant, 2000)
Found in a variety of habitats, often arid areas, from chaparral, Sagebrush flats, deserts, suburban lots and gardens, mountain meadows, grassland.
Most commonly found in areas with abundant surface cover.
This subspecies, Hypsiglena chlorophaea deserticola - Northern Desert Nightsnake, is found throughout southern California, north to San Luis Obispo County, east and north along the western Sierra Nevada mountains, and into the Great Basin desert in the far northeast part of California, including Lava Beds National Monument. There is also a record for Siskiyou county north of Yreka near the Oregon Border. Outside of California, it ranges south into Baja California, east throughout the southwest, and north into Washington.
Outside of Califorina, the species, Hypsiglena chlorophaea - Desert Nightsnake, occurs from British Columbia south through central Washington, eastern Oregon, southwest Idaho, Nevada, Utah, extreme western Colorado and New Mexico, into Arizona, Baja Califonria, And Sonora, Mexico.
Sea level to 8,700 ft. (2,650 meters).
Notes on Taxonomy
Mulcahy, 2008, conducted a comprehensive genetics study of Hypsiglena, recognizing 6 species, three in the USA, and an undescribed species, all from the one previous species of Hypsiglena torquata. He also maintained several subspecies designations. Within California: H. chlorophaea, and H. ochrorhyncha "…were each recovered as groups of multiple subspecies. The subspecies within these wide-ranging species were maintained pending further evaluation. These subspecies may represent incipient species that may not yet have achieved reciprocal monophyly, but possess unique morphologies, and are geographically discrete." 1
Grismer et al. (1994 Bulletin of the Southern California Academy of Science 93(2): 45-80) synonymized the Hypsiglena torquata subspecies deserticola and klauberi because they intergraded widely.
Alternate and Previous Names (Synonyms)
Hypsiglena chlorophaea - Desert Night Snake (Stebbins & McGinnis 2012) H. torquata - NIght Snake (Stebbins 1985, 2003) H. torquata deserticola - Desert NIght Snake (Stebbins 1966) H. torquata deserticola - Desert Spotted Night Snake; Great Basin Spotted Night Snake (Wright & Wright 1957) H. torquata deserticola (Stebbins 1954)
1 Daniel G. Mulcahy. Phylogeography and species boundaries of the western North American Night snake (Hypsiglena torquata): Revisiting the subspecies concept. ScienceDirect - Molecular Phylogenetics and Evolution 46 (2008) 1095-1115.
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.
John E. Werler and James R. Dixon. Texas Snakes: Identification, Distribution, and Natural History. University of Texas Press, Austin. 2000.
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.