Range in California: Red
A zoomable Google Map
of Heloderma localities in California
based on Lovich and Beaman, 2007 3
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Venomous and Potentially Dangerous!
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Adult, Piute Mountains, San Bernardino County © Earl Curran |
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Many thanks to Harold De Lisle for contributing the two photos shown above.
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Adult, Arizona. © Gary Nafis. Specimen courtesy of Randy Babb |
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Gila Monster tongue. © Gary Nafis. Specimen courtesy of Randy Babb |
Habitat, 4,000 ft. Providence Mountains, San Bernardino County
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Eastern Providence Mountains, San Bernardino County |
| Description |
| Venom |
| Gila Monster venom is potentially dangerous to humans, though it is not known to be fatal. This is the only venomous lizard native to the United States. |
| Size |
| 9 - 14 inches long (22.8- 35.5 cm.) The largest native lizard in California and the United States. |
| Appearance |
| A large lizard with a stout body, large head, thick limbs and a short fat tail. The color is orange or pink with 4 irregular dark bands or saddles across the back with little mottling between them. The tail is striped with 5 dark bands. The sides and snout of the head are black. There are loose folds of skin on the neck and a gular fold. The dorsal surfaces of the skin are covered with hard round bead-like scales. The ventral scales are flat and squarish. The tongue is dark and forked like that of a snake. |
| Behavior |
| Terrestrial, but occasionally seen climbing brush. Slow moving and not very defensive unless harassed. Active day or night. Probably diurnal after emergence becoming nocturnal as temperatures increase. Often seen at dusk or after dark following summer rains. Spends most of its life underground (over 96% of their time 2), taking shelter in mammal burrows, under rocks, in crevices, packrat nests, thickets and other natural cavities. May be active on the surface for a total of only 3 or 4 weeks per year, much of it probabaly in April and May. |
| Diet |
| Eats small mammals, reptiles and their eggs, insects, bird eggs and nestlings, especially those of ground-nesters such as quail and doves. Can probably survive on only 3 - 4 meals per year, storing extra fat in the tail for later use. |
| Reproduction |
| Mating occurs in spring and early summer. Males fight each other for access to females. Females lay eggs usually every other year from July to August. Hatchlings have been observed in the spring, suggesting that the eggs overwinter after incubating for 8 - 10 months. |
| Range |
Gila Monsters range from the far southwest corner of Utah through extreme southern Nevada into extreme eastern Riverside and San Bernardino Counties in California, south through Arizona into extreme southwestern New Mexico and south into Sonora and possibly Nayarit, Mexico.
According to Robert Stebbins1 this lizard occurs in the "Paiute, Clark, Kingston, and perhaps New York Mts. (sight record), San Bernardino Co." and there are "old records for Providence Mts., San Bernardino Co., vicinity of Desert Center, in Chuckwalla Mts., Riverside Co., and Imperial Dam area, Imperial Co. on the Colorado R."
Jeffrey E. Lovich and Kent R. Beaman3 write "The distribution of the species in California suggests an invasion into the high mountain ranges of the northeastern Mojave during the last interglacial via the Colorado River corridor."
They
state that there are as many as 26 credible records that have been documented from four California counties; Inyo, San Bernardino, Riverside, and Imperial, including sightings from the Kingston Range, Clark Mountain, the Providence Mountains, near Blythe, Imperial Dam, Cadiz Valley near Iron Mountain, Chuckwalla Valley (Granite Mountains), Piute Creek (Piute Mountains), and the Mojave River. I have made a Google Map approximating these records. |
| Habitat |
Prefers rocky areas in desertscrub and semi-desert grassland. Found in lower mountain slopes, rocky bajadas, canyon bottoms, and arroyos. Occasionally found in woodland in Arizona.
According to Jeffrey E. Lovich and Kent R. Beaman3 " Habitat in which the species has been observed in California is characterized by rocky, deeply incised topography, in most cases, associated with large and relatively high mountain ranges. Most localities are associated with riparian areas (including the lower Colorado River) and range from near sea level to over 1,200 m. All records except one (Mojave River) occur east of about 1160 longitude....Summer precipitation may be important in the foraging ecology of the species." |
| Taxonomic Notes |
| Two subspecies of Heloderma suspectum are recognized. Heloderma suspectum suspectum, the Reticulate Gila Monster, occurs south and east of the range of H. s. cinctum. |
| Conservation Issues (Conservation Status) |
Fully protected from all interference.
"Conservation of the Gila monster in California requires an understanding of the factors defining its rarity along with the interaction of historical and climatic factors. It is likely that the Gila monster was rare in California long before the arrival of Europeans due to climatic changes and the marginal location of the state in the range of this species. The current restriction of the range to areas east of 1160 longitude provides a focal area for conservation efforts. Fortunately, this part of California, often referred to as the "Lonesome Triangle," is stil largely undisturbed (but see Lovich and Bainbridge 1999 4), and much of the Gila monster habitat therein is protected in designated wilderness areas or the Mojave National Preserve. However, the small population size of Gila monsters in California presents special challenges, including the Allee effect, loss of genetic diversity, and inbreeding (Meyers 1997), that are not easy to manage and increase the risk of local or regional extirpation. Recognition of these challenges will be required to maintain the elusive and enigmatic Gila monster as a viable part of California's exceptionally diverse biota (Meyers et al.. 2000 5)." Lovich and Beaman, 2007 3
4 Lovich J. E., Bainbridge D. 1999. Anthropogenic degradation of the southern California desert ecosystem
and prospects for natural recovery and restoration. Environ. Mgmt. 24: 309-326.
5 Meyers N., Mittermeier RA, Mittermeier C.G., Fonseca GAB., Kent J. 2000. Biodiversity hotspots for
conservation priorities. Nature. 403: 853-845. |
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Taxonomy |
| Family |
Helodermatidae |
Venomous Lizards |
| Genus |
Heloderma |
Gila Monsters and Beaded Lizards |
| Species |
suspectum |
Gila Monster |
Subspecies
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cinctum
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Banded Gila Monster |
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Original Description |
Heloderma suspectum -Cope, 1869 - Proc. Acad. Nat. Sci. Philadelphia, Vol. 21, p. 5
Heloderma suspectum cinctum - Bogert and Martin del Campo, 1956 - Amer. Mus. Nat. Hist. Bull., Vol. 109, Art. 1, p. 46
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Heloderma - Greek helos - a nail or stud and derma - skin - refers to the rough texture of the skin of this genus
suspectum - Latin - mistrusted or suspected - refers to a venomous nature which was suspected but not proven at time of naming.
cinctum - Latin - belted - referring to the broad double crossbands.
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
None
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Related or Similar California Lizards |
None, although sometimes Banded Geckos and juvenile Chuckwallas may be mistaken for Gila Monsters.
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
Reptiles and Amphibians of Arizona
Dr. Seward's Gila Monster Site
1 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.
Brennan, Thomas C., and Andrew T. Holycross. Amphibians and Reptiles in Arizona. Arizona Game and Fish Department, 2006.
Smith, Hobart M. Handbook of Lizards, Lizards of the United States and of Canada. Cornell University Press, 1946.
Brown, David E., Neil B. Carmony. Gila Monster: Facts and Folklore of America's Aztec Lizard. High-Lonesome Books, 1991.
2 Degenhardt, William G., Charles W. Painter, & Andrew H. Price. Amphibians and Reptiles of New Mexico. University of New Mexico Press, 1996.
3 Volume 106. Issue 2 (August 2007) Bulletin, Southern California Academy of Sciences Article: pp. 39-58 I Abstract I PDF (3.15M) A History of Gila Monster (Heloderma suspectum cinctum) Records from California with Comments on Factors Affecting their Distribution Jeffrey E. Lovich1, Kent R. Beaman2
1 U.S. Geological Survey, Southwest Biological Science Center, 2255 North Gemini Drive, MS-9394, Flagstaff,
Arizona 86001 jeffrey_lovichcgusgs.gov
2 Ichthyology and Herpetology, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los
Angeles, California 90007 helodermacgadelphia.net |
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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.
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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 |
BLM:S |
Sensitive |
| USDA Forest Service |
USFS:S |
Sensitive |
| Natureserve Global Conservation Status Ranks |
G3 |
Vulnerable |
World Conservation Union - IUCN Red List
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IUCN:VU |
Vulnerable |
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