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Adult with regenerating tail, Kern County |
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Habitat, Kern County |
Habitat, Kern County |
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Habitat, Kern County |
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| Description |
| Size |
| 1.5 - 2.75 inches long from snout to vent (3.8 - 7 cm). (Stebbins 2003) |
| Appearance |
A small thin lizard with soft skin with fine granular scales on most of the body, a head covered with large plates, lidless eyes with vertical pupils, a gular fold, and a detachable tail. The head and body tend to be flattened, an adaptation to this lizard's rock-crevice habitat. Males have enlarged femoral pores. Dorsal scales in 40 -44 lengthwise rows at mid-body.
Color is olive, grayish, or brown with light brown or black spots which tend to be interconnected, forming a dark net-like pattern. A broad and conspicuous stripe extends from the eye to the shoulder. The underside is whitish and made up of large square scales, usually in 12 rows. |
| Behavior and Natural History |
| Little is known about this lizard. Presumably it is similar to other California Xantusiids, being diurnal (contrary to the common name) and crepuscular. It is certainly secretive - spending most of its life undercover, and a specialized rock-crevice dweller, living under flakes of granite on rocky outcrops and in rock crevices. It is not typically active on the surface away from cover. The tail breaks off easily and continues wriggling to distract would-be predators as the lizard runs away. |
| Diet |
| Little is known about the diet of this lizard. Presumably it is similar to other related California Xantusiids, which eat small invertebrates such as ants, termites, beetles, caterpillars, crickets, and spiders. |
| Reproduction |
| Little is known about this lizard's reproduction. Related California Xantusiids breed in late spring. Young are born live, 1-3 per brood, from August to October. |
| Range |
| Endemic to California. Found only in the southwestern foothills of the Sierra Nevada Mountains along the western edge of the Greenhorn mountains around Granite Station, in Kern Co. |
| Habitat |
| Inhabits rocky outcrops around Granite Station in open grassland with scattered oak woodland and low shrubs. |
| Taxonomic Notes |
Described by Bezy in 1967.
Several subspecies of Xantusia vigilis are traditionally recognized, including two in California - X. v. vigilis, and X. v. sierrae.
Using nuclear DNA studies, Leavitt et al, 2007, provide support for the recognition of new species within the X. vigilis complex, including X. wigginsi in California, but they continue to recognize the subspecies X. v. vigilis and X. v.sierrae. In addition, they identify several major clades, four of which occur in California - X. vigilis, X. wigginsi (now a full species), a Yucca Valley clade, and a San Jacinto clade.
The 2008 Society for the Study of Amphibians and Reptiles Standard Names List uses X. sierrae based on Sinclair et. al (2004, Am. Nat. 164:396-141). |
| Conservation Issues (Conservation Status) |
| Due to its small range, the Sierra Night Lizard is very suceptible to any habitat alteration. This lizard needs exfoliated and fissured granite outcrops to survive. It takes thousands of years for this exfoliation and fissuring to occur, so this habitat will not be replaced for many centuries. When flakes and slabs are torn off rock outcrops by someone searching for this lizard or other reptiles, the habitat is irreparably damaged. Such rock destruction is illegal in California: "It is unlawful to use any method or means of collecting that involves breaking apart of rocks, granite flakes, logs or other shelters in or under which reptiles may be found." (2007 regulations 5.60.4.) However, this does not protect the lizard from other sources of rock destruction including human development of its habitat. |
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Taxonomy |
| Family |
Xantusiidae |
Night Lizards |
| Genus |
Xantusia |
Night Lizards |
Subspecies
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sierrae |
Sierra Night Lizard |
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Original Description |
Xantusia vigilis - Baird, 1858 - Proc. Acad. Nat. Sci. Philadelphia, Vol. 10, p. 255
Xantusia vigilis sierrae - Bezy, 1967 - Journ. Arizona Acad. Sci., Vol. 4, p. 163
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Xantusia - honors Xantus, John
sierrae - of the Sierra Nevada Mountains - type locality, Kern County, CA
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Xantusia vigilis sierrae
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Related or Similar California Lizards |
X. henshawi - Granite Night Lizard
X. gracilis - Sandstone Night Lizard
X. vigilis - Desert Night Lizard
X. r. reticulata - San Clemente Night Lizard
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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.
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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.
Listed as Xantusia vigilis sierrae.
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Organization
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Status Listing
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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 Game |
DFG:SSC |
California Species of Special Concern |
| Bureau of Land Management |
None |
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| USDA Forest Service |
USFS:S |
Sensitive |
| Natureserve Global Conservation Status Ranks |
G5 |
Secure |
World Conservation Union - IUCN Red List
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None |
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