California Reptiles & Amphibians

Elgaria coerulea shastensis - Shasta Alligator Lizard



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Range in California: Green

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Gravid adult female, Siskiyou County
 
Adult Humboldt County
 
Adult, Humboldt County
Adult, Humboldt County
Adult, Humboldt County
Adult, Siskiyou County
Adult, Humboldt County
One day old neonate, Siskiyou County
Adult, Humboldt County, with ticks
Underside of adult, Humboldt County
Juvenile, Siskiyou County
Habitat, Siskiyou County

Habitat, Siskiyou County
Habitat, Siskiyou County
 
Habitat, Humboldt County


Habitat, Humboldt County
 
Description
Size
Elgaria coerulea ranges from 2 3/4 - 5 7/8 inches in snout to vent length (7 - 13.6 cm) (Stebbins)
Appearance
Alligator lizards, genus Elgaria, are members of the family Anguidae, a family of lizards found in the Americas, Europe, Asia, and Africa. Large bony scales, a large head on an elongated body and powerful jaws probably give the lizards their common name. They are characterized by a slim body with short limbs and long tail. The tail can reach twice the length of its body if it has never been broken off and regenerated.

Color is brown, grey, olive, or brown, above, with heavy dark blotches or irregular crossbands edged with white spots. Body color may be yellowish with the head slate gray in some areas. Underside can be bright yellow on some males.
Usually the dark bands on the back are so irregular that they cannot be counted.

Scales are keeled on the back, sides, and legs, with 16 rows of scales across the back at the middle of the body. The temporals are not keeled.

A band of small granular scales separates the larger bone-reinforced scales on the back and on the belly, creating a fold along each side. These folds allow the body to expand to hold food, eggs, or live young. The fold contracts when the extra capacity is not needed.

The eyes are dark around the pupils. (Compare with the light eyes of Elgaria multicarinata .)
The head is usually mottled with dark color. The head of a male is broader than a female's with a more triangular shape.
Usually there are dark lines running lengthwise on the underside which run between the scales, along their edges. (Compare with the underside lines on Elgaria multicarinata which run through the middle of the scales.)
Young usually lack the dark barring and can have a plain copper or brownish band on the back.
Behavior
Active during the day. Inactive during cold periods in winter.
Moves with a snake-like undulating motion. A good swimmer, sometimes diving into the water to escape by swimming away.
The tail of an alligator lizard is easily broken off, as it is with many lizards. The tail will grow back, although generally not as perfectly as the original. A lizard may detach its tail deliberately as a defensive tactic. When first detached, the tail will writhe around for several minutes, long enough to distract a hungry predator from the lizard.
Other defensive tactics used by alligator lizards are smearing the contents of the cloaca on the enemy and biting.Males sometimes also extrude the hemipenes when threatened.

Alligator lizards are generally secretive, tending to hide in brush or under rocks, although they are often seen foraging out in the open or on roads in the morning and evening.
Diet
Eats a variety of small invertebrates, including slugs, snails, and worms. Will also eat small lizards and small mammals. Occasionally feed on bird eggs and young birds. (Stebbins)
Reproduction
Young are born live from June to September.
Range
Ranges from a zone of intergradation with E. c. coerulea in northern Sonoma County, north to northern Humboldt County, and east around the central valley into the Northern Sierra Nevada mountains. Isolated populations occur in the Warner Mountains. Also occurs in southern Oregon, with isolated populations occuring in southeastern Oregon and northwestern Nevada.

The species Elgaria coerulea ranges from Southern British Columbia south chiefly west of the Cascades and Coast Ranges to northern Monterey County, east into northern Idaho and northwestern Montana, with isolated populations occuring in southeastern Oregon, northwestern Nevada and the Warner Mountains in California, and south through the Sierra Nevada Mountains to Kern County. From sea level to 10,500 ft. (3200 m)
Habitat
Woodland, forests, grassland, coastal chaparral. Commonly found hiding under rocks, logs, bark, boards, trash, or other surface cover. Prefers wetter and cooler habitats than E. multicarinata, but generally found near sunny clearings.
Taxonomic Notes
Formerly placed in the genus Gerrhonotus, with the Latin name Gerrholotus coeruleas shastensis.
Conservation Issues  (Conservation Status)
None.

Taxonomy
Family Anguidae Alligator Lizards & Allies
Genus Elgaria Western Alligator Lizards
Species coerulea Northern Alligator Lizard
Subspecies

shastensis Shasta Alligator Lizard
Original Description
Elgaria coerulea - (Wiegmann, 1828) - Isis von Oken, Vol. 21, p. 380
Elgaria coerulea shastensis - (Fitch, 1934) - Copeia, p. 6

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

Meaning of the Scientific Name
Elgaria - obscure - possibly named for an "Elgar" or a pun on "alligator."
coerulea
- Latin - dark colored, dark blue - referring to the dorsal color of the type specimen
shastensis - belonging to the Shasta Mountains - type locality is Shasta County, CA 1932

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Alternate Names
Formerly Gerrhonotus coeruleus shastensis

Related or Similar California Lizards
E. c. coerulea - San Francisco Alligator Lizard
E. c. palmeri - Sierra Alligator Lizard
E. c. principis - Northwestern Alligator Lizard
E. m. multicarinata - California Alligator Lizard
E. m. scincicauda - Oregon Alligator Lizard
E. m. webbii - San Diego Alligator Lizard
E. panamintina - Panamint Alligator Lizard

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.

Smith, Hobart M. Handbook of Lizards, Lizards of the United States and of Canada. Cornell University Press, 1946.

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 animal 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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