California Reptiles & Amphibians

Trimorphodon biscutatus lyrophanes - Baja California Lyresnake



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Range in California: Red

Green: Sonoran Lyresnake






Adult, San Diego County
Adult, San Diego County
Juvenile, San Diego County. © Gary Nafis. Specimen courtesy of Tim Burkhardt
Adult, San Diego County
Adult, Santa Barbara County
© Patrick Briggs
Adult, San Bernardino County © Patrick Briggs
Adult, San Diego County
© Michael Clarkson
Adult, San Diego County © Bruce Edley  
Habitat, San Diego County
Habitat, coastal San Diego County
Habitat, Lava Flow, San Bernardino County
Habitat, Riverside County
Habitat, San Diego County


Habitat, San Diego County
Description

Mildly Venomous
One of the larger rear-fanged snakes, but considered harmless to humans, but handle with caution, as some people have had unpleasant reactions to this snake's bite.
Size
Trimorphodon biscutatus 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).
Appearance
A slender snake with a broad head well-differentiated from the slim neck. 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 pupils are vertical, like those of a cat. The underside is off-white or yellowish with dark spots. The anal plate is usually undivided.
According to Stebbins there is a dark form of this snake with a light brown middorsal stripe found at the Pisgah lava flow.
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.
Diet
Primarily lizards, but also known to eat small mammals, nestling birds, and snakes.
Reproduction
Not well known. Lyre snakes apparently originated in the tropics, where breeding is year round, and the northern races may have retained this capability.
Range
In California, this snake occurs from around Santa Barbara County northeast into Inyo County, and south along the coast into Baja California, in two strips through the peninsular ranges, and along the Colorado River, splitting around the Imperial Valley. It is also absent from a large area of the Mojave Desert except for isolated localities including the Pisgah lava flow area. This may be due to the secretive nature of this snake. It may be more widespread in this area.
Habitat
Associated primarily with rocky locations in desert scrub and grassland, chaparral, oak woodland, coniferous forest, but found in rockless areas, also.
Taxonomic Notes
Some researchers do not recognize any subspecies of Trimorphodon biscutatus.

The former subspecies T. b. vandenburghi was synonymized with T. b. lyrophanes in 1994 (Grismer et al. (1994 Bull. So,. California Acad. Sci. 93: 45-80).
Conservation Issues  (Conservation Status)
None.

Taxonomy
Family Colubridae Colubrids
Genus Trimorphodon Lyresnakes
Species biscutatus Lyresnake
Subspecies


lyrophanes Baja California Lyresnake
Original Description
Trimorphodon biscutatus - (Dumeril, Bibron and Dumeril, 1854) - Erpet. Gen., Vol. 7, Pt. 2, p. 1153
Trimorphodon biscutatus lyrophanes - Cope, 1860

from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz

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.
biscutatus
- Latin - bis - two, and scutatus- plated - refers to the doubled loreal plate
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

Alternate Names
Trimorphodon biscutatus - Western Lyre Snake (no subspecies recognized)

Formerly called California Lyre Snake - T. b. vandenburghii

Related or Similar California Snakes
T. b. lambda - Sonoran Lyresnake
Great Basin Gopher Snake
San Diego Gopher Snake
Desert Glossy Snake
California Glossy Snake

More Information and References
Natureserve Explorer

California Dept. of Fish and Game

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., & F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

Bartlett, R.D. , & Alan Tennant. Snakes of North America - Western Region. Gulf Publishing Co., 2000.

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.

Brown, Philip R. A Field Guide to Snakes of California. Gulf Publishing Co., 1997.


Conservation Status

The following status listings come from the Special Animals List which is published several times each year by the California Department of Fish and Game.

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
U.S. Endangered Species Act (ESA)
California Endangered Species Act (CESA)
California Department of Fish and Game
Bureau of Land Management
USDA Forest Service
Natureserve Global Conservation Status Ranks
World Conservation Union - IUCN Red List





 

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