A Guide to the Amphibians
and Reptiles of California

Coast Nightsnake - Hypsiglena ochrorhyncha

California Nightsnake - Hypsiglena ochrorhyncha nuchalata

(Tanner, 1943)

(= Hypsiglena torquata nuchalata = Hypsiglena ochrorhychus nuchalata)

Click on a picture for a larger view

Description • Taxonomy • Species Description • Scientific Name • Alt. Names • Similar Herps • References • Conservation Status

Purple: Range of this subspecies in California
Hypsiglena ochrorhyncha nuchalata - California Nightsnake

Range of other nightsnakes in California:

Red: Hypsiglena Chlorophaea deserticola -
Desert Nightsnake

Orange: Hypsiglena ochrorhyncha klauberi -
San Diego Nightsnake

Click on the map for a topographical view

Map with California County Names

Adult, Alameda County

Adult, San Joaquin County

Juvenile, Alameda County

Adult, Alameda County

Adult, Contra Costa County

Adult head close-up, Alameda County
© Faris K

Adult head close-up, Alameda County
© Mandy Colombo Murphy

Adult, Contra Costa County
© Mark Gary

Juvenile, Calaveras County © Chad M. Lane

Adult, Tuolumne County
© 2005 Rick Staub

Adult, San Joaquin County
© Sam Murray

Adult, Santa Cruz County © Zach Lim

Adult, Santa Clara County
© John Worden

Adult, San Mateo County © Zach Lim

Adults, Contra Costa County © Luke Talltree

Adult, Alameda County, showing how this species coils up defensively when it is alarmed. © Mandy Colombo Murphy

California Nightsnake and habitat,
3,400 ft. elevation, Alameda County
© Mandy Colombo Murphy.

Night snakes from the eastern edge of Monterey County © Benjamin German

Adult, 2200 ft., Mayacamas mountains, Sonoma County © Jared Heald

Adult, Mayacamas mountains,
Sonoma County © Jared Heald

Adult, Greenhorn Mountains,
Kern County © Ryan Sikola

3 snakes under one rock, Contra Costa County © Luke Talltree

California Nightsnakes are found in the extreme northwest part of Solano County. This adult was found recently killed on a rainy day in March next to a trail busy with mountain bikers.
© Lou Silva

Juvenile in habitat, Contra Costa County © Faris K

Adults, Contra Costa County
© Faris K

Adult, Contra Costa County
© Faris K

Adult, Fresno County
© Dave D

The underside of this Alameda County nightsnake shows a line of violet color
on the underside. © Richard Porter

This dark, high contrast adult was found in Santa Cruz County © Jared Heald

Juvenile coiled defensively, Vacaville, Solano County © JoWhitehouse

Juvenile, Vacaville, Solano County
© JoWhitehouse

Adult in a defensive coiled pose, Alameda County © Faris K

Three California Nightsnakes found within 5 feet apart from each other at the same exact time, Alameda County
© Faris K

Adult, Santa Cruz County, with an adult California Mountain Kingsnake, found nearby. © Faris K

Adult, Tuolumne County
© Faris K

Habitat

Habitat, Alameda County

Habitat, San Joaquin County

Habitat, Contra Costa County

Habitat, San Joaquin County

Habitat, San Mateo County © Zach Lim

Habitat, Sonoma County

Habitat, Solano County

Habitat, Contra Costa County

Short Video

An uncooperative California Nightsnake found on a road at night refuses to do anything worth putting on video, but it's all I could get.

Description

Not Dangerous - This snake may produce a mild venom that does not typically cause death or serious illness or injury in most humans, but its bite should be avoided.

Commonly described as "harmless" or "not poisonous" to indicate that its bite is not dangerous, but "not venomous" is more accurate since the venom is not dangerous. (A poisonous snake can hurt you if you eat it. A venomous snake can hurt you if it bites you.)

Rear teeth on the upper jaw are enlarged and grooved to aid in injecting a mild saliva/venom mixture into prey.

Size

Adults can be 12 - 26 inches long (30-66 cm.) Most seen are 8 - 12 inches long, rarely over 16 inches.
Bartlett & Bartlett (2009) shows the size of Hypsiglena hatchlings to be about 7 inches in length (18 cm) but some have been estimated to be as small as 5 inches long (12.7 cm).

Appearance

A small slender snake with a narrow flat head, smooth scales in 19 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.

Subspecies Variation

H. o. nuchalata is "…characterized by large nuchal blotches on the sides that often come together to form a collar, and one row of large dorsal body blotches; the eye stripe comes to a point, just contacting the lateral blotches or collar."

H. o. klauberi "is characterized by a three-part nuchal collar formed by two lateral blotches, not in contact with the eye stripe, and an elongate, irregular median nape spot." ¹

Click this image to see an example of the eye stripe differences. This difference may not be always consistent, but it seems to be the best way to differentiate the subspecies.

The vertical pupils on a night snake can help you tell them apart from
gophersnakes and other similar species which have circular pupils.

Identifying Nightsnakes in California

Life History and Behavior

Activity

Nocturnal, and also active at dusk and dawn.
Can be found under rocks, boards, logs, and other surface objects.
Sometimes seen crossing 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.

Venom

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)

Reproduction

Oviparous. After mating, females lay a clutch of 2-9 eggs from April to September. (Stebbins, 2003)

Incubation is probably similar to that of the Desert Nightsnake species, H. clorophaea, the eggs of which hatch in 50-65 days with hatchlings about 7 inches in length. (Bartlett & Tennant, 2000)

Habitat

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.

Geographical Range

This subspecies, Hypsiglena ochrorhyncha nuchalata - California Nightsnake, is found along the south Coast Ranges from San Luis Obispo county north to the Bay Area, then north on the eastern slopes of the north Coast Range to Shasta County, and down the western slopes of the Sierra Nevada mountains, basically ringing the central valley, but not found in the valley itself. This snake is known to inhabit Santa Cruz Island from a specimen collected in 1939, but the current status of the species on the island is unclear.

The species, Hypsiglena ochrorhyncha - Nightsnake, is found in a ring around the San Joaquin and Sacramento valleys, including the south coast ranges, and the inner north coast ranges and the foothills of the Sierra Nevada, and south into coastal Southern California to the southern tip of Baja California.

Elevational Range

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)

H. ochrorhyncha - Coast Night Snake (Stebbins & McGinnis 2018)
H. ochrorhynchus - Coast Night Snake (Stebbins & McGinnis 2012, Reptile Database, 10/23)
H. torquata - NIght Snake (Stebbins 1985, 2003)
H. torquata nuchalata - California NIght Snake (Stebbins 1966)
H. torquata nuchalata (Stebbins 1954)
H. torquata nuchalata - Sierra Nevada Spotted Night Snake (Tanner 1943)
Hypsiglena ochrorhynchus - Spotted Night Snake (Rock Snake; Xantus's Snake) (Grinnell and Camp 1917)

Conservation Issues (Conservation Status)

None

Taxonomy
Family	Colubridae	Colubrids	Oppel, 1811
Genus	Hypsiglena	North American Nightsnakes	Cope, 1860
Species	ochrorhyncha	Coast Nightsnake	Cope, 1860
Subspecies	nuchalata	California Nightsnake	(Tanner, 1943)
Original Description
Hypsiglena ochrorhyncha - Cope, 1860 klauberi - (Tanner, 1943)
Meaning of the Scientific Name
Hypsiglena - Greek - hypsi - on high and glenes - eyeball - probably refers to the vertical pupil nuchalata - Latin - nucha - neck and latus - side -- "pertaining to the side of the neck" from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz ochrorhyncha - yellow-ochre snout: ochro - Greek (ochra) - yellow-ochre, and rhynchos - a beak, snout from Jaeger, Edmund C. A Source-book of Biological Names and Terms Third Edition. Charles C. Thomas Publisher, 1962.
Related or Similar California Snakes
H. o. klauberi - San Diego Nightsnake H. clorophaea deserticola - Northern Desert Nightsnake T. hobartsmithi - Smith's Black-headed Snake Tantilla planiceps - Western Black-headed Snake
More Information and References
California Department of Fish and Wildlife 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. Flaxington, William C. Amphibians and Reptiles of California: Field Observations, Distribution, and Natural History. Fieldnotes Press, Anaheim, California, 2021. 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. Taylor, Emily. California Snakes and How to Find Them. Heyday, Berkeley, California. 2024. 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. Joseph Grinnell and Charles Lewis Camp. A Distributional List of the Amphibians and Reptiles of California. University of California Publications in Zoology Vol. 17, No. 10, pp. 127-208. July 11, 1917.

Conservation Status
The following conservation status listings for this animal are taken from the April 2024 State of California Special Animals List and the April 2024 Federally Listed Endangered and Threatened Animals of California list (unless indicated otherwise below.) Both lists are produced by multiple agencies every year, and sometimes more than once per year, so the conservation status listing information found below might not be from the most recent lists. To make sure you are seeing the most recent listings, go to this California Department of Fish and Wildlife web page where you can search for and download both lists: https://www.wildlife.ca.gov/Data/CNDDB/Plants-and-Animals. A detailed explanation of the meaning of the status listing symbols can be found at the beginning of the two lists. For quick reference, I have included them on my Special Status Information page. 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 also go to the NatureServe and IUCN websites to check their rankings. Check the current California Department of Fish and Wildlife sport fishing regulations to find out if this animal can be legally pursued and handled or collected with possession of a current fishing license. You can also look at the summary of the sport fishing regulations as they apply only to reptiles and amphibians that has been made for this website. This snake is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.
Organization	Status Listing	Notes
NatureServe Global Ranking
NatureServe State Ranking
U.S. Endangered Species Act (ESA)	None
California Endangered Species Act (CESA)	None
California Department of Fish and Wildlife	None
Bureau of Land Management	None
USDA Forest Service	None
IUCN

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