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| Adult, San Diego County desert |
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| Adult, San Diego County desert |
Adult, San Diego County desert |
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| Adult, San Diego County desert |
Adult, San Diego County desert |
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| Adult, Mesquite Mountains San Bernardino County © Adam G. Clause |
Adult, Santa Rosa Mountains Riverside County © Adam G. Clause |
Adult, San Diego County desert |
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Adult, San Diego County desert
© Bruce Edley |
Adult, San Diego County desert
© Michael Clarkson |
Adult, San Diego County desert |
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Adult from the Granite Mountains, San Bernardino County desert
© Zach Lim |
Adult, San Bernardino County desert © Patrick Briggs |
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| Adult, coastal San Diego County © Patrick Briggs |
Adult, southern Santa Barbara County © Patrick Briggs |
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Adult, east of the Granite Mountains, San Bernardino County desert
© Keith Condon |
Adult, San Diego County mountains.
© Stuart Young |
Adult, San Bernardino County
© Sean Barefield |
Adult, San Bernardino County desert
© Richard Cazares
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| Adult, Inyo County © Ryan Sikola |
Adult, San Diego County desert
© Michael Clarkson |
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| Adult, San Diego County desert |
Adult, San Diego County desert |
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| Adult, Los Angeles County mountains © Ryan Sikola |
The California Lyresnake in the picture on the left is thermoregulating in the rock crevice shown in the picture on the right on a cool and foggy March morning in coastal Riverside County. © Steve Bledsoe |
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Adult, San Bernardino County desert, west of the Providence Mountains.
© Brad Sillasen |
This is the same Lyresnake seen to the left, showing the undivided anal plate characteristic of this species in California. © William Flaxington |
Adult found dead on a road in Orange County © Tadd Kraft |
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| Head study, adult, San Bernardino County desert © Patrick Briggs |
Adult, coastal San Diego County © Michael Van Zandt |
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| Atypically Colored or Patterned California Lyresnakes |
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Adult, Pisgah, San Bernardino County © John Buckman
This is the striped form of lyre snake mentioned by Robert Stebbins his 2003 field guide information about the Western Lyre Snake: "Dark individuals that tend to have a middorsal stripe of light brown have been found at the Pisgah lava flow in the Mojave Desert, Calif." |
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Anerythristic adult, Inyo County © Ryan Sikola
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| Juveniles |
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| Hatchling in September, Inyo County, approximately 6 inches long (15.2 cm) © Ryan Sikola |
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Hatchling in September, Inyo County
© Ryan Sikola |
Sub-adult, Imperial County desert
© Stuart Young |
Juvenile, San Diego County desert. © Gary Nafis.
Specimen courtesy of Tim Burkhardt |
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Juvenile, Riverside County
© Grigory Heaton |
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| Males in Combat |
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| These two adult males were found combatting on a road at night in mid June near Puertectios, B.C. Norte. A video of the pair can be watched below. © Stuart Young |
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| Habitat |
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| Habitat, San Diego County desert |
Habitat, San Diego County desert |
Habitat, San Diego County desert |
Habitat, Riverside County riparian canyon |
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Habitat, San Bernardino County desert.
© William Flaxington |
Habitat, coastal San Diego County |
Habitat, desert Lava Flow,
San Bernardino County |
Habitat, San Diego County desert |
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| Short Videos |
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| A lyre snake coils up defensively and strikes. |
A lyre snake crawls up a steep rock outcrop at night. |
A lyre snake shows off its rock climbing skills at night in San Diego County. |
I put the video camera on the dashboard one night while road cruising a rocky pass in San Diego County and eventually a lyre snake showed up on the road. It might look like I stopped in the middle of the road, but actually I drove ahead and parked safely before running back to film the snake from closer up. |
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Two males found in combat at night on a road in Baja California Norte. At the end, one of them gives up and races away.
© Stewart Young |
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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.)
The rear teeth on the upper jaw are enlarged and grooved to aid in injecting mild venom into prey, especially when the snake is allowed to chew, which helps to deliver more venom into the skin, so handle it with caution. Symptoms can include local swelling, redness, itching, and numbness, but the the effects are not systemic.
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| Size |
Trimorphodon have been recorded from 18 - 47 3/4 inches in length (46 - 121 cm).
Most snakes encountered are 24 - 36 inches long (61 - 91 cm).
Hatchlings are approximately 6 inches in length (15.2 cm).
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| Appearance |
A slender snake with a broad head well-differentiated from the slim neck.
The pupils are vertical, like those of a cat.
The anal plate is divided or entire. |
| Color and Pattern |
Coloring closely matches a snake's rocky habitat, from gray to light brown.
There are usually about 35 dorsal blotches with light edges and a pale crossbar in the center, and smaller irregular blotches on the lower sides.
A lyre-shaped marking is present on top of the head.
The underside is off-white or yellowish with dark spots.
According to Stebbins (2003) there is a dark form of this snake with a light brown middorsal stripe found at the Pisgah lava flow.
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| Comparison of the Two Species of Lyresnake Found in California |
Sonoran Lyresnake - Trimorphodon lambda
Has fewer body blotches than T. lyrophanes.
(Fewer than 31 primary dark body blotches - average of 24.)
Body blotches are more widely separated than those on T. lyrophanes.
(The seventh and eighth blotches are separated by an average of four scale rows.)
The anal scale is divided.
California Lyresnake - Trimorphodon lyrophanes
Has a greater number of body blotches than T. lambda.
(Fewer than 48 primary dark body blotches - (average of 34.)
Body blotches are more narrowly separated than those on T. lambda.
(The seventh and eighth blotches are separated by an average of two scale rows.)
The anal scale is divided or undivided (entire).
(From Devitt et al, 2008 * See more detailed information here.)
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| Life History and Behavior |
Activity |
Nocturnal, active in very dry conditions as well as during rains.
Terrestrial, and good climbers.
This snake often searches rock crevices for prey.
It can be found during the day inside crevices in large rock outcrops, as well as crossing desert roads at night. |
| Defense |
| When threatened, a lyresnake will sometimes vibrate its tail similar to the behavior of a rattlesnake. Sometimes it will raise up the front of its body and strike. |
| Diet and Feeding |
| Primarily lizards, but also known to eat small mammals, nestling birds, and snakes. |
| Reproduction |
Not well known.
Breeding probably takes place in Spring .
Females are oviparous, laying a clutch of 10 or more eggs in Summer which hatch in late Summer and early Fall.
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| Habitat |
Associated primarily with rocky locations in desert scrub and grassland, chaparral, oak woodland, coniferous forest, but found in rockless areas, also.
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| Geographical Range |
In California, this species is found from Santa Barbara County south along the coast and the peninsular ranges into Baja California, and to the east north of the Imperial Valley to near the Colorado River where it meets Trimorphodon lambda, and around the eastern side of the Sierra Nevada mountains north into Inyo County around Death Valley. It is not known from a large area of the Mojave Desert in San Bernardino except for a few reported isolated localities listed below. The small number of records for the species in this area may be due to the secretive nature of this snake. It may be more widespread.
Some reported localities in the Mojave Desert:
Pisgah lava flow
Kelso Dunes
Granite Mountains
Bristol Mountains
Clark Mountains
Mesquite Mountains
Amboy
South Nopah Range
Cima lava flow
Barstow
Panamint Mountains
Argus Mountains
Amargosa Mountains
Devitt et al 2008 * described the entire range of Trimorphodon lyrophanes:
Found throughout most of the Baja California Peninsula and on Cerralvo, Danzante, San Jose´, San Marcos, and Tiburon islands; in southern California generally west of the Salton Trough region north to the vicinity of Los Angeles on the coast, and inland in the Mohave Desert north to the Argus and Amargosa mountains in Inyo County."
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In his 2006 study ** Thomas Devitt did not sample any specimens west or east of the Salton Sea in the apparent contact area, or any specimens along the Colorado River in California. He used no specimens of T. lambda from California at all, as you can see in the map detail taken from the study to the right. This leaves me uncertain as to exactly where the contact zone exists between T. lambda and T. lyrophanes. I have found no museum records which are identified down to subspecies that help. In the range maps shown in field guides from those authors who recognize the two species (or former subspecies) the area of contact is shown in more than one place; some show T. lyrophanes ranging all the way east to the Colorado River, others show its range ending somewhere northeast of the Salton Sea in Riverside County, and another shows it ranging even farther west. I have chosen to show the two species meeting west of the river in Riverside County, following Devitt's 2006 map, but I will change this if I find more accurate information. (Please let me know if you discover any new papers published on Trimorphodon taxonomy.)
The northern range of T. lambda is also uncertain. While the maps in Devitt et al 2008 and in Devitt 2006 show the species ranging north and west of the Colorado River into Nevada somewhere above Needles, as I have done, some maps show it ranging only as far north as the Whipple Mountains/Parker Dam area, and I can find no museum or other records of Trimorphodon consistent with either interpretation, (or even any farther north than Riverside County in that area.) |
From Devitt 2006** |
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A note that describes a record for T. lyrophanes in the Mesquite Mountains (Adam Clause. Herpetological Review 52(3), 2021) also describes an old unvouchered T. lyrophanes locality mentioned by Robert Stebbins that has been placed in the Clark Mountains, I have extended the range of T. lyrophanes in San Bernardino County farther north and west to include those mountain ranges. The eastern limit of the species range is still unknown.
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| Notes on Taxonomy |
Devitt et al 2008 * recommended that the subspecies of Trimorphodon biscutatus - lambda, lyrophanes, and vilkinsonii, be recognized as distinct species - Trimorphodon lambda, Trimorphodon lyrophanes, and Trimorphodon vilkinsonii. They recommended that the common names be Peninsular Lyresnake for T. lyrophanesand Sonoran Lyresnake for T. lambda.
This species was formerly regarded as a subspecies of Trimorphodon biscutatus: T. b. lyrophanes - Baja California Lyresnake.
According to The Reptile Database (4/23) there are currently seven distinct species of Trimorphodon.
Alternate and Previous Names (Synonyms)
Trimorphodon lyrophanes - California Lyre Snake (Stebbins & McGinnis 2012)
Trimorphodon biscutatus - Western Lyre Snake (Stebbins 2003)
Trimorphodon biscutatus vandenburghi - California Lyre Snake (Stebbins 1985)
Trimorphodon vandenburghi - California Lyre Snake (Stebbins 1954, 1966)
Trimorphodon vandenburghi - California lyre snake (Klauber 1924)
Van Denburgh's lyre snake (Ditmars 1936)
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| Conservation Issues (Conservation Status) |
| None |
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| Taxonomy |
| Family |
Colubridae |
Colubrids |
Oppel, 1811 |
| Genus |
Trimorphodon |
Lyresnakes |
Cope, 1861 |
Species
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lyrophanes |
California Lyresnake |
(Cope, 1860) |
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Original Description |
Trimorphodon lyrophanes - Cope, 1860
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Trimorphodon - Greek - tri - three, and morph - shape, and odon- teeth - refers to the 3 tooth shapes in the upper jaw, recurved anterior teeth; the shorter middle teeth and elongate, grooved fangs at the rear.
lyrophanes - Greek - lyro - lyre, and phaneros - visible - probably refers to they lyre-like pattern on the head
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Related or Similar California Snakes |
T. lambda - Sonoran Lyresnake
Great Basin Gopher Snake
San Diego Gopher Snake
Desert Glossy Snake
California Glossy Snake
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More Information and References |
California Department of Fish and Wildlife
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.
* Devitt, Thomas J., Travis J. LaDuc, and Jimmy A. McGuire. The Trimorphodon biscutatus (Squamata: Colubridae) Species Complex Revisited: A Multivariate Statistical Analysis of Geographic Variation. Copeia. 2008 (2): 370-387.
** Devitt, T. J. Phylogeography of the Western Lyresnake (Trimorphodon biscutatus): testing aridland biogeographi- cal hypotheses across the Nearctic–Neotropical transition. Molecular Ecology 2006 15:4387–4407.
Clinical Toxinology Resources - The University of Adelaide, Australia, accessed 12/19.
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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.
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| Organization |
Status Listing |
Notes |
| NatureServe Global Ranking |
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| NatureServe State Ranking |
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| U.S. Endangered Species Act (ESA) |
None |
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| California Endangered Species Act (CESA) |
None |
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| California Department of Fish and Wildlife |
None |
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| Bureau of Land Management |
None |
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| USDA Forest Service |
None |
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| IUCN |
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Red: Range of this species in California
