{"elementGlobalId":103164,"circumscripConfidence":{"id":1,"circumscripConfidenceDescEn":"1 - Strong","circumscripConfidenceDescEs":"1 - Fuerte","circumscripConfidenceDescFr":"1 – Forte"},"classificationLevel":{"id":7,"classificationLevelNameEn":"Species","classificationLevelNameEs":"Especies","classificationLevelNameFr":"Espèce"},"classificationStatus":{"id":1,"classificationStatusDescEn":"Standard","classificationStatusDescEs":"Estándar","classificationStatusDescFr":"Standard"},"iucn":{"id":10,"iucnDescEn":"Near threatened","iucnDescEs":"Cerca de estar amenazado","iucnDescFr":"Quasi-menacée","iucnCode":"NT"},"nameCategory":{"id":1,"nameCategoryDescEn":"Vertebrate Animal","nameCategoryDescEs":"Animal vertebrado","nameCategoryDescFr":"Animal vertébré","nameTypeCd":"A","nameTypeDesc":"Zoological"},"rankMethodUsed":null,"formattedScientificName":"<i>Heloderma suspectum</i>","scientificName":"Heloderma suspectum","scientificNameAuthor":"Cope, 1869","primaryCommonName":"Gila Monster","relatedItisNames":"<i>Heloderma suspectum</i> Cope, 1869 (TSN 174113)","uniqueId":"ELEMENT_GLOBAL.2.103164","elcode":"ARACE01010","conceptRefFullCitation":"Bogert, C. M., and R. M. del Campo. 1956. The Gila monster and its allies: the relationships, habits, and behavior of the lizards of the family Helodermatidae. Bulletin of the America Museum of Natural History 109(1):1-238.","conceptName":"<i>Heloderma suspectum</i>","taxonomicComments":"Douglas et al. (2010) stated that they found no mtDNA evidence to support the two subspecies of <i>H. suspectum</i> and they are not recognized by Nicholson (2025). Although they did not provide information on the collection localities of the sampled specimens needed to evaluate that conclusion, that information was provided subsequently by Schuett and Reiserer (2017) (Nicholson 2025).","roundedGRank":"G4","conservationStatusFactorsEditionDate":"2005-06-24","conservationStatusFactorsEditionAuthors":"Hammerson, G.","primaryCommonNameLanguage":"EN","recordType":"SPECIES","elementNationals":[{"elementNationalId":165260,"classifConfidence":null,"nation":{"id":225,"nameEn":"United States","nameEs":"Estados Unidos","nameFr":"États-Unis","isoCode":"US","region":"United States"},"roundedNRank":"N4","elementSubnationals":[{"elementSubnationalId":268897,"subnation":{"id":6,"nameEn":"Arizona","nameEs":"Arizona","nameFr":"Arizona","subnationCode":"AZ","dnationId":225},"roundedSRank":"S4","dataSensitive":{"id":1,"dataSensitiveDescEn":"Yes","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"Y"},"dataSensitiveCategory":null,"srank":"S4","speciesSubnational":{"elementSubnationalId":268897,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":400951,"subnation":{"id":52,"nameEn":"Utah","nameEs":"Utah","nameFr":"Utah","subnationCode":"UT","dnationId":225},"roundedSRank":"S2","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S2","speciesSubnational":{"elementSubnationalId":400951,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":386282,"subnation":{"id":7,"nameEn":"California","nameEs":"California","nameFr":"Californie","subnationCode":"CA","dnationId":225},"roundedSRank":"SNR","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNR","speciesSubnational":{"elementSubnationalId":386282,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":1376667,"subnation":{"id":88,"nameEn":"Navajo Nation","nameEs":"La Nación Navajo","nameFr":"Nation Navajo","subnationCode":"NN","dnationId":225},"roundedSRank":"SH","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SH","speciesSubnational":{"elementSubnationalId":1376667,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":392961,"subnation":{"id":40,"nameEn":"Nevada","nameEs":"Nevada","nameFr":"Nevada","subnationCode":"NV","dnationId":225},"roundedSRank":"S2","dataSensitive":{"id":1,"dataSensitiveDescEn":"Yes","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"Y"},"dataSensitiveCategory":null,"srank":"S2","speciesSubnational":{"elementSubnationalId":392961,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":395943,"subnation":{"id":39,"nameEn":"New Mexico","nameEs":"Nuevo México","nameFr":"Nouveau-Mexique","subnationCode":"NM","dnationId":225},"roundedSRank":"S2","dataSensitive":{"id":1,"dataSensitiveDescEn":"Yes","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"Y"},"dataSensitiveCategory":null,"srank":"S2","speciesSubnational":{"elementSubnationalId":395943,"hybrid":false,"exotic":false,"native":true}}],"nrankReviewYear":1996,"nrank":"N4","speciesNational":{"elementNationalId":165260,"exotic":false,"native":true}}],"lastModified":"2026-10-02T21:40:34.518141Z","lastPublished":"2026-10-02T21:32:08.892226Z","promotionalDescription":null,"conceptLineageSummary":null,"nsxUrl":"/Taxon/ELEMENT_GLOBAL.2.103164/Heloderma_suspectum","grankAdjustmentReasons":null,"grankChangeDate":"1996-10-23","grankReviewDate":"2005-06-24","grankReasons":"Occurs in the southwestern U.S. and northwestern Mexico; fairly common in some areas; some habitat has been lost to agriculture and urbanization, and illegal collecting may limit certain local populations, but the species is apparently secure at the present time.","grank":"G4","rankInfo":{"elementGlobalId":103164,"aooPercentGood":null,"enviromentalSpecificity":null,"intrinsicVulnerability":{"id":4,"intrinsicVulnerabilityDescEn":"Moderately vulnerable","intrinsicVulnerabilityDescEs":"Moderadamente vulnerable","intrinsicVulnerabilityDescFr":"Moyennement vulnérable"},"longTermTrend":null,"numberEos":{"id":11,"numberEosDescEn":"21 - 300","numberEosDescEs":"De 21 a 300","numberEosDescFr":"De 21 à 300"},"numberGoodEos":{"id":22,"numberGoodEosDescEn":"Unknown","numberGoodEosDescEs":"Desconocido","numberGoodEosDescFr":"Inconnu"},"numberProtEos":{"id":6,"numberProtEosDescEn":"Few (1-3) occurrences appropriately protected and managed","numberProtEosDescEs":"Pocos casos (1 a 3) están adecuadamente protegidos y controlados","numberProtEosDescFr":"Peu d’occurrences (de 1 à 3) protégées et contrôlées convenablement"},"popSize":{"id":37,"popSizeDescEn":"Unknown","popSizeDescEs":"Desconocido","popSizeDescFr":"Inconnu"},"rangeExtent":{"id":33,"rangeExtentDescEn":"200,000-2,500,000 square km (about 80,000-1,000,000 square miles)","rangeExtentDescEs":"200.000 a 2.500.000 kilómetros cuadrados (aproximadamente 80.000 a 1.000.000 millas cuadradas)","rangeExtentDescFr":"De 200 000 à 2 500 000 km carrés (de 80 000 à 1 000 000 miles carrés approximativement)"},"shortTermTrend":{"id":46,"shortTermTrendDescEn":"Unknown","shortTermTrendDescEs":"Desconocido","shortTermTrendDescFr":"Inconnu"},"threatImpactAssigned":{"id":8,"threatImpactAssignedDescEn":"Medium","threatImpactAssignedDescEs":"Medio","threatImpactAssignedDescFr":"Moyen"},"rangeExtentComments":"The Gila monster ranges from extreme southwestern Utah, southern Nevada, and adjacent southeastern California south through southern Arizona, southwestern New Mexico, and much of Sonora to Sinaloa, Mexico (Stebbins 2003). The core of the range is in Arizona and Sonora. Elevational range extends from near sea level in Sonora and 30 m in Arizona to at least 1,545 m in southeastern Arizona (Lowe et al. 1986); 1,180-1,950 meters in New Mexico (Degenhardt et al. 1996).","areaOfOccupancy":null,"areaOfOccupancyComments":null,"numberEosComments":"This species is represented by well over 100 collection/observation sites that are well distributed throughout the range (e.g., see Campbell and Lamar 2004). Degenhardt et al. (1996) mapped approximately 17 collection sites in New Mexico (Campbell and Lamar 2004 mapped only 5); these represent several relatively distinct occurrences. The easternmost locations may represent displaced, released, or escaped captive individuals (Degenhardt et al. 1996).","popSizeComments":"Total adult population size is unknown but probably is at least several thousand; the species is fairly common in at least some parts of the range. Lowe et al. (1986) stated that Gila monsters are infrequently seen but not rare or uncommon in Arizona. In New Mexico, the species is commonly encountered in the Redrock Wildlife Area in Grant County and at Granite Gap in Hidalgo County; a density of approximately 5 individuals per square kilometer was estimated for one area (Degenhardt et al. 1996).","viabilityComments":null,"threatImpactComments":"Populations have been exploited (illegally) by commercial and private collectors, and they have suffered from habitat destruction due to urbanization and agricultural development (New Mexico Department of Fish and Game 1985). Concrete-lined canals are barriers to movement (Brown and Carmony 1999), as are busy highways. Mortality on roads likely is increasing as traffic volume increases on established highways and new roads are built. The most important reason for the decline is habitat loss resulting from development (Campbell and Lamar 2004).","shortTermTrendComments":"Populations are declining over most of the range (Campbell and Lamar 2004), but the rate of decline is unknown.","longTermTrendComments":"Beck (1985) estimated that the population in Utah included 450-800 individuals, down from an estimated 2,000-5,000 before the 1930s.","inventoryNeeds":null,"numberProtEosComments":"Individuals are protected from collection throughout the range, but some degree of illegal collection certainly occurs. Sizable areas of habitat are protected from development in national parks and monuments and in federal wilderness areas (Brown and Carmony 1999).","protectionNeeds":"Stringent prohibitions against commercial explitation and unnecessary killing should be maintained.","otherConsiderations":null,"intrinsicVulnerabilityComments":null,"enviromentalSpecificityComments":null},"animalCharacteristics":{"elementGlobalId":103164,"majorHabitat":{"id":3,"majorHabitatDescEn":"Terrestrial","majorHabitatDescEs":"Terrestre","majorHabitatDescFr":"Terrestre"},"nonMigrant":true,"localMigrant":true,"longDistanceMigrant":false,"mobilityMigrationComments":"May migrate locally (usually less than 1 km) between highland winter retreat and lowland summer habitat (Lowe et al. 1986).<br><br>May travel up to several hundred meters in one day but typically much less. In northwestern Arizona, moved an average of 26 m per day in April-May, 3 m per day in June-July (Jones 1983). In Utah, 27 individuals (including only one immature) were observed in an area of 2 sq km over 3 years; home ranges of 3 individuals were 66, 33, and 6 ha (Beck 1990). In New Mexico, home ranges of 7 individuals ranged from 6 to 105 ha (mean 58 ha), were up to at least 3.5 km long (Beck and Jennings 2003).<br>","foodHabitsComments":"Eats small mammals, eggs (especially of ground-nesting birds, also of reptiles), lizards, insects, and carrion. In northwestern Arizona in April-May, ate mainly eggs of ground-nesting birds; in June-July, diet apparently shifted to small mammals (Jones 1983). Ate eggs and young mammals taken from nests in Utah (Beck 1990). Two juveniles salvaged in Arizona contained reptile eggshells (McGurty 2002). Prey is detected mainly by olfaction.","animalPhenologyComments":"In Arizona and Utah, active mainly from early spring through early fall (surface activity peaks in spring in Arizona); some may bask in winter. In summer, crepuscular-nocturnal or relatively inactive. In northwestern Arizona, relatively inactive (in rodent burrows) in June-July (Jones 1983). Often encountered on roads at dusk or after dark following warm summer rains (Stebbins 1985). In Utah, activity peaked between late April and mid-June, from 0800-1200 h; some nocturnal activity may occur in summer (Beck 1990).","colonialBreeder":false,"length":61,"width":null,"weight":null,"animalPhenologies":[{"animalCagPhenologyId":102275,"animalPhenology":{"id":3,"animalPhenologyDescEn":"Diurnal","animalPhenologyDescEs":"Diurno","animalPhenologyDescFr":"Diurne","displayOrder":3},"adult":true,"immature":true},{"animalCagPhenologyId":102276,"animalPhenology":{"id":5,"animalPhenologyDescEn":"Crepuscular","animalPhenologyDescEs":"Crepuscular","animalPhenologyDescFr":"Crépusculaire","displayOrder":5},"adult":true,"immature":true}],"animalFoodHabits":[{"animalCagFoodHabitsId":104245,"foodHabits":{"id":1,"foodHabitsDescEn":"Carnivore","foodHabitsDescEs":"Carnívoro","foodHabitsDescFr":"Carnivore","displayOrder":1},"adult":true,"immature":true},{"animalCagFoodHabitsId":104246,"foodHabits":{"id":3,"foodHabitsDescEn":"Invertivore","foodHabitsDescEs":"Invertívoro","foodHabitsDescFr":"Invertivore","displayOrder":3},"adult":true,"immature":true}]},"occurrenceDelineations":[{"eoSpecsDetailId":1472,"locationUseClass":{"id":1,"locationUseClassDescEn":"Not applicable","locationUseClassDescEs":"No se aplica","locationUseClassDescFr":"Sans objet","displayOrder":1},"eoSpecGroupName":"Gila Monster","subtypes":null,"inferredExtentDistance":2.0,"inferredExtentNotes":null,"minimumEoCriteria":"Occurrences are based on evidence of historical presence, or current and likely recurring presence, at a given location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals (including eggs) in or near appropriate habitat where the species is presumed to be established and breeding.","mappingGuidance":null,"separationBarriers":"Busy highway or highway with obstructions such that lizards rarely if ever cross successfully; major river, lake, pond, or deep marsh; urbanized area dominated by buildings and pavement.","separationDistanceUnsuitableHabitatat":1.0,"separationDistanceSuitableHabitatat":10.0,"altSeparationProcedure":null,"separationJustification":"Gila monsters may travel up to several hundred meters in one day but typically much less. In northwestern Arizona, individuals moved an average of 26 m per day in April-May, 3 m per day in June-July (Jones 1983). In Utah, home ranges of 3 individuals were 66, 33, and 6 ha (Beck 1990). In New Mexico, home ranges of 7 individuals ranged from 6 to 105 ha (mean 58 ha) (Beck and Jennings 2003). Lowe et al. (1986:13) stated that annual home range size tends to be less than 1 kilometer in maximum dimension, but Beck and Jennings (2003) mapped several home ranges that were larger than this (up to about 3.5 km long). <br /><br />The separation distance of 10 km for suitable habitat is approximately three times the diameter of a large home range.","versionDate":"2003-10-08","versionAuthor":"Hammerson, G.","versionNotes":null,"lastModified":"2021-10-02T17:04:34.077811Z"}],"plantCharacteristics":null,"elementManagement":{"elementGlobalId":103164,"eoManagementGroupName":null,"stewardshipOverview":null,"impacts":null,"restorationPotential":null,"siteConservationPlansConsidered":null,"managementMethods":"Translocation of individuals away from urban locations does not appear to be an effective conservation tool. In Arizona, individuals that were moved less than 1,000 m from the site of capture returned within 30 days, whereas those translocated farther incurred a high mortality rate (Sullivan et al. 2004).","monitoringMethods":null,"managementProgramContacts":null,"monitoringProgramContacts":null,"managementResearchPrograms":null,"managementResearchNeeds":null,"biologicalResearchNeeds":null,"additionalTopics":null},"occurrenceViabilities":[{"eoRankSpecsDetailId":104651,"eoRankSpecsGroupName":null,"locationUseClass":{"id":1,"locationUseClassDescEn":"Not applicable","locationUseClassDescEs":"No se aplica","locationUseClassDescFr":"Sans objet","displayOrder":1},"excellentViability":null,"goodViability":null,"fairViability":null,"poorViability":null,"viabilityJustification":"Use the Generic Guidelines for the Application of Occurrence Ranks (2008).<br>The Key for Ranking Species Occurrences Using the Generic Approach provides a step-wise process for implementing this method.","versionDate":null,"versionAuthor":null,"versionNotes":null,"lastModified":"2020-05-14T02:23:24.569574Z"}],"references":[{"id":763072,"citation":"Beck, D. D. 1985. The natural history, distribution, and present status of the gila monster in Utah. Department of Biology and Ecology Center, Utah State University, Logan, Utah. Report submitted to Utah Division of Wildlife Resources.","shortCitationAuthor":"Beck","shortCitationYear":1985,"referenceCode":"U85BEC61HQUS","lastModified":"2020-02-25T18:19:27.857863Z"},{"id":105730,"citation":"Beck, D. D. 1990. Ecology and behavior of the Gila monster in southwestern Utah. J. Herpetol. 24:54-68.","shortCitationAuthor":"Beck","shortCitationYear":1990,"referenceCode":"A90BEC01NAUS","lastModified":"2020-02-25T18:19:27.857863Z"},{"id":464565,"citation":"Beck, D. D. 2005. Biology of Gila monsters and beaded lizards. University of California Press, Berkeley. 256 pp.","shortCitationAuthor":"Beck","shortCitationYear":2005,"referenceCode":"B05BEC01NAUS","lastModified":"2020-02-25T18:19:27.857863Z"},{"id":175336,"citation":"Beck, D. D., and R. D. Jennings. 2003. Habitat use by Gila monsters: the importance of shelters. Herpetological Monographs 17:111-129.","shortCitationAuthor":"Beck and Jennings","shortCitationYear":2003,"referenceCode":"A03BEC01NAUS","lastModified":"2020-02-25T18:19:27.842046Z"},{"id":137372,"citation":"Behler, J. L., and F. W. King. 1979. The Audubon Society field guide to North American reptiles and amphibians. Alfred A. Knopf, New York. 719 pp.","shortCitationAuthor":"Behler and King","shortCitationYear":1979,"referenceCode":"B79BEH01NAUS","lastModified":"2020-02-25T14:38:24.173666Z"},{"id":1066853,"citation":"Bogert, C. M., and R. M. del Campo. 1956. The Gila monster and its allies: the relationships, habits, and behavior of the lizards of the family Helodermatidae. Bulletin of the America Museum of Natural History 109(1):1-238.","shortCitationAuthor":"Bogert and del Campo","shortCitationYear":1956,"referenceCode":"A56BOG01NAUS","lastModified":"2020-11-11T02:05:57.421389Z"},{"id":464561,"citation":"Brown, D. E., and N. B. Carmony. 1999. Gila monster: facts and folklore of America's Aztec lizard. University of Utah Press, Salt Lake City. 129 pp.","shortCitationAuthor":"Brown and Carmony","shortCitationYear":1999,"referenceCode":"B99BRO01NAUS","lastModified":"2020-02-25T18:19:27.857863Z"},{"id":130385,"citation":"Campbell, J. A., and W. W. Lamar. 1989. The venomous reptiles of Latin America. Comstock Publ. Associates, Division of Cornell Univ. Press, Ithaca, New York. xii + 425 pp.","shortCitationAuthor":"Campbell and Lamar","shortCitationYear":1989,"referenceCode":"B89CAM01NAUS","lastModified":"2020-02-25T18:11:51.08501Z"},{"id":381359,"citation":"Campbell, J. A., and W. W. Lamar. 2004. The venomous reptiles of the Western Hemisphere. 2 volumes. Cornell University Press.","shortCitationAuthor":"Campbell and Lamar","shortCitationYear":2004,"referenceCode":"B04CAM01NAUS","lastModified":"2020-02-25T18:11:51.08501Z"},{"id":137880,"citation":"Collins, J. T. 1990. Standard common and current scientific names for North American amphibians and reptiles. 3rd ed. Society for the Study of Amphibians and Reptiles. Herpetological Circular No. 19. 41 pp.","shortCitationAuthor":"Collins","shortCitationYear":1990,"referenceCode":"B90COL01NAUS","lastModified":"2020-02-25T14:38:15.579798Z"},{"id":621810,"citation":"Crother, B. I. (editor). 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Sixth edition. Society for the Study of Amphibians and Reptiles Herpetological Circular 37:1-84. Online with updates at: http://www.ssarherps.org/pages/comm_names/Index.php","shortCitationAuthor":"Crother","shortCitationYear":2008,"referenceCode":"B08CRO01NAUS","lastModified":"2020-02-25T14:38:20.142383Z"},{"id":722484,"citation":"Crother, B. I. (editor). 2012. 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Sampling localities and corresponding haplotype data for helodermatid lizards analyzed in Douglas et al.(2010). Herpetological Review 48(4):798-801.","shortCitationAuthor":"Schuett and Reiserer","shortCitationYear":2017,"referenceCode":"A17SCH06NAUS","lastModified":"2026-07-03T01:56:21.502721Z"},{"id":144435,"citation":"Stebbins, R. C. 1985a. A field guide to western reptiles and amphibians. Second edition. Houghton Mifflin Company, Boston, Massachusetts. xiv + 336 pp.","shortCitationAuthor":"Stebbins","shortCitationYear":1985,"referenceCode":"B85STE01NAUS","lastModified":"2020-02-25T18:11:51.08501Z"},{"id":266629,"citation":"Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.","shortCitationAuthor":"Stebbins","shortCitationYear":2003,"referenceCode":"B03STE01NAUS","lastModified":"2020-02-25T18:11:51.08501Z"},{"id":460220,"citation":"Sullivan, B. K., M. A. Kwiatkowski, and G. W. Schuett. 2004. Translocation of urban Gila monsters: a problematic conservation tool. 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Eggs are laid primarily in July-August. Clutch size averages about 6, ranges up to 13 (Goldberg and Lowe 1997). In Arizona, eggs reportedly overwinter underground and hatch the following late April-early June, after an incubation period of about 10 months (Lowe et al. 1986, Goldberg and Lowe 1997). Females are sexually mature at about 24 cm SVL; mature females evidently reproduce every year (Goldberg and Lowe 1997).","ecologyComments":"Basically solitary but may use communal overwintering sites.","habitatComments":"Occupied vegetation types include desert grassland, Mohave and Sonoran desert scrub, and thorn scrub (Sonora); less often oak or pine-oak woodland. In Mexico, it occurs on lower mountain slopes and adjacent plains and beaches (Stebbins 2003), sometimes in irrigated areas. Canyon bottoms, arroyos, and rocky slopes may support relatively dense populations in some parts of Arizona and Sonora. In southern Arizona, the Gila monster is more abundant in wetter and rockier palo verde-sahuaro desert than in drier and sandier creosote-bursage desert, where it occurs mainly in or near rocky buttes or mountains (Lowe et al. 1986). In New Mexico, the species is most commonly associated with desert scrub vegetation in rocky regions of mountain foothills and canyons; sometimes it is found along the lower fringes of pinyon-juniper woodland or oak woodland; rarely encountered in agricultural areas (Degenhardt et al. 1996). Gila monsters are mainly terrestrial but infrequently climb into vegetation. Refuges include spaces under rock, dense shrubs, burrows, or woodrat nests. Sub-surface shelters are important components of the habitat, and certain ones are used with a high degree of fidelity (particularly in winter), sometimes by multiple individuals concurrently (Beck and Jennings 2003). In Arizona, Gila monsters spend about 98% of the year under cover (Lowe et al. 1986). In Utah, individuals spent over 95% of active season underground; occasionally they basked near shelters in spring; shelters were burrows or crevices in rocky areas; hibernacula faced south (Beck 1990).","generalDescription":"A large, heavy-bodied lizard with a massive head, short thick tail (thin in emaciated individuals), beadlike dorsal scales, short limbs with strong claws, and loose folds of skin on the neck; dorsal coloration gaudy, black and pink, orange, or yellow; adult snout-vent length 22-35 cm (Stebbins 1985). Occasionally exceeds 50 cm in total length (Campbell and Lamar 1989, which see for further description details).","diagnosticCharacteristics":"Differs from other U.S. lizards in large size and bulk, beadlike dorsal scales, and bold dorsal pattern of black and yellow, orange, or pink. Differs from the similar H. HORRIDUM of Mexico as follows: tail length less than 55% of snout-vent length (vs. at least 65%); 48-62 scales in longitudinal midline from vent to tip of tail (vs. 74-87); dorsal coloration includes yellowish, orange, or pink (vs. black with or without yellow). See Campbell and Lamar (1989) for further details.","speciesMarineHabitats":[],"speciesTerrestrialHabitats":[{"cagTerrHabId":-109019,"terrestrialHabitat":{"id":4,"terrestrialHabitatDescEn":"Woodland - Hardwood","terrestrialHabitatDescEs":"Lote de madera - Madera dura","terrestrialHabitatDescFr":"Terrain boisé — Feuillu","displayOrder":6}},{"cagTerrHabId":-109020,"terrestrialHabitat":{"id":7,"terrestrialHabitatDescEn":"Shrubland/chaparral","terrestrialHabitatDescEs":"Matorral/Chaparral","terrestrialHabitatDescFr":"Fruticée/Chaparral","displayOrder":9}},{"cagTerrHabId":-109018,"terrestrialHabitat":{"id":11,"terrestrialHabitatDescEn":"Desert","terrestrialHabitatDescEs":"Desierto","terrestrialHabitatDescFr":"Désert","displayOrder":13}}],"speciesRiverineHabitats":[],"speciesPalustrineHabitats":[{"cagPalusHabId":-102530,"palustrineHabitat":{"id":6,"palustrineHabitatDescEn":"Riparian","palustrineHabitatDescEs":"Ribereño","palustrineHabitatDescFr":"Riverain","displayOrder":6}}],"speciesLacustrineHabitats":[],"speciesSubterraneanHabitats":[],"speciesEstuarineHabitats":[]},"primaryReference":{"id":1153425,"citation":"Nicholson, K. E. (ed.). 2025. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding. Ninth Edition. Society for the Study of Amphibians and Reptiles. 87 pp. Online database available at: https://cnah.org/SSARnames.aspx","shortCitationAuthor":"Nicholson","shortCitationYear":2025,"referenceCode":"B25NIC01NAUS","lastModified":"2026-06-06T01:36:32.018241Z"},"predecessors":[{"predecessorId":117603,"elCode":"ARACE01011","name":"Heloderma suspectum cinctum","formattedName":"<i>Heloderma suspectum cinctum</i>","classficationCode":null,"uniqueId":"ELEMENT_GLOBAL.2.103811","lineageDate":null,"nsxUrl":null},{"predecessorId":117604,"elCode":"ARACE01012","name":"Heloderma suspectum suspectum","formattedName":"<i>Heloderma suspectum suspectum</i>","classficationCode":null,"uniqueId":"ELEMENT_GLOBAL.2.101765","lineageDate":null,"nsxUrl":null}],"elementGlobalThreatAssessments":[{"elementGlobalThreatAssessId":16459,"iucnThreatCategory":{"id":5,"iucnThreatCategoryCd":"2","iucnThreatCategoryDescEn":"Agriculture & aquaculture","iucnThreatCategoryDescEs":null,"iucnThreatCategoryDescFr":null,"displayValueEn":"2 - 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