CaliforniaHerps.com

A Guide to the Amphibians
and Reptiles of California


San Francisco Alligator Lizard - Elgaria coerulea coerulea

(Wiegmann, 1828)
Click on a picture for a larger view



Northern Alligator Lizards California Range Map
Range in California: Red & Gray

Click the map for a guide
to the other subspecies



observation link





San Francisco Alligator Lizard
Adult with original tail, San Mateo County
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Adult with mostly original tail, Marin County Adult, Marin County Adult with regenerated tail,
Mendocino County
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Adult with regenerated tail, Mendocino County Adult, Contra Costa County
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Adult, Marin County with mostly original tail Sometimes these lizards will bite and hold on until you leave them alone.
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Darkly-patterned adult with regenerated tail, Contra Costa County Adult with original tail, San Mateo County
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Sub-adult with regenerated tail from Monterey County coastal sand dunes Adult, San Francisco County
© Zachary Lim
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Adult with original tail, from Monterey County coastal sand dunes. Adult, San Francisco County
© Zachary Lim
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Dark adult with regenerated tail from Monterey County coastal sand dunes. Alligator lizards have very strong jaws with teeth
which can sometimes break the skin.
lizard with ticks Great Basin Collared Lizard    
It is common to find blood-engorged ticks attached to alligator lizards, especially around and behind the ears, as you can see on this Shasta Alligator Lizard.

Western Alligator Lizards, genus Elgaria, have large rectangular keeled scales on the back that are reinforced with bone.
(Elgaria multicarinata multicarinata is shown here).
   
       
Juveniles
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard  
Juvenile, Marin County Juvenile, San Francisco County
© Zachary Lim
Older juvenile with partly regenerated tail from Monterey County coastal sand dunes  
       
Interesting Pattern and Color Variations
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Adult with mostly original tail with no brown coloring, Contra Costa County Adult with well-defined dark stripe on back, San Mateo County © Zach Lim
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard
Patternless adult (probably amelanistic) Santa Clara County. © Nick Esquivel
A patternless adult from Santa Cruz County. © Scott Peden
     
Breeding Activity
San Francisco Alligator Lizard San Francisco Alligator Lizard    
Two males attempting to court a female in southern Mendocino County. It looks like the bottom male is a California Alligator Lizard, a different species. © Emily Nelson    
     
Habitat
San Francisco Alligator Lizard Habitat San Francisco Alligator Lizard Habitat San Francisco Alligator Lizard Habitat San Francisco Alligator Lizard Habitat
Habitat, San Mateo County Habitat, Marin County Coastal dunes habitat, Monterey County Habitat, Contra Costa County
Pacific Ring-necked Snake Habitat San Francisco Alligator Lizard Habitat Speckled Black Salamander Habitat San Francisco Alligator Lizard Habitat
Habitat, Contra Costa County Coastal scrub habitat, Marin County Habitat, Mendocino County
Habitat, Napa County
       
Short Videos
San Francisco Alligator Lizard San Francisco Alligator Lizard San Francisco Alligator Lizard Alligator Lizard detached tail
Disturbed from his hiding spot under a rock, an alligator lizard threatens to bite and hisses several times when he is touched.
A feisty alligator lizard tries to get away. A couple of SF alligator lizards found in Marin County, including one that bites onto a finger and won't let go. This video shows how an alligator lizard's tail thrashes around after it has been dropped to distract a predator. The tail moved for about 4-5 minutes, which has been cut down here to about a minute, showing several different speeds until it is just barely moving.
     
Description
 
Size
Elgaria coerulea ranges from 2 3/4 - 5 7/8 inches in length from snout to vent (7 - 13.6 cm) (Stebbins, 2003)

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 thick rounded 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.

Scales are keeled on the back, sides, and legs, usually with 14 - 16 rows of scales across the back at the middle of the body.
The temporals are weakly 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 a similar species - the Southern Alligator Lizard - 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.)
Color and Pattern
Color is brown, gray, olive, or brown, above, with heavy dark blotches or irregular crossbands edged with white spots.
Usually the dark bands on the back are so irregular that they cannot be counted.
Some lizards have very little pattern, appearing to have only faint dark markings.
Others have a broad stripe on the back.
Young
Newborn lizards are very thin and small, roughly 4 inches long, with smooth shiny skin with a plain tan, light brown, or copper colored back and tail. The sides are darker and sometimes mottled or barred as they are on adults. Juveniles gradually develop the large scales and heavy dark barring found on the back and tails of adults.
Life History and Behavior

Activity
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.

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.
Defense
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.
Diet and Feeding
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)
Breeding
Young are born live and fully-formed sometime between June and September.
During the spring breeding season, a male lizard grabs on to the head of a female with his mouth until she is ready to let him mate with her. They can remain attached this way for many hours, almost oblivious to their surroundings. Besides keeping her from running off to mate with another male, this probably shows her how strong and suitable a mate he is.

Habitat
Woodland, forests, grassland, coastal chaparral, coastal dunes and marshes, under beach driftwood. 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.

Geographical Range
The subspcies Elgaria coerulea coerulea is endemic to California. It ranges from a zone of intergradation with E. c. shastensis starting in Northern Sonoma County, south along the coast to northern Monterey County. Also found on Angel, Brooks, and Yerba Buena islands in San Francisco Bay and on Ano Nuevo Island.

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 occurring in southeastern Oregon, northwestern Nevada and the Warner Mountains in California, and south through the Sierra Nevada Mountains to Kern County.

Full Species Range Map
Elevational Range
Stebbins (2003) shows the elevational range of the species Elgaria coerulea as sea level to around 10,500 ft. (3,200 m.) but only the subspecies E. c. palmeri can be found that high up. The other subspecies range much lower.

Notes on Taxonomy
Formerly placed in the genus Gerrhonotus, with the Latin name Gerrholotus coeruleas coeruleas.


Alternate and Previous Names (Synonyms)

Elgaria coerulea coerulea - San Francisco Alligator Lizard (Stebbins 2003)
Gerrhonotus coeruleus coeruleus
- San Francisco Alligator Lizard (Smith 1946, Stebbins 1954, 1966, 1985)

Conservation Issues  (Conservation Status)
None
Taxonomy
Family Anguidae Alligator Lizards & Allies Gray, 1825
Genus Elgaria Western Alligator Lizards Gray, 1838
Species coerulea Northern Alligator Lizard Wiegmann, 1828
Subspecies

coerulea San Francisco Alligator Lizard (Wiegmann, 1828)
Original Description
Elgaria coerulea - (Wiegmann, 1828) - Isis von Oken, Vol. 21, p. 380

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

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

Related or Similar California Lizards
E. c. palmeri - Sierra Alligator Lizard
E. c. shastensis - Shasta 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
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.

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 Turtles and Lizards of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.

Jones, Lawrence, Rob Lovich, editors. Lizards of the American Southwest: A Photographic Field Guide. Rio Nuevo Publishers, 2009.

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 and the Endangered and Threatened Animals List which are published by the California Department of Fish and Wildlife.


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
NatureServe Global Ranking
NatureServe State Ranking
U.S. Endangered Species Act (ESA) None
California Endangered Species Act (CESA) None
California Department of Fish and Wildlife None
Bureau of Land Management None
USDA Forest Service None
IUCN

 

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