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.
Mildly Venomous - but not considered dangerous to humans.
Capable of delivering a mild venom from small fangs in the rear of the mouth, but the venom is not considered dangerous to humans. Handle this snake with caution, as some people have had unpleasant reactions to this snake's bite, especially when the snake is allowed to chew, which helps to put more venom into the skin. Symptoms can include local swelling, redness, itching,
and numbness, but the the effects are not systemic.
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).
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.
Comparison of the Two Species of Lyresnake Found in California
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.)
Life History and Behavior
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.
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.
Not well known.
Breeding probably takes place in Spring with females laying a clutch of 10 or more eggs laid in Summer which hatch in late Summer and early Fall.
Associated primarily with rocky locations in desert scrub and grassland, chaparral, oak woodland, coniferous forest, but found in rockless areas, also.
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 absent from a large area of the Mojave Desert except for isolated localities including the Pisgah lava flow area, and south of the Kelso Dunes. This may be due to the secretive nature of this snake. It may be more widespread in this area.
Devitt et al 2008 *described the entire range of Trimorphodon lyrophanes:
Found throughout most of the Baja California Peninsula and on Cerralvo, Danzante, San JoseŽ, 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."
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 below. 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. (Museum records still use Trimorphodon biscutatus with subspecies as I write this 2/14.) 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 map below, however I will change this if I can obtain more accurate information. The northern range of T. lambda is also uncertain. While the maps in Devitt et al 2008 and in Devitt 2006 below 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 lyresnakes consistent with either interpretation, (or even any farther north than Riverside County in that area.)
From Devitt 2006**
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.
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)
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
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.
* 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.
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.